Trinuclear organooxotin assemblies from solvothermal synthesis reaction: Crystal structure, hydrogen bonding and π–π stacking interaction

Journal of Molecular Structure 833 (2007) 203–207 www.elsevier.com/locate/molstruc

Trinuclear organooxotin assemblies from solvothermal synthesis reaction: Crystal structure, hydrogen bonding and – stacking interaction Chunlin Ma a,b,¤, Junshan Sun a, Rufen Zhang a a

Department of Chemistry, Liaocheng University, Liaocheng 252059, PR China b Taishan University, Taian 271021, PR China

Received 25 August 2006; received in revised form 17 September 2006; accepted 17 September 2006 Available online 30 October 2006

Abstract Two new trinuclear mono-organooxotin(IV) complexes with 2,3,4,5-tetraXuorobenzoic acid and sodium perchlorate of the types: [(SnR)3(OH)(2,3,4,5-F4C6HCO2)4 · ClO4] · [O2CC6HF4](R D PhCH2, 1; o-F-PhCH2 for 2), have been solvothermally synthesized and structurally characterized by elemental, IR, 1H, 13C and 119Sn NMR and X-ray crystallography diVraction analyses. Complex 2 is also characterized by X-ray crystallography diVraction analyses. In complex 2, four carboxyl groups and a perchlorate bridged three tin atoms in a cyclohexane chair arrangement and form the basic framework. A hydroxyl group comprises the oxygen components of the stannoxane ring system. In these complexes, weak but signiWcant intramolecular hydrogen bonding and – stacking interaction are also shown. These contacts lead to aggregation and supramolecular assembly of complexes 1 and 2 into 1D or 2D framework. © 2006 Elsevier B.V. All rights reserved. Keywords: 2,3,4,5-tetraXuorobenzoic acid; Sodium perchlorate; Organotin; Assembly; Hydrogen bonding; – stacking interaction; Solvothermal synthesis

1. Introduction There is considerable interest in the assembly and structural analysis of organooxotin cages, clusters and coordination polymers. In most instances these complexes are prepared by the reaction of an appropriate organotin precursor such as R3SnOSnR3, R3SnOH, (R2SnO)n or RSn(O)OH with a carboxylic, phosphinic, phosphonic or sulfonic acid [1]. However, much few work has been carried out to investigate Xuorated organotin carboxylic acid ligands [2] and mixed-ligands [3]. Therefore, we select 2,3,4,5-tetraXuorobenzoic acid as the ligand and sodium perchlorate as coligand with the hope of construction novel organooxotin(IV) cluster with fascinating structures and/or characteristic properties.

Herein, we report the syntheses of two trinuclear organooxotin(IV) complexes: oxygen-capped cluster composition [(SnR) 3 (OH)(2, 3,4,5-F 4 C 6 HCO 2 ) 4 · ClO 4 ][O 2 CC 6 HF 4 ] (R D PhCH2, for 1; o-F-PhCH2, 2) with 2,3,4,5-tetraXuorobenzoic acid and sodium perchlorate under the solvothermal condition. Weak but signiWcant intermolecular hydrogen bonding and – stacking interaction assemble these moleculars into dimer, 1D or 2D framework. 2. Results and discussion 2.1. Synthesis The synthesis procedures are shown in Scheme 1. 2.2. Spectra

*

Corresponding author. Tel.: +86 635 8230660; fax: +86 538 6715521. E-mail address: [email protected] (C. Ma).

0022-2860/$ - see front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.molstruc.2006.09.013

The stretching frequencies of interest are those associated with the acid COO, Sn–C, Sn–O and Sn–O–Sn groups.

204

C. Ma et al. / Journal of Molecular Structure 833 (2007) 203–207

F

F OH + NaClO4 O

R2SnO + F F

benzene 150¡æ

F F F F O O F F R O Sn O Sn R F . C6HF4CO O F FO O O OF F O F O Sn O F F O Cl O F F R O

R = PhCH2

1

R =o-F-PhCH2

2

Scheme 1.

