title: Photophysical properties and semiempirical calculations of perylene-3,4,9,10-tetracarboxylic tetramethylester (PTME).
abstract: The spectral behavior and fluorescence quantum yield of perylene-3,4,9,10-tetracarboxylic tetramethylester (PTME) have been measured in different solvents. Both electronic absorption and fluorescence spectra are not sensitive to medium polarity. The dye exhibits high fluorescence quantum yield and high photostable. Crystalline solid of PTME gives excimer-like emission at 530 nm. The laser activity of PTME has been investigated. The dye solution in N,N-dimethylformamide (DMF) gives laser emission around 480 nm upon excitation by 337.1 nm nitrogen laser pulse. The excitation energy transfer from 7-dimethylamino-4-methylcoumarine (DMC) to PTME has also has been studied and the value of energy transfer rate constant, k(ET), and critical transfer distance, R(0) indicate a Förster-type mechanism. The photodecomposition of PTME in chloromethane solvents has been also studied. We applied semiempirical MO calculations using (PM3 and ZINDO-CI) calculations to explain the geometric and electronic behaviors of the PTME molecule in both ground and excited states and make a correlation with the experimental observations.
authors.affiliation: Chemistry Department, Faculty of Science, Tanta University, Tanta, Egypt. samyeldaly@yahoo.com
authors.forename: Samy A
authors.initials: SA
authors.lastname: El-Daly
authors.forename: Mohamed K
authors.initials: MK
authors.lastname: Awad
authors.forename: Shakir T
authors.initials: ST
authors.lastname: Abdel-Halim
authors.forename: Dina A
authors.initials: DA
authors.lastname: Dowidar
mesh_terms: D003460:Crystallization; D004735:Energy Transfer; D005456:Fluorescent Dyes / Q000737:chemistry*; D007834:Lasers; D008737:Methyl Chloride; D015394:Molecular Structure; D010569:Perylene / Q000031:analogs & derivatives* / Q000737:chemistry; D055668:Photochemical Processes; D011789:Quantum Theory; D012996:Solutions; D012997:Solvents; D013050:Spectrometry, Fluorescence; D013053:Spectrophotometry
chemical_list: D005456:Fluorescent Dyes; D012996:Solutions; D012997:Solvents; D010569:Perylene; D008737:Methyl Chloride