19656-34-9Relevant academic research and scientific papers
Experimental evidence of the occurrence of intramolecular electron transfer in catalyzed 1,2-dioxetane decomposition
Ciscato, Luiz Francisco M. L.,Bartoloni, Fernando H.,Weiss, Dieter,Beckert, Rainer,Baader, Wilhelm J.
supporting information; experimental part, p. 6574 - 6580 (2010/11/17)
The activation parameters for the thermal decomposition of 13 acridinium-substituted 1,2-dioxetanes, bearing an aromatic moiety, were determined and their chemiluminescence emission quantum yields estimated, utilizing in situ photosensitized 1,2-dioxetane generation and observation of its thermal decomposition kinetics, without isolation of these highly unstable cyclic peroxides. Decomposition rate constants show linear free-energy correlation for electron-withdrawing substituents, with a Hammett reaction constant of Φ = 1.3 ± 0.1, indicating the occurrence of an intramolecular electron transfer from the acridinium moiety to the 1,2-dioxetane ring, as postulated by the intramolecular chemically initiated electron exchange luminescence (CIEEL) mechanism. Emission quantum yield behavior can also be rationalized on the basis of the intramolecular CIEEL mechanism, additionally evidencing its occurrence in this transformation. Both relations constitute the first experimental evidence for the occurrence of the postulated intramolecular electron transfer in the catalyzed and induced decomposition of properly substituted 1,2-dioxetanes.
Study on second harmonic generation of 9-benzylidene-substituted-10-methyl-9,10-dihydroacridines
Song,Jin,Zheng,Ying
, p. 2729 - 2736 (2007/10/03)
Eight 9-benzylidene-substituted-10-methyl-9,10-dihydroacridine derivatives were synthesized from acridine as starting material and were characterized by 1H-NMR, 13C-NMR, Ms and elemental analysis. The second harmonic generation (SHG) values of these compounds were determined in powder using Nd:YAG as a laser source, as compared with urea powder, and the values of second-order polarizabilities (βxxx), the values of the composite magnitude (βCTμg) of molecular hypersusceptibilities and their moment of these compounds were obtained by the solvatochromic method under ground state for everyone. The results showed that SHG value of 10 is higher than that of urea; the βCTμg of 5 (107.8 × 10-30 esu) is lower than that of 4-nitro-N,N-dimethylaniline (30 × 10-30 esu); the βCTμg of 7 (350.8 × 10-30 esu) and 10 (244.6 × 10-30 esu) are higher than that of 4-nitro-N,N-dimethylaniline; the βCTμg of 8 (3553 × 10-30 esu), 11 (1187 × 10-30 esu) and 12 (1163 × 10-30 esu) are much more higher than that of 4-nitro-N,N-dimethylaniline. The results demonstrated that this series of compounds possesses good second-order nonlinear optical (NLO) property. The regular relationship could not be obtained between electronegativity of substituents (R) attached to benzylidene ring and SHG values or βCTμg values although the Rs are different in electronegativity and should make an effect on the extent of intramolecular electron-transfer and would consequently influence SHG or βCTμg. The electron-withdrawing ability of R from benzylidene ring played an important role on λmax of these compounds.
Substituent Effect on the Chemiluminescence Quantum Efficiency of Some Acridan Derivatives
Perkizas, George,Nikokavouras, John
, p. 3 - 11 (2007/10/02)
Eight 9-benzylidene-N-methylacridan derivatives were synthesized and their chemiluminescence quantum yields on recation with NAOCl-H2O2 or O3 in N,N-dimethylformamide were plotted versus Hammett's "?" values.A good linear fit was obtained, the higher quantum yields being associated with negative "?" values.Two acridans did not fit in the plot and a novel treatment of chemiluminescence quenching is outlined to account for the discrepancy. - Keywords: Acridans; Chemiluminescence; Hammett; Quenching
