Vibrational predissociation and intramolecular vibrational relaxation in dimethyl-s-tetrazine–argon complexes.

Autor: Osborn, David L., Alfano, Joseph C., Dantzig, Niels van, Levy, Donald H.
Předmět:
Zdroj: Journal of Chemical Physics; 8/15/1992, Vol. 97 Issue 4, p2276, 8p
Abstrakt: The one- and two-argon van der Waals complexes of dimethyl tetrazine (DMT) have been investigated by means of laser-induced excitation and dispersed fluorescence spectroscopy. The band shifts D‘0 - D’0 range from -23 to -31 cm-1 for DMT–Ar relative to DMT. The excited state dissociation energy of the DMT–Ar bond was estimated to be 270 ≤ D’0 ≤ 484 cm-1. In all levels with energy greater than the argon dissociation energy, predissociation is very fast. A dissociation rate constant kD = 3 × 109 s-1 has been determined for dissociation from the 6a1 level. This rate constant is an order of magnitude larger than that observed in tetrazine–argon. The dissociation rate constant of DMT–Ar2 from the 6a1 level is approximately 2 × 1010 s-1. Unlike aminotetrazine–Ar2, DMT–Ar2 shows no mode-selective variations in the branching ratios between the DMT and DMT–Ar photoproducts. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index