Properties of tetramethyleneethane (TME) as revealed by ion chemistry and ion photoelectron spectroscopy

被引:56
作者
Clifford, EP [1 ]
Wenthold, PG
Lineberger, WC
Ellison, GB
Wang, CX
Grabowski, JJ
Vila, F
Jordan, KD
机构
[1] Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA
[2] Natl Inst Stand & Technol, Boulder, CO 80309 USA
[3] Univ Colorado, JILA, Boulder, CO 80309 USA
[4] Univ Pittsburgh, Dept Chem, Pittsburgh, PA 15260 USA
来源
JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 2 | 1998年 / 05期
关键词
D O I
10.1039/a707322d
中图分类号
O62 [有机化学];
学科分类号
070303 ; 081704 ;
摘要
The negative ion chemistry and photoelectron spectra of [CH2=C(CH3)-C(CH2)(2)](-) and [(CH2)(2)C-C(CH2)(2)](-) have been studied. The negative ion photoelectron spectra reveal the tetramethyleneethane diradical, TME, to have two low-lying electronic states, (X) over tilde and (a) over tilde. The ground (X) over tilde state is assigned as [TME] (1)A and the excited (a) over tilde state as [TME] B-3(1). The energy separation between these states is about 2 kcal mol(-1); Delta E[(a) over tilde B-3(1) <-- (X) over tilde(1)A] congruent to 0.1 eV. The experimental electron affinities of the neutrals are: E-ea[CH2=C(CH3)-C(CH2)(2)] = 0.654 +/- 0.010 eV and E-ea[(CH2)(2)C-C(CH2)(2)] = 0.855 +/- 0.010 eV. The experimental gas phase acidities are: Delta(acid)H(298)[CH2=C(CH3)-C(CH2)CH2-H] = 388 +/- 3 kcal mol(-1) and Delta(f)H(298)[(CH2)(2)C-C(CH2)-CH2-H] = 388 +/- 4 kcal mol(-1). These findings can be used to establish the bond energies and heats of formation: DH298[CH2=C(CH3)-C(CH2)CH2-H] = 90 +/- 3 kcal mol(-1) and Delta(f)H(298)[(CH2)(2)C-C(CH2)=CH2] = 48 +/- 3 kcal mol(-1); DH298[(CH2)(2)C-C(CH2)CH2-H] = 94 +/- 4 kcal mol(-1) and Delta(f)H(298)[(CH2)(2)C-C(CH2)(2)] = 90 +/- 5 kcal mol(-1).
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页码:1015 / 1022
页数:8
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共 50 条
[41]   2,2-DIMETHYL-4,5-DIMETHYLENE-1,3-CYCLOPENTANEDIYL [J].
ROTH, WR ;
KOWALCZIK, U ;
MAIER, G ;
REISENAUER, HP ;
SUSTMANN, R ;
MULLER, W .
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION IN ENGLISH, 1987, 26 (12) :1285-1287
[42]   ISOLATION AND ENERGY WELL OF THE 2,3-DIMETHYLENE-1,4-CYCLOHEXADIYL DIRADICAL [J].
ROTH, WR ;
BIERMANN, M ;
ERKER, G ;
JELICH, K ;
GERHARTZ, W ;
GORNER, H .
CHEMISCHE BERICHTE-RECUEIL, 1980, 113 (02) :586-597
[43]   DIRADICALS AS INTERMEDIATES IN CHEMICAL REACTIONS - 2,3-DIMETHYLENE-1,4-CYCLOHEXADIYL [J].
ROTH, WR ;
ERKER, G .
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION IN ENGLISH, 1973, 12 (06) :503-504
[44]   MOLECULAR PHOTODETACHMENT SPECTROMETRY .1. ELECTRON AFFINITY OF NITRIC-OXIDE AND MOLECULAR CONSTANTS OF NO- [J].
SIEGEL, MW ;
BENNETT, RA ;
CELOTTA, RJ ;
HALL, JL ;
LEVINE, J .
PHYSICAL REVIEW A, 1972, 6 (02) :607-&
[45]   3,4-DIMETHYLENEFURAN AND 3,4-DIMETHYLENETHIOPHENE, HETEROCYCLIC-ANALOGS OF THE DISJOINT NON-KEKULE HYDROCARBON TETRAMETHYLENEETHANE [J].
STONE, KJ ;
GREENBERG, MM ;
GOODMAN, JL ;
PETERS, KS ;
BERSON, JA .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1986, 108 (25) :8088-8089
[46]  
Weltner W., 1983, MAGNETIC ATOMS MOL
[47]   REGIOSELECTIVE SYNTHESIS OF BIRADICAL NEGATIVE-IONS IN THE GAS-PHASE - GENERATION OF TRIMETHYLENEMETHANE, M-BENZYNE, AND P-BENZYNE ANIONS [J].
WENTHOLD, PG ;
HU, J ;
SQUIRES, RR .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1994, 116 (15) :6961-6962
[48]   Photoelectron spectroscopy of the allyl and 2-methylallyl anions [J].
Wenthold, PG ;
Polak, ML ;
Lineberger, WC .
JOURNAL OF PHYSICAL CHEMISTRY, 1996, 100 (17) :6920-6926
[49]   Photoelectron spectroscopy of the trimethylenemethane negative ion. The singlet-triplet splitting of trimethylenemethane [J].
Wenthold, PG ;
Hu, J ;
Squires, RR ;
Lineberger, WC .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1996, 118 (02) :475-476
[50]   BIRADICAL THERMOCHEMISTRY FROM COLLISION-INDUCED DISSOCIATION THRESHOLD ENERGY MEASUREMENTS - ABSOLUTE HEATS OF FORMATION OF ORTHO-BENZYNE, META-BENZYNE, AND PARA-BENZYNE [J].
WENTHOLD, PG ;
SQUIRES, RR .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1994, 116 (14) :6401-6412