Analyses of 1H- and 13C-NMR spectra of methyl (1-indenyl)germanium(IV) compounds

The H-1- and C-13-NMR spectra of trimethyl(1-indenyl)germanium (IV) and dimethylbis(1-indenyl)germanium (IV) compounds were measured. Assignments of the chemical shifts for H-1 and C-13 in those compounds were obtained by means of hydrogen-hydrogen nuclear Overhauser effect spectroscopy (H-H NOESY), hydrogen-hydrogen correlation spectroscopy (H-H COSY) and carbon-hydrogen correlation spectroscopy (C-H COSY). The methyl proton and carbon signals for two stereoisomers (R,R and RS) in the dimethylbis(1-indenyl)germanium(IV) compound were separated into three signals, with a relative signal intensity of 1 : 2 : 1; the other protons and carbons were separated, except for H-1, H-4, C-5, C-9, into two signals. These results were considered to show that the separated signals were caused by being magnetically nonequivalent in the two stereoisomers.