Metal–organophosphine and metal–organophosphonium frameworks with layered honeycomb-like structuresElectronic supplementary information (ESI) available: XRPD patterns for PCM-1, -2, -3 and -5. CCDC reference numbers 708772–708775. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/b820038f

Phosphanotriylbenzenecarboxylic acid (ptbcH3; P(C6H4-p-CO2H)3) and its methyl phosphonium iodide derivative (mptbcH3I; {H3CP(C6H4-p-CO2H)3}I) have been used as organic building blocks in reaction with Zn(ii) salts to obtain a series of related two-dimensional coordination polymers with honeycomb-like networks. The variable coordination number and oxidation states available to phosphorus have been exploited to produce a family of related phosphine coordination materials (PCMs) using a single ligand precursor. The phosphine carboxylate trianion, ptbc3−, reacted with Zn(ii) to form 3,3-connected undulating hexagonal sheets based on tetrahedral P and Zn nodes, where Zn–ptbc = 1 : 1. When hydroxide was used as an additional framework ligand, Zn4(OH)2clusters were obtained. The clusters support 6,3-connected bilayers that consist of pairs of fused hexagonal sheets (Zn–ptbc = 2 : 1) with intra-layer pore spaces. The Zn4(OH)2clusters are also coordinated by solvent, which was preferentially displaced when the bilayer material was synthesized in the presence of ethylene diamine. Treatment of ptbc3−with MeI resulted in methylation of the phosphine to give the P(v) phosphonium iodide salt derivative. The formally dianionic methylphosphonium tricarboxylate building block, mptbc2−, has the same trigonal-pyramidal bridging geometry as the parent phosphine. However, mptbc2−reacted with Zn(ii) on a 1 : 1 stoichiometric ratio to give an unusual trilayer sheet polymer that is based exclusively on 3-connected nodes. Solid-state 31P NMR studies confirmed that the phosphine ligands were resistant to oxidation upon solvothermal reaction under aerobic conditions. [ABSTRACT FROM AUTHOR]