Coordination geometry isomerism induced by N–H⋯Cl, C–H⋯Cl, C–H⋯N, C–H⋯π and π⋯π supramolecular interactions in mercury(II) complexes with tripyridylimidazole chelating ligands

Crystal Engineering and Self-Assembled Nanoring Formation with Purine-CdII /HgII Supramolecular Frameworks

We report three complexes of CdII and HgII with two purine rare tautomers, N9-(pyridin-2-ylmethyl)-N6 -methoxyadenine, L1 and N7-(pyridin-2-ylmethyl)-N6 -methoxyadenine, L2, highlighting diverse crystallographic signatures exhibited by them. Influence of substituents, binding sites, steric effects and metal salts on the different modes of binding enabled an insight into metal-nucleobase interactions. L1 interacted with two and three equivalents of Cd(NO3 )2 .4H2 O and HgCl2 , respectively, while L2 interacted with two equivalents of HgCl2 , altogether leading to three different complexes (1 [C48 H48 Cd6 N34 O50 ], 2 [C12 H12 Cl4 Hg2 N6 O] and 3 [C12 H12 Cl2 HgN6 O]) possessing varied dimensionality and stabilising interactions. The photoluminescent properties of these coordination frameworks have also been probed. Notably, nanoring-like structures were obtained, as a result of self-assembly of 3 when investigated by transmission electron microscopy, additionally supported by molecular dynamics simulations.

Synthesis, crystal structure, DFT studies and photophysical properties of a copper(I)–triphenylphosphane complex based on trans-(±)-2,4,5-tris(pyridin-2-yl)-2-imidazoline

The possibility of using less expensive and nontoxic metals, such as copper, as substitutes for more expensive heavy metals in the synthesis of new transition-metal complexes to be used as sensitizers in dye-sensitized solar cells (DSSCs) has stimulated research in this field. The novel photoluminescent copper(I) complex bis(triphenylphosphane-κP)[trans-(±)-2,4,5-tris(pyridin-2-yl)-2-imidazoline-κ2 N 2,N 3]copper(I) hexafluorophosphate, [CuI(C18H15N5)(C18H15P)2]PF6, has been successfully synthesized and characterized by IR and 1H NMR spectroscopy, as well as by single-crystal X-ray diffraction and thermogravimetric analysis. The complex showed interesting photophysical properties, which were studied experimentally in solution and in the solid state by UV–Vis and fluorescence spectroscopy. Density functional theory (DFT) calculations with dichloromethane as solvent reproduced reasonably well the HOMO and LUMO orbitals of the title compound.

Synthesis, structure, characterization and photophysical properties of copper(i) complexes containing polypyridyl ligands

Two novel photoluminescent copper(i) complexes have been successfully synthesized and characterized. Both complexes showed interesting photophysical properties.