1638466-01-9Relevant academic research and scientific papers
Novel bright blue emissions IIB group complexes constructed with various polyhedron-induced 2-[2′-(6-methoxy-pyridyl)]-benzimidazole derivatives
Chen, Shuo,Fan, Rui-Qing,Wang, Xin-Ming,Yang, Yu-Lin
, p. 6114 - 6125 (2014)
Five IIB group complexes, [ZnL1Cl2] (1), {[CdL 1Cl2]}2 (2), [Cd(L1) 2(NO3)2]·H2O (3), [HgL 1Cl2] (4), and [ZnL2Cl2] (5) [L 1 = 1-[2-(6-methoxy-2-pyridylmethyl)]-2-[2-(6-methoxy-pyridyl)] benzimidazole; L2 = 2-[2-(6-methoxypyridyl)]benzimidazole] have been synthesized and structurally characterized by elemental analysis, IR spectroscopy, 1H NMR, 13C NMR and X-ray single-crystal analyses. The structural investigations testify that the ionic radius and counterions (Cl- and NO3-) cooperatively affect the coordination mode of central metal. As small and medium radii, four-coordinated Zn2+ (1 and 5) and five-coordinated Cd2+ (2) possess tetrahedron and trigonal bipyramid geometries, respectively. Though Hg2+ (4) has a larger radius, its three-coordinated geometry is trigonal planar in order to eliminate repulsive forces. Further observations illustrate that Cd2+ (3) is bound to two ligands L1 when NO3- is the counter anion, forming seven-coordinated monocapped trigonal prismatic geometry. Complexes 1-5 display bright blue luminescence with the emission maxima (λmax) ranging from 399 to 499 nm at 298 K, depending on the N,N′-chelating ligand-centered π* → π transition. Upon cooling to 77 K, the complexes show rich structured emission profiles compared to those at 298 K. The emission lifetimes of L and 1-5 are on the microsecond scale. The emission efficiency of 1-5 is shown by quantum yields ranging from 0.23 to 0.40. Complexes 1-5 offer a good insight into the opportunities in the utilization of blue materials for application and function. the Partner Organisations 2014.
