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First-principles study of the electronic transport properties of a 1,3-diazabicyclo[3.1.0]hex-3-ene molecular optical switch
Optik 153 (2018) 135–143
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Original research article
First-principles study of the electronic transport properties of a 1,3-diazabicyclo[3.1.0]hex-3-ene molecular optical switch Ayoub Kanaani a , Davood Ajloo a,b,∗ , Hamzeh Kiyani a,∗ , Sayyed Ahmad Nabavi Amri a a b
School of Chemistry, Damghan University, Damghan, 36715-364, Iran Institute of Biological Science, Damghan University, Damghan, 36716-41167, Iran
a r t i c l e
i n f o
Article history: Received 18 June 2017 Accepted 29 September 2017 Keywords: Optical molecular switch Electronic transport Non-equilibrium green’s function
a b s t r a c t We analyze the transport properties of 4-(6-(4-chlorophenyl)-4-phenyl-1,3-diazabicyclo[3.1.0]hex-3-en-2-yl)-2-nitrophenol molecular optical switch using first-principles calculations. Molecule consisting switch can transform among closed and open forms by visible or ultraviolet irradiation. We have studied multiple attributes such as I–V characteristics, electronic transmission coefficients T(E), the effect of electrode materials (Au, Ag, and Pt) on electronic transport properties, on-off ratio and spatial distribution of molecular projected self-consistent Hamiltonian (MPSH) orbitals corresponding to the closed and open forms. The physical origin of switching behavior is interpreted based on the different molecular geometries, location and size of the frontier molecular orbitals and the HOMO–LUMO gap. According to the theoretical results, one can found that when the open form converts to the closed form, there is a switch from low resistance (on state) to high resistance (off state). We hope that the results of this study can help researchers to design new functional molecular devices. © 2017 Elsevier GmbH. All rights reserved.
1. Introduction Photochromism is a phenomenon in which a compound follows reversible changes between two states with different absorption spectrums such that different colors are created from compounds in crystal, amorphous or liquid states. Under electromagnetic radiation (usually UV light), stable thermodynamic shape A transforms to a new colorful type B via photochemical reaction and type B changes to the initial shape A on reverse direction via another light source like visible light or heat [1–4]. Photochromism delivers a suitable insight to the expansion of optical sensing applications [5], high-density optical memory [6], photo – switches [7], molecular photonic devices [8] and light-sensitive eyewear [2]. The photochromism of 4-(6-(4-chlorophenyl)-4-phenyl-1,3-diaza-bicyclo[3.1.0]hex-3-en-2-yl)-2-nitrophenol is shown in Fig. 1 [9]. Also, photochromic behavior can be observed when the 1,3-diazabicyclo[3.1.0]hex-3-ene connect to the silver [10]. Recently, a lot of interesting physical properties such as highly nonlinear I–V characteristics, memory effects, negative differential resistance (NDR), switching properties, electric rectification behavior and etc. are found in various systems such as organics [11], DNA [12] and carbon nanotubes [13]. The supreme aim in microelectronic crafts is the perpetual miniaturization of electronic devices and the final target is to synthesize devices by using a molecule, a cluster or even an
∗ Corresponding authors at: School of Chemistry, Damghan University, Damghan, 36715-364, Iran. E-mail addresses: [email protected] (D. Ajloo), [email protected] (H. Kiyani). https://doi.org/10.1016/j.ijleo.2017.09.125 0030-4026/© 2017 Elsevier GmbH. All rights reserved.
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Fig 1. Chemical structures corresponding to closed and open form of the 4-(6-(4-chlorophenyl)-4-phenyl-1,3-diaza-bicyclo[3.1.0]hex-3-en-2-yl)-2nitrophenol.
atom [14–16]. Lately, synthesis, design and investigation of photochromism molecular switches of effective components in nanoelectronics research, become a research hotspot. Meantime, the computational researches of photochromism molecular switches, adopting to first-principles methods have also attracted growing considerations [16,17]. Wide areas of molecular switches have been published in the literature [18–20], with bistable and high/low conductance forms which are activated by several types of external motivations [21–23]. Among those, light is a very attractive stimulus due to its quick response time, feasibility of addressing, a wide range of condensed phases and compatibility with already existing experimental setups [20,24]. According to this, azobenzene- and diarylethene-based photochromic switches have been investigated, comprehensively [16,25–29]. Generally, due to light treatment, molecular optical switches involve changes in the molecular structure such isomerization reactions of the molecular bridge and ring-opening reactions. Newly, we have described another mechanism which is based on solvent induced hydrogen shift in molecular bridge [30]. Also in previous work, 2-([1,1 -biphenyl]-4-yl)-2-methyl-6-(4-nitrophenyl)-4-phenyl-1,3 diazabicyclo [3.1.0]hex-3ene photochromic switch has been studied [31]. The closed form of switch can be transformed into the open one upon irradiation with 300 nm ultraviolet light (UV) which results in increasing the magnitude of conductivity by 103 . These two forms can survive in a wide temperature range and can reversibly change to each other, which make the title compound as an excellent candidate for light-driven molecular switches. In this project, Non-equilibrium Green’s function (NEGF) formalism merged with first-principles density functional theory (DFT) were used to study the conductive behavior of the switch of the title compound. 2. Model and computational methods In the present work, the calculations are done in two steps. In the first step, geometry optimization of 4-(6-(4chlorophenyl)-4-phenyl-1,3-diaza-bicyclo[3.1.0]hex-3-en-2-yl)-2-nitrophenol with one SH group as linker is performed by Gaussian 03 program [32] with B3LYP type exchange correlation functional [33] and the popular 6–311 + +G(d,p) basis set [34]. Positive values of all calculated vibrational wave numbers certified the location of geometries at real positional least minimum on the potential energy surface. Chlorine atom can be easily attached to metal [35], but it is generally accepted that hydrogen atoms are unzipped upon adsorption to metal surfaces [36,37]. So we construct a two-probe system in which the one terminal hydrogen atom that bonded to the sulfur atom is deleted from the optimized structure, and the remained segment is located between two parallel metal surfaces. It’s both closed and open forms have one S-linker and are connected into the Gold junction with (1 1 1) surfaces. The modelled molecular connection structure is illustrated schematically in Fig. 2. The central section involves sections of the electrodes, so the screening results can be included in computations. The most common X (1 1 1) surface [38,39] is used with (6 × 6) periodic boundary conditions. The 6 × 6 supercell is big sufficient to avoid any interplay with molecules in the subsequent supercell [30,31]. The sulfur and chlorine atoms are elected to place at the hollow location of the X triangle. Since the main purpose of this work is to determine the switch of conductivity through a photochemical reaction, the nature of Au–S interaction is not investigated here. The vertical distance between the sulfur and chlorine atoms with X (Au, Ag and Pt) surface are set to be 1.9, 2.0, 2.4 Å and 2.3, 2.7, 2.8 Å, respectively [35,40–43]. The core electrons are modelled with Troullier–Martins nonlocal pseudopotential [44], while the valence electrons wave functions are expanded by a SIESTA basis set [45]. Since transport properties are going to be calculated after the structural relaxations, only atoms in the scattering region are fully relaxed within a force convergence criteria of 0.02 eV/◦ A, while
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Fig. 2. Schematic molecular junctions used in our calculations. Table 1 Optimized geometrical parameters of DPQ at B3LYP/6-311++G(2d,p) level. Parametersa
closed
open
Parametersa
closed
open
Bond lengths (Å) C4 C10 C10 N11 C10 N12 N12 C13 N11 C24 N11 C26
1.522 1.484 1.471 1.283 1.470 1.464
1.525 1.518 1.439 1.312 1.362 1.335
C26 C13 C13 C14 C14 C28 C28
1.490 1.472 1.500 1.404 1.402 1.399 1.399
1.439 1.422 1.477 1.402 1.401 1.414 1.418
Bond angles (◦ ) A(4,10,11) A(4,10,12) A(10,11,24) A(10,11,26) A(10,12,13) A(12,13,24)
111.8 110.3 104.6 113.9 108.7 112.8
111.8 109.8 105.1 128.0 106.8 113.1
A(11,26,28) A(26,28,29) A(26,28,30) A(12,13,14) A(24,13,14) A(13,14,15) A(13,14,16)
118.2 121.8 119.4 123.7 123.6 120.3 120.6
130.9 127.8 115.6 121.9 125.0 119.5 121.6
Dihedral angles (◦ ) D(3,4,10,12) D(3,4,10,11) D(4,10,12,13) D(4,10,11,24) D(4,10,11,26) D(10,12,13,14) D(10,12,13,24)
−48.8 −169.6 −119.5 119.7 −175.0 177.4 −3.1
−73.9 168.4 −114.7 112.6 −66.3 177.9 −3.4
D(10,11,24,13) D(11,26,28,29) D(11,26,28,30) D(12,13,14,15) D(12,13,14,16) D(24,13,14,16) D(24,13,14,15)
0.5 14.5 −166.3 −10.4 169.3 −10.2 170
5.2 4.0 −174.7 3.4 −176.6 4.8 −175.19
a
C28 C24 C14 C15 C16 C29 C30
For atom numbering from Fig. 3.
