Crystal structures of MoCl 2(O)(O 2)(OPMePh 2) 2 and mixtures of MoCl 2(O 2)(OPPh 3) 2 and MoCl 2(O)(O 2)(OPPh 3) 2: allylic alcohol isomerization studies using MoCl 2(O)(O 2)(OPMePh 2) 2

Abstract

Adding one equivalent of H 2O 2 to compounds of stoichiometry MoCl 2(O) 2(OPR 3) 2, OPR 3 = OPMePh 2 or OPPh 3, leads to the formation of oxo–peroxo compounds MoCl 2(O)(O 2)(OPR 3) 2. The compound MoCl 2(O)(O 2)(OPMePh 2) 2 crystallized with an unequal disorder, 63%:37%, between the oxo and peroxo ligands, as verified by single-crystal X-ray diffractometry, and can be isolated in reasonable yields. MoCl 2(O)(O 2)(OPPh 3) 2, was not isolated in pure form, co-crystallized with MoCl 2(O) 2(OPPh 3) 2 in two ratios, 18%:82% and 12%:88%, respectively, and did not contain any disorder in the arrangement of the oxo and peroxo groups. These complexes accomplish the isomerization of various allylic alcohols. A mechanism of this reaction has been constructed based on 18O isotopic studies and involves exchange between the alcohol and metal bonded O atoms.