Darstellung,Kristallstrukturen, Schwingungsspektren und Normalkoordinatenanalyse der bindungsisomeren Chlororhodanoiridate(III) trans-[IrCl2(SCN)4]3− und trans-[IrCl2(NCS)(SCN)3]3−

Preparation, Crystal Structures, Vibrational Spectra, and Normal Coordinate Analysis of the Linkage Isomeric Chlororhodanoiridates(III) trans-IrCl₂(SCN)₄]^3? and trans-IrCl₂(NCS)(SCN)₃]^3? By treatment of Na₂IrCl₆] with NaSCN in 2N HCl the linkage isomers trans-IrCl₂(SCN)₄]^3? and trans-IrCl₂(NCS)(SCN)₃]^3? are formed which have been separated by ion exchange chromatography on diethylaminoethyl cellulose. X-ray structure determinations on single crystals of trans-(n-Bu₄N)₃IrCl₂(SCN)₄] ( 1 ) (monoclinic, space group P2₁/a, a = 18.009(4), b = 15.176(3), c = 23.451(4) Å, β = 93.97(2)°, Z = 4) and trans-(Me₄N)₃IrCl₂(NCS)(SCN)₃] ( 2 ) (monoclinic, space group P2₁/a, a = 17.146(5), b = 9.583(5), c = 18.516(5) Å, β = 109.227(5)°, Z = 4) reveal the complete ordering of the complex anions. The via S or N coordinated thiocyanate groups are bonded with Ir? S? C angles of 105.7–109.7° and the Ir? N? C angle of 171.4°. The torsion angles Cl? Ir? S? C and N? Ir? S? C are 3.6–53.0°. The IR and Raman spectra of ( 1 ) are assigned by normal coordinate analysis using the molecular parameters of the X-ray determination. The valence force constants are f_d(IrS) = 1.52 and f_d(IrCl) = 1.72 mdyn/Å.