keeping all the electrod atoms fixed. The X atoms are characterized by a single- plus single polarization (SZP) basis set whereas for the other atoms, a double- plus single polarization (DZP) basis set is used. The k-grid sampling of 2 × 2 × 100 by Monkhorst-Pack method to describe the Brillouin zone[46], was employed simultaneously with the mesh cutoff of 150 Ry for the grid integration. There is a good agreement between previous simulation with empirical evaluation [47]. The transport calculations are performed using TRANSIESTA-C package based on SIESTA [48]. In this code, the NEGF is used to compute the current while a bias is applied among the two electrodes. The bias voltage is scanned from 0.0 to 2 V at 300 K. The current through the device is computed using the Landauer–Büttiker formula in TranSIESTA package [48]. I=
2e h
T (E, V )[f (E − L ) − f (E − R )]dE
(1)
Here e is the electron charge, h Planck’s constant, T(E, V) the transmission function at energy E under bias voltage V, and f(E−L(R) ) is the Fermi–Dirac distribution function with the electrochemical potential L(R) of the left (right) electrode. 3. Results and discussion The optimized geometrical parameters of 4-(6-(4-chlorophenyl)-4-phenyl-1,3-diaza-bicyclo[3.1.0]hex-3-en-2-yl)-2nitrophenol are computed using DFT/B3LYP method with 6–311++G(d,p) basis set. Some selected geometrical parameters (Å, ◦ ) of closed and open forms are listed in Table 1 according to numbering scheme given in Fig. 3.
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Fig. 3. Optimized geometry by B3LYP/6–311++G(d,p) for closed and open forms.
Fig. 4. The I–V characteristics of the molecular switch with two forms.
The physical reason of the switch behavior is related to various factors. One of these factors changes in conjugation length for these two isomers. From Table 1, we can conclude that the dihedral angle ϕ which determines the -electron conjugation and the -overlapping [49] is 174.7◦ for closed form and 166.3◦ for open form. It indicates that the effective conjugation length for these two isomers of the closed form is reduced. It is known that there is a strong relation between electrical conductivity and efficient conjugation length of the molecular wire [50]. The photochromism of 1,3 −diazabicyclo[3.1.0]hex-3-enes is happened in the aziridine unit with a reversible photochemical splitting of the C N bond. This phenomenon leads to the formation of a zwitterion species (the open form) leading to the relatively longer -conjugation. The current–voltage (I–V) curves for the molecular device with two different isomers in the bias voltage ranged from 0.0 to 2.0 V are with gold electrod given in Fig. 4. The switching behavior can be clearly seen in Fig. 4, as at the same bias, the current of the open form is greater than that of the closed form. For example, the calculated current at 1.0 V is about 344 A and 6 A for the open and closed forms, respectively. It can be concluded from Fig. 4 that when the closed form molecule changes to an open one, a switching behavior happens from off (high resistance) state to on (low resistance) state. This significant discrepancy in current severity happening in the closed and open forms, can be found within LandauerBütiker formalism [51] by foreseeing the transmission factor possibility for electrons to scatter through the molecular wire. The energy dependence of zero-bias transmission spectra are computed and demonstrated in Fig. 5. From Fig. 5, we can see that the transmission spectra present considerably different characteristics for two explained isomers. In our calculation, the average Fermi level is set to be zero. From Eq. (1), we may anticipate that only electrons with energies at a small range
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Fig. 5. The transmission spectra of the molecular switch at zero bias.
Fig. 6. The spatial distribution of the MPSH states corresponding to HOMO, LUMO, HOMO-1 and LUMO+1 of closed form with electrode: (a) Au, (b) Ag, (c) Pt.
around the Fermi level EF contribute to the total current. As can be seen from Fig. 5, if we focus on the most interesting area around the Fermi level EF , one can see that the transmission coefficients of the open form are bigger than those of the closed form in the energy range of [−3.0, 3.0 eV]. This behavioral difference can be understood more clearly in the spatial repartition of the molecular projected selfconsistent Hamiltonian (MPSH) [52]. The HOMO and LUMO levels are −0.571 eV and 1.075 eV for the open form, −1.873 eV and 1.311 eV for the closed form. As a result, the HOMO–LUMO gap in the closed form is larger than that of the open form. Therefore, because of the large HOMO–LUMO gap and the low transmission coefficient caused by changes in the molecular structure, conductivity in the closed form decreases. The spatial distribution of the MPSH states corresponding to the HOMO, LUMO, HOMO-1 and LUMO+1 of the closed and open forms is presented in Figs. 6 and 7. As shown in these Figs, both HOMO and LUMO have large weight and delocalized in the open form while they have small weight and localized in the closed form. Both HOMO and LUMO have delocalized orbitals which give the principal electronic transport channel for the open form making a low obstacle for electron transportation. Also, applying the external bias help us to understand how the evolution in transmission curves changes the coupling between the electrodes and molecules. So, in the next step, the dependence of voltage on transmission function will be
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Fig. 7. The spatial distribution of the MPSH states corresponding to HOMO, LUMO, HOMO-1 and LUMO+1 of open form with electrode: (a) Au, (b) Ag, (c) Pt.
Fig. 8. The transmission spectrum under various bias voltages (0.4–2 V) for (a) closed form and (b) open form.
studied. The dependence of the transmission characteristics, T (E, V), on the bias voltages of 0.4, 0.8, 1.2, 1.6 and 2.0 V of the closed and open forms are presented in Fig. 8. According to Fig. 8, we can see that increasing the applied bias, makes the transmission peaks to be closer to the Fermi level (EF ), while in the open form, the main part of HOMO transmission peaks gradually enters into the bias window. The integral area in the bias window becomes larger by growing the bias and the current through the switch increases. However, the integral area for the open form is bigger than the closed form. Furthermore, both HOMO and LUMO of the open form is closer to the Fermi level EF than that of the closed form. As a result, the current of the open form is always greater than that of the closed form in the presented bias window.
