Non-oxido mixed-valence Mn6IIMn4 III cluster with benzoate, triethanolamine and phosphonate bridging ligands

The synthesis, structure and magnetic properties of a new non-oxido mixed-valence decanuclear heterometallic manganese cluster [K3Mn 10(PhCOO)10(PhPO3)2(Htea) 6](PhCOO)· 6MeCN}n (1), where Htea2- is the dianion of triethanolamine, is reported. Compound 1 can be regarded as an analogue of 24-metallacrown-10, acting as a host for three potassium ions. The resulting (Mn10) cage crystallises as a cation; benzoate anions link the cages into a ID polymer within the crystal. Direct current magnetic susceptibility measurements were collected at temperatures between 1.8 and 300 K and applied magnetic fields of 1 and 10 kG. The room-temperature value is very close to the spin-only value of 38.25 cm3 mol-1 K expected for an Mn10-cage repeat unit comprising six MnII and four MnIII ions. At 2 K and 70 kG the magnetisation reaches a value of 19.5 NμB, suggesting a ground state larger than S = 10. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.