Pl.RTICIPANTS

Agranat Israel, Department of Chemistry, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel

Arnold Donald D., Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4J3

Aurich Hans G., Fachbereich Chemie der Phi1ipps-universit.i;t, Hans­Meerwein Strasse, 0-3550 Marburg, Germany

Bachi Mario D., The Weizmann Institute of Science, Department of Organic Chemistry, 76100 Rehovot, Israel

Balaban A.T., Str.Poenaru Bordea 6, Apt13, R-70502 Bucharest Roumania.

Barton Sir Derek, Institut de Chimie des Substances Naturel1es, CNRS, F-91190 Gif-sur-Yvette, France

Beckhaus Hans-Dieter, Institut f\.i.r Organische Chemie und Biochemie, Universitat Freiburg, A1bertstrasse 21, 0-7800 Freiburg 1, Germany

Chanon Michel, Universite de Droit, d'Economie et des Sciences Natu­relIes d'Aix-Marsei11e, Laboratoire de Chimie Inorganique Molecu1aire, rue H. Poincare, F-13397 Marseille Cedex 13, France

Citterio Attilio, Politecnico di Milano, Istituto di Chimica Piazzo L. de Vinci 32 1-20133 Milano, Italy

Clark Timothy, Friedrich-Alexander Uni versi tat Erlangen-Nurnberg, Institut fur Organ. Chemie, Henkestrasse 42, 0-8520 Erlangen, Germany

Costantini M., Rhone-Poulenc Industries, Centre de Recherches de St. Fons, BP62, F-69190 Saint-Fons, France

Creary Xavier, Department of Chemistry, Uni versi ty of Notre Dame, Notre Dame IN 46556 U.S.A.

Crozet Michel P., Uni versi te de Droit, d' Economie et des Sciences Naturelles d'Aix-Marseille III. CNRS VA 109, Rue H. Poincare, F-13397 Marseille Cedex 13, France

Dale Johannes, Department of Chemistry, University of Oslo, P.O.Boks 1033, Blindern, Oslo 3, Norway

DOPP Dietrich, Universitat Duisburg, Fachgebiet Organische Chemie Postfach 101629, 0-4100 Duisburg 1, Germany

Fischer Hanns, Physikalisch-Chemisches Insti tut der Uni versi tat zUrich, Winterthurerstr.190, 8057 Zurich, Switzerland

467

468 PARTICIPANTS

Fossey Jacques, L.E.S.C.O.-C.N.R.S. 2 A 8, rue Henri Dunant, BP 28, F-94320 Thiais, France

Giese Bernd, Technische Hochschule Darmstadt, Insti tut fur Organische Chemie, Petersenstrasse 22, D-6100 Darmstadt, Germany

Griller David, National Research Council of Canada, Division of Che­mistry, Ottawa, Canada KIA OR9

Ingold Kei th U., National Research Council of Canada, Division of Chemistry, Ottawa, Canada KIA OR9

Jackson Richard A., School of Chemistry and Molecular Sciences, Uni­versity of Sussex, Brighton BNl 9QJ, Great Britain

Janousek Zdenek, Universite de Louvain, Laboratoire de Chimie Organi­que, Place Louis Pasteur, 1, B-1348 Louvain-la-Neuve, Belgium

Katritzky Alan R., University of Florida, Department of Chemistry, Gainesville, FL Florida 32611, U.S.A.

Koch Tad H., University of Colorado, Department of Chemistry and Biochemistry, Boulder Co 80309-0215, U.S.A.

Korth H.G., Institut f{lr Organische Chemie, Universitat Essen, GHS, D-4300 Essen 1, Germany

Kost Daniel, Ben Gurion University of the Negev, Department of Chemis­try, Beer-Sheva 84105, Israel

Leroy George, Universite de Louvain, Laboratoire de Chimie Quantique, Place Louis Pasteur, 1, B-1348 Louvain-la-Neuve, Belgium

Louw Robert, Center for Chemistry and the Environment Gorleaus Labs, The State University of Leiden, P.O. Box 9502, NL-2300 RA Leiden, The Netherlands

Lwowski Walter, New Mexico State University, Department of Chemistry, P.O.Box 3C Las Cruces, N.M. 88003 U.S.A.