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Fig. 9. The calculated I–V characteristics of the molecular switch with electrode: (a) Ag, (b) Pt, (c) the calculated current ratio of the molecular switches with different electrodes.
In the investigated molecular wire, the EF is close to LUMO and HOMO levels, for closed and open forms, respectively. These systems are called HOMO-based junctions for the open form and LUMO-based junctions for the closed form. It can be seen that the amplitude and location of the transmission peaks are related to the practical bias voltage. Furthermore, in order to improve the performance of the switch, the electron transport through the molecular device can be controlled by the electrode materials (Au, Pt and Ag) which their I–V characteristic curves are shown in Figs. 4 and 9. It can be seen from this Figs that the current through the switch is significantly affected by the electrode. The current of the open form increases by replacing platinum with gold. Note that regardless of the electrode type, the current of the open form is always greater than that of the closed form. We used the current ratio, Iopen-form /Iclosed-form , to study the conductivity changes due to the isomer conversion. The calculated current ratio vs. bias curves for the molecular switches with different electrodes is shown in Fig. 9c. From this Fig., one can see that the best switching performance occurred in gold electrode; the maximum current ratio is about 57.3 at 1.0 V.
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4. Conclusion The electronic transport properties of 4-(6-(4-chlorophenyl)-4-phenyl-1,3-diaza-bicyclo[3.1.0]hex-3-en-2-yl)-2nitrophenol molecular optical switch with two different configurations (closed and open forms) have been checked using NEGF formalism combined with DFT. The electronic transmission coefficients, I–V characteristics, on-off ratio, physical reason of the switching behavior and frontier orbitals corresponding to the various isomers were computed and analyzed. The obvious difference in conductance in two different forms can be understood. The I–V curves showed that current through the open form is higher than that of the closed form. The appearance of the switching behavior is interpreted based on the physical characteristics such as different effective conjugation lengths (due to differences in molecular geometry), the HOMO–LUMO gap, location and distribution of HOMO and LUMO. Furthermore, the electron transport through the molecular device can be controlled by the electrode materials (Au, Pt and Ag). The best switching performance occurred in gold electrode. Acknowledgements Authors are grateful to Damghan University and Pajooheshgaran Part Porsa for financial support. References [1] H. Rau, H. Durr, H. Bouas-Laurent, Photochromism: molecules and systems, photochromism, Mol. Syst. (1990) 165–192. [2] J.C. Crano, T. Flood, D. Knowles, A. Kumar, B. Van Gemert, Photochromic compounds: chemistry and application in ophthalmic lenses, Pure Appl. Chem. 68 (1996) 1395–1398. [3] C.J. Xia, D.S. Liu, H.C. Liu, Phenylazoimidazole as a possible optical molecular switch: an ab initio study, Optik 123 (2012) 1307–1310. [4] C.-J. Xia, D.-S. Liu, H.-C. Liu, Y.-T. Zhang, Effect of carbon nanotubes chirality on the E–C photo-isomerization switching behavior in moelcular device, Optik 125 (2012) 4522–4525. [5] J.D. Winkler, K. Deshayes, B. Shao, Photodynamic transport of metal ions, J. Am. Chem. Soc. 111 (1989) 769–770. [6] A. Dvornikov, J. Malkin, P. Rentzepis, Spectroscopy and kinetics of photochromic materials for 3D optical memory devices, J. Phys. Chem. 98 (1994) 6746–6752. [7] S. Pu, F. Zhang, J. Xu, L. Shen, Q. Xiao, B. Chen, Photochromic diarylethenes for three-wavelength optical memory, Mater. Lett. 60 (2006) 485–489. [8] I. Willner, S. Rubin, R. Shatzmiller, T. Zor, Reversible light-stimulated activation and deactivation of. alpha.-chymotrypsin by its immobilization in photoisomerizable copolymers, J. Am. Chem. Soc. 115 (1993) 8690–8694. [9] H. Kiyani, S.A. Pourmousavi, M. Farahani, N.O. Mahmoodi, Synthesis of 1, 3-diazabicyclo [3.1. 0] hex-3-ene system under microwave irradiation, J. Taibah Univ. Sci. 7 (2013) 72–78. [10] A. Ghavidast, N.O. Mahmoodi, M.A. Zanjanchi, Synthesis and photochromic properties of disulfide-1, 3-diazabicyclo [3.1. 0] hex-3-ene functionalized silver nanoparticles, J. Mol. Liq. 198 (2014) 128–133. [11] Y. -h. Zhou, X. -h. Zheng, Y. Xu, Z.Y. Zeng, Current rectification by asymmetric molecules: an ab initio study, J. Chem. Phys. 125 (2006) 244701–244705. [12] G. Maruccio, P. Visconti, V. Arima, S. D’Amico, A. Biasco, E. D’Amone, R. Cingolani, R. Rinaldi, S. Masiero, T. Giorgi, Field effect transistor based on a modified DNA base, Nano Lett. 3 (2003) 479–483. [13] A.R. Rocha, M. Rossi, A. Fazzio, A.J. da Silva, Designing real nanotube-based gas sensors, Phys. Rev. Lett. 100 (2008) 176803. [14] P. Zhao, P. Wang, Z. Zhang, D. Liu, Electronic transport properties of a molecular switch with carbon nanotube electrodes: a first-principles study, Physica B 405 (2010) 446–450. [15] P. Zhao, C. Fang, C. Xia, Y. Wang, D. Liu, S. Xie, A possible anthracene-based optical molecular switch driven by a reversible photodimerization reaction, Appl. Phys. Lett. 93 (2008) 013113. [16] C. Zhang, M.-H. Du, H.-P. Cheng, X.-G. Zhang, A. Roitberg, J. Krause, Coherent electron transport through an azobenzene molecule: a light-driven molecular switch, Phys. Rev. Lett. 92 (2004) 158301. [17] M. Ashraf, N.A. Bruque, J.L. Tan, G.J. Beran, R.K. Lake, Conductance switching in diarylethenes bridging carbon nanotubes, J. Chem. Sci. 134 (2011) 024524. [18] S.J. van der Molen, P. Liljeroth, Charge transport through molecular switches, J. Phys. Condens. Matter. 22 (2010) 133001. [19] M. Galperin, A. Nitzan, Molecular optoelectronics: the interaction of molecular conduction junctions with light, Phys. Chem. Chem. Phys. 14 (2012) 9421–9438. [20] N. Fuentes, A. Martín-Lasanta, L.