The explicit feather in the infrared spectra of 1 and 2 is the absence of the band in the 2600–3436 cm¡1, which appears in the free ligand as the (O–H) vibration, indicating metal– ligand bond formation through this site. All these values are consistent with that detected in number of organotin(IV)–oxygen derivatives [4,5]. Based on the previous reports, it is possible to distinguish the coordination mode of the COO¡ group [6]. The IR spectrums of 2 shows characteristic bands of carboxylate groups occur at near 1697 and 1619 cm¡1 for asymmetric stretching and at near 1513 and 1279 cm¡1, which are higher than that for non-Xuorinated carboxylates [7]. The magnitude of  of about 168 cm¡1, compared with those for the corresponding sodium salts, revealed that the carboxylate ligands function as bidentate ligands under the conditions employed. The 1H NMR spectra show the expected integration and peak multiplicities. In the spectrum of the free ligand, the resonance observed at about  D 10.114 ppm, which is absent in the spectra of the complexes, indicates the replacement of the carboxylic acid proton on complex formation. The 2JSnH of dibenzyltin derivative 2 has a value of 95.6 Hz, comparable with those previously reported for six-coordinated octahedral tin(IV) adducts [8]. The 13C NMR spectra of all complexes show a signiWcant downWeld shift of all carbon resonance, compared with the free ligand. There are only signal resonances in the region 168–182 ppm, indicating the same types of carboxyl groups are present in complexes 1 and 2. Complementary information is given by the values of the coupling constant. The 119Sn NMR data show only one signal for complexes 1 and 2, typical of a six-coordinate species, and has been found in accordance with the solid state structure [9]. For complex 2, a new triplet appeared at ¡621.8 ppm in the 119 Sn spectrum and increased in intensity at the expense of the triplet at ¡598.6 ppm. The 119Sn chemical shift is especially diagnostic of the type of structure present. 2.3. Description crystal structure of complex 2 The molecular structure and unit cell of complex 2 are shown in Figs. 1 and 2. Selected bond distances and angles are listed in Table 2. X-ray analysis shows tin(IV) present in an oxygen-capped cluster molecular. Three tin atoms formed a triangle plane, which is capped by a 3-O atom with an average Sn–O distance of 2.048 (4) Å. The four

Fig. 1. The molecular structure of complex 2.

Fig. 2. Unit cell of complex 2, the broken lines show O,O interaction.

carboxylate residues and a ClO4 ligand adopt chelating– bridging mode linking two tin atoms. A oxygen atom acts as a bridge connecting two tin atoms and forms a stannoxane ring. Thus, there are three types of tin environments: Sn(1) is coordinated by three O(carboxyl), a 3-O and a bridging O atom from a ClO4 ligand. Sn(2) is coordinated by three O(carboxyl) and two single O atoms. While Sn(3) is coordinated by two O(carboxyl) atoms, a single, a 3 and a O atom from bridging ClO4 ligand.

C. Ma et al. / Journal of Molecular Structure 833 (2007) 203–207

Though this, each tin atom is hexa-coordinated with a distorted pentagonal bipyramidal geometry. The axial angles O(1)–Sn(1)–C(28) 175.8(3)°, O(1)–Sn(2)–C(35) 171.4(3)° and O(1)–Sn(3)–C(42) 173.9(3)° are close to a linear arrangement, which show the distortion is only slight from a regular geometry. The sum of the angles subtended at the tin atom in the pentagonal plane is 359.3(2)°

Fig. 3. The dimer of complex 2, formed by intermolecular C–H , F hydrogen bonding.

205

for Sn(1), 358.7(2)° for Sn(2), and 358.1(2)° for Sn(3), so that the atoms O(4), O(7), O(9), O(14); O(2), O(11), O(10), O(8) and O(2), O(3), O(12), O(13) are almost in the same plane. The Sn–O angle lengths are in the normal range [10]. The O(1) atom is away from the mean plane of the three tin atoms by 0.1210 Å, showing the slight departure from the basal plane. As shown in Figs. 3 and 4, two molecules of complex 2 formed a macrocyclic dimer, which is linked by intermolecular C–H , F and C–H , O hydrogen bonding, respectively. Moreover, the distances of H28A , F15 and H31A,O6 are 2.508 and 2.585 Å, respectively, smaller than the sum of the van der Waals radii (2.67 and 2.73 Å). The angles of C28– H28A , F15 and C31–H31A , O6 are 132.96° and 150.71°, similar to that reported by Thalladi [11]. In Fig. 5, the supramolecular of complex 2 shows a 1D chain structure formed by the combination with noncovalent interactions of face-to-face – stacking interaction. The centroid–centroid distance between two phenyl units is 3.790 Å, a typical distance for systems held by – stacking interactions [12]. The angle between the plane of the phenyl ring and the stack column axis (c-axis) is 29.4°, which shows the extent of departure between phenyl groups. Besides, the dihedral angel of phenyl–phenyl is 0°, showing the completely parallel phenyls. In Fig. 6, these 1D chains were further assembled into a 2D framework via interchain face-to-face – stacking interactions.

