Browsing Τμήμα Χημείας / Department of Chemistry by Author "Radom, L."
Now showing items 1-11 of 11
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Classical and nonclassical isomers of tropylium, silatropylium, and germatropylium cations. Descending the periodic table increases the preference for nonclassical structures
Nicolaïdes, Andrew N.; Radom, L. (1997)Ab initio calculations at the G2(MP2,SVP) level predict that there is a striking transition from a preference for classical isomers on the C7H7+ surface to a preference for nonclassical isomers on the C6H7Ge+ surface. The ...
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Determination of the chirality of enantiomeric [16O, 17O, 18O] sulfate esters by IR spectroscopy: An ab initio evaluation
Nicolaïdes, Andrew N.; Radom, L. (1995)The calculated shifts accompanying oxygen isotopic substitution in the symmetric and antisymmetric >SO2 stretching vibrational frequencies of 2,2-dioxo-1,3,2-dioxothianes confirm the experimental finding that these shifts ...
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An evaluation of the performance of G2, G2(MP2) and G2(MP2, SVP) theories for heats of formation and heats of reaction in the case of 'large' hydrocarbons
Nicolaïdes, Andrew N.; Radom, L. (1996)Heats of formation for benzene, cyclohexane and other selected hydrocarbons, along with the heats of several isodesmic and isogyric reactions involving these species, are reported at the G2, G2(MP2) and G2(MP2, SVP) levels ...
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Heats of formation from G2, G2(MP2), and G2(MP2,SVP) total energies
Nicolaïdes, Andrew N.; Rauk, A.; Glukhovtsev, M. N.; Radom, L. (1996)The translation of G2, G2(MP2), and G2(MP2,SVP) total energies to heats of formation via atomization and formation reaction procedures is evaluated. While both approaches give similar results, the former is shown to perform ...
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Is the most stable gas-phase isomer of the benzenium cation a face-protonated π-complex?
Glukhovtsev, M. N.; Pross, A.; Nicolaïdes, Andrew N.; Radom, L. (1995)The recent suggestion, based on gas-phase experimental data, that the most stable isomer of protonated benzene has a face-protonated π-complex structure is not supported by our detailed computations which indicate that the ...
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Phenyl radical, cation, and anion. The triplet-singlet gap and higher excited states of the phenyl cation
Nicolaïdes, Andrew N.; Smith, D. M.; Jensen, F.; Radom, L. (1997)High-level ab initio molecular orbital calculations have been carried out for the phenyl cation (1), the phenyl radical (2), and the phenyl anion (3). Our best estimate for the heat of formation (ΔH(f298)) of the phenyl ...
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Relative stabilities and hydride affinities of silatropylium and silabenzyl cations and their isomers. Comparison with the carbon analogues tropylium and benzyl cations
Nicolaïdes, Andrew N.; Radom, L. (1996)High-level ab initio calculations on silatropylium (1-Si) and silabenzyl (2-Si) cations and seven of their low-lying isomers (3-8), as well as on their carbon analogues, tropylium (1-C) and benzyl (2-C) cations, are reported. ...
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Ring opening of the cyclopropylcarbinyl radical and its N- and O- substituted analogues: A theoretical examination of very fast unimolecular reactions
Smith, D. M.; Nicolaïdes, Andrew N.; Golding, B. T.; Radom, L. (1998)High level ab initio molecular orbital calculations have been used to examine the ring opening of the cyclopropylcarbinyl radical and its heterosubstituted analogues. The applicability of various theoretical techniques to ...
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Seven-Membered Ring or Phenyl-Substituted Cation? Relative Stabilities of the Tropylium and Benzyl Cations and Their Silicon Analogs
Nicolaïdes, Andrew N.; Radom, L. (1994)
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A simple failing of G2 theory: Heats of combustion
Nicolaïdes, Andrew N.; Radom, L. (1994)G2 theory, which is normally very reliable for the prediction of reaction thermochemistry, is shown to be quite unsuitable for the prediction of heats of combustion. This arises because of significant errors in G2 energies ...
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A theoretical study of chlorine atom and methyl radical addition to nitrogen bases: Why do Cl atoms form two-center - Three electron bonds whereas CH3 radicals form two-center - Two-electron bonds?
McKee, M. L.; Nicolaïdes, Andrew N.; Radom, L. (1996)Ab initio molecular orbital calculations have been carried out on a series of adducts between chlorine atom and NH3, NMe3, NCl3, HN=CH2, and pyridine, and between methyl radical and HN=CH2 and pyridine. A two-center-three-electron ...