KCS

The syntheses, characterizations and alkali metal recognition studies of iron complexes containing tetrazole ligands, which form high dimensional coordination polymers in the solid status, are investigated. From the reaction of iron(III) perchlorate, {5-(2-hydroxy) phenyl}tetrazole (LH2) and 2,2’-bipyrimidine(bpym) in H2O, high dimensional mixed metal coordination polymers, [Li3(bpym)1.5FeL3(H2O)6]n (1a), [Na3(bpym)1.5FeL3(H2O)7] n (2a), [K3(bpym)FeL3(H2O)7]n (3a) were synthesized with high yield and their solid structure were determined from X-ray diffraction studies. In all three structure, dual-tridentate iron anion fragment (FeL33-) was observed. As the ion sizes of alkali metals increased, more strong binding between alkali metal ion and iron fragment were observed. Because iron fragment has outstanding coordination ability, extremely short Fe - K distance, which is most short distance among reported in literature, was observed in complex 3a. When bpym was excluded in the reaction, 0-D [Li3FeL3(H2O)3] (1b), 2-D [Na3FeL3(H2O)7] (2b) and [K3FeL3(H2O)7] (3b) were synthesized and coordination between alkali metal ion and iron fragment (FeL33-) was stronger than bpym contained species. In particular, due to lack of binding sites, potassium binds to TzOH ligands with σ and π character in complex 3b. {2-(1-hydroxy-2-dimethylethyl)-5-(2-hydroxy) phenyl}tetrazole is tridentate ligand like scorpionates. we synthesized same method of using LH2 ligand but {2-(1-hydroxy-2-dimethylethyl)-5-(2-hydroxy) phenyl}tetrazole could not observe alkali metal in iron complexes.