Chemie der schweren Carben-Analogen R2M, M = Si, Ge, Sn XVIII. Eine unerwartete Ge-C-Spaltung des als Dimethylgermylen-Speicher dienenden 7,7-Dimethyl-7-germanorbornadiens

Article abstract of DOI:10.1016/0022-328X(93)80142-X

During thermolysis of the 7-germanorbornadiene 1 in chlorobenzene at 70 deg C in the presence of concentrated hydrochloric acid, besides the well-known formation of free germylene Me2Ge and its consecutive product dimethylchlorogermane 2, the polar splitting of only one Ge-C bond in 1 has been observed for the first time.It does not yield Me2Ge, but instead it rapidly forms the 1-germyl-1,4-dihydronaphthalene 3.The kinetics of this reaction at 53 deg C are of 2nd order, t_1/2 = 20 min, k = 0.22 l mol^-1 min^-1.At room temperature 3 is formed quantitatively.Also,at 70 deg C the slower formation of the germylene Me2Ge from 1 can be suppressed completely if HCl gas is bubbled through the reaction mixture, thus favouring the rapid formation of 3.As a by-product the 1,2-dihydropnaphthalene 5 is generated.