Two-step radical reactions that switch low multiplicity channels leading to the carbene and carbyne species detected for Ru(F-5) + CH4-nFn (n=2-4) interactions under matrix isolation conditions

作者：Torres Ana E^*; Mendez Oscar; Colmenares Fernando

来源：RSC Advances, 2013, 3(29): 11607-11613.

DOI：10.1039/c3ra41316k

The results obtained from a CASSCF-MRMP2 study of Ru(F-5,F-3) + CH4-nFn (n = 2-4) reactions are used to propose a two-reaction model that explains the high-oxidation state products, which primarily include carbene and carbyne complexes, detected for these interactions in infrared matrix-isolation determinations, without invoking intersystem crossings between electronic states of different multiplicities. For each of these reactions, it was determined that the channels emerging from the ground and first excited states of the reactants both evolve nearly degenerate radical asymptotes involving the species center dot Ru-F and center dot CH4-nFn-1 that differ only in the spin of the non-metal fragment. Therefore, under cryogenic-matrix conditions, the caged radicals produced from the ground state of the reactants can recombine and yield species that exhibit quintuplet and triplet multiplicities. The calculated energy profiles for the recombination reactions show that the low-spin channels evolve to the products under matrix conditions.

• 出版日期2013