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

Abstract A new cyano-bridged Ca(II)–Fe(III) complex, [Ca 2 (phen) 4 (H 2 O) 6 Fe(CN) 6 ][{Ca(phen) 2 (H 2 O) 2 Fe(CN) 6 } 2 ]·3(phen)·(phenH)·14H 2 O·CH 3 OH (where phen=1,10-phenanthroline) 1 has been synthesized and structurally characterized. It contains a cyano-bridged trimetallic cationic species [Ca 2 (phen) 4 (H 2 O) 6 Fe(CN) 6 ] + 1a with a nearly linear Ca–Fe–Ca arrangement, and an anionic species [{Ca(phen) 2 (H 2 O) 2 Fe(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.