Assignment of benzodiazepine UV absorption spectra by the use of photoelectron spectroscopy

Khvostenko, O. G.; Tzeplin, Evgeniy E.; Lomakin, G. S.

doi:10.1016/s0009-2614(02)00267-1

Cited by 16 publications

(12 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The corresponding ionization energies are assigned and correlated in Fig. 7 assignment [3] but in disagreement with the Khvostenko et al assignment [4] (Fig. 7).…”

Section: Compounds 3 (Medazepam) and 6 (Nordazepam)mentioning

confidence: 58%

“…The most remarkable discrepancy lies in the assignment of the structured band at 9.4-9.6 eV which we assign to the ionization from the  B (a 2 ) level at 9 eV, which on the basis of the correlation line in Fig. 2 should be found at the beginning of the broad band envelope centred at 13.32 eV in the photoelectron spectrum [4].…”

Section: Compounds 1 Andmentioning

confidence: 60%

“…The PE spectrum of medazepam was reported by Khvostenko et al [4] and by Andreocci et al the basis of the same previous area ratio approach. This is in agreement with the results of the deconvolution of the first two ionization bands in the PE spectrum of 3 ( Fig.…”

Section: Compounds 3 (Medazepam) and 6 (Nordazepam)mentioning

confidence: 71%

“…Dyson orbitals and energy levels of diazepine rings A and D are presented in Fig by Khvostenko et al [4]. The most remarkable discrepancy lies in the assignment of the structured band at 9.4-9.6 eV which we assign to the ionization from the  B (a 2 ) level at 9 eV, which on the basis of the correlation line in Fig.…”

Section: Compounds 1 Andmentioning

confidence: 75%

“…In this respect, ultraviolet photoelectron spectroscopy (UV-PES), supported by reliable theoretical calculations, may provide precious information on the outer valence molecular orbital shapes and energies [2]. In this report we are dealing with the electronic structure of 7-chloro-5-phenyl-1,3-dihydro-2H-1,4-benzodiazepin-2-one 6 (nordazepam) and molecular subunits 4 The experimental UV-PES of compounds 3, 5 and 6 have been reported [3,4]. The suggested assignments of the photoionization processes are, however, very different to each other.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Electronic properties of neuroleptics: ionization energies of benzodiazepines

Millefiori

Alparone

2010

J Mol Model

View full text Add to dashboard Cite

International audienceVertical ionization energies (VIEs) of medazepam, nordazepam and their molecular subunits have been calculated using the electron propagator method in the P3/CEP-31G* approximation. Vertical electron affinities (VEAs) have been obtained with a ∆SCF procedure at the DFT-B3LYP/6-31+G* level of theory. Excellent correlations have been achieved between IE and IE, allowing reliable assignment of the ionization processes. Our proposed assignment differs in many instances from that previously reported in the literature. The electronic structure of the frontier Dyson orbitals shows that the IE and EA values of the benzodiazepines can be modulated by substitution at the benzene rings. Hardness values, evaluated as (IE − EA)/2, follow the trend of the experimental singlet transition energies. Medazepam is a less hard (i.e., less stable) compound than nordazepam

show abstract

“…The corresponding ionization energies are assigned and correlated in Fig. 7 assignment [3] but in disagreement with the Khvostenko et al assignment [4] (Fig. 7).…”

Section: Compounds 3 (Medazepam) and 6 (Nordazepam)mentioning

confidence: 58%

Section: Compounds 1 Andmentioning

confidence: 60%

Section: Compounds 3 (Medazepam) and 6 (Nordazepam)mentioning

confidence: 71%

Section: Compounds 1 Andmentioning

confidence: 75%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Electronic properties of neuroleptics: ionization energies of benzodiazepines

Millefiori

Alparone

2010

J Mol Model

View full text Add to dashboard Cite

show abstract

Anomalously long‐lived molecular negative ions of duroquinone

Khvostenko

Lukin

Tseplin

2012

Rapid Comm Mass Spectrometry

View full text Add to dashboard Cite

The problem under investigation here is establishment of mechanisms of the resonant electron capture by molecules, using the example of duroquinone (2,3,5,6-tetramethyl-1,4-benzoquinone). A solution is important because it will provide new insights into the fundamental physical laws and widespread applications in various fields like molecular nanoelectronics, touched upon herein too. Resonant electron capture (REC) in duroquinone was studied with negative ion mass spectrometry of the REC as the main method, and UV absorption and the photoelectron spectroscopy as the auxiliary ones. The latter were used to study the electronic structures of the various neutral molecular states that are the parent ones for the negative molecular ions formed by electron attachment to the molecules. B3LYP/6-311 + G(d,p) calculations were widely used throughout the study. As a result, an intensive peak of the negative molecular ions with anomalously high lifetime (200 microseconds) was registered at the attached electron energy of 1.8 eV. The ions were determined to be quartets delaying the electron autodetachment because of spin prohibition and appearing via inter-system crossing from the negative molecular ion doublets produced in the core-excited Feshbach resonances. Finally, the pattern of the REC in duroquinone was obtained for the energy region of 1-4 eV which is presented by shape resonances, core-excited Feshbach resonances and by mechanisms little-known for molecules of inter-shell resonances and the formation of ion quartets. The latter were proposed to be related to the negative differential resistance in molecular nanoelectronics.

show abstract