Á. de Cienfuegos, M. Ribagorda, A. Parra, J.M. Cuerva, Organic-based molecular switches for molecular electronics, Nanoscale 3 (2011) 4003–4014. [21] E.G. Emberly, G. Kirczenow, The smallest molecular switch, Phys. Rev. Lett. 91 (2003) 188301. [22] S.Y. Quek, M. Kamenetska, M.L. Steigerwald, H.J. Choi, S.G. Louie, M.S. Hybertsen, J. Neaton, L. Venkataraman, Mechanically controlled binary conductance switching of a single-molecule junction, Nat. Nanotechnol. 4 (2009) 230–234. [23] R. Pati, S.P. Karna, Current switching by conformational change in a -- molecular wire, Phys. Rev. B 69 (2004) 155419. [24] N. Katsonis, T. Kudernac, M. Walko, S.J. van der Molen, B.J. van Wees, B.L. Feringa, Reversible conductance switching of single diarylethenes on a gold surface, Adv. Mater. 18 (2006) 1397–1400. [25] M. Irie, Diarylethenes for memories and switches, Chem. Rev. 100 (2000) 1685–1716. ´ S.J. van der Molen, T. Kudernac, H. Jonkman, J. De Jong, T. Bowden, J. Van Esch, B. Feringa, B. Van Wees, One-way optoelectronic switching of [26] D. Dulic, photochromic molecules on gold, Phys. Rev. Lett. 91 (2003) 207402. [27] A. Staykov, K. Yoshizawa, Photochemical reversibility of ring-closing and ring-opening reactions in diarylperfluorocyclopentenes, J. Phys. Chem. C 113 (2009) 3826–3834. [28] C. Zhang, Y. He, H.-P. Cheng, Y. Xue, M.A. Ratner, X.-G. Zhang, P. Krstic, Current-voltage characteristics through a single light-sensitive molecule, Phys. Rev. B 73 (2006) 125445. [29] S. Monti, G. Orlandi, P. Palmieri, Features of the photochemically active state surfaces of azobenzene, J. Chem. Phys. 71 (1982) 87–99. [30] A. Kanaani, D. Ajloo, H. Kiyani, H. Ghasemian, M. Vakili, M. Feizabadi, Molecular structure, spectroscopic investigations and computational study on the potential molecular switch of (E)-1-(4-(2-hydroxybenzylideneamino) phenyl) ethanone, Mol. Phys. 115 (2016) 1–17. [31] A. Kanaani, D. Ajloo, H. Kiyani, F. Shaheri, M. Amiri, Synthesis molecular structure, spectroscopic investigations and computational study of a potential molecular switch of 2-([1,1(-biphenyl]-4-yl)-2-methyl-6-(4-nitrophenyl)-4-phenyl-1, 3 diazabicyclo [3.1. 0] hex-3-ene, J. Chem. Sci. 128 (2016) 1211–1221. [32] M. Frisch, G. Trucks, H. Schlegel, G. Scuseria, M. Robb, J. Cheeseman, J. Montgomery Jr, T. Vreven, K. Kudin, J. Burant, Gaussian 03, Revision c. 02, 4, Gaussian, Inc Wallingford, CT, 2004.
A. Kanaani et al. / Optik 153 (2018) 135–143
143
[33] C. Lee, W. Yang, R.G. Parr, Development of the Colle-Salvetti correlation-energy formula into a functional of the electron density, Phys. Rev. B 37 (1988) 785. [34] B. Miehlich, A. Savin, H. Stoll, H. Preuss, Results obtained with the correlation energy density functionals of becke and Lee, Yang and Parr, Chem. Phys. Lett. 157 (1989) 200–206. [35] L. Messori, F. Abbate, G. Marcon, P. Orioli, M. Fontani, E. Mini, T. Mazzei, S. Carotti, T. O’Connell, P. Zanello, Gold (III) complexes as potential antitumor agents: solution chemistry and cytotoxic properties of some selected gold (III) compounds, J. Med. Chem. 43 (2000) 3541–3548. [36] Y. Cao, Q. Ge, D.J. Dyer, L. Wang, Steric effects on the adsorption of alkylthiolate self-assembled monolayers on Au (111), J. Phys. Chem. B 107 (2003) 3803–3807. [37] H. Sellers, A. Ulman, Y. Shnidman, J.E. Eilers, Structure and binding of alkanethiolates on gold and silver surfaces: implications for self-assembled monolayers, J. Am. Chem. Soc. 115 (1993) 9389–9401. [38] W. Geng, J. Nara, T. Ohno, Adsorption of benzene thiolate on the (111) surface of M (M = Pt, Ag, Cu) and the conductance of M/benzene dithiolate/M molecular junctions: a first-principles study, Thin Solid Films 464 (2004) 379–383. [39] H. Kondo, J. Nara, H. Kino, T. Ohno, Transport properties of a biphenyl-based molecular junction system—the electrode metal dependence, J. Phys. Condens. Matter. 21 (2009) 064220. [40] S.-H. Ke, H.U. Baranger, W. Yang, Contact atomic structure and electron transport through molecules, J. Chem. Phys. 122 (2005) 074704. [41] S. Parashar, P. Srivastava, M. Pattanaik, Effect of electrode materials on transport properties of asymmetric biphenyl molecular junctions, Solid State Commun. 191 (2014) 54–58. [42] G. Lamble, R. Brooks, S. Ferrer, D. King, D. Norman, Surface structural determination for a weakly ordered and a disordered phase of Cl on Ag (111), Phys. Rev. B 34 (1986) 2975. [43] E.C. Alyea, G. Ferguson, J. Malito, B.L. Ruhl, Crystal and molecular structures of bis (. mu.-chloro) bis [o-(dimesitylphosphino)-3, 5-dimethylbenzyl] dipalladium (II) acetone solvate,[Pd (P (mes) 2C6H2 (CH3) 2CH2) Cl] 2. cntdot. 2 (CH3COCH3), and its platinum analog [Pt (P (mes) 2C6H2 (CH3) 2CH2) Cl] 2. cntdot. 2 (CH3COCH3). Cyclometalated complexes of the bulkiest known phosphine trimesitylphosphine, Organometallics 8 (1989) 1188–1191. [44] N. Troullier, J.L. Martins, Efficient pseudopotentials for plane-wave calculations, Phys. Rev. B 43 (1991) 1993. [45] J.M. Soler, E. Artacho, J.D. Gale, A. García, J. Junquera, P. Ordejón, D. Sánchez-Portal, The SIESTA method for ab initio order-N materials simulation, J. Phys. Condens. Matter. 14 (2002) 2745. [46] H.J. Monkhorst, J.D. Pack, Special points for Brillouin-zone integrations, Phys. Rev. B 13 (1976) 5188. [47] G.-P. Zhang, G.-C. Hu, Z.-L. Li, C.-K. Wang, Theoretical studies on protonation-Induced inversion of the rectifying direction in dipyrimidinyl–diphenyl diblock molecular junctions, J. Phys. Chem. C 116 (2012) 3773–3778. [48] M. Brandbyge, J.-L. Mozos, P. Ordejón, J. Taylor, K. Stokbro, Density-functional method for nonequilibrium electron transport, Phys. Rev. B 65 (2002) 165401. [49] A. Staykov, D. Nozaki, K. Yoshizawa, Photoswitching of conductivity through a diarylperfluorocyclopentene nanowire, J. Phys. Chem. C 111 (2007) 3517–3521. [50] M.J. Marsella, Z.-Q. Wang, R.H. Mitchell, Backbone photochromic polymers containing the dimethyldihydropyrene moiety: toward optoelectronic switches, Org. Lett. 2 (2000) 2979–2982. [51] S. Datta, Electronic Transport in Mesoscopic Systems, Cambridge University Press, 1997. [52] A. Staykov, D. Nozaki, K. Yoshizawa, Theoretical study of donor--bridge-acceptor unimolecular electric rectifier, J. Phys. Chem. C 111 (2007) 11699–11705.
