Cationic half-sandwich Ru(II) complexes containing (N,N)-bound Schiff-base ligands: Synthesis, crystal structure analysis and spectroscopic studies

Accepted Manuscript Cationic half-sandwich Ru(II) complexes containing (N,N)-bound Schiff-base ligands: synthesis, crystal structure analysis and spectroscopic studies Li Tao, Qian Miao, Alireza Azhdari Tehrani, Taraneh Hajiashrafi, Mao-Lin Hu, Ali Morsali PII:

S0022-2860(16)30269-1

DOI:

10.1016/j.molstruc.2016.03.091

Reference:

MOLSTR 22402

To appear in:

Journal of Molecular Structure

Received Date: 26 February 2016 Revised Date:

18 March 2016

Accepted Date: 21 March 2016

Please cite this article as: L. Tao, Q. Miao, A.A. Tehrani, T. Hajiashrafi, M.-L. Hu, A. Morsali, Cationic half-sandwich Ru(II) complexes containing (N,N)-bound Schiff-base ligands: synthesis, crystal structure analysis and spectroscopic studies, Journal of Molecular Structure (2016), doi: 10.1016/ j.molstruc.2016.03.091. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

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Graphical abstract (Pictogram):

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Cationic half-sandwich Ru(II) complexes containing (N,N)-bound Schiff-base ligands: synthesis, crystal

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structure analysis and spectroscopic studies

Li Tao1, Qian Miao1, Alireza Azhdari Tehrani2, Taraneh Hajiashrafi3, Mao-Lin Hu1*, Ali Morsali2*

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College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, China

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Department of Chemistry, Faculty of Sciences, Tarbiat Modares University, P.O. Box 14115-175, Tehran, Iran 3

Department of Chemistry, Alzahra University, P.O. Box 1993891176, Tehran, Iran

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E-mail: [email protected] (M.-L. Hu), [email protected] (A. Morsali).

ABSTRACT. Three Ru(II) half-sandwich complexes containing (N,N)-bound Schiff-base ligands, [(η6C6H6)

RuCl(L1)]PF6

(1)

L1=(E)-1-(6-methylpyridin-2-yl)-N-(p-tolyl)methanimine,

[(η6-p-

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cymene)RuCl(L1)]PF6 (2) and [(η6-p-cymene)RuCl(L2)]PF6 (3) L2= (E)-1-(6-bromopyridin-2-yl)-N(p-tolyl)methanimine, were synthesized, characterized and their supramolecular structures were

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analyzed. The crystal packing of these compounds was studied using geometrical analysis and Hirshfeld surface analysis. The fluorescence behavior of these compounds was also studied. TD-DFT calculations were carried out to better understand the fluorescence properties of complexes 1-3. These compounds could be promising for the design of organometallic dye systems.

Keywords: Ru(II) half-sandwich complex; Organometallic; Fluorescence

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1. Introduction In recent years, organometallic ruthenium compounds have been attracting significant interest, owing to

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their potential applications in various areas [1,2]. Dinuclear chloro-bridged [Ru(η6-arene)Cl2]2 complexes are known as useful synthetic precursors in preparative organometallic chemistry. These dimeric complexes are readily undergo cleavage with neutral ligand to give neutral or cationic halfsandwich Ru(II) complexes [3]. Based on this synthetic pathway, various (η6-arene) ruthenium(II)

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complexes have been synthesized and their structure-activity relationships were studied [4]. Since many

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of the bulk properties of molecular materials are dictated by the manner in which the molecules (building blocks) are assembled in the solid state, it is clear that the ability to control this ordering would afford control over these properties. Despite the enormous interest related to the systematic crystal engineering study of metal-containing compounds, crystal engineering of organometallic compounds has not received such thorough attention, even though organometallic compounds are

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nowadays employed in scientific areas of research from catalysis to optics [5]. Noteworthy, in the last few years, there is an increasing interest in the chemistry of Ru(II) organometallic complexes with N,Nchelating ligands for applications in pharmaceutical chemistry and in homogeneous catalysis [6-9]. In

