PHYSICAL-CHEMICAL STUDIES AND REACTIVITY OF NEW DIVALENT GERMANIUM SPECIES

This work concerns the synthesis of five- and six-membered ring hetero cyclic germylenes, derived from hydroxy or thiohydroxy acids and germa nium spiranic corresponding structures. These compounds were prepared by the exchange reaction of dichlorogermylene or germanium tetrachlori de with different germanium heterocycle compounds containing Ge(IV). S tructural studies (IR, C-13 NMR) of 11-17 revealed that these derivati ves, which show a double or triple mass peak in mass spectroscopy, are intermoleculary associated by the carbonyl group to the metal C=O\--> Ge. However, different cycloaddition reactions with dienes, quinones a nd heterobutadienes showed these dimers or trimers had a germylene typ e reactivity. Oxidation reactions of germylenes 10 and 12 are also des cribed.