Syntheses and Structures of Two New Organically Templated Borogermanates

Two new organically templated borogermanates, [H2DACH][Ge3B2O9(OH)2] (1) (DACH = trans-1,4-diaminocyclohexane) and [H2BAPPZ][Ge3B2O9(OH)2]·1.5H2O (2) (BAPPZ = trans-1,4-bis(3-aminopropyl)piperazine),
have been synthesized under mild hydrothermal conditions in the presence of DACH and BAPPZ acting as structure-directing agents, respectively. The two compounds both crystallized in an orthorhombic system, space group Pbcn
(No. 60), with the following lattice constants:  (1) a = 6.7947(2) Å, b = 11.6963(2) Å, c = 19.9102(3) Å, V = 1582.32(6) Å3, Z = 4; (2) a = 6.8736(2) Å, b =11.7423(3) Å, c = 27.6476(2) Å, V = 2231.49(9) Å3, Z = 4. X-ray analysis
reveals that the layered structure consists of three- and nine-membered rings formed by strictly alternating two
corner-shared germanium tetrahedra and one pair of boron tetrahedra. The diprotonated organic amines exist between
the adjacent borogermanate layers and interact with the inorganic framework by extensive hydrogen bonds.