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continuation of our research interest in understanding of the factors governing the supramolecular architecture of Ru(II) half-sandwich complexes [10], we describe herein the synthesis, characterization,

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crystal structure and spectroscopic studies of three novel Ru(II) half-sandwich complexes containing (N,N)-bound Schiff-base ligands, [(η6-C6H6)RuCl(L1)]PF6 (1), [(η6-p-cymene)RuCl(L1)]PF6 (2) and [(η6-p-cymene)RuCl(L2)]PF6 (3). From chemical point of view, these compounds exhibit interesting features because their emission properties may readily be manipulated by substitution of different functional groups in the Schiff-base ligand backbone. Thus, this work shows that these compounds could be promising for the design of organometallic dye systems.

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2. Experimental 2.1 Apparatus and reagents [Ru(η6-p-cymene)Cl2]2 and [(η6-C6H6)RuCl2]2 were synthesized according to the literature procedures

commercial vendors and used as received. 1H (500 MHz) and

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[12]. All other chemicals and solvents were purchased from Aldrich Chemical Company or other C (125 MHz) NMR spectra were

recorded on a Bruker AVANCE-500 spectrometer using tetramethylsilane (TMS) as an internal standard

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and DMSO-d6 as the solvent at room temperature and coupling constant J is given in Hz. IR spectra were recorded on a Perkin-Elmer Model 1725X spectrophotometer (KBr pellets). Elemental analyses

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were performed on a Carlo-Erba 1112 Elemental Analyzer. Fluorescence measurements were made in methanolic solutions on a Perkin Elmer-LS55 Fluorescence Spectrometer at room temperature. . UV– Vis measurements were carried out on a JASCO V-530 and Perkin Elmer (LAMBAD 2) UV–Vis spectrophotometers.

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2.2 Single-Crystal Diffraction Studies.

Crystallographic measurements of compounds 1-3 were made using a Bruker APEX area-detector diffractometer. The intensity data were collected using graphite monochromated Mo–Kα radiation

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(λ=0.71073 Å) at 298 K. Cell parameters were retrieved using SMART software and refined with

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SAINT on all observed reflections [11]. Data reduction was performed with the SAINT software. Absorption corrections were applied with the program SADABS [12]. The structures were solved by direct methods with SHELXS-97 [14]. The refinement and all further calculations were carried out with SHELXL-97 [13].

2.3 Computational Details. Time-dependent density functional theory (TD-DFT) calculations were performed using ORCA quantum chemistry suite [15]. The BLYP exchange–correlation functional was used in all calculations 3

ACCEPTED MANUSCRIPT [16]. Gradient-corrected geometry optimizations were performed by using the generalized gradient approximation (Perdew-Wang non-local exchange and correlation corrections-PW91)[17-18]. Large atom basis sets TZP are used to ascribe all the atoms here. Scalar relativistic effects were taken into account by using the zeroth-order regular approximation (ZORA) [19]. Frontier MOs were plotted at an

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isovalue of 0.02 au.

2.4 Synthesis

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2.4.1-Synthesis of L1, (E)-1-(6-methylpyridin-2-yl)-N-(p-tolyl)methanimine

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To a solution of 6-methylpyridine-2-carboxaldehyde (0.240 g, 2.240 mmol) in EtOH (10 mL), ptoluidine (0.250 g, 2.06mmol) was added. The solution was stirred at 80 ℃ for 2 h, and then it was reduced to a quarter the volume and a yellow solid formed. It was filtered and dried in vacuum. Yield: 85%. 1H-NMR (500 MHz，d6-DMSO) δ 2.34 (3H，s)；2.55 (3H，s)；7.23-7.27 (4H，m)；7.38 (1H

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，d，J = 8.0 Hz)；7.83 (1H，t，J = 8.0 Hz)；7.95 (1H，d，J = 8.0 Hz)；8.56 (1H，s). IR (KBr, cm-1): 2973.0, 2910.9 ; 1455.9 ; 1250.9 ; 1159.2.

