Surface organometallic chemistry : facile mu2-carbene to mu3-carbyne transformation of organocobalt carbonyls on silica surface

mu2-[ROC(O)C(R)]-mu2-(CO)Co2(CO)5 (R = Me, i-Pr, t-Bu, Ph) bridging carbene-type dinuclear Co carbonyls (1) undergo a facile surface-mediated clusterification while chromatographed on silica gel, yielding [mu3-RC(O)OC]Co3(CO)9 (2a) complexes. These latter are then transformed to the corresponding (mu3-RC)Co3(CO)9 (2b) derivatives by silica-mediated decarboxylation. The x-ray diffraction structure of 2a (R = t-Bu) was determined and that of 2b (R = Ph) was confirmed.