Fig. 4. The dimer of complex 2, formed by intermolecular C–H , O hydrogen bonding.

Fig. 5. The supramolecular assembly of complex 2, showing a inWnite 1D chain structure via intermolecular face-to-face – stacking interaction.

206

C. Ma et al. / Journal of Molecular Structure 833 (2007) 203–207

Fig. 6. The supramolecular assembly of complex 2, showing a 2D framework via interchain face-to-face – stacking interaction.

3. Conclusions

Table 1 Crystal data and structure reWnement for the complexes 2

In summary, through solvothermal synthesis reaction, we succeed in obtaining two novel trinuclear organooxotin frameworks from Xexible 2,3,4,5-tetraXuorobenzoic acid and sodium perchlorate. Moreover, the cleavage of Sn–CH2Ph bonding also occurred in these complexes. The supramolecular of dimer,1D and 2D framework were established via intermolecular hydrogen bonding and – stacking interaction.

Complex

2

Empirical formula Formula weight Wavelength (Å) Crystal system Space group a (Å) b (Å) c (Å)  (°)  (°)  (°) V (Å3) Z Dcalc(Mg m¡3) F(0 0 0) Absorption coeYcient (mm¡1) Crystal size (mm)  range for data collection (°) Index ranges

C56H23ClF23O16Sn3 1780.26 0.71073 Monoclinic P2(1)/C 16.9790 (18) 27.632 (3) 13.1202 (13) 90 101.994 (2) 90 6021.1(11) 4 1.964 3444 1.420 0.45 £ 0.38 £ 0.29 1.92–28.38 ¡22 < D h < D 22 ¡25 < D k < D 36 ¡14 < D l < D 17 39197 14627 [R(int) D 0.0513] Semi-empirical from equivalents 0.6836, 0.5675 Full-matrix least-squares on F2 14627/1872/892 1.005 R1 D 0.0543, wR2 D 0.1268 R1 D 0.1214, wR2 D 0.1727

4. Experimental 4.1. Materials and measurements 2,3,4,5-tetraXuorobenzoic acid and sodium perchlorate were commercially available, and they are used without further puriWcation. Di-benzyltin chloride, o-Xuoro-dibenzyltin and m-chloro-dibenzyltin were prepared by a standard method reported in the literature [13]. The melting points were obtained on a KoXer micro-melting point apparatus and were uncorrected. Infrared-spectra were recorded on a Nicolet–460 spectrophotometer using KBr discs and sodium chloride optics. 1H, 13C and 119Sn NMR spectra were recorded on a Varian Mercury Plus 400 spectrometer operating at 400, 100.6 and 149.2 MHz, respectively. The spectra were acquired at room temperature (298 K) unless otherwise speciWed; 13C spectra are broadband proton decoupled. The chemical shifts are reported in ppm relative to Me4Si in CDCl3 as solvent. Elemental analyses (C, H) were performed with a PE-2400II apparatus. 4.2. Syntheses of the complexes 1 and 2 4.2.1. [(SnR)3(OH)(2,3,4,5-F4C6HCO2)4 · ClO4] [O2CC6F4] (R D PhCH2) 1 The reaction was carried out under nitrogen atmosphere. Di-o-F-benzyltin dichloride (0.385 g, 1 mmol), 2,3,4,5-tetraXuorobenzoic acid (0.194 g ,1 mmol), and sodium perchlorate

ReXections collected Unique reXections Absorption correction Max/min transmission ReWnement method Data/restraints/parameters Goodness of Wt on F2 Final R indices [I > 2 (I)] R indices (all data)

