Syntheses, Crystal Structures and Fluorescence Properties of Two Triazolyl Derivatives with Biphenyl Links

<Abstract>Two novel triazolyl derivatives with biphenyl links, namely 4,4-bis(1,2,4-triazol-1-yl-methyl)biphenylene 1 and 4,4-bis(3,5-dimethyl-1,2,4-triazol-1-ylmethyl)biphenylene 2, have been synthesized and structurally characterized by single-crystal X-ray diffraction. Compounds 1·H2O·HCl and 2·2H2O·2HCl crystallize in the monoclinic system with space group C2/c and P21/c, respectively. The dihedral angles of the two phenyl rings are 30.26(6)° in 1·H2O·HCl, while co-planar (0.00(7)°) in 2·2H2O·2HCl. In 1·H2O·HCl, the N-H……O hydrogen bonds link 1 to form chain-like structures which are further connected by O-H……Cl, C-H……Cl, C-H……O and π-π supramolecular interactions. The hydrogen bonds of O-H……Cl in 2·2H2O·2HCl provide distinguishing P/M helical chains along the b axis, and these chains are further connected by N-H……O hydrogen bonds to generate a 2D structure. Compounds 1 and 2 in methanol solution show much stronger emission bands at 319 nm than biphenyl at 316 nm under excitation at 260 nm.