Synthesis and characterization of a series of manganese phosphonate complexes with various valences and nuclearity.

A series of new manganese phosphonate clusters with unprecedented topologies, [Mn(20)Na(4)O(12)(t-BuPO(3))(12)(O(2)CMe)(16)(H(2)O)(12)].5H(2)O (), [Mn(15)O(6)(MePO(3))(2)(MeCOO)(18)(H(2)O)(12)][MePO(3)H](2).12H(2)O (), and [Mn(t-BuPO(3)H)(2)(phen)(2)].MeCOOH () have been synthesized and characterized. The core of is composed of two folded "butterfly-like" [Mn(4)(mu(3)-O)(2)] units and two trigonal prism [Mn(6)O(6)] units connected by four mu(3)-O, resulting in a twisted oval of twenty homovalent manganese(iii) ions. The pentadecanuclear core of complex is mixed-valent, containing six Mn(III) and nine Mn(II) ions and features six mu(4)-O and two capping MePO(3)(2-) anions adopting the binding mode [6.222], forming a rudder-like cage structure with a chiral D(3) symmetry. Compound is a manganese(ii) phosphonate and features a 1D chain configuration packed by hydrogen bonds and pi-pi stacking interactions. Magnetic susceptibility measurements reveal that compounds 1, 2 , and 3 display antiferromagnetic interactions between the adjacent manganese ions, while the in-phase signal chi'(M)T and out-of-phase signal chi''(M) of complex 1 exhibit frequency-dependence below approximately 3 K, but no frequency-dependence is observed in the ac signals of complex 2.