A new cyano-bridged Ca(II)–Fe(III) complex containing both molecular square and linear trimetallic species

A new cyano-bridged Ca(II)–Fe(III) complex, [Ca2(phen)4(H2O)6Fe(CN)6][{Ca(phen)2(H2O)2Fe(CN)6}2]·3(phen)·(phenH)·14H2O·CH3OH (where phen=1,10-phenanthroline) 1 has been synthesized and structurally characterized. It contains a cyano-bridged trimetallic cationic species [Ca2(phen)4(H2O)6Fe(CN)6]+ 1a with a nearly linear Ca–Fe–Ca arrangement, and an anionic species [{Ca(phen)2(H2O)2Fe(CN)6}2]2− 1b which has a cyano-bridged tetrametallic Ca–Fe–Ca–Fe molecular square framework. In both the species, the Ca atoms are eight coordinated with distorted anti-squareprismatic geometry and the Fe atoms have six coordinated octahedral geometry. The charge is balanced by the protonation of one phen molecule in the lattice.