Synthesis and Structural Study of Triphenylbismuth Bis ( Salicylate )

The crystal of triphenylbismuth bis (Salicylate) pentavalent was synthesized from the reaction of triphenylbismuth dichloride with salicylic acid dissolved in methylene chloride at room temperature. The molecular and crystal structures of triphenylbismuth bis (Salicylate) were determined by X-ray diffraction analysis. This compound crystallizes in the triclinic space group 1 P with crystallographic parameters: a = 11.2937 (3) Å, b = 14.6516 (3) Å, c = 17.8253 (4) Å, α = 78.2958 (7) ̊, β = 76.232 (6) ̊, γ = 85.351 (6) ̊, 6.332 mm   , V = 2803.59 (11) Å, 2 Z  , 3 1.693g cm Dc  , . The final residual factor is 0.0602 for 5806 reflexions with   00


Introduction
Bismuth is nontoxic and relatively cheap, and bismuth compounds have been widely used in catalysis and organic synthesis [1].Inorganic bismuth compounds such as bismuth halides have been used as Lewis acid catalysts in a number of organic reactions [1][2][3][4][5].However, the utilization of organobismuth compounds trivalent and pentavalent for organic synthesis is rarely reported partly due to the unstable nature of the Bi-C bonds [6,7].Recent developments show that the incorporation of a bulky substituent in pentavalent organobismuth complex can result of organobismuth compounds that have stable Bi-C bonds [8][9][10].In our research group, we have been working on the synthesis of stable pentavalent organobismuth compounds.In previous works we have synthesized organobismuth compounds such as pentavalent triphenylbismuth dichloride, triphenylbismuth diacetate and triphenylbismuth bis (thiophene carboxylate) [7,11].In this work, we report synthesis and structure determination of the organobismuth compound triphenylbismuth bis (salicylate), I, where I is the pentavalent complex, bulky and more stable at room temperature.

Synthesis
The compound triphenylbismuth bis (salicylate) I was prepared from the triphenyl dichloride and salicylic acid in solution of methylene chloride.The mixture is heated to react for one hour of stirring.At the end of the reaction, the mixture is removed and then recrystallized from dichloromethane/pentane (1.1) [12] (Scheme 1).
The obtained compound has the empirical formula C 32 H 25 BiO 6 containing an OH and carboxylate groups that were chosen for our investigation for the following considerations: 1) the hydroxyl group can act as both proton acceptor to promote the formation of intermolecular hydrogen bond; 2) the oxygen atoms of the car- es in di acbonyl of carboxylate ligand is weakly associated with theceptor and participate in the formation of hydrogen bonds; 3) The oxygen atom of the carboxylate links to the central atom of bismuth, forming a stable coordination bond.The resulting compound is studied using X-ray diffraction to obtain molecular crystal structure.
The crystal structure of I was determined tal X-ray diffraction method.X-ray data were collected at room temperature (293 K) on a Kappa CCD diffractometer (Bruker Nonius, 1998) [13] using MoK  radiation (k = 0.71073 Å), at a voltage of 50 kV and current of 20 mA.Cell parameters were obtained from refinement of 25 reflections collected from a random searching.Data reduction was performed with Denzo and Scalepack software [14].Data obtained were processed with the WinGX integrated system software package for single crystal X-ray diffraction data solution, refinement and analysis [15].The crystal structure was solved by direct methods and was refined by full-matrix least-squares refinement on F 2 using the software package SHELX-97 [16].Molecular graphics were done with ORTEP-3 [17].In the absence of significant anomalous scattering effects Friedel pairs have been merged.The crystal data and structure refinement details are listed in Table 1.

Bond Length and Angles
In Figure 1, the central bismuth-cont a distorted pseudo-trigonal-bipyramidal structure.
The average values of bond distances and angl fferent aryl rings are in agreement with the literature    The Bi atom does not almost extend from the equatorial plan as we can view in Figure 2.  6) Å) respectively.We note that, from Figure 3 that the ligands of carboxylate groups are in cis-position compared to the phenyl group.In the other hand, intermolecular interaction between the bismuth atom and the two carbonyl groups forms the Van-Der-Waals bond.
The distances between valence-non-bonded Bi-O(2) and Bi-O( 5) are respectively 2.814 (4) and 2.861 (3) igure 3) which indicate that oxygen atoms are weakly coordinated with the bismuth atom and form a cis conformation together.
This conformation apparently causes significant deviation of the C-Bi-C a an.However, Figure 4 shows, in the equatorial plane, that the tw

Hydrogen Bonds
The bond distance betwee drogen and oxygen noted X-H (Å) and the possible intramolecular interactions by hydrogen bonds noted X-H (Å) of molecule I is shown in Table 4.These different hydrogen bonds showed in Figure 6 are responsible of the molecular packing in the unit cell.

Crystal Packing
Hydrogen bonds played cru ing. Figure 7 shows the presence of two molecules in the which corresponds to the centrosymmetric triclinic space group P1 with two general positions   , , x y z and   , , x y z    .

Conclusions
The new pentavalent triphenylbismuth bis (salicylate) bo was synthesized with a good yield and its crystal structure was determined by X-ray diffraction analysis at room temperature.This work shows that coordination by the salicylate group is more stable, when compared to pentaphenylbismuth.This is caused by rigidity of the ligand between the bismuth and oxygen atoms, and the presence of hydrogen nding and the Van-Der-Waals bonding.The three-di-

Figure 1 .
Figure 1.Perspective view of the molecule of triphenyl- ].The bond distances and valence angles of ata of compound I an v molecule I are shown in Table 2.According to X-ray diffraction d d as shown in Figure 2, Bi atom has distorted trigonal-bipyramidal coordination with oxygen atoms in apical positions.The O(1) and O(4) atoms are located at the apical positions and the C(21), C(27) and C(15) atoms are at the equatorial positions.The sum of angles in the axial angle O-Bi-O for the title e compound are 360˚ (144.4˚,104.1˚ and 111.5˚) and 172.6˚, respectively.(Bi-C(15), Bi-C(21), Bi-C(27)) distances are (2.215(9), 2.238 (8) and 2.200 ( e Bi-O(1) and Bi-O(4) distances are (2.303(6) Å) and (2.313 (

Figure 2 .
Figure 2. Three dimensional structure of compound I showing different angles in equatorial plan.

Figure 3 .
Figure 3. Bond lengths of atoms surrounding the bismuth atom.

Figure 4 .
Figure 4. A, B and C rings compared to Bi-O bond apical position.A and B rings are in the sam is parallel to

Figure 6 .
Figure 6.Hydrogen bonds representation ensuring the molecular packing in the unit cell of compound I.

Figure 7 .
Figure 7. Molecular packing in the unit cell showing two molecules in symmetric positions (x, y, z) and (−x, −y, −z).Hydrogen atoms are shown as small spheres for clarity.
mensional representation of the m shows xial position groups and the equatorial posit e thre yls.This shows that the crystal struc iphenylbismuth bis te) pe lent has a shape distorted trigonal-bipyramid.

Figure 5 .
Figure 5.Bond distances and valence angles around the bismuth atom.

. The synthetic route of the triphenylbismuth bis
IScheme 1

Table 1 . Crystal data and structure refinement details C 32 H 25 BiO 6 compound.
Reflections collected/unique 3274Range of h, k, l