Synthesis of a novel tetracationic acidic organic salt based on DABCO and its applications as catalyst in the Knoevenagel condensation reactions in water

Synthesis of a novel tetracationic acidic organic salt based on DABCO containing two sulfonic acid groups in the skeleton and four hydrogensulfate groups as counterion is described. Its catalytic efficiency in the Knoevenagel condensation of aldehydes with active cyclic methylene compounds in water is investigated. While 2,2'-(phenylmethylene)bis(3-hydroxy-5,5-dimethylcyclohex-2-enone) derivatives were obtained in 40–98% isolated yields in the reaction of aldehydes with dimedone, the corresponding Knoevenagel adducts were provided in 85–95% yields using 1,3-dimethylbarbituric acid. In addition, a DABCO-based polycationic organic salt polymer was prepared and characterized for the first time.     

Coordination polymer with a staircase molecular architecture: Connecting binuclear Zn(II) bis-chelate platforms with bridging 4,4′-bipyridyl

A new tetraketone ligand with two separated β-diketone functions was prepared, 1,3-[CO-CH₂-COC(CH₃)₂OCH₃]₂Ph (H₂L ^iPrOMe). The title coordination polymer, [Zn₂(L ^iPrOMe)₂(DMSO)₂(bipy)]_n (DMSO = dimethylsulfoxide; bipy = 4,4′-bipyridyl), formed as the only crystalline product upon interaction of Zn(II) acetate, H₂L ^iPrOMe and bipy in 1:1:1 to 1:1:5 molar ratios in DMSO as a solvent. A single crystal XRD study of the compound revealed a staircase polymeric architecture of the complex. The architecture is based on binuclear ′Zn₂(L ^iPrOMe)_2′ platforms where each Zn(II) cation is chelated by two β-diketonate groups of two L ^iPrOMe ligands in the equatorial plane, while each L ^iPrOMe ligand chelates two Zn(II) cations. The coordination environment of each Zn(II) is completed to a distorted octahedron by an O atom of a terminal DMSO and an N atom of bridging bipy ligands. The resulting staircase polymeric ribbons are packed in a self-inclusion mode as would be expected for van der Waals interactions. Most fragments of the molecule were found to be disordered over two equally populated orientations, which was interpreted as evidence of a modulated structure. In addition, several fragments reveal additional minor disordering and high thermal motion.     

含苯并呋喃环的聚苯基单醚喹噁啉

由含苯并呋喃环的芳族四酮与芳族四胺进行溶液缩聚反应，合成了两种新的含苯并呋喃环的聚苯基单醚喹啉，用红外光谱、元素分析、差热及热重分析对聚合物进行了表征，测试了力学性能，并对其在较低温度下形成的多孔薄膜进行了分离、透过性能的研究，实验结果表明，聚合物不仅具有优良的耐热性与力学性能，也具有良好的纯水透过率和截留性能．