Synthesis and structure of tetraphenylstibonium diiododicyanoaurate [Ph4sb][Au(CN)2I2]

The reaction of potassium diiododicyanoaurate with tetraphenylstibonium chloride has led to the synthesis of the [Ph4Sb][Au(CN)2I2] (1) complex. The crystal structure of compound 1 has been determined by X-ray diffraction (XRD) analysis for the first time. According to the XRD data, tetraphenylstibonium diiododicyanoaurate (1) [C26H19N2SbI2Au, M = 931.95; triclinic crystal system, P-1 space group; cell parameters: a = 8.176(5) Å, b = 9.998(6) Å, c = 18.579(15) Å; a = 84.55(3)°, β = 77.37(3)°, g = 67.42(3)°, V = 1368.4(16) Å3, Z = 2; r(calc.) = 2.262 g/cm3; 2qmax: 5.62°-74.5°; -13 ≤ h ≤ 13, -16 ≤ k ≤ 16, -31 ≤ l ≤ 31; 91938 reflections collected; 14033 independent reflections (Rint = 0.0559); GOOF = 1.033; R-factor 5.95%] has the ionic structure and consists of tetraphenylstibonium cation with practically undistorted tetrahedral coordination of the antimony atom (the CSbC angles vary in the range 102.2(3)-119.8(2)°; the Sb-C distances vary within 2.087(6)-2.099(6) Å) and two types of almost undistorted square-planar diiododicyanoaurate anions (the trans- and cis-angles are close to 180° and 90° respectively; the Au-I and Au-C distances are 2.5863(13), 2.6071(15) Å and 1.986(8), 1.991(7) Å, respectively). The crystal organization in crystal 1 is caused by the interionic С-H∙∙∙N≡C (2.54, 2.55 Å) and С-H∙∙∙I-Au (3.16 Å) hydrogen bonds, as well as by the weak Sb∙∙∙N≡C contacts with the length of 3.30 Å. Complete tables of atomic coordinates, bond lengths, and bond angles for compound 1 have been deposited with the Cambridge Crystallographic Data Centre (CCDC 1900936) and are available, free of charge, at deposit@ccdc.cam.ac.uk and http://www.ccdc.cam.ac.uk.