Kristallstrukturen, Schwingungsspektren und Normalkoordinatenanalyse von cis- und trans-[ReCl₄ (NCSe)(SeCN)]^2- / Crystal Structures, Vibrational Spectra, and Normal Coordinate Analysis of cis- and trans-[ReCl₄ (NCSe)(SeCN)]^2-

Abstract

m-Tetrachloroselenocyanato(N)-selenocyanato(Se)-rhenate(IV), /ra«5-Tetrachloroselenocyanato(N)-selenocyanato(Se)-rhenate(IV), Crystal Structure, Vibrational Spectra, Normal Coordinate Analysis The crystal structures of c/s-(«-Bu4N)2[ReCl4(NCSe)(SeCN)] (monoclinic, space group P 2,/n a = 10.794(3), b = 11.687(3), c = 35.716(4) Ä, ß = 96.97(1)°, Z = 4) and trans-(CH2Py2)[ReCl4(NCSe)(SeCN)] (monoclinic, space group P 2,/c, a = 8.348(2), b = 7.518 (1), c -31.295(7) Ä, ß = 97.12(2)°, Z = 4) have been determined by single crystal X-ray diffraction analysis. Based on the molecular parameters of the X-ray determinations the low temperature (10 K) IR and Raman spectra of the (rc-Bu4N) salts have been assigned by normal coordinate analysis. The valence force constants are fd(ReN) = 1.68 and fd(ReSe) =1.15 mdyn/A. Einleitung