IR and UV study of reversible water-induced structural transformations of poly(manganese 1,1′-ferrocenediyl-bis(H-phosphinate)) and poly(cobalt 1,1′-ferrocenediyl-bis(H-phosphinate))

Abstract

Recently new flexible and hydrolytically stable metal-organic framework [M(H2O)2(Fc(PHOO)2)·2H2O]n, M = Co has been synthesized by the use of synthetic technique, described earlier for M = Mn [1]. The heating of both complexes leads to elimination of water molecules and in the case of Co complex is accompanied by change of its color from orange to dark blue. The corresponding structural changes are reversible and are reflected in vibrational and electronic absorption spectra. Analysis of IR, Raman and UV–vis spectra of complexes shows the same structures of Mn and Co complexes before and after heating and suggests that both Mn and Co coordination polyhedra undergo reversible changes under heating from octahedral to tetrahedral form with ferrocene part remaining unchanged.