2.4.2-Synthesis of L2, (E)-1-(6-bromopyridin-2-yl)-N-(p-tolyl)methanimine

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To a solution of (0.39g, 2.1mmol) of 6-Bromo-2-pyridinecarboxaldehyde in 10 ml of methanol, (0.220

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g, 2.060 mmol) of p-toluidine was added. The solution was stirred at 80℃ for 2 h, and then the crude product was isolated by filtration and recrystallized from methanol to yield yellowish title compound and dried in vacuum. Yield: 80%. 1H-NMR (500 MHz，d6-DMSO) δ 2.35 (3H，s)；7.26-7.32 (4H， m)；7.79 (1H，d，J = 8.0 Hz)；7.92 (1H，t，J = 8.0 Hz)；8.16 (1H，d，J = 8.0 Hz)；8.58 (1H， s). IR (KBr, cm-1): 3033.4, 2907.8 ; 1434.9 ; 1207.3 ; 1115.8 ; 628.8 . 2.4.3-Synthesis of [(η6-C6H6) RuCl(L1)]PF6 (1)

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ACCEPTED MANUSCRIPT (η6-C6H6)RuCl2 (0.25g, 0.5mmol) was dissolved in dried methanol (30 mL), and the L1 (0.275 g, 1.00 mmol) was added in one portion. The reaction was stirred under N2 at 65℃ for 8h, then NH4PF6 (0.163 g, 1.00 mmol) was added, continued to stirred for 1 h, cooled to room temperature, the volume of the reaction mixture was slowly condensed to ca. 2mL on a rotary evaporator, after slowly adding diethyl

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ether (10 mL), a black-brown precipitate was formed, collected by filtration, washed with petroleum ether (5 mL) and dried in vacuo. Yield: 72%. M.p: 260 ºC, Anal. Calcd for C20H20ClF6N2PRu: C, 41.72; H, 3.45; N, 4.53. Found (%): C, 42.15; H, 3.54; N, 4.92. 1H NMR (500 MHz，d6-DMSO) δ 2.45 (3H，

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s)；3.18 (3H，s)；5.94 (6H，s)；7.45 (2H，d，J = 8.5Hz)；7.78 (2H，d，J = 8.5 Hz)；7.86 (1H， dd，J = 1.0，8.0Hz)；8.07 (1H，dd，J = 1.0，8.0 Hz)；8.17(1H，t，J = 8.0 Hz)；8.85 (1H，s). 13

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C-NMR (126 MHz，d6-DMSO) δ 167.91，156.09，155.16，155.01，149.69，139.51，129.83，

129.26，127.65，122.17，87.22，28.02，20.80. IR (KBr, cm-1): 3084.4; 1468.2 ; 1246.8 ; 1056.9 ; 844.7.

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2.4.4-Synthesis of [(η6-p-cymene)RuCl(L1)]PF6 (2)

This complex was prepared by following the above mentioned procedure (1) except that the complex [(η6-p-cymene)RuCl2]2 was used in place of [([(η6-C6H6)RuCl2]2. Yield: 78%. M.p: 265 ºC, Anal. Calcd

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for C24H28ClF6N2PRu: C, 46.12; H, 4.48; N, 4.45. Found (%): C, 45.99; H, 4.50; N, 4.47. 1H-NMR (500

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MHz，d6-DMSO) δ 0.92 (3H，d，J = 7.0 Hz)；1.01 (3H，d，J = 7.0 Hz)；2.22 (3H，s)；2.45 (3H ，s)；2.63-2.68 (1H，m)；3.14 (3H，s)；5.41 (1H，d，J = 6.0 Hz)； 5.49 (1H，d，J = 6.0 Hz)； 5.72 (1H，d，J = 6.0 Hz)；6.15 (1H，d，J = 6.0 Hz)；7.45 (2H，d，J = 8.5 Hz)；7.76 (2H，d，J = 8.5 Hz)；7.85 (1H，dd，J = 1.0，7.5 Hz)；8.07 (1H，d，J = 6.5 Hz)；8.16 (1H，t，J = 7.5 Hz) ；8.85 (1H，s).

