A New Non-Centrosymmetricorganotin (IV) Hybrid Compound C5H14N2 [SnCl6] 2H2O: Crystal Structure And Optical Study Characterization

A new non-centrosymmetricorganotin (IV) hybrid compoundC 5 H 14 N 2 [SnCl 6 ] 2H 2 O was determined by single crystal X-ray diffraction at 150(2) K. Its crystal structure was solved by single crystal X-ray diffraction reveling that compound crystallizes in the orthorhombic system with Pbca space group with the following lattice parameters: a = 12.1486 (15) Å, b= 15.4571 (17) Å, c = 16.7610 (18) Å with Z = 8. The bonding between inorganic and organic entities in the compounds is realized by hydrogen bonding O−H…O ,O−H…Cl , NH • • • Cl, N-H…Cl and O−H…Cl. Finally,UV-visible absorption measurements exhibit two absorption bands ( 226 nm and 262 nm ).The optical band gap (Eg) is deduced to be 3.46 Ev.

The chemistry of organo-metal halide materials has developed belongs to the large the attention family has increased; present of a differences types de structures. This structures are built up from isolatedMX6octahedra, sharing, corners, edges, or faces to form two dimensional slabs (2D), one dimensional chains (1D) or zero dimensional clusters (0D) separated by the organic cations. This characterization due to a charge number of parameters and done their numerous applications such as solid state batteries, high ionic or mixed conductors, capacitors, including catalysis, biochemistry, magnetism and materials science [1][2][3][4][5][6][7][8].These organo-metal are the subject of various applied studies, thanks to their structural properties [9,10] , luminescence, semi-conductivity, ferroelectric and nonlinear optical activities [9][10][11][12].
A novel group of these crystals, containing hetero aromatic cations have been recently synthesized and characterized [13,14]. Since aromatic heterocyclic cations are characterized by a significant electric dipole moment, some halogenobismuthates (III) and halogenostannates(IV) containing these cations form strongly polar structures. The presence of the polar properties in these materials is usually a result of the organic cations dynamics, which play a key role in the induction of ferroelectricity.  [19].
Moreover, piperazine and substituted piperazine nuclei had constituted an attractive pharmacological scaffold present invarious potent marketed drugs. In fact, hybrid materials are traditionally used in medicine, with the presence of piperazine introduces a very important synthetic strategy discovery indrug due to its easy modifiability, proper alkalinity and water solubility [20][21][22][23][24].
In this context we undertake in our laboratory several systematic studies in search of  °C under auto-genous pressure for 20 h. After cooling these solutions for five days at room temperature, colourless single crystals suitable for an X-ray structure determination were obtained. Schematically the reaction is shown in the following equation:

Measurements
All reagents and solvents were obtained from commercial sources and used without further purification.

Single-crystal X-ray diffraction
The study of a single-crystal X-ray data collection was performed on plate single crystal with All calculations were made using the WINGX crystallographic suite of programs [25]. The crystal structure for this compound was determined by the direct method and refined using the SHELXL and SHELXS crystallographic software package, respectively [26,27]. The positions of nitrogen, oxygen and carbon atoms have been identified on the subsequent Fourier difference map. The basic crystallographic parameters and some details of the the measurements structural and refinement are summarized in Table 1. The molecular structure of the studied compound was drawn and presented using ORTEP-3 [28], DIAMOND [29], Mercury [30] and Gauss-view programs [31]. The fractional atomic coordinates and equivalent isotropic displacement parameters (Å2) are presented in Table 2;3.
Crystallographic parameters for the structural analysis reported in this work are also deposited in Cambridge Crystallographic Data Centre and can be freely accessed atwww.ccdc.cam.ac.uk (CCDC no. 1969512).

.Optical measurement
UV-Vis spectrum was recorded on an Ellice SLe164 Double BEAM UV-Vis spectrophotometer in the range 200-800 nm using methanol as solvent.

Results and discussion
3.1. Structure properties description   Fig.1.c).. These values are in good agreement with those found for other hexachlorostannates (IV) [35,36].
These values are in agreement with those observed in similar compounds [37][38][39][40].  (Table   3).This distortion can be explained by the stereochemical inactivity of the 5s 2 lone pair of Sn (IV) and also by the fact of interaction of [SnCl6] 2octahedron with neighbors molecules by the means of different hydrogen bonds. A more complete listing of bond distances and angles is given in Table 4.  b-axis direction .Moreover, the 1-methylpiperzine is inserted between these chains via the above mentioned additional N−H…O hydrogen bonds that give rise to this layer( Table 5). The hydrogen bonding interactions between these layers give rise to a three-dimensional network and add stability to the structure. Fig.4 presents the π…π interaction follow a parallel-displaced configuration of cation aromatic ring.

3.2.Optical properties
The optical absorption spectrum of C5H14N2 [SnCl6] 2H2O title compound measured at room temperature shown in Fig. 4 exhibits two distinct absorption bands centered at 226 nm and 262 nm . This is very similar to results found in other previous studies in the literature containing organic-inorganic compound films [42][43][44][45].
The lower energy absorption peak at 262 nm is due to band gap absorption and it is assigned to the excitation of free electron-hole pairs within the [SnCl6] 2inorganic part. Under excitation, an electron is excited from the valence band to the conduction band, leaving a hole in the valence band. The electron transition back to the ground state that is the recombination of the electron and hole yields an emission, which suggests that the material behaves as semiconductor and is consistent with the dark red of the crystal [46][47][48].
The peak which occurred at 226 nm can be attributed to the absorption of the highest energetic level in the conduction band. The optical band gap (Eg) for 4-(ammonium methyl) pipyridinium hexachlorostanate (II) trihydrate can be determined by extrapolation from the absorption edge which is given by the following equation [49].
(αhν) n =A (hν-Eg) (3) Where α is the absorption coefficient, A is constant, hν is the energy of light and n is a constant depending on the nature of the electron transition which takes different values depending on the mechanism of interband transitions n= 2 and 1/2 [50][51].
The best fit is obtained for n=1/2.
Indeed, the optical band gap was determined from the intersections of the extensions of the linear parts of the curves (αhν) 1/2 with the energy axis. Therefore, the transition is indirect and the value of the optical band gap is judged 3, 46 eV (Fig. 5).

Conclusion
In brief, this manuscript reports a novel organic-inorganic hybrid material with the formula     Absorption curves. energy gap optical properties.

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