title: Observation of anomalous C-O bond weakening on discandium and activation process to CO dissociation.
abstract: Sc2[eta2(mu2-C,O)], the first homoleptic dinuclear metal carbonyl with an unprecedented bridging and side-on-bonded CO, generated from the reaction of laser-ablated Sc atoms with CO in a solid argon matrix, exhibits an unusually low C-O stretching frequency at 1193.4 cm-1, characteristic of an anomalously weakened C-O bond. This CO-activated molecule undergoes ultraviolet-visible photoinduced rearrangement to the CO-dissociated molecule, c-Sc2(mu-C)(mu-O). The infrared absorptions of the new molecules are accurately predicted by quantum chemical calculations, and the activation energy for the isomerization of Sc2[eta2(mu2-C, O)] to c-Sc2(mu-C)(mu-O) is calculated to be 15.10 kcal/mol. Our experimental and theoretical results schematically depict an activation process to CO dissociation.
authors.affiliation: National Institute of Advanced Industrial Science and Technology, Ikeda, Osaka 563-8577, Japan.
authors.forename: Ling
authors.initials: L
authors.lastname: Jiang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Xu