Bis(Dipyrrinate) Based Bis(Germylenes): Synthesis, Reactivity, and UV-Vis Spectroscopic Analysis

The first examples of air and water stable bis(germylenes) 5–9 and bis(germacarbonyl) compounds 10–12 are reported. Bis(germylene monochloride) 5 is isolated by starting from bis(dipyrromethene) 4, which in turn has been synthesized by oxidizing bis(dipyrromethane) 3 using DDQ. Terephthaldehyde 1 and mesityl pyrrole 2 were the precursors for compound 3. Bis(germylene monochloride) 5 reacts with alcohols and phenol in the presence of a mild base (Cs₂CO₃) to afford bis(germylene alkoxides) 6–7 and bis(germylene phenoxide) 8, respectively. Compound 5′s reaction with sodium pyrrolide has resulted in bis(germylene pyrrolide) 9. Further, compounds 7 and 9 react with elemental sulfur and selenium under ambient conditions, resulting in bis(germacarbonyl) compounds 10–12. The UV-Vis spectroscopic investigations on compounds 4–12 are done experimentally and computationally.