Crystal structures of dimetal terephthalate di-hydroxides, M 2 (C 8 H 4 O 4 )(OH) 2 ( M = Co, Ni, Zn) from powder diffraction data and DFT calculations.

The crystal structure of poly[di-hydroxido(μ 6 -terepthalato)dizinc], [Zn 2 (C 8 H 4 O 4 )(OH) 2 ] n , was solved and refined using synchrotron powder data, and the structures of the isostructural Co and Ni analogues were refined using laboratory powder X-ray data. The structure of [Co 2 (C 8 H 4 O 4 )(OH) 2 ] n has been reported previously in space group C 2/ m , which yields disordered terephthalate anions. Doubling the c -axis of that cell results in an ordered model in space group C 2/ c . The octa-hedral M O 6 coordination polyhedra of the metal cations share edges, forming chains running parallel to the b -axis direction. These chains share corners (hydroxyl groups), forming layers lying perpendicular to the a -axis direction.