1072 INDEX
Wave-function calculations
density functional theory (DFT) vs., 979–981 electronic structure calculations, 967, 968–977 electron correlation calculations, 973–977
configuration interaction (CI) calculations, 974–977
perturbation theory calculations, 974–975 Hartree-Fock theory, 969–970
linear combination of atomic orbitalsmolecular orbital (LCAO-MO) calculation, 970–973
Wave packet structures, femtosecond laser pulses coherence mechanism, 905–906
sodium iodide, 907
Wet chemistry, singlet-triplet separation, 171 Wittig rearrangement
carbanion intermediates, 105–106 1,2-phenyl migrations, 107
Wolff rearrangement, singlet-triplet equilibration, 307–308
Wurster’s blue ion, 209
(W,W)-carbenes, singlet vs. triplet ground state, 332
Xanthate esters, group transfer reactions, 156 Xanthylidene, singlet-triplet energy gap,
preequilibrium mechanism, 399–400 X-band ESR spectra, non-Kekule´ molecules, zero-
field splitting, 172–173
Xenon, imidogen, matrix isolation spectroscopy, 507
X-radiolysis, radical ions, matrix isolation, 821–823
X-ray crystallography carbocations, 13–15
N-Heterocyclic carbenes (NHC), 360–362 stable singlet carbenes
p-electron-donating heteroatom substituents (D-C-D), 340
single electronically active heteroatomic substituents, 346–347
Ylide formation
carbene synthesis, diazo compounds, 578 carbon atom reactivity, 487–488
metal carbene synthesis, 567
single bond silylene insertions, 670–671 singlet carbene-alkene addition, rate constants
and activation parameters, 287–289 singlet carbenes
carbene mimics, 308–314
reaction rate constants and activation parameters, 287–289
stable singlet carbenes
Lewis acids and bases, reactions, 354–358
singlet vs. triplet ground state, 332 transient dibromocarbene, 365–366 triplet carbenes
chemically induced dynamic nuclear polarization (CIDNP) effects, 408
time-resolved ultraviolet-vis (TRUV-Vis), 394
Ylidene, 782–784
Yukawa-Tsuno equation, carbocation reactivity, rate-equilibrium correlation, 23–25
Zeeman mixing, triplet carbenes, excited states, 437–439
Zeolites
carbocation reactivity mechanisms, 32–33 organic radical ions, n donors, 218 radical ion generation, 209–211
sulfur anions, 206–207 Zero-field splitting
electron spin resonance (ESR) immobilizing media, 172–173 trimethylene-methane (TMM),
174–175 triplet carbenes
electron paramagnetic resonance spectroscopy, 385–390 annealing-related geometrical changes,
390
carbenic substituents, 386 geometrical isomerism, 388–389 remote para substituents, 386–388
excited state geometry, 438–439 halogen-protected diphenylcarbenes,
446–447
persistent triplet carbenes, 443–444 Zero-point corrections, electronic structure
calculations, enthalpy predictions, 966
Zwitterions
intra-pair reactions, 243–246 overcrowded diarylsilenes, 689 single bond silylene insertions, 668
triplet carbenes, singlet-triplet energy gap, solvent effects, 401–402
