title: Crystal structure of a compact three-dimensional metal-organic framework based on Cs+and (4,5-di-cyano-1,2-phenyl-ene)bis-(phospho-nic acid).
abstract: A new metal-organic framework compound, poly[[μ7-dihydrogen (4,5-di-cyano-1,2-phenyl-ene)diphospho-nato]-(oxonium)caesium], [Cs(C8H4N2O6P2)(H3O)]n(I), based on Cs+and the organic linker 4,5-di-cyano-1,2-phenyl-ene)bis-(phospho-nic acid, (H4cpp), containing two distinct coordinating functional groups, has been prepared by a simple diffusion method and its crystal structure is reported. The coordination polymeric structure is based on a CsO8N2complex unit comprising a monodentate hydro-nium cation, seven O-atom donors from two phospho-nium groups of the (H2cpp)2-ligand, and two N-atom donors from bridging cyano groups. The high level of connectivity from both the metal cation and the organic linker allow the formation of a compact and dense three-dimensional network without any crystallization solvent. Topologically (I) is a seven-connected uninodal network with an overall Schäfli symbol of {417.64}. Metal cations form an undulating inorganic layer, which is linked by strong and highly directional O-H⋯O hydrogen-bonding inter-actions. These metallic layers are, in turn, connected by the organic ligands along the [010] direction to form the overall three-dimensional framework structure.
authors.affiliation: Department of Chemistry, CICECO - Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: Ricardo F
authors.initials: RF
authors.lastname: Mendes
authors.affiliation: Department of Chemistry, QOPNA, University of Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: Nutalapati
authors.initials: N
authors.lastname: Venkatramaiah
authors.affiliation: Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal; Department of Chemistry, QOPNA, University of Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: João P C
authors.initials: JP
authors.lastname: Tomé
authors.affiliation: Department of Chemistry, CICECO - Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: Filipe A
authors.initials: FA
authors.lastname: Almeida Paz
keywords: caesium; crystal structure; metal–organic framework; phospho­nic acid ligand