Pivalate Bridged High Spin Manganese(II) and Iron(II) Polymers

Abstract

Antiferromagnetic Mn(II) polymers of general formula {[L2Mn(μ-OOCCMe3)2][Mn2(μ-OOCCMe3)4]}n (L = 1,2-phenylenediamine (3) and 4,5-dimethyl-1,2-phenylenediamine (4)) were synthesized from [Mn(μ-OOCCMe3)2(HOEt)] n (1) polymer and arenediamines in MeCN solution. The tetranuclear cluster Fe4(μ3-OH)2(μ-OOCCMe3)4(η2-OOCCMe3)2(EtOH)6 (5) was prepared by reacting FeSO4·7H2O with KOOCCMe3 in EtOH and was used as starting pivalate iron(II) agent in further reactions. The thermolysis of 5 in MeCN was shown to result in a ferromagnetic polymer [Fe(μ-OOCCMe3)2] n (6) containing tetrahedral iron(II) atoms. Cluster 5 was found to react with o-phenylenediamine giving rise to ferrimagnetic polymer [Fe(μ-OOCCMe3)2(HOEt)]n (7). The reaction 7 with 2,6-diaminopyridine in MeCN results in binuclear antiferromagnetic complex (2,6-(NH2)2C5H3N)2Fe2(μ-OOCCMe3)4· 4MeCN (8). However the reaction of 4,5-dimethyl-1,2-phenylenediamine with polymer 7 yields a polymer {[L2Fe(μ-OOCCMe3)2][Fe2 (μ-OOCCMe3)4]} n (9), which is an analogue of the manganese polymer 4. All newly synthesized compounds were characterized by the by X-ray diffraction studies and magnetic measurement.