Electron affinities of naphthalene, anthracene and substituted naphthalenes and anthracenes

Abstract

The determination of electron transfer equilibria A-+ B = A + B-in the gas phase, with a pulsed-electron highpressure mass spectrometer, leads to AGIO, AH,', and ASlo values. These can be converted into the free energy, enthalpy and entropy changes, AGC(B), AH,O(B) and AS,O(B), for the reaction e + B = B-, since the correspond-ing values for the reference compounds A are known. Results were obtained for 18 substituted aaphthaleues, anthracene and substituted anthracenes. The results are compared with some theoretical predictioos and the come sponding reduction potentials in solution. Rate constants for 13 exoergic electron-transfer reactions were also measured. These were found to be close to the ADO collision rates.

The role of electronic properties to the mutagenic activity of 1,6- and 3,6-dinitrobenzo[a]pyrene isomers

“…Previous ε LUMO /mutagenic activity QSARs studies often employed ε LUMO values obtained at semiempirical levels [11,51,52], which for some cases gave inadequate EA estimations. In fact, for the prototypical nitronaphthalene (NN) isomers, AM1 ε LUMO values were calculated to be −1.266 and −1.415 eV for 1-NN and 2-NN isomers, respectively, [11], in disagreement with the observed EA values of 1.23 and 1.18 eV, respectively [53]. In addition, for the different mutagenic 3-NBaP and 6-NBaP isomers, AM1 predicts almost similar ε LUMO values of −1.766 and −1.767 eV, respectively [11], in disagreement with recent B3LYP/6-31+G* SCF computations which give EA values of 1.55 and 1.34 eV, respectively [54].…”

Prediction of mutagenic activity of nitronaphthalene isomers by infrared and Raman spectroscopy

“…These results were later confirmed by photoionization mass spectrometry experiments [15]. In addition, the experimental EA values of 1-NN and 2-NN obtained from temperature dependent equilibrium ion/molecule reaction method [16], are 1.23 and 1.18 eV, respectively. Differently to s NO 2 + C N mode, asymmetric stretches of N O bonds ( as NO 2 ) are strongly mixed with ring stretching ( ring ) and in-plane C H bending (␦CH) motions.…”

“…two [12] or four [13] times less mutagenic than 2-NN isomer. In addition, experimental values of both first ionization potential (IP) [14,15] and electron affinity (EA) [16] of both NN isomers are close to each other, indicating that oxidations and reductions are not crucial steps for the mutagenic properties of NNs. Alternatively, mutagenic pathways might be ruled by binding between NPAHs and the acitve site of enzymes [8].…”

Photochemical Reactions of Aminonaphthols Caused by Laser Desorption/Ionization

“…Although the electron a nity (EA) of naphthalene has negative value, the derivatizations of the naphthalene skeleton by polar or electron-withdrawing functional groups change from negative to positive values in EA. 31,32) In the case of 1,2-ANL, 2,1-ANL and 8,2-ANL, furthermore, a cooperative-e ect owing to the presence of relatively adjacent functional groups of -OH and -NH 3 having non-bonding electrons may increase in the electron a nity due to the electron-withdrawing effect.…”