Dimethylaluminium iminophosphoranylenamides and iminophosphoranylanilides: Synthesis, characterisation, and their controlled ring-opening polymerisation of ε-caprolactone

Abstract

A series of aluminium iminophosphoranylenamide complexes, [Me(2)Al{N(Ar)C(Ph)=CHP(Ph(2))=N-Ar(1)}] (Ar = Ph, Ar(1) = p-MeC(6)H(4) (9); Ar = Ph, Ar(1) = o-ClC(6)H(4) (10); Ar = Ph, Ar(1) = o-FC(6)H(4) (11); Ar = p-MeC(6)H(4), Ar(1) = o-FC(6)H(4) (12)), were synthesised by the reactions of ArN=C(Ph)CH(2)P(Ph(2))=NAr(1) (5-8) with AlMe(3) in toluene. Similar reactions between o-{ArN=P(Ph(2))}C(6)H(4)NHC(Ph)=CHP(Ph(2))=NAr (Ar = p-MeC(6)H(4), 13), and AlMe(3) in toluene generates aluminium iminophosphoranylanilide, 14. All new compounds were characterised by NMR spectroscopy and elemental analysis. The molecular structures of complexes 9 and 14 were further characterised by single-crystal X-ray structure determination. In the presence of benzyl alcohol (BnOH) each of the complexes is catalytically active for the ring-opening polymerisation (ROP) of ε-caprolactone (ε-CL), and complex 14 has the highest activity among them.