Integration of Cyanine, Merocyanine and Styryl Dye Motifs with Synthetic Bacteriochlorins.

摘要: Understanding the effects of substituents on spectral properties is essential for rational design tailored bacteriochlorins light-harvesting and other applications. Toward this goal, three new containing previously unexplored conjugating have been prepared characterized. The include two positively charged species, 2-(N-ethyl 2-quinolinium)vinyl- (B-1) 4-pyridinium)vinyl- (B-2), a neutral group, acroleinyl- (B-3); species resemble cyanine (or styryl) dye motifs whereas unit resembles merocyanine motif. are examined by static time-resolved absorption emission spectroscopy density functional theoretical calculations. B-1 B-2 Qy bathochromically shifted well into NIR region (822 852 nm), farther than B-3 (793 nm) 3,13-disubstituted studied previously. broad fluorescence features with large peak separation (Stokes shift), low yields, shortened S1 (Qy ) excited-state lifetimes (~700 ps ~100 ps). More typical spectra lifetime (~2.3 ns) found B-3. combined photophysical molecular-orbital characteristics suggest altered enhanced nonradiative decay derive from configurations in which electron between macrocycle substituents.