structure structure (solids and liquids) D 2000
-002Synthesis, Crystal Structure, NMR, Vibrational Spectra, and Normal Coordinate Analysis of the Cluster Anions ((Mo6Ii8)Xa6)2-, Xa: F, Cl, Br, I. -The structures of the compounds (III), (IV), and (VI) are determined by single crystal XRD. The compounds (IIa) and (IIb) crystallize in the monoclinic space group P21/n (Z = 2), (IIc) in P21/c with Z = 2, ( IV) is orthorhombic, space group Pcnb, Z = 4, and (VI) is triclinic, P1, Z = 1. The anions consist of an octahedral Mo6 core, eight inner I atoms capping the faces, and six outer terminal X ligands (X: F, Cl, Br, I). The anions show regular geometry with systematic stretchings in the Mo-Mo bond length and a slight compression of the I8-cube on going from F to I for the outer X atom. The IR, Raman and 95Mo NMR spectra are given and the valence force constants are determined. -(BRUECKNER, P.; PREETZ, W.; PUENJER, M.; Z. Anorg.