Photoelectron spectroscopy of the CH3N− ion

Travers, Michael J.; Cowles, Daniel C.; Clifford, Eileen P.; Ellison, G. Barney; Engelking, P. C.

doi:10.1063/1.479795

Cited by 68 publications

(91 citation statements)

References 69 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, as discussed in Section 4.2.3, this principle explains (a) the much smaller value of E ST , both predicted 45,46,50 and measured in PhN, [47][48][49] compared to HN 36 and CH 3 N. 43 (b) the bond lengths that are calculated for the open-shell singlet state of PhN, 45,46,50 and (c) the large differences between the reactivities that are observed for the singlet states of PhN and PhCH. 51,52 The ability of the phenyl group to delocalize the nonbonding electron on nitrogen in the open-shell singlet state of PhN, thus confining this  electron to a region of space different from that occupied by the  electron of opposite spin, is responsible for all three of these calculated and observed properties of PhN.…”

Section: Discussionmentioning

confidence: 95%

The synergy between qualitative theory, quantitative calculations, and direct experiments in understanding, calculating, and measuring the energy differences between the lowest singlet and triplet states of organic diradicals

Lineberger

Borden

2011

Phys. Chem. Chem. Phys.

106

107

View full text Add to dashboard Cite

This Perspective describes research, carried out in the authors' labs over the past forty years, aimed at understanding, predicting, and measuring the singlet-triplet energy differences ( ST ) in diradicals. A theory for qualitatively predicting the ground states of diradicals and the use of Negative Ion Photoelectron Spectroscopy (NIPES) for measuring  ST are described. The application of this theory, ab initio calculations, and NIPES to the prediction and measurement of  ST in a wide variety of organic diradicals is detailed. Among the diradicals that are discussed in this Perspective are HN, CH 3 N, PhN, CH 2 , trimethylenemethane (TMM), oxyallyl (OXA), meta-benzoquinodimethane (MBQDM), meta-benzoquinone (MBQ), tetramethyleneethane (TME), 1,2,4,5-tetramethylenebenzene (TMB), and D 8h cyclooctateraene (COT). All of these diradicals have been studied in one and, in most cases, in both of the authors' laboratories. The studies of OXA and D 8h COT were, in fact, collaborations between the research groups of the authors. These two projects both took advantage of the ability of NIPES to provide information about transition states. Transition-state spectroscopy was used to measure the cabonyl stretching frequency in the singlet state of OXA and to establish that D 8h COT violates the strictest version of Hund's rule. However, in some cases, it is not qualitative theories but the results of high-level calculations that motivate experimentalists to test how quantitatively accurate the calculations are. In other cases calculations are performed to see how well they reproduce experimental results that have already been obtained. When the results of calculations and experiments are found to be at odds with each other, additional experiments and/or calculations almost inevitably follow.Investigations of the energy differences between the lowest singlet and triplet state (E ST ) of organic diradicals 1 have provided many illustrations of the above types of synergies. Qualitative theories have resulted in computational and/or experimental tests, and calculations and experiments have not only stimulated each other but, in some cases, also led to the development of qualitative theories.For example, in response to the results of experiments and calculations on cyclobutadiene and trimethylenemethane, one of the coauthors of this review (WTB) helped to develop a qualitative theory, which allows the qualitative prediction of the approximate size and sign of

show abstract

Section: Discussionmentioning

confidence: 95%

The synergy between qualitative theory, quantitative calculations, and direct experiments in understanding, calculating, and measuring the energy differences between the lowest singlet and triplet states of organic diradicals

Lineberger

Borden

2011

Phys. Chem. Chem. Phys.

