Hydrogen bonding in Be[C 2(COO) 2]·4H 2O—A neutron diffraction study at 15 K

Abstract

Lattice constants for orthorhombic Be[C 2 (COO) 2 ]·4H 2 O at 15 K are a =1006.4(6), b =663.0(4), and c =1263.1(7) pm, Z =4, space group Cmcm . Anisotropic refinement on single crystal neutron diffraction data led to R w =0.0229. The crystal structure is made up by slightly distorted Be(H 2 O) 2+ / 4 tetrahedra (Be−H 2 O 161. 3 and 162.0 pm) and planar [C 2 (COO) 2 ] 2− anions linked together by strong (O… H 2 O 262.0 and 263.5 pm) asymmetric hydrogen bonds. A layer-like arrangement extending parallel to (010) consisting of [C 2 (COO) 2 ] 2− anions and hydrogen bound water molecules of the Be(H 2 O 2+ / 4 tetrahedra is the primary structural feature of Be[C 2 (COO) 2 ]·4H 2 O. These layers are stacked in … ABAB … sequence and interlinked by coordinative bonds between Be 2− and H 2 O to yield a rigid three-dimensional framework. O−H bond length corrected for thermal motion are 100.4 and 100.5 pm, respectively. The H−O−H angle are rather wide (111.12 and 114.36°). The anion has mmm symmetry.