Crystal structure and Hirshfeld-surface analysis of (benzenecarbothioamide-κS)bromidobis(triphenylphosphane-κP)silver(I)

The mononuclear complex exhibits a distorted tetrahedral coordination geometry about the metal atom, arising from one S atom of the benzenecarbothioamide ligand, two P atoms of two triphenylphosphane molecules and one bromide ion. An intramolecular N—H⋯Br hydrogen bond is observed and in the crystal structure, inversion dimers linked by pairs of N—H⋯Br and C—H⋯Br hydrogen bonds are observed. In addition, C—H⋯π interactions occur, leading to [101] chains.


Chemical context
Mixed-ligand complexes of Ag I -containing phosphorus and sulfur donor ligands have been studied and published extensively in recent years (Dennehy et al., 2007;Ruangwut & Pakawatchai, 2014) because of their potential ability to inhibit bacteria (Isab et al., 2010;Nawaz et al., 2011). Triphenylphosphane and thione ligands, which contain P and S donor atoms, respectively, are capable of forming mixed-ligand silver(I) complexes as mononuclear (Aslanidis et al., 1997) and dinuclear models (Cox et al., 2000). In this paper, we report the synthesis and structure of the mixed-ligand complex of silver(I) bromide with triphenylphosphane and benzenecarbothioamide ligands. ISSN 2056-9890

Structural commentary
The monomeric complex of the title compound crystallizes in the monoclinic crystal system, space group P2 1 /n, and is shown in Fig. 1. The silver ion is four-coordinated exhibiting a distorted tetrahedral environment. This deviation can be explained by P1-Ag1-P2 angle which has the highest value of 121.60 (2) due to the steric hindrance and the repulsion between two bulky triphenylphosphane molecules. The range of angles around the Ag atom of 97.338 (18)-121.60 (2) is similar to that observed in the analogous mononuclear silver(I) complex [AgCl(C 7 H 7 NS)(C 18 H 15 P) 2 ] previously synthesized by us (Ruangwut & Pakawatchai, 2014), in which the angles about the metal ion are 97.298 (16)-120.053 (16) . The Ag-S bond length of 2.6015 (8) Å is slightly longer than in [AgCl(C 7 H 7 NS)(C 18 H 15 P) 2 ], 2.5580 (5) Å . The Ag-P bond lengths of 2.4682 (7) and 2.4671 (6) Å for Ag1-P1 and Ag1-P2, respectively, are similar to those of the Ag-P bond lengths in [AgCl (C 7 , 1998]. An intramolecular hydrogen bond N1-H1BÁ Á ÁBr1 [3.413 (3) Å ; Table 1] is found between one of the H atoms from an amine group of the benzenecarbothioamide molecule and the bromide ion, as depicted in Fig. 2, which also shows the intermolecular dimeric hydrogen bonds.

Supramolecular features
In the crystal, the dimeric intermolecular interactions are generated through a crystallographic inversion center by The molecular structure of the title compound, showing 30% probability displacement ellipsoids. Table 1 Hydrogen-bond geometry (Å , ).
Cg3 is the centroid of the C13-C18 ring.

Figure 2
An inversion dimer in the crystal of the title compound linked by two pairs of N-HÁ Á ÁBr interactions, forming R 2 4 (8) loops, and pairs of C-HÁ Á ÁBr interactions, forming R 2 2 (14) loops.

Hirshfeld surface analysis
For the title complex, the Hirshfeld-surfaces analysis (McKinnon et al., 2004;Spackman & Jayatilaka, 2009) was generated by Crystal Explorer 3.1 (Wolff et al., 2012) and mapped over d norm , d e and d i fingerprint plot (Spackman & McKinnon 2002;McKinnon et al., 2007). The contact distances to the closest atom inside (d i ) and outside (d e ) of the Hirshfeld surface analyse the intermolecular interactions via the mapping of d norm , as depicted in Fig. 4. The interactions are shown on the Hirshfeld surfaces with short contacts indicated in red. The corresponding fingerprint plots ( Fig. 5a-d) for Hirshfeld surfaces of the complex are shown with characteristic pseudo-symmetry wings in the upper left and lower right sides of the de and di diagonal axes that represent the overall 2D fingerprint plot and those delineated into HÁ Á ÁH, HÁ Á ÁBr/ BrÁ Á ÁH, and CÁ Á ÁH/HÁ Á ÁC contacts are shown in Fig. 5a-d, respectively. The fingerprint plot of HÁ Á ÁH contacts represented by the largest contribution within the Hirshfeld surfaces (60.8%) are shown as one distinct pattern with a minimum value of d e + d i $2.6 Å . The reciprocal HÁ Á ÁBr/ BrÁ Á ÁH contacts consist of 5.4% of the total Hirshfeld surface with d e + d i $3.3 Å , exhibited by two symmetrical narrow pointed wings indicating the intermolecular hydrogen-bond interactions N1-H1AÁ Á ÁBr1 and C17-H17Á Á ÁBr1 in the crystal packing. The presence of C-HÁ Á Á interactions on the fingerprint plot, which contribute 29.7% of overall Hirshfeld surface, are indicated by d e + d i $3.0 Å .

Synthesis and crystallization
Silver(I) bromide (0.10 g, 0.5 mmol) was dissolved in the mixed solvent of 15 ml of acetonitrile and 15 ml of ethanol and then triphenylphosphane (0.27 g, 1 mmol) was added. The mixture was refluxed for 2 h at 343 K and a white precipitate   was formed. After that, benzenecarbothioamide (0.13 g, 1 mmol) was added and continually refluxed for 5 h. At that time, the white precipitate dissolved. The clear yellow solution was filtered and left to evaporate at room temperature. After a day, pale-yellow blocks of the title compound were filtered off and dried in vacuo. Calculated for C 43 H 37 AgBrNP 2 S: C 61.07, H 4.37, N 1.65 and S 3.78%. Found: C 60.50, H 4.21, N 1.43 and S 3.70%.

Refinement
Crystal data and details of structure determination are summarized in Table 2. All H atoms on carbon atoms were positioned geometrically and refined using a riding-model approximation with C-H = 0.93 Å with U iso (H) = 1.2 U eq (C). N-bound H atoms were found from difference maps and refined isotropically with distance restraint N-H = 0.85-0.86 Å . Crystal structure and Hirshfeld-surface analysis of (benzenecarbothioamide-

Wattana Ruangwut, Saowanit Saithong and Chaveng Pakawatchai
Computing details Data collection: SMART (Bruker, 2003); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT (Bruker, 2003); program(s) used to solve structure: SHELXT2014 (Sheldrick, 2015); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: Mercury (Macrae et al., 2008); software used to prepare material for publication: WinGX (Farrugia, 2012) and publCIF (Westrip, 2010). Special details Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.