Maillard Bernard, CNRS VA 35, Laboratoire Organometallique, Universite de Bordeaux 1, tion, F-33405 Talence-Cedex, France

de Chimie Organique et 351 Cours de la Libera-

Merenyi Robert, Universite de Louvain, Laboratoire de Chimie Organi­que, Place Louis Pasteur, 1, B-1348 Louvain-la-Neuve, Belgium

Minisci Francesco, Politechnico di Milano, Dipartimento di Chimica, Piazza L. da Vinci, 32, 1-20133 Milano, Italy

PARTICIPANTS

Neumann Wilhelm P., Universitat Dortmund, Otto-Hahn-Strasse, Postfach 50 05 00, D-4600 Dortmund 50, Germany

Rassat A., Universite Scientifique et Medicale de Grenoble, ~timent 52, Chimie-Recherche, BP 68, F-38402 Saint-Martin-d'Heres Cedex, France

Roth W., Lehrstuhl fur Organische Chemie I, Ruhr-Universitat Bochum, Postfach 10 21 48, Universitatsstrasse 150, D-4630 Bochum 1, Germany

Ruchardt Christoph, Institut fur Organische Chemie und Biochemie, Albertstrasse, 21, D-7800 Freibl,rg 1 , Germany

Stella Lucien, Universite de Droit, d'Economie et des Sciences Natu­relles d' Aix-Marseille III, Laboratoire de Chimie Organique B, Rue Henri Poincare, F-13397 Marseille Cedex 13, France

Surzur Jean-Marie, Universite de Droit, d'Economie et des d'Aix-Marseille III, Laboratoire de Chimie Organique B, Poincare, F-13397 Marseille Cedex 13, France

Sciences Rue Henri

Sustmann Reiner, Institut fur Organische Chemie, Universitat-GHS Essen Universitatsstrasse 5, D-4300 Essen 1, Germany

Tedder Lord John M., Department of Chemistry, University of St. Andrews, St. Andrews Fife, KY16 9ST, United Kingdom

Tiecco Marcello, Isti tuto di Chimica Organica, Facol ta di Farmacia, Universita di Perugia , 1-06100 Perugia, Italy

Timberlake Jack W., University of New Orleans, Department of Chemis­try, Lakefront, New Orleans, LA 70122, U.S.A.

Tordo Paul, Universite Especes Paramagnetiques, Marseille Cedex 4, France

de Provence Structure C.N.R.S. UA 126, Rue H.

et Reactivite des Poincare, F-13397

Vertommen Luc, AKZO, Research Laboratories, Velperweg, 76, NL-6824 BM Arnhem, The Netherlands

Viehe Heinz Gunter, Laboratoire de Chimie Organique, Uni versi te de Louvain, Place Louis Pasteur, 1, B-1348 Louvain-la-Neuve, Belgium

von Rague Schleyer Nurnberg, Institut Erlangen, Germany

Paul, Friedrich-Alexander-Universitat fur Organische Chemie, Henkestrasse

Erlangen-42, 8520

Walton John C., Department of Chemistry, University of St. Andrews, St. Andrews Fife, KY16 9ST, United Kingdom

469

INDEX

Acetonaphtone, 383 Acetylpyridine, 439 Acrylic ester, tert-butyl addition, 135 Acrylonitrile, 42,384 addition of radicals, 126,128,283

Activation barrier, 29,30 energy, 31, 36

Acyloxy rearrangement, 291 Acyl radicals, 414 Adamantoic acid, 458 Adamantyl radicals, 436,459 Additivity of substituent effects, 18,67,92,153,158,211,215,319 Adduct-dimers, 361 Adriamycin, 268,269 Aglycone deoxy, 268 Alanyl radicals, 263 Alcohols, deoxygenation, 387

homopropargylic, 387 Alcoxymethyl radicals, 293,299 Alder rule, 367 Aldonitrones, 362,379 Alkane halogenation by haloamines, 396 Alkane radical cations, 223-244 Alkene radical cations, 223-244 Alkoxyphenols as antioxidants, 107-122 Alkylidenelactones, 387 Alkyl cations, H-abstraction, 223-244 Alkyl radicals, addition to diazonium salts, 394

addition rates, 392 ionisation energies, 98 substituted, 5,62,93

Allene cycloadditions, 371-374 Allinger force field, 71 Allyl tert-butylperoxide, 343 Allylic delocalisation energy (ADE), 147 Allylic resonance energy (ARE), 148 Allylic radicals, 24,128 anisotropic ESR parameters, 145 antagonistic effect in, 168 c-c bond lengths, 10 tert-butyl substituted, 156 conformations, 154 deuterated, 144,149 dimerisation rates, 162 from dimers, 305,309 l,l-disubstituted, 151 monosubstituted, 150

