A New Candidate Laser Dye Based 1,4-Bis[β-(2-Naphthothiazolyle)Vinyl]Benzene. Spectroscopic Behavior, Laser Parameters and Excitation Energy Transfer

Abstract

A new candidate laser dye based 1,4-bis[β-(2-naphthothisolyl) vinyl] benzene (BNTVB) were prepared, and characterized in various organic solvents. The center polarity is less sensitive than electronic absorption. A red shift was noticed in the fluorescence spectra (ca. 40 nm) with increment in the solvent's polarity, this means that BNTVB's polarity appreciates upon excitation. The dipole moment of ground state (μ) and the excited singlet state dipole moment (μ) are determined from Kawski - Chamma and Bakshiev-Viallet equations using the disparity of Stokes shift with solvent polarity function of ε (dielectric constant) and n (refractive index) of the solvent. The result was found to be 0.019D and 5.13D for ground and exited state, in succession. DFT/TD-DFT manners were used to understand the electronic structures and geometric of BNTVB in other solvents. The experimental and theoretical results showed a good agreement. The photochemical quantum yield (Ф) of BNTVB was calculated in variable organic reagents such as Dioxane, CHCl, EtOH and MeOH at room temperature. The values of φ were calculated as 2.3 × 10, 3.3 × 10, 9.7 × 10 and 6.2 × 10 in Dioxane, CHCl, EtOH and MeOH, respectively. The dye solutions (2 × 10 M) in DMF, MeOH and EtOH give laser emission in the blue-green region. The green zone is excited by nitrogen pulse 337.1 nm. The tuning range, gain coefficient (α) and cross - section emission (σ) of laser were also estimated. Excitation energy transfer from BNTVB to rhodamine-6G (R6G) and N,N-bis(2,6-dimethyphenyl)-3,4:9,10-perylenebis-(dicarboximide) (BDP) was also studied in EtOH to increase the laser emission output from R6G and BDP when excited by nitrogen laser. The dye-transfer power laser system (ETDL) obeys the Foster Power Transmission (FERT) mechanism with a critical transmission distance, R of 40 and 32 Ả and k equals 2.6 × 10 and 1.06 × 10 M s for BNTVB / R6G and BNTVB / BDP pair, respectively.

Photoinduced and Classical Sol-Gel Synthesis: Spectral and Photophysical Behavior of Silica Matrix Doped by Novel Fluorescent Dye Based on Boron Difluoride Complex

“…The last one is typical, indicating that the S 0 →S 1 transition is a strongly permitted type π→π*. The weak absorption peak at approximately 481 nm indicates S 0 →S 2 transitions [ 34 , 36 ]. The absorption spectrum has vibronic peaks, which lost in the emission spectrum, indicating that the planarity of the molecule is lost upon excitation, and exhibiting that the shoulder peaks at 450 nm correspond to the vibrational band of the S 0 –S 1 transitions [ 36 ].…”

“…18 nm), indicating that the S 1 of the DBDMA has higher polarity than the S 0 . This means that a change in the dipole moment of DBDMA molecule occurs when it is excited [ 34 ]. The DBDMA dopped in photosol-gel matrix was prepared and characterized (see Figure S3 ).…”

“…This later, shows absorption maximum at 465 nm and strong red emission with peak maximum at 562 nm when it is excited at 465 nm. This behavior was attributed to the emission from the accumulation of the excited state with a fluorescence of 97 nm red-shifted relative to the emitted solid state (photosol-gel matrix) [ 34 ].…”

“…The oscillator strength ( f ) and transition dipole moment from ground to excited state ( µ 12 ) are calculated using Equations (2) and (3) [ 34 , 35 ]. The oscillator strength is defined as the number of active electrons traveling from the ground to the excited state.…”