Reaction of Ph 2 C(X)(CO 2 H) (X = OH, NH 2 ) with [VO(OR) 3 ] (R = Et, n Pr): structure, magnetic susceptibility and ROP capability.

Reaction of [VO(OR) 3 ] (R = Et, n Pr) with 2,2'-diphenylglycine afforded the alkoxide-bridged dimers {[VO(OR)(μ-OR)][Ph 2 C(NH 2 )(CO 2 )]} 2 , whereas use of benzilic acid, in the presence of alkali metals, afforded 16-membered metallocycles {V 8 (O) 4 M(OR) 8 [Ph 2 C(OH)(CO 2 )] 12 } (M = <1 Na, K). For the ring systems, magnetic susceptibility data is consistent with mixed-valence vanadium with an average oxidation state of 3.5. The dimer and ring systems are capable of the ring opening polymerisation (ROP) of ε-caprolactone under N 2 , air, or as melts affording mostly low to medium molecular weight cyclic and linear products.