Filtern
Volltext vorhanden
- nein (129)
Erscheinungsjahr
Dokumenttyp
- Wissenschaftlicher Artikel (129) (entfernen)
Sprache
- Englisch (129) (entfernen)
Gehört zur Bibliographie
- ja (129)
Schlagworte
- NICS (8)
- Through-space NMR shieldings (TSNMRS) (8)
- NMR spectroscopy (7)
- Theoretical calculations (7)
- Anisotropy effect (6)
- Ring current effect (6)
- Aromaticity (5)
- DFT calculations (5)
- Conformational analysis (4)
- ICSS (4)
- NMR (4)
- TSNMRS (4)
- conformational analysis (4)
- GIAO (3)
- (Anti)aromaticity (2)
- Anisotropic effect (2)
- Cytotoxicity (2)
- Iso-chemical-shielding surfaces (ICSS) (2)
- Leguminosae (2)
- NBO analysis (2)
- NHCs (2)
- Plasmodium falciparum (2)
- Push-pull character (2)
- Steric effect (2)
- Taft equation (2)
- anisotropic effects (2)
- aromaticity (2)
- modified Mannich reaction (2)
- shieldings (TSNMRS) (2)
- (+)-Tephrodin (1)
- (1)H NMR (1)
- (13)C NMR (1)
- (TSNMRS) (1)
- 1 (1)
- 1,2,4-Dithiazole (1)
- 1,2-Dithiole (1)
- 1,2-diboretane-3-ylidene (1)
- 2'-bipyridine (1)
- 2,2-Disubstituted adamantane derivatives (1)
- 2-Dicyanoethene-1 (1)
- 2-Dithiooxalate (1)
- 2-Dithiosquarate (1)
- 2-Substituted adamantane derivatives (1)
- 2-dithiolate (1)
- 3,4-Dihydroisoquinoline (1)
- 3c,2e-bonding (1)
- 4 (1)
- 4'-Bis(tert-butyl)-2 (1)
- 4-Oxothiazolidine (1)
- 4-Substituted cyclohexanones (1)
- 4-methylene-cyclohexyl pivalate (1)
- 6 alpha-Hydroxy-alpha-toxicarol (1)
- 9-Arylfluorenes (1)
- ALTONA equation (1)
- Ab initio MO computations (1)
- Alkenyl cyclohexanone (1)
- Alkenyl cyclohexenone (1)
- Aminonaphthol (1)
- Aminonaphthols (1)
- Annelation effect (1)
- Anserine (1)
- Anti-aromaticity (1)
- Anti-inflammatory (1)
- Antimicrobial (1)
- B,N heterocycles (1)
- B3LYP/6-31+G(d,p) calculations (1)
- Benzazepine (1)
- Benzenoid structure (1)
- Benzenoid structures (1)
- Benzyne-allene or cumulene-like structure (1)
- Betaines (1)
- C-13 NMR (1)
- C-13 NMR spectroscopy (1)
- C-13 chemical shift (1)
- C-13 chemical shifts (1)
- CAACs (1)
- Carbene or zwitterions (1)
- Carbenes (1)
- Chelatoaromaticity (1)
- Conformation analysis (1)
- Conformational equilibria (1)
- Copper (1)
- Copper Metal Complexes (1)
- Coumaronochromone (1)
- Coumestan (1)
- Cyanine/merocyanine-like structures (1)
- Cyclazines (1)
- Cyclobutylcarbene (1)
- Cyclohexyl esters (1)
- Dative vs. coordinative NHC -> BR3 bond (1)
- Dehydro[n]annulenes (1)
- Dual Scale Factors (1)
- Dual scale factors (1)
- Dynamic NMR (1)
- Dynamic NMR spectroscopy (1)
- EPR (1)
- F-C coupling constants (1)
- GIAO calculations (1)
- Glycol podands (1)
- H-1 NMR (1)
- H-1 NMR spectroscopy (1)
- Hammett-Brown plots (1)
- Hemiporphyrazines (1)
- IR and Raman spectra (1)
- Iso-chemical shielding surfaces (ICSS) (1)
- Isoflavone (1)
- Lannea rivae (1)
- Lannea schweinfurthii (1)
- Matrix IR spectrum (1)
- Mesomeric equilibrium of carbene/zwitterion (1)
- Mesomerism (1)
- Millettia dura (1)
- Millettia lasiantha (1)
- Millettia micans (1)
- Modified Mannich reaction (1)
- Multiple NHC(CAAC)-Boron bonds (1)
- NBO and STERIC analyses (1)
- Naphthoxazinoquinazolines (1)
- Naphthoxazinoquinazolinones (1)
- Nickel (1)
- Peripheral ring current (1)
- Polar effect (1)
- Polar substituent constant (1)
- Porphyrins (1)
- Pterocarpan (1)
- Push-pull allenes (1)
- Quantum Chemical Calculations (1)
- Quantum chemical calculations (1)
- Quasi-aromaticity (1)
- Quinonoid structure (1)
- Quotient method (1)
- RA-intramolecular hydrogen bond (1)
- Rearrangement to trithiaazapentalene (1)
- SQM FF (1)
- SQM-FF (1)
- Salicylic acid (1)
- Simulation of H-1 NMR spectra (1)
- Spatial NICS (1)
- Stereochemistry (1)
- Steric substituent constant (1)
