Structures of dicobalt and dinickel 4,4'-bi-phenyldi-carboxyl-ate di-hydroxide, M 2 (O 2 CC 6 H 4 C 6 H 4 CO 2 )(OH) 2 , M = Co and Ni, and di-ammonium 4,4'-bi-phenyldi-carboxyl-ate from powder diffraction data.

The triclinic structures of poly[(μ 4 -4,4'-bi-phenyldi-carboxyl-ato)di-μ-hydroxido-dicobalt], [Co 2 (C 14 H 8 O 4 )(OH) 2 ] n , and poly[(μ 4 -4,4'-bi-phenyldi-carboxyl-ato)di-μ-hydroxido-dinickel], [Ni 2 (C 14 H 8 O 4 )(OH) 2 ] n , were established using laboratory X-ray powder diffraction data. These structures, as well as that of poly[(μ 4 -4,4'-bi-phenyldi-carboxyl-ato)di-μ-hydroxido-dimanganese], [Mn 2 (C 14 H 8 O 4 )(OH) 2 ] n , were optimized using density functional techniques. The structure of di-ammonium 4,4'-bi-phenyldi-carboxyl-ate, 2NH 4 + ·C 14 H 8 O 4 2- , was also solved using laboratory powder data. The Mn and Co compounds are isostructural: the octa-hedral MO 6 groups share edges to form chains running parallel to the c -axis. These chains share corners (OH groups) to link into layers lying parallel to the bc plane. The hydroxyl groups do not participate in hydrogen bonds. The structure of (NH 4 ) 2 BPDC consists of alternating layers of BPDC and ammonium ions lying parallel to the ab plane. Each hydrogen atom of the ammonium ions in (NH 4 ) 2 BPDC participates in a strong N-H⋯O hydrogen bond.