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C-NMR (125 MHz，d6-DMSO) δ 169.72，167.65，164.97，154.83，149.61，

139.65，139.32 ，132.45，129.97 ，129.30，127.96 ，125.98，122.11， 99.49，30.56，28.13 ， 22.10，21.30. IR (KBr, cm-1): 3028.3, 2973.9 ; 1470.1 ; 1242.5 ; 1027.6 ; 841.6

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2.4.5-Synthesis of [(η6-p-cymene)RuCl(L2)]PF6 (3) This complex was prepared by following the above mentioned procedure (1) except that the compound

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L1 was used in place of L2. It isolated as yellow-red microcrystalline solid. It was filtered, washed with methanol, diethyl ether and dried in vacuo. The product was further recrystallized from dichloromethane/petroleum ether. Yield: 62%. M.p: 250 ºC, Anal. Calcd for C23H25BrClF6N2PRu: C,

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41.08; H, 3.49; N, 4.23. Found (%): C, 39.99; H, 3.65; N, 4.05. 1H-NMR (500 MHz，d6-DMSO) δ 1.01 (3H，d，J = 7.0 Hz)；1.12 (3H，d，J = 7.0 Hz)；2.25 (3H，s)；2.46 (3H，s)；2.61-2.69 (1H，m)

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；5.45 (1H，s)； 5.56 (1H，d，J = 6.0 Hz)；5.75 (1H，d，J = 6.0 Hz)；6.16 (1H，s)；7.46 (2H， d，J = 8.5 Hz)；7.76 (2H，d，J = 8.5 Hz)；8.17 (1H，t，J = 7.5 Hz)；8.23-8.27(2H，m)；8.85 (1H，s) .13C-NMR (126 MHz，d6-DMSO) δ 167.79，164.00，161.27，156.02，149.47，148.96， 141.29，139.90，134.13，130.00，129.31，128.75，122.11，99.50，30.69，21.46，20.81，18.50.

3. Results and Discussion

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IR (KBr, cm-1): 3098.8, 2973.0; 1444.8; 1234.4; 1057.9; 841.3; 731.8

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The ligands L1 and L2 were synthesized according to the literature procedure by mixing the same equivalents of p-toluidine and corresponding aldehydes in EtOH [20, 21]. Complexes 1-3 were prepared

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from the reaction of [(η6-C6H6)RuCl(L1)]PF6 and [(η6-p-cymene)RuCl2]2 with an equimolar of corresponding L1 and L2 Schiff-base ligands in dry methanol under an inert atmosphere of nitrogen, followed by exchanging the chloride counterion with PF6-. These complexes were characterized by elemental analysis, NMR and IR spectroscopies. The FT-IR characteristic frequencies of 1 and 2 are summarized in section 2.4.1 and 2.4.2, respectively. The IR spectrum of the compounds 1-3 shows absorption bands resulting from the skeletal vibrations of aromatic rings in the 1400–1600 cm−1 range. The relatively weak absorption bands at around 2900 and 3050 cm−1 are due to the C-H modes

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Table 1. Selected bond length and angles are summarized in Table 2.

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dichloromethane/petroleum ether mixture. The crystallographic data for complexes 1-3 are listed in

3.1-Crystal Structure analysis

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X-ray crystallography analyses reveal that 1, 2 and 3 crystallize in Orthorhombic P212121, Orthorhombic Pbca and Monoclinic P21/c , respectively. The asymmetric units of 1 and 2 contain one crystallography independent Ru(II) complex and a PF6- anion, whereas the asymmetric unit of 3 consists of two crystallographically independent Ru(II) half-sandwich complexes and two PF6- counterions,

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Figure 1. The coordination geometry around the Ru(II) ion can be described as pseudo-octahedral, with three sites occupied by the η6-benzene (for 1) or η6-p-cymene (for 2 and 3) ligand and the remaining three by the chloride ion and nitrogen atoms of chelating Schiff-base ligand. The Ru-Npy and Ru-Nimine

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bond distances are listed in Table 2. The distances between ruthenium and the centroid of the benzene/p-cymene ring are 1.645, 1.695 Å, 1.672 Å, and 1.689 Å for 1, 2 and 3, respectively.