471

472

structure of, 144 ESR study, 143-166 synergistic effect, 159

Allyltin compounds, 291 Amination homolytic, 406 Aminoalkyl radicals ESR, 189-190 heats of formation, 97 ionisation energies, 97,416 oxidation potentials, 100 as reducing agents, 98 umpolung, 312

Aminocyanoethylene, 42 Aminocyanomethyl radical, 3,5,66 Aminodicyanomethyl radicals, 35,39 Aminoethynyl radicals, 5 Aminomethyl radical, 14,24,57,58,96 Aminyl radicals, 83

in benzylic halogenation, 410 protonated, 391-394 reaction with alkanes, 396 reaction with aromatics, 393,404,407

Ammonia, inversion rate, 116 Angle strain, in small rings, 69-82 Anomeric effect, 67 Antagonistic substituent effect, 168 Anthracycline antitumor drugs, 263-270 extravasation necroses, 269

Antimony reagents, 457 Antioxidants, 107-113 Appearance energy method, 94 Aromatic radical cations, 223-244 Aromatic substitution homolytic, 391-434,435-442 Arrhenius plot, 32,44

parameters for radical additions, 395 Aryldiazomethanes, 246 Atom transfer reactions, 2 Autooxidation, 107,204 Azo compounds, 22,271-282 solvent effects in decomposition, 312 thermolysis of, 23,271-282

Benzaldehydes by oxidation of toluenes, 339 Benzene radical ions, 238-244 Benzhydryl radicals, 211,219-222 Benzil, reduction of, 216 Benzofurans dihydrotetramethyl, 108 Benzonitrile oxide, 375 Benzylic radicals, captodative ESR, 167-170 delocalisation in, 321 from dimers, 304 hfc constants, 152,171-178

INDEX

INDEX

resonance stabilisation energy, 171,176,326 spin delocalisation, 171-188

Benzylidenemethylamine N-oxide, 377 Biradical oligomers, 268 tetramethylenes, 308 transition states, 181,362,375,379,385 trimethylene methane, 245-262

Bond dissociation energy, BOE, 21,51,72,74,93 of C-C bonds, 34 of radical ions, 101

Bond homolysis, 199-218,219-222,263-270 effect of Mg salts, 267

Bond lengths, 51 Bond strengths, 61,91 of allylic dimers, 305 of C-C bonds, 199-218 of di-and tetrasulfides, 93

Boranylhydrazyl radicals, 84 Boranylmethyl radicals, 60 Bridged radicals, 63 dehydrodimerisation, 301

Bromotrichloromethane, 202,451 Butadiene, addition of tert+butyl, 135 Butanes, reaction with CH4" , 224 Butenyl radical cations, 231 tert-Butoxy radicals, 126,168,191 di-tert-Butyl ketone photolysis, 125 tert-Butyl radicals, addition rates, 123-142 generation, 125 ionisation potential, 124 muonated, 126 SOMO-LUMO energy gap, 135

Camphorsulfonic acid, 457 Captodative effect 5,19,301

in aminoalkyl radicals, 189,190 in benzylic radicals, 167-70 in cycloadditions, 361-70 in cyclopropane isomerisations, 257 in methylenecyclopropane rearrangement, 256 in phosphonohydrazyls, 192 in tetraphenylethylene isomerisation, 257

Captodative kinetic effect, in cycloadditions, 361 in hydrogen abstraction, 304,329 in radical addition, 304 in S reactions, 424-426,442

capto~ative olefins, in cycloadditions, 361-370,371-74 as dienophiles, 361-370 as dipolarophiles, 363,375,379 in photo Oiels-Alder, 383 as radicophiles, 361

473

474 INDEX

Captodative radical, 3,18,38,44,66,205,213,214,215,216,301-324 Captodative allenic radicals, 83 Captodative allylic radical, 83,164 Captodative stabilisation, 1-48,256-9,263 Carbenes, 102 Carbene E values, 103 Carbohydrate radicals, 283-296 Carbon tetrachloride, 202 Chalcogenation reductive, 451 Chloroacrylonitrile, 286 Chlorobenzene hydroxylation, 331 Chloromethyl cation, 239 Chloropropene, addition of tert-butyl, 128-130 Chromans, 108 Collision induced decomposition, 226 Competition constants, 376 Conformational preferences, 87,118 Coronands, 268 Cumyl radicals, 178 Cyanoacetylene, 366 Cyanomethyl rad:i cals, 66,312 Cyanopyridine, S , 393 Cyclic alkanes, ~23 Cyclic voltametry, 359 Cyclobutane nonbonded interactions, 70 strain, 70