106

107

View full text Add to dashboard Cite

show abstract

“…In the error analysis for each isomer, rotational contours were also considered. In every case, the analysis of Engelking was used 59 and in all cases the shift between peak centers of a particular transition and the true origin were estimated to be less than 0.1 meV. Thus this effect was accounted for in the uncertainty of the measurements contained in this work, but was determined to have a small impact on the reported error, even in the case of the EA measurements.…”

Section: Resultsmentioning

confidence: 99%

Anion photoelectron spectroscopy of deprotonated ortho-, meta-, and para-methylphenol

Nelson

Gichuhi

Miller

et al. 2017

The Journal of Chemical Physics

View full text Add to dashboard Cite

The anion photoelectron spectra of ortho-, meta-, and para-methylphenoxide, as well as methyl deprotonated meta-methylphenol, were measured. Using the Slow Electron Velocity Map Imaging (SEVI) technique, the Electron Affinities (EAs) of the o-, m-, and p-methylphenoxyl radicals were measured: 2.1991 ± 0.0014, 2.2177 ± 0.0014, and 2.1199 ± 0.0014 eV, respectively. The EA of mmethylenephenol was also obtained, 1.024 ± 0.008 eV. In all four cases, the dominant vibrational progressions observed are due to several ring distortion vibrational normal modes that were activated upon photodetachment, leading to vibrational progressions spaced by ~500 cm -1 . Using the

show abstract

“…Instead, they found signals of a mixture of alkylimines and different by-products such as HCN, NH 3 , CH 4 , H 2 , etc. From a careful analysis of Bock's experimental process, it is obvious that: the pyrolysis temperature ͑higher than 620 K͒ was much too high to record the PES signals of the short-lived and unstable transient species, such as nitrenes in their PES experiment the distance from the pyrolysis point to the photoionization point was too long ͑maybe more than half meter͒.…”

Section: Introductionmentioning

confidence: 99%

“…[1][2][3][4][5] The most thoroughly studied nitrenes are amidogen NH 6 and phenylnitrene C 6 H 5 N. 7 In contrast to aromatic nitrenes, much less is known about alkylnitrenes such as CH 3 -N, CH 3 CH 2 -N, ͑CH 3 ͒ 2 CH-N, and ͑CH 3 ͒ 3 C-N. Even basic physical and chemical data, such as ionization energies, are not available for nitrenes yet.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The diradical (CH3)2CHN and its isomeric molecule (CH3)2C=HN: Generation and characterization

Sun

Wang

Ding

et al. 2003

The Journal of Chemical Physics

View full text Add to dashboard Cite

A continuously flowing ͑CH 3 ͒ 2 CHN beam is generated by pyrolysis of ͑CH 3 ͒ 2 CHN 3 at 113͑Ϯ0.5͒°C using normal inlet system with an 8 mm bore of the exit of the quartz tube under the presence of molecular sieve ͑30 Å͒ and stabilizing NO gas, and its HeI photoelectron ͑PE͒ spectrum is also recorded in situ. A spectrum recorded further away from the pyrolysis catalyst or by using a 0.4 mm bore of the quartz tube is the PE spectrum of ͑CH 3 ͒ 2 CvNH, which comes from the isomerization of ͑CH 3 ͒ 2 CHN. The ionization energies of ͑CH 3 ͒ 2 CHN and ͑CH 3 ͒ 2 CvNH are determined for the first time by the photoelectron spectroscopy experiment, and Gaussian 2 and improved density functional theory calculations. Experimental and theoretical results agree reasonably well, and show that ͑CH 3 ͒ 2 CHN is a diradical with C s symmetry and has a 3 AЉ ground state, and ͑CH 3 ͒ 2 CvNH is a closed shell molecule with C s symmetry.

show abstract

Photoelectron spectroscopy of the CH3N− ion

Cited by 68 publications

References 69 publications

The synergy between qualitative theory, quantitative calculations, and direct experiments in understanding, calculating, and measuring the energy differences between the lowest singlet and triplet states of organic diradicals

The synergy between qualitative theory, quantitative calculations, and direct experiments in understanding, calculating, and measuring the energy differences between the lowest singlet and triplet states of organic diradicals

Anion photoelectron spectroscopy of deprotonated ortho-, meta-, and para-methylphenol

The diradical (CH3)2CHN and its isomeric molecule (CH3)2C=HN: Generation and characterization

Contact Info

Product

Resources

About