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In the crystal packing of 1, 2 and 3, the PF6- anion plays an important role in linking neighboring Ru(II) complexes via C-H···F hydrogen bonding interactions, Figure 2-4 and Table 3. Figure 2 shows how cationic Ru(II) complexes of 1 are connected to each other via PF6- anions. In the case of 2, the overall supramolecular structure results from the linkage of neighboring Ru(II) half-sandwich complexes via a combination of C-H···F, C-H···π hydrogen bonds and weak π-interactions, namely C-H···π and π···π stacking interactions, Figure 3. The crystal structure analysis of 3 also reveals that the C-H···F hydrogen bonding interactions are the major driving force in the crystal packing while C-Br···Cl-Ru (C-

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has been demonstrated that the organic (C-X) and inorganic (M–Xʹ) halogens are serving different roles in C–X⋯Xʹ-M halogen bonds, the former as an electrophile (XB donor) and the latter as a nucleophile (XB acceptor) [23]. A search of the Cambridge Structural Database (CSD) reveals 477 compounds that

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feature (η6-arene)RuCl(L)], where L is the bidentate nitrogen-donor chelating ligand. Narrowing the search to include a bidentate nitrogen-donor Schiff base ligand drops the number of hits to 32,

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illustrating that the use of chelating Schiff base ligand in arene Ru(II) organometallic compounds is somewhat established. An important feature of the crystal packing of these compounds is the lack of a strong hydrogen bond donor and two metal-coordinated halide ions in the structure, which means that these complexes could not self-assemble through the formation of well-known inverted piano stool

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dimer. The common feature in the crystal packing of these compounds is that there is a strong tendency to form hydrogen bonds of the type

areneC-H•••Xcounterion.

Also, a CSD search shows that there are 37

(η6-arene) ruthenium(II) complexes containing Ru-Cl•••X-C halogen-halogen interactions, among

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which only a few compounds engage in halogen-halogen interactions of the type Ru-Cl•••X-C, where the XB donor is not a solvated chloroform [24-27].

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The intermolecular contacts in the crystal structure of 1, 2 and 3 are also quantified via Hirshfeld surface analysis using crystal Explorer 3.1 [28]. A histogram of percentage contributions of different intermolecular contacts is shown in Figure 5. The results of Hirshfeld surface analysis revealed that the H•••H and C-H•••F interactions are indeed the dominating ones, whereas less than 25% was found to be related to the combination of C-H•••Cl, C-H•••π, π•••π, and Cl•••Br (for 3) intermolecular contacts. This analysis also reveals that the replacement of benzene ring by the sterically more hindered p-cymene decreases the probability of π•••π stacking interactions, while that of H•••H increases. 8

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shoulder at lower wavelength values (~295 nm). Also, there are shoulders in higher wavelength. Fluorescence measurements of these compounds were made in methanol solution on a Perkin ElmerLS55 Fluorescence Spectrometer at room temperature (Figure 6). The emission spectra of 1-3 display

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two well-defined bands with the maximum at 330 nm, 373 nm for 1, 340 nm, 370 nm for 2 and 374 nm, 424 nm for 3, accompanied by shoulders at lower frequencies. Also, compound 3 displays a red shift

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relative to 1 and 2. This can be related to the polar effect of heavy atoms on the HOMO-LUMO energy gap observed in different classes of chromospheres and the heavy atoms [29, 30]. In order to understand the fluorescence behavior, time-dependent DFT (TD-DFT) calculations of electron transitions have been carried out for compounds 1-3 (see Supplementary Table S1, Table S2 and Figure S2). The frontier

