Spin crossover in a series of iron(II) complexes of 2-(2-alkyl-2H-tetrazol-5-yl)-1, 10-phenanthroline: Effects of alkyl side chain, solvent, and anion

The synthesis and characterization of a series of iron(II) complexes by using 2-(2-alkyl-2H-tetrazol-5-yl)-1,10-phenanthrolineand its alkyl-substituted derivatives as ligands is presented. The results have proved that the alkyl side chains, in addition to the solvent molecules and anions, play an extremely essential role in the complicated spin crossover (SCO) behaviors of the system.