Benzyl cobaloximes with thiodioximes: Synthesis, structure and reactivity

Five benzyl cobaloximes with different thiodioximes, BnCo[d(SR)gH]2Py, have been synthesized and four of these complexes have been characterized by X-ray. The reactivity of these complexes towards molecular oxygen has been studied. The puckering of the Co(dioxime)2 unit, caused by dioxime side chain, the SR group, significantly influences the Co–C bond reactivity. Structural features in one of the oxygen inserted cobaloximes have been studied to confirm if puckering of dioxime is the guiding factor. The reactivity is also affected, to some extent, by the C–H…π interaction between the benzyl and the dioxime moiety.

Five benzyl cobaloximes with different thiodioximes, BnCo[d(SR)gH]2Py, have been synthesized and four of these complexes have been structurally characterized by X-ray. The strategic variation of the dioxime side chain leads to puckering of the metallabicycle which in turn affects the Co–C bond reactivity. This has been confirmed from the X-ray structure of the oxygen inserted product. In addition, the weak interactions between the benzyl and the dioxime moiety also affect the rate of oxygen insertion but only to small extent. Figure optionsDownload as PowerPoint slideResearch highlights
► Correlation of Co–C bond reactivity with the puckering in the dioxime.
► Puckering is caused by the strategic variation of the dioxime side chain.
► Weak interactions between the benzyl and the dioxime moiety affect the rate of oxygen insertion.