Cyclohexyl radicals, 137,140 Cyclohexylmethyl radicals, 118 Cyclopentylmethyl radicals, 201 Cyclopropane, angle strain, 69

Z,E isomerisation, 303,307 radical cation, 65 torsional strain, 69

Cyclopropyl radicals, 74,114-117 deuterium labelled, 116 inversion barrier, 114 ESR spectrum, 114 trapping with CC1 3Br, 116

Daunomycin, 268 Deamination, radical, 444 Decarboxylation, radical, 446 Dehydrodimerisation, 301 Delocalisation energy of allylic radicals, 146 parameters, definition of, 153,167 of allylic radicals, 154 of benzylic- rad:i cals, 176

Deoxygenation of alcohols, 387,444 Deoxysugars, 294 Diazonium salts as radical trap, 426 Dibenzylmercury compounds, 175,185,245

INDEX

Dichloromethane, radical addition, 343 Dichloropropene, 130 Dicyanomethyl radical, 137,140,212 Diels-Alder reactivity of olefins, 361-370 Diffusion control, 384 Dimerisation of allylic radicals, 162 of C-radicals, 163 of vinylnitroxides 195,198

Dimer-radical equilibrium, 263 Dimesityl carbenes, 103 Dimethylallene, reaction with carbenes, 246 Dioxanyl radicals, 436 Diphenyl carbene spin states, 102 Diphenylmethyl radicals, 211,219-222 Diphenylpicrylhydrazyl, 266 Diphosphine radical cation, 57,58 Disciplinary group concept, 443 Disilane, 77 Disproportionation, 164 Dissociation of vinylnitroxide dimers, 197 of allylic dimers, 301

Disulphides, BDE, 95 heats of formation, 95

Double adducts, 361 Doublet spin states, 4

Electrochemistry of radicals, 98 Electron affinities of allenes, 136,137 Electron beam energy resolved, 94 Electron energy loss spectroscopy, 126 Electron transfer sUbstituton reactions, 335 Epoxypropanation, 343 Equilibration meso d,l, 264,301-324 Endo-exo ratios, 367 Energy gap in carbenes, 103 in diarymethyl radicals, 221 exchange broadening technique, 189 in phosphinylhydrazyls, 191 in vinylnitroxides, 195-198

Entropy of activation, solvent effects, 309 Entropy controlled recombination, 267 Entropy enthalpy compensation, 301 ESR spectroscopy of allylic radicals, 143-166 aminoallyl radicals, 189-190 aryloxyls, 110 captodative benzylic radicals, 167-170 diarylmethyl radicals, 219-222 line shape analysis, 149,158 modulation, 126 oxomorpholinyl radicals, 263-270 oxopiperazinyl radicals, 265

475

476 INDEX

steady-state, 124 sugar radicals, 284-296, 297-300 time-resolved, 124

Ethenyl cations, 232 radical cations, 228-238

Ethylenediamines, fragmentation, 97 Ethylene radical addition, 135 Ethyl radicals substituted, 5,62,87 Evans-Polanyi relation, 22,30,41 Excited triplet states, 384 Extended Hammett treatment, 175,180,182 Extrastabilisation, 67,83

Fisher relation, 319 Fluoromethyl cation, 239 Formylhydrazyl radicals, 84 Frontier Molecular Orbital (FMO) theory, 135,203 control in cycloaddition, 379,380

Fumararate, phenylthio, 379 Fumarodinitrile, radical addition, 285,287 Furan, 238,240

Galactosyl radicals, 300 Gaussian programs, 41,50 Gaussian type orbitals, 4 Geometry optimisation, 3,13 Germyl radicals, 114 Glucosyl chloride, 290 Glucosyl rad:icals, conformations, 287 Glutamic acid, 455 Gradient techniques, 13 Ground state effects, 144,272

Haloamines, 396 Hammett equation, 277,325 Hammond postulate, 275 Hartree-Fock, 49 Heat of atomisation, 9,12 Heat of formation, 13,14 Heptane, reaction with CH '+, 227 Hexadiene 1,5, dissociati~n, 310 Hexenyl radicals, 201 Hexopyranosyl radicals, 284 Homoconjugation, 87 Hunsdiecker reaction, 451 Hydrazine radical cation, 57,59 Hydrazyl radicals, 3,83-86 Hydrogen atom addition, 40 abstraction, 201,245 shift, 64 transfer, 27,30

