Vapour-adsorption and chromic behaviours of luminescent coordination polymers composed of a Pt(ii)-diimine metalloligand and alkaline-earth metal ionsElectronic supplementary information (ESI) available: IR spectra of MPt·4H2O, plots of the emission energies of MPt·4H2O against dielectic constants of the soaking liquids, emission spectral changes of CaPt·4H2O soaked in water-containing solvents and under exposure to MeOH vapor, UV-Vis diffuse reflectance spectra of MgPt·4H2O in air, suspended in DMF and MeOH, and EtOH vapour-adsorption isotherms of MPtat 298 K. See DOI: 10.1039/c1dt10518c

Four new bimetallic coordination polymers (CPs), {M[Pt(CN)2(5,5′-dcbpy)]·4H2O}n(M = Mg2+, Ca2+, Sr2+, Ba2+; 5,5′-H2dcbpy = 5,5′-dicarboxy-2,2′-bipyridine) were synthesized using four alkaline-earth metal ions and a Pt(ii)-diimine metalloligand [Pt(CN)2(5,5′-H2dcbpy)]. All four CPs are isomorphous with the Zn complex, {Zn[Pt(CN)2(5,5′-dcbpy)]·4H2O}n, which exhibits effective metallophilic interactions between Pt(ii) ions. These CPs exhibited colourful thermochromic behaviour and solid-state solvatochromic-like behaviours when suspended in various solvents. Thermogravimetric analysis and vapour-adsorption measurements revealed that the CPs can reversibly adsorb water and MeOH vapours. The emission energy of the triplet metal-metal-to-ligand charge-transfer (3MMLCT) state varied markedly upon guest adsorption/desorption. The chromic and vapour-adsorption properties of these CPs depend strongly on the cross-linking M2+ions. [ABSTRACT FROM AUTHOR]