Synthesis, structure, and polarized optical spectra of a new fluoromanganate(III): [(H3N(CH2)(2))(2)NH2](2)[MnF5(H2O)](3)

The synthesis and crystal structure of a new fluoromanganate(III), [(H3N(CH 2)(2))(2)NH2](2)[MnF5(H2O)](3), is reported. The unit cell is unusually lar ge: monoclinic, P2(1)/c (no. 14), a = 41.0512(13) Angstrom; b = 9.6469(4) A ngstrom; c = 12.8021(7) Angstrom; beta = 91.927(4)degrees; Z = 8, R = 0.062 7 and wR(2) = 0.1347. The [MnF5(H2O)](2-) anions are octahedral with a stro ng distortion along the F-Mn OH2 axes due to the Jahn-Teller effect. A very rich intermolecular hydrogen bond framework is present, leading to chains of octahedra linked by double-hydrogen bonds. The polarized optical spectra on single crystals are explained in terms of the intraconfigurational d(4) transitions split by a ligand field of C-4v symmetry.