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Optik journal homepage: www.elsevier.de/ijleo
Original research article
First-principles study of the electronic transport properties of a 1,3-diazabicyclo[3.1.0]hex-3-ene molecular optical switch Ayoub Kanaani a , Davood Ajloo a,b,∗ , Hamzeh Kiyani a,∗ , Sayyed Ahmad Nabavi Amri a a b
School of Chemistry, Damghan University, Damghan, 36715-364, Iran Institute of Biological Science, Damghan University, Damghan, 36716-41167, Iran
a r t i c l e
i n f o
Article history: Received 18 June 2017 Accepted 29 September 2017 Keywords: Optical molecular switch Electronic transport Non-equilibrium green’s function
a b s t r a c t We analyze the transport properties of 4-(6-(4-chlorophenyl)-4-phenyl-1,3-diazabicyclo[3.1.0]hex-3-en-2-yl)-2-nitrophenol molecular optical switch using first-principles calculations. Molecule consisting switch can transform among closed and open forms by visible or ultraviolet irradiation. We have studied multiple attributes such as I–V characteristics, electronic transmission coefficients T(E), the effect of electrode materials (Au, Ag, and Pt) on electronic transport properties, on-off ratio and spatial distribution of molecular projected self-consistent Hamiltonian (MPSH) orbitals corresponding to the closed and open forms. The physical origin of switching behavior is interpreted based on the different molecular geometries, location and size of the frontier molecular orbitals and the HOMO–LUMO gap. According to the theoretical results, one can found that when the open form converts to the closed form, there is a switch from low resistance (on state) to high resistance (off state). We hope that the results of this study can help researchers to design new functional molecular devices. © 2017 Elsevier GmbH. All rights reserved.
1. Introduction Photochromism is a phenomenon in which a compound follows reversible changes between two states with different absorption spectrums such that different colors are created from compounds in crystal, amorphous or liquid states. Under electromagnetic radiation (usually UV light), stable thermodynamic shape A transforms to a new colorful type B via photochemical reaction and type B changes to the initial shape A on reverse direction via another light source like visible light or heat [1–4]. Photochromism delivers a suitable insight to the expansion of optical sensing applications [5], high-density optical memory [6], photo – switches [7], molecular photonic devices [8] and light-sensitive eyewear [2]. The photochromism of 4-(6-(4-chlorophenyl)-4-phenyl-1,3-diaza-bicyclo[3.1.0]hex-3-en-2-yl)-2-nitrophenol is shown in Fig. 1 [9]. Also, photochromic behavior can be observed when the 1,3-diazabicyclo[3.1.0]hex-3-ene connect to the silver [10]. Recently, a lot of interesting physical properties such as highly nonlinear I–V characteristics, memory effects, negative differential resistance (NDR), switching properties, electric rectification behavior and etc. are found in various systems such as organics [11], DNA [12] and carbon nanotubes [13]. The supreme aim in microelectronic crafts is the perpetual miniaturization of electronic devices and the final target is to synthesize devices by using a molecule, a cluster or even an
∗ Corresponding authors at: School of Chemistry, Damghan University, Damghan, 36715-364, Iran. E-mail addresses: [email protected] (D. Ajloo), [email protected] (H. Kiyani). https://doi.org/10.1016/j.ijleo.2017.09.125 0030-4026/© 2017 Elsevier GmbH. All rights reserved.
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Fig 1. Chemical structures corresponding to closed and open form of the 4-(6-(4-chlorophenyl)-4-phenyl-1,3-diaza-bicyclo[3.1.0]hex-3-en-2-yl)-2nitrophenol.
atom [14–16]. Lately, synthesis, design and investigation of photochromism molecular switches of effective components in nanoelectronics research, become a research hotspot. Meantime, the computational researches of photochromism molecular switches, adopting to first-principles methods have also attracted growing considerations [16,17]. Wide areas of molecular switches have been published in the literature [18–20], with bistable and high/low conductance forms which are activated by several types of external motivations [21–23]. Among those, light is a very attractive stimulus due to its quick response time, feasibility of addressing, a wide range of condensed phases and compatibility with already existing experimental setups [20,24]. According to this, azobenzene- and diarylethene-based photochromic switches have been investigated, comprehensively [16,25–29]. Generally, due to light treatment, molecular optical switches involve changes in the molecular structure such isomerization reactions of the molecular bridge and ring-opening reactions. Newly, we have described another mechanism which is based on solvent induced hydrogen shift in molecular bridge [30]. Also in previous work, 2-([1,1 -biphenyl]-4-yl)-2-methyl-6-(4-nitrophenyl)-4-phenyl-1,3 diazabicyclo [3.1.0]hex-3ene photochromic switch has been studied [31]. The closed form of switch can be transformed into the open one upon irradiation with 300 nm ultraviolet light (UV) which results in increasing the magnitude of conductivity by 103 . These two forms can survive in a wide temperature range and can reversibly change to each other, which make the title compound as an excellent candidate for light-driven molecular switches. In this project, Non-equilibrium Green’s function (NEGF) formalism merged with first-principles density functional theory (DFT) were used to study the conductive behavior of the switch of the title compound. 2. Model and computational methods In the present work, the calculations are done in two steps. In the first step, geometry optimization of 4-(6-(4chlorophenyl)-4-phenyl-1,3-diaza-bicyclo[3.1.0]hex-3-en-2-yl)-2-nitrophenol with one SH group as linker is performed by Gaussian 03 program [32] with B3LYP type exchange correlation functional [33] and the popular 6–311 + +G(d,p) basis set [34]. Positive values of all calculated vibrational wave numbers certified the location of geometries at real positional least minimum on the potential energy surface. Chlorine atom can be easily attached to metal [35], but it is generally accepted that hydrogen atoms are unzipped upon adsorption to metal surfaces [36,37]. So we construct a two-probe system in which the one terminal hydrogen atom that bonded to the sulfur atom is deleted from the optimized structure, and the remained segment is located between two parallel metal surfaces. It’s both closed and open forms have one S-linker and are connected into the Gold junction with (1 1 1) surfaces. The modelled molecular connection structure is illustrated schematically in Fig. 2. The central section involves sections of the electrodes, so the screening results can be included in computations. The most common X (1 1 1) surface [38,39] is used with (6 × 6) periodic boundary conditions. The 6 × 6 supercell is big sufficient to avoid any interplay with molecules in the subsequent supercell [30,31]. The sulfur and chlorine atoms are elected to place at the hollow location of the X triangle. Since the main purpose of this work is to determine the switch of conductivity through a photochemical reaction, the nature of Au–S interaction is not investigated here. The vertical distance between the sulfur and chlorine atoms with X (Au, Ag and Pt) surface are set to be 1.9, 2.0, 2.4 Å and 2.3, 2.7, 2.8 Å, respectively [35,40–43]. The core electrons are modelled with Troullier–Martins nonlocal pseudopotential [44], while the valence electrons wave functions are expanded by a SIESTA basis set [45]. Since transport properties are going to be calculated after the structural relaxations, only atoms in the scattering region are fully relaxed within a force convergence criteria of 0.02 eV/◦ A, while
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Fig. 2. Schematic molecular junctions used in our calculations. Table 1 Optimized geometrical parameters of DPQ at B3LYP/6-311++G(2d,p) level. Parametersa
closed
open
Parametersa
closed
open
Bond lengths (Å) C4 C10 C10 N11 C10 N12 N12 C13 N11 C24 N11 C26
1.522 1.484 1.471 1.283 1.470 1.464
1.525 1.518 1.439 1.312 1.362 1.335
C26 C13 C13 C14 C14 C28 C28
1.490 1.472 1.500 1.404 1.402 1.399 1.399
1.439 1.422 1.477 1.402 1.401 1.414 1.418
Bond angles (◦ ) A(4,10,11) A(4,10,12) A(10,11,24) A(10,11,26) A(10,12,13) A(12,13,24)
111.8 110.3 104.6 113.9 108.7 112.8
111.8 109.8 105.1 128.0 106.8 113.1
A(11,26,28) A(26,28,29) A(26,28,30) A(12,13,14) A(24,13,14) A(13,14,15) A(13,14,16)
118.2 121.8 119.4 123.7 123.6 120.3 120.6
130.9 127.8 115.6 121.9 125.0 119.5 121.6
Dihedral angles (◦ ) D(3,4,10,12) D(3,4,10,11) D(4,10,12,13) D(4,10,11,24) D(4,10,11,26) D(10,12,13,14) D(10,12,13,24)
−48.8 −169.6 −119.5 119.7 −175.0 177.4 −3.1
−73.9 168.4 −114.7 112.6 −66.3 177.9 −3.4
D(10,11,24,13) D(11,26,28,29) D(11,26,28,30) D(12,13,14,15) D(12,13,14,16) D(24,13,14,16) D(24,13,14,15)
0.5 14.5 −166.3 −10.4 169.3 −10.2 170
5.2 4.0 −174.7 3.4 −176.6 4.8 −175.19
a
C28 C24 C14 C15 C16 C29 C30
For atom numbering from Fig. 3.
