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The study describes the synthesis and structural attributes of two new cadmium phosphites, [Cd{OP(O)(OH)H}

Three new zinc phosphites, [HIm]2[Zn3(HPO3)4] (1), [Zn2(HPO3)2Im2] (2), and [Zn(HPO3)Im] (3) (Im = imidazole), have been synthesized from the hydro/solvothermal reaction of zinc acetate, dimethyl phosphite, and imidazole by varying the temperature and solvent of the reaction medium. The structure of 1 is built from vertex-sharing of four HPO3-capped Zn3P3 units and adopts an open framework with 12-ring channels stabilized by HIm cations via N-H···O hydrogen bonds. For 2, the inorganic skeleton is comprised of alternating ZnO4 and HPO3 tetrahedra, while the coordinatively associated ZnN2O2 fragments occupy the 12-ring hexagonal channels. Compound 3 adopts a ladder-type one-dimensional structure and exhibits N-H···O hydrogen-bonding interactions to afford a supramolecular assembly. A plausible rationale on the genesis of 1-3 has been put forth by reacting the preformed inorganic zinc phosphites Zn{OP(O)(OMe)H}2 or [Zn2(HPO3)2(H2O)4]·H2O with imidazole as the structure-directing ligand. Alternating-current impedance measurements reveal that 1 and 3 exhibit proton conductivities on the order of 10-3-10-4 S cm-1 between 25 and 100 °C under 35 and 77% relative humidity in repeated impedance cycles (Ea = 0.22-0.35 eV). On the contrary, the conduction property is completely impaired in 2 under similar conditions.

The study presents a rational synthesis of new dimethyltin carboxylates, Me2Sn(H2btec) (1), Me2Sn(btec)0.5(2), [Me2Sn(H2O)2(btec)0.5]·H2O (3), and [{Me2SnOSn(OH)Me2}(Me2SnOH)(btec)0.5]·H2O (4), derived from tetratopic 1,2,4,5-benzenetetracarboxylic acid (H4btec). The method relies upon hydrothermal reaction (130 °C, 72 h) of dimethyltin dichloride and H4btec under optimized pH (2 < pH < 8) conditions that allow control over dimethyltin speciation in aqueous medium as well as degree of deprotonation of the tetrafuntional carboxylic acid. The formation of a three-dimensional assembly in 1 is assisted by the bridging bidentate (μ2) mode of the carboxylate and O–H···O hydrogen bonds involving −COOH groups. The structure represents a unique example of the diorganotin framework derived from a partially deprotonated polyfuntional carboxylic acid. The structure of 2 adopts a three-dimensional motif wherein each pair of μ2-carboxylate groups (designated by C1 and C4) of the tetraanionic ligand form different spati...