作者:Helmut Görner                                    
                                    
                                        DOI:10.1016/j.jphotochem.2010.12.019
                                    
                                    
                                        日期:2011.2
                                    
                                    The photoprocesses of trans-1-methyl-4-[4-R-styryl]pyridinium iodide (R = H, P1) and derivatives with a cyano, a nitro and a methoxy group at the phenyl moiety, P2-P4, respectively, were studied in solution. In solvents of relatively low polarity, e.g. tetrahydrofuran, where contact ion pairs are present, the fluorescence spectrum of the styrylpyridinium is significantly red-shifted and the quantum yield is strongly enhanced. These findings are due to photoinduced electron transfer from I- to the excited singlet state of the cation. The features of complementary trans-styrylquinolinium iodides are in good accordance. (C) 2011 Elsevier B.V. All rights reserved.