keeping all the electrod atoms fixed. The X atoms are characterized by a single- plus single polarization (SZP) basis set whereas for the other atoms, a double- plus single polarization (DZP) basis set is used. The k-grid sampling of 2 × 2 × 100 by Monkhorst-Pack method to describe the Brillouin zone[46], was employed simultaneously with the mesh cutoff of 150 Ry for the grid integration. There is a good agreement between previous simulation with empirical evaluation [47]. The transport calculations are performed using TRANSIESTA-C package based on SIESTA [48]. In this code, the NEGF is used to compute the current while a bias is applied among the two electrodes. The bias voltage is scanned from 0.0 to 2 V at 300 K. The current through the device is computed using the Landauer–Büttiker formula in TranSIESTA package [48]. I=
2e h
T (E, V )[f (E − L ) − f (E − R )]dE
(1)
Here e is the electron charge, h Planck’s constant, T(E, V) the transmission function at energy E under bias voltage V, and f(E−L(R) ) is the Fermi–Dirac distribution function with the electrochemical potential L(R) of the left (right) electrode. 3. Results and discussion The optimized geometrical parameters of 4-(6-(4-chlorophenyl)-4-phenyl-1,3-diaza-bicyclo[3.1.0]hex-3-en-2-yl)-2nitrophenol are computed using DFT/B3LYP method with 6–311++G(d,p) basis set. Some selected geometrical parameters (Å, ◦ ) of closed and open forms are listed in Table 1 according to numbering scheme given in Fig. 3.
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Fig. 3. Optimized geometry by B3LYP/6–311++G(d,p) for closed and open forms.
Fig. 4. The I–V characteristics of the molecular switch with two forms.
The physical reason of the switch behavior is related to various factors. One of these factors changes in conjugation length for these two isomers. From Table 1, we can conclude that the dihedral angle ϕ which determines the -electron conjugation and the -overlapping [49] is 174.7◦ for closed form and 166.3◦ for open form. It indicates that the effective conjugation length for these two isomers of the closed form is reduced. It is known that there is a strong relation between electrical conductivity and efficient conjugation length of the molecular wire [50]. The photochromism of 1,3 −diazabicyclo[3.1.0]hex-3-enes is happened in the aziridine unit with a reversible photochemical splitting of the C N bond. This phenomenon leads to the formation of a zwitterion species (the open form) leading to the relatively longer -conjugation. The current–voltage (I–V) curves for the molecular device with two different isomers in the bias voltage ranged from 0.0 to 2.0 V are with gold electrod given in Fig. 4. The switching behavior can be clearly seen in Fig. 4, as at the same bias, the current of the open form is greater than that of the closed form. For example, the calculated current at 1.0 V is about 344 A and 6 A for the open and closed forms, respectively. It can be concluded from Fig. 4 that when the closed form molecule changes to an open one, a switching behavior happens from off (high resistance) state to on (low resistance) state. This significant discrepancy in current severity happening in the closed and open forms, can be found within LandauerBütiker formalism [51] by foreseeing the transmission factor possibility for electrons to scatter through the molecular wire. The energy dependence of zero-bias transmission spectra are computed and demonstrated in Fig. 5. From Fig. 5, we can see that the transmission spectra present considerably different characteristics for two explained isomers. In our calculation, the average Fermi level is set to be zero. From Eq. (1), we may anticipate that only electrons with energies at a small range
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Fig. 5. The transmission spectra of the molecular switch at zero bias.
Fig. 6. The spatial distribution of the MPSH states corresponding to HOMO, LUMO, HOMO-1 and LUMO+1 of closed form with electrode: (a) Au, (b) Ag, (c) Pt.
around the Fermi level EF contribute to the total current. As can be seen from Fig. 5, if we focus on the most interesting area around the Fermi level EF , one can see that the transmission coefficients of the open form are bigger than those of the closed form in the energy range of [−3.0, 3.0 eV]. This behavioral difference can be understood more clearly in the spatial repartition of the molecular projected selfconsistent Hamiltonian (MPSH) [52]. The HOMO and LUMO levels are −0.571 eV and 1.075 eV for the open form, −1.873 eV and 1.311 eV for the closed form. As a result, the HOMO–LUMO gap in the closed form is larger than that of the open form. Therefore, because of the large HOMO–LUMO gap and the low transmission coefficient caused by changes in the molecular structure, conductivity in the closed form decreases. The spatial distribution of the MPSH states corresponding to the HOMO, LUMO, HOMO-1 and LUMO+1 of the closed and open forms is presented in Figs. 6 and 7. As shown in these Figs, both HOMO and LUMO have large weight and delocalized in the open form while they have small weight and localized in the closed form. Both HOMO and LUMO have delocalized orbitals which give the principal electronic transport channel for the open form making a low obstacle for electron transportation. Also, applying the external bias help us to understand how the evolution in transmission curves changes the coupling between the electrodes and molecules. So, in the next step, the dependence of voltage on transmission function will be
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Fig. 7. The spatial distribution of the MPSH states corresponding to HOMO, LUMO, HOMO-1 and LUMO+1 of open form with electrode: (a) Au, (b) Ag, (c) Pt.
Fig. 8. The transmission spectrum under various bias voltages (0.4–2 V) for (a) closed form and (b) open form.
studied. The dependence of the transmission characteristics, T (E, V), on the bias voltages of 0.4, 0.8, 1.2, 1.6 and 2.0 V of the closed and open forms are presented in Fig. 8. According to Fig. 8, we can see that increasing the applied bias, makes the transmission peaks to be closer to the Fermi level (EF ), while in the open form, the main part of HOMO transmission peaks gradually enters into the bias window. The integral area in the bias window becomes larger by growing the bias and the current through the switch increases. However, the integral area for the open form is bigger than the closed form. Furthermore, both HOMO and LUMO of the open form is closer to the Fermi level EF than that of the closed form. As a result, the current of the open form is always greater than that of the closed form in the presented bias window.
