Kristallstrukturen und Normalkoordinatenanalyse der bindungsisomeren Pentachloroselenocyanatorhenate (IV)

Crystal Structure and Normal Coordinate Analysis of Linkage Isomeric Pentachloroselenocyanatorhenates (IV) The X-ray structure determinations on single crystals of (Ph₃PNPPh₃)₂ReCl₅(NCSe)] ( 1 ) (monoclinic, space group P2₁/n, a = 10.806(2), b = 13.349(2), c = 46.071(4) Å, β = 94.947(9)°, Z = 4) and (Py₂CH₂)ReCl₅(SeCN)] ( 2 ) (monoclinic, space group P2₁/n, a = 12.044(1), b = 9.838(1), c = 15.686(2) Å, β = 105.913(8)°, Z = 4) reveal, that the nearly linear selenocyanate group (178°) is coordinated via N with the Re–N–C angle of 172.7 ( 1 ) and via Se with the Re–Se–C angle of 107.4° ( 2 ). Based on the molecular parameters of the X-ray determinations the IR and Raman spectra, known from literature for both linkage isomers, have been assigned by normal coordinate analysis. The valence force constants are f_d(ReN) = 1.72 and f_d(ReSe) = 1.20 mdyn/Å.