AN UNUSUAL HYDROGEN-BONDING NETWORK IN THE LAYERED [BA-2(OH)(2)(H2O)(10)][SE-4] COMPOUND

The layered compound [Ba-2(OH)(2)(H2O)(10)][Se-4] has been prepared hy drothermally (210 degrees C, 22,000 psi). The structure contains alter nating layers of [Se-4](2-) ions and (2)(infinity)[Ba-2(OH)(2)(H2O)(10 )](2+) sheets stacked along the c axis of the unit cell. The (2)(infin ity)[Ba-2(OH)(2)(H2O)(10)](2+) layers comprise (1)(infinity)[Ba(OH)(H2 O)(2)(H2O)(6/2)](+) chains that are crosslinked to form nine coordinat e Ba2+ ions with four interchain O-H ... O hydrogen bonding interactio ns with O ... O separations of 2.65-2.77 Angstrom. The [Se-4](2-) ions are hydrogen bonded to the (2)(infinity)[Ba-2(OH)(2)(H2O)(10)](2+) la yers by virtue of five O-H ... Se hydrogen bonding interactions with O ... Se contacts of 3.44-3.62 Angstrom. The latter are rare examples o f hydrogen bonds to selenium. Crystal data: triclinic, space group <P( 1)over bar>, a = 6.0690(4), b = 8.2956(5), c = 9.8676(8) Angstrom; alp ha = 75.568(6), beta = 73.667(6), gamma = 71.438(6)degrees; V = 444.93 (6) Angstrom(3), Z = 1, R = 0.0261, R(w) = 0.0305. (C) 1995 Academic P ress, Inc.