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molecular orbitals of compounds 1-3 are shown in Figure 7. The HOMO−LUMO energy gap calculated by DFT for 3 is lower relative to those of 1 and 2. Table S1 and Table S2 provide the excitation energies, main transition configurations for transitions in region 300-500 nm, and calculated natural

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bond orbital (NBO), for the studied compounds 1-3, respectively. Figure 7 and S2 reveal that the HOMOs are mainly composed of ruthenium d orbitals and chlorine p-type orbitals. Also, the LUMOs in

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these complexes are localized on the Schiff-base ligand π* orbitals and ruthenium d orbitals. Thus, it can be concluded that the emission bands of compounds 1-3 is attributed to an admixture of metalligand charge transfer (MLCT) and ligand-ligand charge transfer (LLCT) states. It is important to note that the emission properties of these organometallic half-sandwich complexes are sensitive to the substituents on the schiff-base ligands.

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4-Conclusions From a reaction between dinuclear chloro-bridged [Ru(η6-arene)Cl2]2 complex and synthesized schiffbase ligands, namely L1 and L2, three new half-sandwich ruthenium(II) compounds were obtained. These compounds were characterized by different spectroscopic techniques (FT-IR, 1H-NMR, 13C-NMR

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and elemental analysis), and their X-ray crystallographic structures were determined. The crystal structure analysis reveals that H···H and C-H···F intermolecular interactions are strong enough to govern the supramolecular architecture. Beside the dominating interactions, weak intermolecular

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interactions such as π···π stacking and C-Br···Cl-Ru halogen bonding interactions, found the opportunity to play a subtle role in directing the crystal packing. The emission behavior of these

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compounds was also studied and described their potential as a new member of organometallic dye family.

AUTHOR INFORMATION Corresponding Author

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*Phone: +86-577-88661902 and +98-21-82884416. Fax: +86-577-86689300 and +98-21-82884416. E-mail: [email protected] (M.-L. Hu), [email protected] (A. Morsali)

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ACKNOWLEDGMENT. The authors thank Tarbiat Modares University for all the supports. The work

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was supported by the National Natural Science Foundation of China.

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Scheme 1. Schematic representation of the synthetic pathway for complexes 1-3.

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Figure 1. ORTEP view of complexes 1-3, showing displacement ellipsoids at the 30% probability level. Hydrogen atoms were omitted for clarity.

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Figure 2. A side view representation of [(η6-benzene)RuCl(L1)]PF6, 1, in ab-plane, showing how

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cationic Ru(II) complexes of 1 are connected to each other via PF6- anions.

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Figure 3. A side view representation of [(η6-p-cymene)RuCl(L1)]PF6, 2, showing the association of the half-sandwich units through a combination of C-H···F, C-H···π hydrogen bonds and weak π···π stacking interactions.

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Figure 4. A side view representation of [(η6-p-cymene)RuCl(L2)]PF6, 3, Showing the association of

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interactions.

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half-sandwich units via C-H···F hydrogen bonding interactions and C-Br···Cl-Ru halogen bonding

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Figure 5. Relative contributions of various intermolecular contacts to the Hirshfeld surface area in compounds 1-3.

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Figure 6. Fluorescence emission spectra of compounds 1-3 in the methanolic solutions (c = 5 ×10-4 mol/dm3), excited at 340, 337 and 342 nm for 1, 2 and 3 respectively.

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Figure 7. Frontier molecular orbitals of compounds 1-3.

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Table 1. Structural data and refinement parameters for compounds 1-3.

