Publications

Synthesis, crystal structure, and molecular modeling of a layered manganese(II) phosphate : Mn3(PO4)4 2 (H3NCH2CH2)3N 6(H2O)

Thoma, Steven T.; Thoma, Steven T.; Bonhomme, F.; Cygan, Randall T.

A novel layered manganese(II) phosphate, Mn{sub 3}(PO{sub 4}){sub 4} {center_dot} 2(H{sub 3}NCH{sub 2}CH{sub 2}){sub 3}N {center_dot} 6(H{sub 2}O), has been synthesized solvothermally using tris(2-aminoethyl)amine (TREN) as a template. The structure was solved ab initio using X-ray powder diffraction data and confirmed by molecular modeling. The compound was further characterized by SEM, IR spectroscopy, photoluminescence, and elemental and thermal analysis. The compound crystallizes in the trigonal space group P{sub 3}c1 with a = 8.8706(4) {angstrom}, c = 26.158(2) {angstrom}, and V = 1782.6(2) {angstrom}{sup 3}. The structure consists of layers of corner sharing Mn(II)O{sub 4} and PO{sub 4} tetrahedra forming infinite [Mn{sub 3}(PO{sub 4}){sub 4}]{sup 6-} macroanions with 4.6 net topology, sandwiched by layers of TREN and water molecules. The protonated TREN molecules provide charge balancing for the inorganic sheets; the interlayer stability is accomplished mainly by a network of hydrogen bonds between water molecules and the inorganic macroanions. This hybrid organic/inorganic layered material can be reversibly dehydrated.