High spin molecules: (NBun 4)2[Mn8O4(O2CPh)12(Et2mal)2(H2O)2], a mixed-valence managenese(II/III) aggregate with dicarboxylate ligation, an unusual linked-butterfly structure, and an S= 3 ground state

Treatment of (NBun4)[Mn4O2(O2CPh)9(H2O)] with Na2(Et2mal) in MeCN leads to a nuclearity and oxidation level change to give (NBun4)2[Mn8O4(O2CPh)12(Et2mal)2(H2O)2]1; the crystal structure and magnetochemical studies show the core of the anion to have a unique topology consisting of two linked [Mn4O2] butterfly units and to possess an S = 3 ground state, respectively.