INDEX

Hydrogenolysis, 331 Hydrogen peroxide, 266 Hydroperoxide, O-H bond strengths, 204 Hydroxychromane antioxidants, III Hydroxycyanomethyl radicals, 5,18 Hydroxydechlorination, 332 Hydroxylation aromatic, 331 Hydroxyl radicals, 331 Hydroxymethylation of heteroaromatics, 417 Hyperconjugation, 87,248,274 model, 5

Hyperfine splitting constants, 4,5,6,7,25,247 in allylic radicals, 160 in aryloxyls, 108 in benzylic radicals, 171-188 in cumyl radicals, 178 in isopropyl radicals, 277 in oxomorpholinyl radicals, 265 in phenethyl radicals, 178 in sugar radicals, 297-300

3H-Indole oxide, 379 Iodoacetate, iodine abstraction, 412 Ionisation potentials, 51 of benzaldehydes, 341 of naphtalenes, 341 of toluenes, 341

Intrinsic stability, 8 Inversion barriers, 74 Inversion rates, 113 Isaton, 266 Isocyanate group, 276 Isocyanides in deamination, 446 Isodesmic reaction, 13,14,20 Isoequilibrium relationship, 305 Isokinetic temperature, 202,306 Isomerisation E,Z in cyclopropanes, 303 meso-d,l in benzylic dimers, 304

Isoselenocyanates, 446 Isothiocyanates, 446 Isoxazolidines, 362,377

Laser flash photolysis, 103 kinetic studies, 114

Lepidine, homolytic substitution, 419 Leukemia L-1210, 269 Linear free energy, 271 Linnett structures, 2, 272 Lipid peroxidation, 108 Lysoxyl radicals, 300

477

478

Mannosyl chloride, 290 Mannosyl radical, 289 Mc Connell equation, 4,5,172,277 Mercurials, dibenzyl, 325 Mercury carbon bond, 247 Merostabilised radicals, 263 Methacrylonitrile, radical addition, 135 Methane radical cation, 223 Methoxyphenols, 113 Methoxy radicals, 201 Methylenecyclobutane, isornerisation, 308,374 synthesis 371-4

Methylenecyclopropanes, 175,181,245-262 Methyl radical, IP,137

as H-abstracting agent, 201 Metronidazole, 335 Morse functions, 29 Morpholinoacrylonitrile, 362,376,383 Muon spin rotation, 126

Naphtalenes 1,4-ethano, 383 Newrnans rule of six, ~74

Nitrogen centered radicals, 36,84 Nitroirnidazole, 335 Nitronate anions, arnbident nucleophiles, 348 heterocyclic, 336

Nitroxyde di-tert-butyl, 264,266 radicals, 3,195-198

No-bond resonance, 61 Non-bonded interactions, 70 Nor-alcohols, 457

Odd-electron bond strength, 57 One-electron bonds, 50,56 d-Orbital effects, 87,276,283 d-Orbital interactions, 88 Oxornorpholinyl radical, 38,263-270

Paraquat, 266 Penicillin dearnination, 446+ Pentane, reaction with CH . , 226

d . . 4 Penta lenyl radlcal, 161 Pentanolidation, 343 Pentopyranosyl radicals, 295 Peroxyacetate, 344 Peroxyl radical s, 107 trapping, 108

Pers istency, 35 Perthiyl radical, 94 Pertubational MO theory (PMO), 49,87,185,251 Phenethyl radical, 178

INDEX

INDEX 479

Phenoxyl rad:ical, 108 Phenyl radical, 413,422,436 Phenylselenocarbonate, 387 Phosphinylhydrazyl, 191-194 Phosphonate group, 249 Phosphonium salts, 453 Phosphorus d-orbitals, 251 Picrylhydrazyl, 83 pi-type overlap, 50 Pivaloyl radical decarbonylation, 125 Peptides, 455 Polar effects, 39,175 in azocompound decomposition, 271 in dibenzylmercury rearrangement, 185 in methylenecyclopropane rearrangement, 183 in radical additions, 135,137,391,436 of substituents, 172,301

Propene radical cation, 59,230-238 Propenyl cation, 232 Proradical properties, 361 Protonated radicals, 63 Push-pull radicals, 84,263 pyranosyl radical, 289,300 Pyrazoline decomposition, 274,275 Pyridine, homolytic alkylation, 390,435,440 protonated, 240,440

pyridinium salts, reaction with nitronates, 350 pyridinyl radicals, 416 pyrilium salts, homolytic alkylation, 428 pyrrole, 238 Pyruvate heterocyclisation, 263-270

