Trivalent transition metal ion directed macrocycles

Department of Chemistry, National Institute of Technology (Deemed University), Kurukshetra-136 119, India

Fax: 91-1744-238050

Department of Chemistry, Meerut College, Meerut-250 00 I, India

Manuscript received 19 September 2002, revised 14 July 2003, accepted 17 October 2003

Trivalent chromium, manganese and iron salts react in situ with 2,6-diacetylpyridine and 1,2-diaminobenzene to form complexes containing a 18 -membered N₆ tetradentate macrocyclic ligand. The complexes are of distorted octahedral type [M(TML)]X₃ , where M = Cr^III, Mn^III or Fe^III and X = Cl, Br, NO₃ or NCS for Cr^III and Fe^III ; and X= OAc for Mn^III , TML = tetradentate macrocyclic ligand. The ligand coordinates through all the six nitrogen atoms. The complexes behave as 1 : 3 electrolytes and the test for anions are positive, indicate their presence outside the coordination sphere.