Influence of Pyrazine/Piperazine Based Guest Molecules in the Crystal Structures of Uranyl Thiophene Dicarboxylate Coordination Polymers: Structural Diversities and Photocatalytic Activities for the Degradation of Organic Dye

The reaction of uranyl acetate dihydrate with 2,5-thiophenedicarboxylic acid (H₂TDC) as the main ligand and pyrazine (PYZ); piperazine (PZ); 1,4 pyridyl piperazine (PYPZ); 1,4-di­(pyridin-4-yl) piperazine (DPYZ); 1,2 pyrimidyl piperazine (PMPZ) as auxiliary ligand leads to the formation of five new compounds [UO₂(TDC)­(H₂O)]·(PYZ)_0.5·H₂O, (<b>I</b>); [(UO₂)₂(TDC)₃]·(HPZ)·4­(H₂O), (<b>II</b>); [UO₂(TDC)₂(H₂O)]·(H₂DPYZ)·H₂O, (<b>III</b>); [UO₂(TDC)₃]·(H₂DPYZ), (<b>IV</b>); [(UO₂)₂(TDC)₃(H₂O)]·(H₂PMPZ).H₂O, (<b>V</b>). They were analyzed by IR, UV–vis, thermogravimetric analysis, X-ray diffraction analysis, powder X-ray diffraction, and fluorescence spectroscopy. Depending on the countercation, uranyl thiophene dicarboxylate is shown to crystallize as 2D layer in (<b>I</b>, <b>IV</b>), 2D layer with twofold interpenetrated (6,3) nets in (<b>II</b>), 1D chains in (<b>III</b>), and 2D layer without 2-fold interpenetrated (6,3) nets in (<b>V</b>). The coligand DPYZ in structures of (<b>III</b> and <b>IV</b>) had not been added to the reaction but has been formed by the N-arylation of the PYPZ ligand. Compound (<b>IV</b>) was obtained serendipitously while trying some mixed metal compound. Furthermore, their functional properties, photoluminescence, and photocatalytical activity for oxidation of organic dyes have also been studied. Interestingly, compounds (<b>II</b> and <b>V</b>) with uranyl organic frameworks (UOF’s) and honeycomb (6,3) nets possess highest efficiency in degradation of dyes

Redetermination of the crystal structure of 2-oxo-1,3-thiazolidin-4-iminium chloride

In the redetermination of the title compound, C3H5N2OS+·CI−, the asymmetric unit consists of one independent 2-oxo-1,3-thiazolidin-4-iminium cation and one independent chloride anion. The cation interacts with a chloride anion via N—H...Cl hydrogen bonds forming a supramolecular chain along [010]. These supramolecular chains are further extended by weak C—H...Cl and C—H...O interactions, forming a two-dimensional network parallel to (001). The crystal structure is further stabilized by weak C—O...π interactions, supporting a three-dimensional architecture. The structure was previously determined by Ananthamurthy & Murthy [Z. Kristallogr. (1975). 8, 356–367] but has been redetermined with higher precision to allow the hydrogen-bonding patterns and supramolecular interactions to be investigated