A new diolefinic laser dye: 2,5-bis-2-(2-naphthyl) vinyl pyrazine (B2NVP)

The title dye acts as a laser dye upon pumping with nitrogen laser (lambda( ex) = 337.1). B2NVP in N,N-dimethylformamide (DMF) gives amplified spontane ous emission (ASE) with a maximum at about 470 nm, but only low laser activ ity upon nitrogen laser pumping. The difference between sigma(epsilon) (emi ssion cross-section) and sigma(epsilon)* (from ASE calculated effective emi ssion cross-section) is interpreted as S-1-S-n , absorption, the maximum of this absorption occurring in DMF at around 500 nm. Thereby the laser effic iency of the dye is strongly reduced. Investigations on the photochemical s tability, photochemical quantum yields, and the dependence efficiency of th e dye. B2NVP has short excited state lifetimes, high fluorescence efficienc ies and low photochemical quantum yields. The dye undergoes solubilization in anionic micelles with subsequent increase in fluorescence efficiencies. Energy transfer from B2NVP to rhodamine6G (R6G) in dimethylsulfoxide (DMSO) has been studied giving a second order quenching rate constant of 8.7 x 10 (13) M-1 s(-1). (C) 1999 Elsevier Science S.A. All rights reserved.