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1 2 3 formula C20H20ClF6N2PRu C24H28ClF6N2PRu C23H25BrClF6N2PRu fw 569.87 625.97 690.85 λ/Å 0.71073 0.71073 0.71073 T/K 298 298 298 crystal system Orthorhombic Orthorhombic Monoclinic space group P212121 Pbca P21/c a/Å 7.7436(8) 8.994(3) 23.951(4) b/Å 9.8973(9) 21.018(6) 9.3215(16) c/Å 28.267(3) 26.614(8) 28.220(3) α/˚ 90.0 90.0 90.0 β/˚ 90.0 90.0 125.410(9) γ/˚ 90.0 90.0 90.0 V/Å3 2166.4(4) 5031(3) 5135.0(13) Dcalc/Mg.m-3 1.747 1.653 1.787 Z 4 8 8 µ (mm-1) 0.982 0.854 2.392 F(000) 1136 2528 2736 2θ (˚) 56.78 48.12 50.20 R (int) 0.0417 0.0916 0.0373 GOOF 1.050 1.033 1.220 R1a(I>2σ(I)) 0.0679 0.0511 0.1589 wR2b(I>2σ(I)) 0.1973 0.1279 0.3872 CCDC No. 1055377 1055378 1055379 a R1 =Σ||Fo| - |Fc||/Σ|Fo|. b wR2 = [Σ(w(Fo2 - Fc2)2)/Σw(Fo2)2]½.

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Table 2. Selected bond distances (Å) and angles (°) for complexes 1-3.

3 2.396(7)

2.125(8) 2.102(6) -

2.079(5) 2.136(4) -

2.05(3) 2.12(2) 2.412(5)

Ru2-N3 Ru2-N4 Cl1-Ru1-N1

86.0(2)

88.3(1)

2.14(2) 2.16(4) 89.6(8)

Cl1-Ru1-N2 N1-Ru1-N2 Cl2-Ru2-N3

86.4(2) 72.6(3) -

83.0(1) 77.0(2) -

84.9(6) 77.0(1) 90.6(6)

Cl2-Ru2-N4 N3-Ru2-N4

-

-

85.0(1) 78.0(1)

Ru1-N1 Ru1-N2 Ru2-Cl2

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Bond angle

2 2.390(1)

Ru1-Cl1

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Bond distance

Complex 1 2.372(3)

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Table 3. Selected hydrogen bond geometries for compounds 1-3. D-H…A

d(D-H)/Å

d(H…A)/Å

d(D…A)/Å


Sym. Code

1

C17-H17…F3

0.980

2.50(3)

3.40(2)

153.2(4)

1-x,-1/2+y,1/2-z

C19-H19…F5

0.980

2.66(2)

3.29(2)

122.8(4)

x,-1+y,z

C8-H8…F5

0.930

2.40(4)

3.20(2)

146.9(4)

-1+x,-1+y,z

C20-H20…Cl1

0.980

2.67(3)

3.53(1)

146.9(4)

½+x,1/2-y,-z

C4-H4…F2

0.930

2.36(8)

3.289(8)

170.3(2)

1-x,-y,1-z

C7-H7…F3

0.930

2.56(2)

3.331(8)

140.2(3)

½+x,1/2-y,1-z

C11-H11…F1

0.930

2.588(2)

3.289(7)

132.5(3)

1+x, y, z

C20-H20….F5

0.980

2.631(5)

3.385(8)

134.0(2)

-x, -y,1-z

C14-H14A…Cl1

0.960

2.918(3)

3.544(6)

123.9(4)

-1/2+x,1/2-y,1-z

C12-H12…F9

0.930

2.61(3)

3.25(5)

127.0(5)

x,y,z

2

3

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Compound

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2.60(5)

3.44(5)

147.0(4)

x,y,z

C33-H33…F7

0.930

2.46(6)

3.22(3)

139.0(2)

x,-1+y,z

C27-H27…F12

0.930

2.67(2)

3.55(5)

157.0(5)

x,-1+y,z

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C23-H23A…F2

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Ru(II) half-sandwich complexes containing Schiff-base ligands were synthesized, characterized and their supramolecular structures were analyzed. The fluorescence behavior of these compounds was studied.

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These compounds could be promising for the design of organometallic dye

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systems.