Synthetic Studies and Structural Aspects of Some Metallacyclic Compounds of Germanium(IV) Incorporating Nitrogen, Oxygen and Sulfur: 1. Reactions of Germanium(IV) isopropoxide with diols and crystal structure of a diolato bridged germanium(IV) compound [Ge2(O2C2H4)4]

Abstract

Germanium(IV) diolates of the type [(OPri)4-2 nGe(O-G-O) n] ( n = 1, 2) have been prepared by the reaction of Ge(OPri)4 with the corresponding diols in 1:1 and 1:2 molar ratios in anhydrous benzene. All these compounds are colourless viscous liquids except the bis(ethanediolato)germanium(IV), which is a white solid. They have been characterised by elemental analysis and IR and NMR (1H and 13C) spectroscopy. Prismatic crystals of [Ge2(O2C2H4)4] were separated out when [(OPri)2Ge(O2C2H4)] was kept for about 3 weeks at room temperature. Single crystal X-ray diffraction study indicates that it is a unique diolato bridged compound in which the geometry around the germanium atom is a distorted trigonal bipyramid of oxygen atoms which belong to one chelating diolato-O,O′ and to a second η1–O, μ2(η1–O′) bound diolato group.