Synthesis and Systematic Reactivity of a Bispyrrole-based Germylene

Germylenes have attracted considerable attention over the last four decades, owing to their stability and versatile reactivity in bond activation and catalysis. In parallel, dipyrromethene-derived frameworks have revolutionized fluorophore design; however, their integration into low-valent heavy main-group chemistry remains largely unexplored. Herein, we report the synthesis, structural characterization, and theoretical investigation of a bispyrrole-based germylene (2), which is structurally and electronically distinct from BOPHY [bis(difluoroboron)1,2-bis{(1H-pyrrol-2-yl)methylene}hydrazine] systems and does not exhibit luminescence. We further examine its reactivity toward transition-metal precursors, leading to the formation of cobalt-bis(germylene) (3) and cobalt-germylene complexes (4 and 5). These results provide insights into the ligand design, stability, and coordination behavior of a bispyrrole-supported heavy tetrylene system.