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The reactions of Zn(II) salts with 4, 4ʹ-(1, 3-phenylenebis (methyleneoxy)) dibenzoic acid(pbd), 1,4-bis(imidazol-1-yl)butane (bib) and 1,10-phenanthroline (1,10-phen) co-ligands afforded two coordination polymers, [Zn(pbd)(bib)] (1) and [Zn(pbd)(1,10-phen)·4H2O] (2). The pbdcaptures the in situ generated scission product of C-O bondwith 4-(3-(hydroxymethyl)benzyloxy)benzoic acid (hbb). A new polymer of [Zn(hbb)(4,4′-bipy)](3) was also synthesized using the rigid N-donor ligand of 4,4′-bipyridine (4,4′-bpy). These polymers were characterized by IR spectroscopy, and Thermogravimetric analysis and further their structures were determined by single-crystal X-ray diffraction analysis. Compound 1 has 2D covalent network. 2 and 3 show 1D chains, which can be further interlinked into 2D supramolecular layer through π─π packing and hydrogen bonded interactions, respectively. The results indicated that 1 displayed good sensing property against most of the nitroaromatic compounds (NACs) by the decrease in its luminescent intensity. With 2,4,6-trinitrophenol (picric acid) Ksv value of 2.93 × 103 M−1 and limit of detection (LOD) of 1.24 ppm was observed. The plausible mechanism of the decline in the luminescent intensity of 1 in presence of NACs has been addressed with the help of theoretical calculations.

The solvothermal reaction of Cd(NO3)2·4H2O and Zn(NO3)·6H2O with phthalic acid (H2pa) and 1,3-bis(2-methyl-imidazol-1-yl)propane (bip) using mixed ligand strategy afforded two new coordination polymers (CPs) of [Cd (pa) (bip) (H2O)]n (1) and {[Zn2 (pa)2 (bip)2]·6H2O}n (2), which have been structurally characterized. Both CPs consist of one-dimensional chains containing two alternative type of rings. Additionally, two types of trimeric water clusters are also present in 2. The uncoordinated carboxylate oxygens of pa ligands interact with free water molecules via hydrogen bonds, which further stabilized the full network. Also, both CPs have been used as photocatalyst for degradation of model organic dyes viz. methyl violet (MV) and rhodamine B (RhB) under UV light. The results indicated that both the CPs display good photocatalytic property. The plausible mechanism associated with photocatalytic activities of 1 and 2 against MV/RhB have been proposed using density of states (DOS) and partial DOS calculations.

The intelligent blending of intriguing functionalities in ligands and incorporation of spectroscopically silent metal cations can produce metal-organic frameworks (MOFs) with multifarious applications viz. selective and specific sensing of nitroaromatic compounds (NACs) an important constituent of explosives as well as photocatalytic properties. A new 3D Zn(II)-based metal-organic framework, [Zn4(μ2-OH)2(BDC)3(bip)2] (1) have been synthesized using a mixed ligand strategy using benzene-1,3-dicarboxylic acid (H2BDC) and 1,4-bis(2-methyl-imidazole-yl)-propane (bip) and zinc nitrate via hydrothermal reaction. The framework of 1 adopts a 5-connected 3D network with the Schlafli symbol {33.4.52.62.72}. The luminescent sensing investigation indicated that 1 can behave as a luminescent sensor for highly sensitive detection of nitroaromatics (NACs) especially against 2,4,6-trinitrophenol (TNP). The possible depletion in the photoluminescence intensity of 1 in presence of NACs have been addressed using theoretical calculations which indicated that charge transfer as well as the weak interaction between NACs and MOF may be responsible for the decline in the photoluminescence intensity. The MOF have been used as the photocatalyst for the decomposition of methyl violet (MV). Also, the mechanism for the photocatalysis have been addressed using density of states (DOS) calculations.

Two new supramolecular coordination polymers of [Zn(L)(bib)] (1) and [Zn(L)(phen)] (2) (H2L = 1,3-bis(3-carboxylphenoxy)benzene, phen = 1,10-phenanthroline and bib = 1,4-bis(1-imidazoly)benzene), were hydrothermally prepared and full characterized. 1 exhibits 6-connected net with hxl topology having Schlafli symbol of {36.46.53}, while 2 shows 1D chain built by ZnII centers and L2− linkers. 1 and 2 demonstrated effectively photocatalytic performance to the disintegration of dyes Rhodamine B (Rh B), methyl orange (MO) and methylene blue (MB). The plausible mechanism displayed by 1 for the catalytic degradation toward Rh B was proposed using the trapping method and LC-MS studies.