Quadrupole mass spectrometer, 94 Quinolinium salts, 353

Radical buffer, 92 electrochemistry, 91-105 generation by photolysis, 99 nucleophilic, SH' 411

Radical scales correlations, 328 RRS, 313 0a ' 171-178,313,326 O· , 325

a C ' 326 Radicaloid mechanism in SNl, 347,357 Radical stabilisation, energy, 171,209,211

by 6-C-O bonds, 297 Radical umpolung, 311 Radicophilicity, 457 Radicophilic properties, 361

480

olefins, 302 Reactivity selectivity relationship, 202,413 Recombination of allylic radicals, 162 of diphenylmethyl radicals, 219-222 processes, 34,36

Redox potentials of radicals, 100 Reductive thermolysis, 331 Relative radical stabilisation scale, 301 Resonance energy, 19,175,143 Rotational barrier, 23,27,57,87 in allylic radicals, 143-166 in aminoalkyl radicals, 189, 190 in benzylic radicals, 176 effect of substituents 158 in phenethyl radicals, 177

Second-row effect, 87 Selectivity of radical attack, 285 Selenocarbonates homopropargylic, 389 Semi-empirical method, 2,13,28 Sigma aromaticity, 71 type overlap, 50

Silacyclopropane, 75 Silicon rings, 69-89 Silyl radicals, 78,114 Solvent effect in radical reactions, 131,301,420 Spin components, 88 contamination, 278

Spin density, 4-6, 319 of allylic radicals, 143-166 of benzylic radicals, 167-188 maps, 3 polarisation, 5, 180

SRNI in nitroheterocyclic series, 338 Stabilisation, kinetic, 8,9,35,199

thermodynamic, 8,9,35,199 energy of cd-radicals, 18

Standard bond energy, 2,9,10 free enthalpy change, 8 increments, 11

Stannyl radicals, 287,297,444 Stereoelectronic effect, 283-296 Stereoselectivity, 283-296 Steric factors, 12,35,87,172 Stilbene isomerisation, 184 Strain enthalpy, 207 Substituent effects, additivity of, 18,67,92,153,158,211,301 SUbstituent constants, 325 Substituent parameter definition, 153 Succinic acids, tetraaryl, 220 Succinodinitrile, tetramethyl, 219

INDEX

INDEX

Sugar radicals, 283-296,446 Sulfinyl groups, 252 Sulfones, 453 Sulfonyl groups, 252 Sulfur d-orbitals, 253,259 Synergistic effect, 84 in allylic radicals, 159 in benzylic radicals, 168

Tandem mass spectrometer, 227 Tellurides, 451 Tetracyanoethylene, 266 Tetrahydrofuranyl radical, 422 Tetrasilabicyclobutane, 76 Tetrasilacyclobutane, 69 Tetrasilatetrahedrane, 76 Tetrasulfides, BDE, 95 Tetroxides, 204 Thermolysis of alkanes, 207 of dinitriles, 210

Thiohydroxamic acids, 448 Thiophosphonate group, 249 Thiopyridone N-hydroxy, 448 Thionoesters, 445 Thiophenes, 238,241, 437 Three electron bond, 50,53,57,97,191 Tin hydrides, 445 Toluene oxidation, 339 Topomerisation, 84 Total energy, 17 Transient radical, 8 Triarylmethyl radicals, 205 Triazacyclopropane, 71 Trichloroethylene, 138 Tricyanomethyl rad.lcal, 35,38 Triethylmethylradical, 207 Trifluorochloroethylene, 302 Trifluoromethyl group, 248 Trigonal bipyramidal structure, 54 Triple quadrupole mass spectrometer, 223,227 Trisilacyclopropane, 69 Trivinylmethyl radical, 161 Tropylium cation, 239 Tunelling correction, 27 effect, 30 in cyclopropyl radicals, 117

Vinyl chloride, 138,331 Vinylglycine, 455 Vinylidene chloride, 138 Vinyl nitroxides, 195-198

481

482

bicyclic dimers, 195 tricyclic dimers, 195

Vinyltriethoxysilane, 128 Vitamin D3 metabolites, 453 Voltametry cyclic, 359

zero-field splitting parameter, 175 Z-values, 265

INDEX