Preparation and Reactions of Dichlorodithienogermoles

The reaction of 3,3′-dilithiobithiophenes
with tetrachlorogermane afforded 4,4-dichlorodithienogermoles, which
readily underwent substitution on the central germanium atom. Reactions
of a dichlorodithienogermole with LiAlH4, MeLi, Me2NC6H4Li, and C6F5MgBr gave the corresponding Ge-substituted products. Dihydrodithienogermole
obtained from the reaction with LiAlH4 was further treated
with LDA to give a dimer whose structure was verified by a single-crystal
X-ray diffraction (XRD) study. Hydrolysis of dichlorodithienogermoles
provided cyclotetragermoxanes. Their optical properties were examined
with respect to the UV absorption and fluorescence spectra. It was
found that one of the cyclotetragermoxanes responded to a nitorobenzene
vapor in the solid state, decreasing the PL intensity.