A Determination of the Structure of the Intramolecular Charge Transfer State of 4-Dimethylaminobenzonitrile (DMABN) by Time-Resolved Resonance Raman Spectroscopy

• Published in: The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory Vol. 105; no. 6; pp. 984 - 990
• Main Authors: Kwok, W. M, Ma, C, Matousek, P, Parker, A. W, Phillips, D, Toner, W. T, Towrie, M, Umapathy, S
• Format: Journal Article
• Language: English
• Published: American Chemical Society 15-02-2001
• ISSN: 1089-5639; 1520-5215
• DOI: 10.1021/jp003705w

Picosecond time-resolved resonance Raman spectra of the A (intramolecular charge transfer, ICT) state of DMABN, DMABN-d 6 and DMABN-15 N have been obtained. The isotopic shifts identify the νs(ph-N) mode as a band at 1281 cm-1. The ∼96 cm-1 downshift of this mode from its ground state frequency rules out the electronic coupling PICT model and unequivocally supports the electronic decoupling TICT model. However, our results suggest some pyramidal character of the A state amino conformation.