Solvent Mediated Photoluminescence Responses Over Mixed-Linker Cadmium (Ii) Based Metal-Organic Frameworks

Three dimensional mixed-linker cadmium based metal-organic framework (MOF), [Cd2(L1)2(L2)0.5(H2O)]n(1) and {[Cd3(L1a)2(L2)2].H2O}n (2) (L1 = pyrazole-3,5 dicarboxylate, L1a = pyrazolate-3,5 dicarboxylate and L2 = 4,4 '-azopyridine) have been synthesized by solvothermal methods. Notably, subtle change in reaction conditions afforded two strikingly different MOFs. Compounds have been characterized structurally by single-crystal X-ray analysis. Both the compounds feature a pillared-layer framework structure. Photoluminescence properties of the framework compounds have been investigated in the solid state as well as in solvent dispersed medium. Interestingly, solvent specific turn-on/turn-off photo-luminescence responses have been observed for both the compounds (1) and (2).