(0.122 g, 1 mmol) were added to the solution of dry benzene in a sealed vessel for 3–5 day. After Wltration, the solvent was evaporated in vacuo. The solid was then recrystallized from mother liquid; colorless crystals were obtained. Yield, 85%; mp 153–155 °C; Anal. Calcd for C56H26ClF20O16Sn3: C, 38.96; H7, 1.52. Found: C, 38.72; H, 1.69%. IR (KBr, cm¡1): (CBO) 1696; (COO)as 1618; (COO)S 1472, 1352; (Sn–O– Sn) 631; (Sn–O) 473 cm¡1. 1H NMR (CDCl3, ppm):  0.956 (t, 12H, 4CH3); 3.970 (d, 6H, 3CH2); 7.52–7.76 (m, 15H,

C. Ma et al. / Journal of Molecular Structure 833 (2007) 203–207 Table 2 Selected bond lengths and angles for the complex 2 Complex 1 Bond Sn(1)–O(1) Sn(1)–C(28) Sn(1)–O(7) Sn(2)–O(1) Sn(2)–C(35) Sn(1)–O(8) Sn(3)–O(1) Sn(3)–O(3) Sn(3)–O(13) Angle O(1)–Sn(1)–O(4) O(4)–Sn(1)–C(28) O(4)–Sn(1)–O(9) O(1)–Sn(1)–O(7) C(28)–Sn(1)–O(7) O(4)–Sn(1)–O(7) O(9)–Sn(1)–O(7) O(4)–Sn(1)–O(14) O(9)–Sn(1)–O(14) O(1)–Sn(2)–O(2) O(2)–Sn(2)–C(35) O(2)–Sn(2)–O(10) O(1)–Sn(2)–O(11) O(8)–Sn(2)–O(11) O(1)–Sn(3)–O(2) O(2)–Sn(3)–O(3)

Distance (Å) 2.018 (4) 2.123 (7) 2.152 (5) 2.053 (4) 2.111 (7) 2.135 (5) 2.073 (4) 2.089 (5) 2.124 (5) Amplitude (°) 87.18 (18) 93.5 (3) 89.5 (2) 86.26 (19) 93.2 (3) 173.14 (19) 88.3 (2) 92.8 (2) 174.4 (2) 73.36 (18) 98.1 (3) 100.4 (2) 86.99 (19) 83.0 (2) 73.33 (17) 97.2 (2)

Bond Sn(1)–O(4) Sn(1)–O(9) Sn(1)–O(14) Sn(2)–O(2) Sn(2)–O(8) Sn(2)–O(11) Sn(3)–O(2) Sn(3)–C(42) Sn(3)–O(12) Angle O(1)–Sn(1)–C(28) O(1)–Sn(1)–O(9) C(28)–Sn(1)–O(9) O(4)–Sn(1)–O(7) O(1)–Sn(1)–O(7) C(28)–Sn(1)–O(7) O(1)–Sn(1)–O(14) C(28)–Sn(1)–O(14) O(7)–Sn(1)–O(14) O(1)–Sn(2)–C(35) O(1)–Sn(2)–O(8) O(8)–Sn(2)–O(10) O(2)–Sn(2)–O(11) O(10)–Sn(2)–O(11) O(1)–Sn(3)–O(3) O(1)–Sn(3)–O(13)

Distance (Å) 2.107 (5) 2.125 (5) 2.160 (5) 2.098 (5) 2.117 (5) 2.152 (5) 2.080 (5) 2.117 (8) 2.171 (5) Amplitude (°) 175.8 (3) 88.83 (18) 95.3 (3) 173.14 (19) 86.26 (19) 93.2 (3) 86.24(19) 89.6 (3) 88.7 (2) 171.4 (3) 89.31 (18) 85.6 (2) 89.7 (2) 168.2 (2) 91.85 (18) 88.98 (18)

