Conclusions Knowing how an allyl ligand will bind to an electron deficient (< l&electron) early transition metal and how easily it will undergo q3 to q1 isomerization is important in attempting to understand the reactivity of early-transition-metal allyl complexes. Under what circumstances will an allyl ligand bind q3 versus ql? We have previously shown that the Cp*(allyl) ZrBr, compounds (allyl= 1, 1, 2-trimethylallyl and 1, 2, 3-trimethylallyl) have q3- ...