Strongly blue fluorescent 1-phenyl-2-(pyridin-2-yl)-1H-phenanthro[9,10-d]imidazole(L1)is a facile block for the construction of multichromophore organic molecules,and simultaneously serves as a chelating diimine ligan...Strongly blue fluorescent 1-phenyl-2-(pyridin-2-yl)-1H-phenanthro[9,10-d]imidazole(L1)is a facile block for the construction of multichromophore organic molecules,and simultaneously serves as a chelating diimine ligand.The coordination of L1 to zinc halides enhances the intraligand charge transfer and decreases the emission energy.For the iodide derivative,intra-and intermolecular heavy atom effects lead to a dual singlet–triplet emission with a temperature-dependent ratio of fluorescence and phosphorescence bands in the crystalline state.Decoration of the anthracene core with pyridyl-phenanthroimidazole units(L2 and L3)changes the localization of the lowest energy electronic transitions to the former polyaromatic motif.The solid-state photophysical characteristics of L2 and L3-based compounds strongly depend on the intermolecular interactions between the constituting π-systems(phenanthrene and anthracene),which are perturbed by the ZnX2 coordinated fragments.Modulation of π-stacking contacts in these molecular materials containing L2 and L3 chromophores forms a basis for dynamic optical properties,responsive to mechanical,thermal,or chemical stimuli.展开更多
基金the Academy of Finland(decision 317903,I.O.K.,Flagship Programme,Photonics Research and Innovation PREIN,decision 320166)the Russian Science Foundation(grant 19-73-20055,J.R.S.,photophysical studies)is gratefully acknowledged.
文摘Strongly blue fluorescent 1-phenyl-2-(pyridin-2-yl)-1H-phenanthro[9,10-d]imidazole(L1)is a facile block for the construction of multichromophore organic molecules,and simultaneously serves as a chelating diimine ligand.The coordination of L1 to zinc halides enhances the intraligand charge transfer and decreases the emission energy.For the iodide derivative,intra-and intermolecular heavy atom effects lead to a dual singlet–triplet emission with a temperature-dependent ratio of fluorescence and phosphorescence bands in the crystalline state.Decoration of the anthracene core with pyridyl-phenanthroimidazole units(L2 and L3)changes the localization of the lowest energy electronic transitions to the former polyaromatic motif.The solid-state photophysical characteristics of L2 and L3-based compounds strongly depend on the intermolecular interactions between the constituting π-systems(phenanthrene and anthracene),which are perturbed by the ZnX2 coordinated fragments.Modulation of π-stacking contacts in these molecular materials containing L2 and L3 chromophores forms a basis for dynamic optical properties,responsive to mechanical,thermal,or chemical stimuli.