3Ph-H); 7.21–7.44 (m, 3H, 3Ph-H). 13C NMR (CDCl3):  171.4 (COO), 148.5, 146.9, 142.8, 134.8, 129.0, 128.6, 125.7, 110.0, 19.9. 119Sn NMR (CDCl3, 298 K): ¡592.8 ppm. 4.2.2. [(SnR)3(OH)(2,3,4,5-F4C6HCO2)4 · ClO4] [O2CC6F4] (R D o-F-PhCH2) 2 The preparation procedure was the same as used for 1. The solid was then recrystallized from ethanol; colorless crystal was obtained. Yield, 78%; mp 162–164 °C; Anal. Calcd for C56H23Cl F23O16Sn3: C, 37.78; H, 1.30. Found: C, 37.53; H, 1.58%. IR (KBr, cm¡1): (CBO) 1712; (COO)as 1634; (COO)S 1483, 1361; (Sn–O–Sn) 651; (Sn–O) 487 cm¡1. 1H NMR (CDCl3, ppm):  0.934 (t, 12H, 4CH3); 3.908 (d, 6H, 3CH2); 7.66–7.73 (m, 15H, 3Ph-H); 7.09–7.37 (m, 3H, 3Ph-H). 13C NMR (CDCl3):  183.1 (COO), 152.3, 147.3, 144.1, 134.8, 130.6, 129.2, 126.3, 110.0, 19.9. 119Sn NMR (CDCl3, 298 K): ¡608.4 ppm. 4.3. X-ray crystallographic Crystals were mounted in Lindemann capillaries under nitrogen. DiVraction data were collected on a Smart-1000

207

CCD area-detector with graphite monochromated MoK radiation ( D 0.71073 Å). A semi-empirical absorption correction was applied to the data. The structure was solved by direct methods using SHELXLS-97 and reWned against F2 by full matrix least squares using SHELXL-97. Hydrogen atoms were placed in calculated positions. Crystal data and experimental details of the structure determinations of 2 listed in Table 1. 5. Supplementary material Crystallographic data (excluding structure factors) for the structure reported in this paper (1 and 2) have been deposited with the Cambridge Crystallographic Data Center as Supplementary Publication No. CCDC: 615051 for 2. Copies of the data can be obtained free of charge on application to the Director, CCDC, 12 Union Road, Cambridge, CB2 1EZ, UK (fax: +44 1223 336033; e-mail:[email protected] or http://www.ccdc.cam.ac.uk). Acknowledgement We thank the National Natural Science Foundation of China (20271025) for Wnancial support. References [1] V. Chandrasekhar, S. Nagendran, V. Baskar, Coord. Chem. Rev. 235 (2002) 1; R.R. Holmes, Acc. Chem. Res. 22 (1989) 190; E.R.T. Tiekink, Trends Organomet. Chem. 1 (1994) 71. [2] V. Chandrasekhar, S. Nagendran, K. Gopal, A. Steiner, S. Zacchini, Chem. Comm. (2003) 862. [3] R.O. Day, V. Chandrasekhar, K.C. Kumara Swamy, J.M. Holmes, S.D. Burton, R.R. Holme, Inorg. Chem. 27 (1988) 2887. [4] R.R. Holmes, C.G. Schmid, V. Chandrasekhar, R.O. Day, J.M. Homels, J. Am. Chem. Soc. 109 (1987) 1048. [5] G.K. Sandhu, R. Hundal, J. Organomet. Chem. 412 (1991) 31. [6] M. Gielen, M. Melotte, G. Atassi, R. Willem, Tetrahedron 45 (1989) 1219. [7] C.L. Ma, Y.F. Han, R.F. Zhang, D.Q. Wang, Eur. J. Inorg. Chem. (2005) 3024. [8] T.P. Lockhart, W.F. Manders, Inorg. Chem. 25 (1986) 892. [9] (a) J. Otera, J. Organomet. Chem. 221 (1981) 57; (b) J. Holebek, A. Lybka, K. Handlír, M. NáDVORNíK, Collect. Czech. Chem. Commun. 55 (1990) 1193. [10] H. PuV, E. Friedrichs, F.Z. Visel, Anorg. Allg. Chem. 477 (1981) 50. [11] V.R. Thalladi, H.-C. Weiss, D. Bläser, R. Boese, A. Nangia, G.R. Desiraju, J. Am. Chem. Soc. 120 (1998) 8702. [12] (a) C. Janiak, J. Chem. Soc. Dalton Trans. (2000) 3885; (b) C.A. Hunter, J.K. Sanders, J. Am. Chem. Soc. 112 (1990) 5525; (c) C.A. Hunter, K.R. Lawson, J. Perkins, C.J. Urch, J. Chem. Soc. Perkin Trans. 2 (2001) 651. [13] K. Sisido, J. Am. Chem. Soc. 83 (1961) 538.