Silver halide complexes [Ph3P(CH2)2CH2Br][AgBr2] and [Ph3PAgCl]4: synthesis and crystal structure

The interaction of silver bromide and silver chloride with the corresponding halides of 3-bromopropyltriphenylphosphonium and hydroxymethyltriphenylphosphonium has led to complexes [Ph3P(CH2)2CH2Br][AgBr2] (1) and [Ph3PAgCl]4 (2). Crystal structure of compound 1 has been determined by X-ray diffraction (XRD) analysis for the first time. According to the XRD data, 3-bromopropyltriphenylphosphonium dibromoargentate (1) [C21H21PBr3Ag, M = 651.95; monoclinic crystal system, P21/c space group; cell parameters: a = 9.82(2) Å, b = 17.29(4) Å, c = 13.42(3) Å; a = 90.00°, β = 91.87(7)°, g = 90.00°, V = 2277(8) Å3, Z = 4; r(calc.) = 1.902 g/cm3; 2qmax: 5.74-57.1°; -13 ≤ h ≤ 13, -23 ≤ k ≤ 22, -17 ≤ l ≤ 17; 73005 reflections collected; 5681 independent reflections (Rint = 0.2104); GOOF = 1.094; R-factor 15.06 %] has the ionic structure and consists of 3-bromopropyltriphenylphosphonium cation with practically undistorted tetrahedral coordination of the phosphorus atom (the CPC angles vary in the range 107.7(6)-112.8(6)°; the P-C distances vary within 1.767(13)-1.793(13) Å) and rare linear dibromoargentate anion (the BrAgBr angle is 177.97(14)°; the Ag(1)-Br(1) and Ag(1)-Br(2) distances are 2.504(6) Å and 2.551(6) Å, respectively). The crystal organization in crystal 1 is caused by the interionic C-H∙∙∙Br-Ag hydrogen bonds (2.98 Å) and by the weak C-Br∙∙∙πPh contacts with distances from the bromine atom to the nearest carbon atom, up to plane of the phenyl ring and to the center of the phenyl ring equaling 3.47 Å, 3.42 Å, and 3.53 Å, respectively. Complete tables of atomic coordinates, bond lengths, and bond angles for compound 1 have been deposited with the Cambridge Crystallographic Data Centre (CCDC 2174357) and are available, free of charge, at deposit@ccdc.cam.ac.uk and http://www.ccdc.cam.ac.uk.