2,6-Bis(1-benzyl-1H-1,2,3-triazol-4-yl)pyridine and its octahedral copper complex

In the tridentate ligand 2,6-bis(1-benzyl-1H-1,2,3-triazol-4-yl)pyridine, C23H19N7, both sets of triazole N atoms are anti with respect to the pyridine N atom, while in the copper complex aqua[2,6-bis(1-benzyl-1H-1,2,3-triazol-4-yl) pyridine](pyridine)-(tetrafluoroborato)copper(II) tetrafluoroborate, [Cu(BF4)-(C5H5N)(C23H19N7)(H2O)] BF4, the triazole N atoms are in the syn-syn conformation. The coordination of the Cu-II atom is distorted octahedral. The ligand structure is stabilized through intermolecular C-H center dot center dot center dot N interactions, while the crystal structure of the Cu complex is stabilized through water-and BF4-mediated hydrogen bonds. Photoluminiscence studies of the ligand and complex show that the ligand is fluorescent due to triazole-pyridine conjugation, but that the fluorescence is quenched on complexation.