| Abstract: | Crystal Structure of (Me4N)3[Ir(SCN)6], Vibrational Spectra and Normal Coordinate Analysis From a mixture of the linkage isomers [Ir(NCS)n(SCN)6–n]3–, n = 0–2, pure [Ir(SCN)6]3– has been isolated by ion exchange chromatography on diethylaminoethyl cellulose. The X-ray structure determination on a single crystal of (Me4N)3[Ir(SCN)6] (trigonal, space group R3, a = 14.838(2), c = 23.827(1) Å, Z = 6) reveals the presence of two crystallographically independent complex anions which C3i symmetry correlates with the cation/anion ratio 3 : 1. The thiocyanate ligands are exclusively S-coordinated with the average Ir–S distance of 2.384 Å and the Ir–S–C angle of 106.4°. The torsion angles S–Ir–S–C are 17.5 and 42.1°. The IR and Raman spectra of the (n-Bu4N) salt are assigned by normal coordinate analysis based on the molecular parameters of the X-ray determination. The valence force constant fd(IrS) is 1.57 mdyn/Å. |