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Fig. 9. The calculated I–V characteristics of the molecular switch with electrode: (a) Ag, (b) Pt, (c) the calculated current ratio of the molecular switches with different electrodes.
In the investigated molecular wire, the EF is close to LUMO and HOMO levels, for closed and open forms, respectively. These systems are called HOMO-based junctions for the open form and LUMO-based junctions for the closed form. It can be seen that the amplitude and location of the transmission peaks are related to the practical bias voltage. Furthermore, in order to improve the performance of the switch, the electron transport through the molecular device can be controlled by the electrode materials (Au, Pt and Ag) which their I–V characteristic curves are shown in Figs. 4 and 9. It can be seen from this Figs that the current through the switch is significantly affected by the electrode. The current of the open form increases by replacing platinum with gold. Note that regardless of the electrode type, the current of the open form is always greater than that of the closed form. We used the current ratio, Iopen-form /Iclosed-form , to study the conductivity changes due to the isomer conversion. The calculated current ratio vs. bias curves for the molecular switches with different electrodes is shown in Fig. 9c. From this Fig., one can see that the best switching performance occurred in gold electrode; the maximum current ratio is about 57.3 at 1.0 V.
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4. Conclusion The electronic transport properties of 4-(6-(4-chlorophenyl)-4-phenyl-1,3-diaza-bicyclo[3.1.0]hex-3-en-2-yl)-2nitrophenol molecular optical switch with two different configurations (closed and open forms) have been checked using NEGF formalism combined with DFT. The electronic transmission coefficients, I–V characteristics, on-off ratio, physical reason of the switching behavior and frontier orbitals corresponding to the various isomers were computed and analyzed. The obvious difference in conductance in two different forms can be understood. The I–V curves showed that current through the open form is higher than that of the closed form. The appearance of the switching behavior is interpreted based on the physical characteristics such as different effective conjugation lengths (due to differences in molecular geometry), the HOMO–LUMO gap, location and distribution of HOMO and LUMO. Furthermore, the electron transport through the molecular device can be controlled by the electrode materials (Au, Pt and Ag). The best switching performance occurred in gold electrode. Acknowledgements Authors are grateful to Damghan University and Pajooheshgaran Part Porsa for financial support. References [1] H. Rau, H. Durr, H. Bouas-Laurent, Photochromism: molecules and systems, photochromism, Mol. Syst. (1990) 165–192. [2] J.C. Crano, T. Flood, D. Knowles, A. Kumar, B. Van Gemert, Photochromic compounds: chemistry and application in ophthalmic lenses, Pure Appl. Chem. 68 (1996) 1395–1398. [3] C.J. Xia, D.S. Liu, H.C. Liu, Phenylazoimidazole as a possible optical molecular switch: an ab initio study, Optik 123 (2012) 1307–1310. [4] C.-J. Xia, D.-S. Liu, H.-C. Liu, Y.-T. Zhang, Effect of carbon nanotubes chirality on the E–C photo-isomerization switching behavior in moelcular device, Optik 125 (2012) 4522–4525. [5] J.D. Winkler, K. Deshayes, B. Shao, Photodynamic transport of metal ions, J. Am. Chem. Soc. 111 (1989) 769–770. [6] A. Dvornikov, J. Malkin, P. Rentzepis, Spectroscopy and kinetics of photochromic materials for 3D optical memory devices, J. Phys. Chem. 98 (1994) 6746–6752. [7] S. Pu, F. Zhang, J. Xu, L. Shen, Q. Xiao, B. Chen, Photochromic diarylethenes for three-wavelength optical memory, Mater. Lett. 60 (2006) 485–489. [8] I. Willner, S. Rubin, R. Shatzmiller, T. Zor, Reversible light-stimulated activation and deactivation of. alpha.-chymotrypsin by its immobilization in photoisomerizable copolymers, J. Am. Chem. Soc. 115 (1993) 8690–8694. [9] H. Kiyani, S.A. Pourmousavi, M. Farahani, N.O. Mahmoodi, Synthesis of 1, 3-diazabicyclo [3.1. 0] hex-3-ene system under microwave irradiation, J. Taibah Univ. Sci. 7 (2013) 72–78. [10] A. Ghavidast, N.O. Mahmoodi, M.A. Zanjanchi, Synthesis and photochromic properties of disulfide-1, 3-diazabicyclo [3.1. 0] hex-3-ene functionalized silver nanoparticles, J. Mol. Liq. 198 (2014) 128–133. [11] Y. -h. Zhou, X. -h. Zheng, Y. Xu, Z.Y. Zeng, Current rectification by asymmetric molecules: an ab initio study, J. Chem. Phys. 125 (2006) 244701–244705. [12] G. Maruccio, P. Visconti, V. Arima, S. D’Amico, A. Biasco, E. D’Amone, R. Cingolani, R. Rinaldi, S. Masiero, T. Giorgi, Field effect transistor based on a modified DNA base, Nano Lett. 3 (2003) 479–483. [13] A.R. Rocha, M. Rossi, A. Fazzio, A.J. da Silva, Designing real nanotube-based gas sensors, Phys. Rev. Lett. 100 (2008) 176803. [14] P. Zhao, P. Wang, Z. Zhang, D. Liu, Electronic transport properties of a molecular switch with carbon nanotube electrodes: a first-principles study, Physica B 405 (2010) 446–450. [15] P. Zhao, C. Fang, C. Xia, Y. Wang, D. Liu, S. Xie, A possible anthracene-based optical molecular switch driven by a reversible photodimerization reaction, Appl. Phys. Lett. 93 (2008) 013113. [16] C. Zhang, M.-H. Du, H.-P. Cheng, X.-G. Zhang, A. Roitberg, J. Krause, Coherent electron transport through an azobenzene molecule: a light-driven molecular switch, Phys. Rev. Lett. 92 (2004) 158301. [17] M. Ashraf, N.A. Bruque, J.L. Tan, G.J. Beran, R.K. Lake, Conductance switching in diarylethenes bridging carbon nanotubes, J. Chem. Sci. 134 (2011) 024524. [18] S.J. van der Molen, P. Liljeroth, Charge transport through molecular switches, J. Phys. Condens. Matter. 22 (2010) 133001. [19] M. Galperin, A. Nitzan, Molecular optoelectronics: the interaction of molecular conduction junctions with light, Phys. Chem. Chem. Phys. 14 (2012) 9421–9438. [20] N. Fuentes, A. Martín-Lasanta, L.