Monoradical-containing four-coordinate Co(iii) complexes: homolytic S–S and Se–Se bond cleavage and catalytic isocyanate to urea conversion under sunlight

Four-coordinate, Co(iii)-monoradical complexes participated in homolytic S–S/Se–Se bonds scission and catalyzed the conversion of RNCO to the corresponding urea derivatives (TON 480) under sunlight.

An elusive vinyl radical isolated as an appended unit in a five-coordinate Co(iii)-bis(iminobenzosemiquinone) complex formed via ligand-centered C-S bond cleavage

Redox-active ligand H4Pra(edt(AP/AP)) experienced C-S bond cleavage during complexation reaction with Co(OAc)2·2H2O in the presence of Et3N in CH3OH in air. Thus, formed complex 1 was composed of two iminobenzosemiquinone radicals in its coordination sphere and an unprecedented stable tethered-vinyl radical. The complex has been characterized by mass, X-ray single crystal, X-band EPR, variable-temperature magnetic moment measurements and DFT based computational study.

Solid-state valence tautomeric octahedral {CoII[(BQ-N-Cat)]2}0 complex formation via ligand-centered phenolic C–O bond breaking and Co–O bond making

An octahedral {Co^II[(BQ-N-Cat)]₂}⁰ complex was formed by ligand-centered phenolic C–O bond cleavage. The complex showed solid-state valence tautomerism that is triggered by lattice solvent molecule.

Inter-ligand azo (NN) unit formation and stabilization of a Co(ii)-diradical complex via metal-to-ligand dπ–pπ* back donation: synthesis, characterization, and theoretical study

Ligand H₂Rich^(AP)N3 provided a diradical-containing Co(ii) complex via an inter-ligand azo (NN) bond formation.