Mixed-valent {Mn14} aggregate encapsulated by the inorganic polyoxometalate shell: [Mn(III)13Mn(II)O12(PO4)4(PW9O34)4]31-

Inorg Chem. 2009 Feb 16;48(4):1606-12. doi: 10.1021/ic802023h.

Abstract

The reaction of [Mn(12)(CH(3)COO)(16)(H(2)O)(4)O(12)].2CH(3)COOH.4H(2)O, Na(8)[HPW(9)O(34)].24H(2)O, K(2)HPO(4), and ethylenediamine hydrochloride in an aqueous solution leads to the isolation of a new polyoxometalate-based mixed-valent manganese aggregate, K(14)Na(17)[(Mn(III)(13)Mn(II)O(12)(PO(4))(4)(PW(9)O(34))(4)]. approximately 56H(2)O (1). Single-crystal X-ray diffraction indicates that the polyoxoanion of 1 exhibits a mixed-valent [Mn(III)(13)Mn(II)(mu(2)-O)(6)(mu(3)-O)(6)(mu(4)-PO(4))(2)(mu(5)-PO(4))(2)](5+) complex encapsulated by four [B-alpha-PW(9)O(34)](9-) trivacant Keggin-type moieties [crystal data for 1: monoclinic, C2/c (No. 15), a = 36.341(7) A, b = 18.325(4) A, c = 36.668(7) A, beta = 119.24(3) degrees, V = 21308(7) A(3), Z = 4]. In a magnetic point of view, all of these paramagnetic manganese aggregates in 1 are well wrapped into the diamagnetic inorganic shells. Variable-temperature, solid-state, direct-current susceptibility measurements show that compound 1 exhibits strong antiferromagnetic interactions inside the [Mn(14)] core.