Reaction of Ph2C(X)(CO2H) (X = OH, NH2) with [VO(OR)3] (R = Et, nPr): structure, magnetic susceptibility and ROP capability

Abstract

Reaction of [VO(OR)₃] (R = Et, nPr) with 2,2′-diphenylglycine afforded the alkoxide-bridged dimers {[VO(OR)(μ-OR)][Ph₂C(NH₂)(CO₂)]}₂, whereas use of benzilic acid, in the presence of alkali metals, afforded 16-membered metallocycles {V₈(O)₄M(OR)₈[Ph₂C(OH)(CO₂)]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 N₂, air, or as melts affording mostly low to medium molecular weight cyclic and linear products.