Á. de Cienfuegos, M. Ribagorda, A. Parra, J.M. Cuerva, Organic-based molecular switches for molecular electronics, Nanoscale 3 (2011) 4003–4014. [21] E.G. Emberly, G. Kirczenow, The smallest molecular switch, Phys. Rev. Lett. 91 (2003) 188301. [22] S.Y. Quek, M. Kamenetska, M.L. Steigerwald, H.J. Choi, S.G. Louie, M.S. Hybertsen, J. Neaton, L. Venkataraman, Mechanically controlled binary conductance switching of a single-molecule junction, Nat. Nanotechnol. 4 (2009) 230–234. [23] R. Pati, S.P. Karna, Current switching by conformational change in a -- molecular wire, Phys. Rev. B 69 (2004) 155419. [24] N. Katsonis, T. Kudernac, M. Walko, S.J. van der Molen, B.J. van Wees, B.L. Feringa, Reversible conductance switching of single diarylethenes on a gold surface, Adv. Mater. 18 (2006) 1397–1400. [25] M. Irie, Diarylethenes for memories and switches, Chem. Rev. 100 (2000) 1685–1716. ´ S.J. van der Molen, T. Kudernac, H. Jonkman, J. De Jong, T. Bowden, J. Van Esch, B. Feringa, B. Van Wees, One-way optoelectronic switching of [26] D. Dulic, photochromic molecules on gold, Phys. Rev. Lett. 91 (2003) 207402. [27] A. Staykov, K. Yoshizawa, Photochemical reversibility of ring-closing and ring-opening reactions in diarylperfluorocyclopentenes, J. Phys. Chem. C 113 (2009) 3826–3834. [28] C. Zhang, Y. He, H.-P. Cheng, Y. Xue, M.A. Ratner, X.-G. Zhang, P. Krstic, Current-voltage characteristics through a single light-sensitive molecule, Phys. Rev. B 73 (2006) 125445. [29] S. Monti, G. Orlandi, P. Palmieri, Features of the photochemically active state surfaces of azobenzene, J. Chem. Phys. 71 (1982) 87–99. [30] A. Kanaani, D. Ajloo, H. Kiyani, H. Ghasemian, M. Vakili, M. Feizabadi, Molecular structure, spectroscopic investigations and computational study on the potential molecular switch of (E)-1-(4-(2-hydroxybenzylideneamino) phenyl) ethanone, Mol. Phys. 115 (2016) 1–17. [31] A. Kanaani, D. Ajloo, H. Kiyani, F. Shaheri, M. Amiri, Synthesis molecular structure, spectroscopic investigations and computational study of a potential molecular switch of 2-([1,1(-biphenyl]-4-yl)-2-methyl-6-(4-nitrophenyl)-4-phenyl-1, 3 diazabicyclo [3.1. 0] hex-3-ene, J. Chem. Sci. 128 (2016) 1211–1221. [32] M. Frisch, G. Trucks, H. Schlegel, G. Scuseria, M. Robb, J. Cheeseman, J. Montgomery Jr, T. Vreven, K. Kudin, J. Burant, Gaussian 03, Revision c. 02, 4, Gaussian, Inc Wallingford, CT, 2004.
A. Kanaani et al. / Optik 153 (2018) 135–143
143
[33] C. Lee, W. Yang, R.G. Parr, Development of the Colle-Salvetti correlation-energy formula into a functional of the electron density, Phys. Rev. B 37 (1988) 785. [34] B. Miehlich, A. Savin, H. Stoll, H. Preuss, Results obtained with the correlation energy density functionals of becke and Lee, Yang and Parr, Chem. Phys. Lett. 157 (1989) 200–206. [35] L. Messori, F. Abbate, G. Marcon, P. Orioli, M. Fontani, E. Mini, T. Mazzei, S. Carotti, T. O’Connell, P. Zanello, Gold (III) complexes as potential antitumor agents: solution chemistry and cytotoxic properties of some selected gold (III) compounds, J. Med. Chem. 43 (2000) 3541–3548. [36] Y. Cao, Q. Ge, D.J. Dyer, L. Wang, Steric effects on the adsorption of alkylthiolate self-assembled monolayers on Au (111), J. Phys. Chem. B 107 (2003) 3803–3807. [37] H. Sellers, A. Ulman, Y. Shnidman, J.E. Eilers, Structure and binding of alkanethiolates on gold and silver surfaces: implications for self-assembled monolayers, J. Am. Chem. Soc. 115 (1993) 9389–9401. [38] W. Geng, J. Nara, T. Ohno, Adsorption of benzene thiolate on the (111) surface of M (M = Pt, Ag, Cu) and the conductance of M/benzene dithiolate/M molecular junctions: a first-principles study, Thin Solid Films 464 (2004) 379–383. [39] H. Kondo, J. Nara, H. Kino, T. Ohno, Transport properties of a biphenyl-based molecular junction system—the electrode metal dependence, J. Phys. Condens. Matter. 21 (2009) 064220. [40] S.-H. Ke, H.U. Baranger, W. Yang, Contact atomic structure and electron transport through molecules, J. Chem. Phys. 122 (2005) 074704. [41] S. Parashar, P. Srivastava, M. Pattanaik, Effect of electrode materials on transport properties of asymmetric biphenyl molecular junctions, Solid State Commun. 191 (2014) 54–58. [42] G. Lamble, R. Brooks, S. Ferrer, D. King, D. Norman, Surface structural determination for a weakly ordered and a disordered phase of Cl on Ag (111), Phys. Rev. B 34 (1986) 2975. [43] E.C. Alyea, G. Ferguson, J. Malito, B.L. Ruhl, Crystal and molecular structures of bis (. mu.-chloro) bis [o-(dimesitylphosphino)-3, 5-dimethylbenzyl] dipalladium (II) acetone solvate,[Pd (P (mes) 2C6H2 (CH3) 2CH2) Cl] 2. cntdot. 2 (CH3COCH3), and its platinum analog [Pt (P (mes) 2C6H2 (CH3) 2CH2) Cl] 2. cntdot. 2 (CH3COCH3). Cyclometalated complexes of the bulkiest known phosphine trimesitylphosphine, Organometallics 8 (1989) 1188–1191. [44] N. Troullier, J.L. Martins, Efficient pseudopotentials for plane-wave calculations, Phys. Rev. B 43 (1991) 1993. [45] J.M. Soler, E. Artacho, J.D. Gale, A. García, J. Junquera, P. Ordejón, D. Sánchez-Portal, The SIESTA method for ab initio order-N materials simulation, J. Phys. Condens. Matter. 14 (2002) 2745. [46] H.J. Monkhorst, J.D. Pack, Special points for Brillouin-zone integrations, Phys. Rev. B 13 (1976) 5188. [47] G.-P. Zhang, G.-C. Hu, Z.-L. Li, C.-K. Wang, Theoretical studies on protonation-Induced inversion of the rectifying direction in dipyrimidinyl–diphenyl diblock molecular junctions, J. Phys. Chem. C 116 (2012) 3773–3778. [48] M. Brandbyge, J.-L. Mozos, P. Ordejón, J. Taylor, K. Stokbro, Density-functional method for nonequilibrium electron transport, Phys. Rev. B 65 (2002) 165401. [49] A. Staykov, D. Nozaki, K. Yoshizawa, Photoswitching of conductivity through a diarylperfluorocyclopentene nanowire, J. Phys. Chem. C 111 (2007) 3517–3521. [50] M.J. Marsella, Z.-Q. Wang, R.H. Mitchell, Backbone photochromic polymers containing the dimethyldihydropyrene moiety: toward optoelectronic switches, Org. Lett. 2 (2000) 2979–2982. [51] S. Datta, Electronic Transport in Mesoscopic Systems, Cambridge University Press, 1997. [52] A. Staykov, D. Nozaki, K. Yoshizawa, Theoretical study of donor--bridge-acceptor unimolecular electric rectifier, J. Phys. Chem. C 111 (2007) 11699–11705.