Fig. 4. (a) The HOMO–LUMO distribution of TCy5 is calculated by TD-DFT (Gaussian 09/B3LYP/6-31+G(d, p)). The ground state optimized geometry by the DFT calculations at the B3LYP/6-31G(d, p) level with Gaussian 09. (b) Femtosecond transient absorption spectra of TCy5-CHO, covering the time interval from 1 ps to 6.1 ps. (c) Nanosecond transient absorption spectra of TCy5-CHO excited with a nanosecond laser at 355 nm, and (d) decay trace at 627 nm of TCy5-CHO excited at 550 nm. c = 3.0 × 10−5 M in deaerated DCM at room temperature. Lifetimes of the single exponential fitting functions are given in the graph. (e) Schematic reduction of the potential energy diagram to illustrate the origin of the photophysical processes involved in TCy5-CHO shown in (b)–(d).