- Substituent chemical shifts (1)
- Substituent effects (1)
- Tautomerism (1)
- Tephrosia purpurea (1)
- Tephrosia subtriflora (1)
- Tephrosia villosa (1)
- Tetraoxo[8]circulenes (1)
- Thienopyridine (1)
- Through -space NMR (1)
- Through-space NMR (1)
- Trithiapentalene (1)
- Trough-space NMR shieldings (TSNMRS) (1)
- X-ray structure (1)
- Y-aromaticity (1)
- Ylide (1)
- Zinc (1)
- [4+2] cycloaddition (1)
- ab initio calculations (1)
- antiplasmodial (1)
- benzenoid structures (1)
- carbene electron deficiency (1)
- carbenes (1)
- ciprofloxacin (1)
- computational chemistry (1)
- cyclic imines (1)
- cycloaddition (1)
- cytotoxicity (1)
- density functional calculations (1)
- dynamic NMR spectroscopy (1)
- electrospray ionization mass spectrometry and modeling (1)
- exo-methylene conformational effect at cyclohexane (1)
- nucleus-independent chemical shift (1)
- nucleus-independent chemical shifts (NICS) (1)
- ortho-quinone methide (o-QMs) (1)
- para-Nitro-pyridine N-oxides (1)
- pi interactions (1)
- pi-Electron delocalization (1)
- prenylated flavanonol (1)
- quantum chemical calculations (1)
- quinoid structures (1)
- silver(1) complexes (1)
- spectroscopy (1)
- stability (1)
- subtriflavanonol (1)
- sulfur heterocycles (1)
- through space NMR shieldings (1)
- zwitterions (1)
Institut
- Institut für Chemie (129) (entfernen)
Ab-initio study and semiempirical calculations of keto-enol tautomerism of triazolopyrimidines
(1995)
1H, 13C, and 15N NMR study of the solution structure of metabridged bis(benzo-15-crown-5-ether)s
(1995)
Competitive resonance at the carbonyl group as visualized by the natural bond orbital analysis
(1997)
NMR spectroscopic and theoretical structural analysis of 5,5-disubstituted hydantoins in solution
(1997)
Study of the tautomerism by experimentally and theoretically estimated 13C and 15N chemical shifts
(1997)
NMR spectroscopic and theoretical structural analysis of 5,5-disubstituted hydantoins in solution
(1997)
Configuration and stereodynamics of exo/endoisomeric push-pull alkenes of pentadiene structure
(1998)
The influence of structure and lipophilicity of hydantoin derivatives on anticonvulsant activity
(1999)
NMR spectroscopic and ab-initio MO study of sterically hindered 2,3-disubstituted quinoxalines
(1999)
The (3)J(P,H) and (4)J(P,H) spin-spin coupling constants of a selected test set of organophosphorus compounds, calculated by density functional theory (DFT) methods, were found to correlate well with the experimentally measured coupling constants. The contribution of the spin-dipole (SD) term to the coupling constants was found to be negligible, and the diamagnetic and paramagnetic spin-orbit (DSO and PSO) terms cancelled each other, as in the case of J(H,H). Calculation solely of the Fermi contact (FC) term was found to be sufficient to provide good estimates of the coupling constants. In the second part of the work, the conformational equilibria and coupling constants in 2-bis(2- chloroethyl)amino-trans-octahydro-2H-1,3,2-benzoxazaphosphinine 2-oxide and its 3-methyl derivative were studied. DFT methods failed in predicting the relative stabilities of the conformations but yielded good geometries and coupling constants. Optimization of the conformations at the Moller-Plesset second-order perturbation theory (MP2) level resulted in energy differences compatible with previous experimental observations. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
(3)J(C,H) coupling constants via a sulfur atom in two series of compounds, both including a sulfide, a sulfoxide and a sulfone, were detected experimentally and calculated by quantum mechanical methods. In the first series (1-3) the coupling between a hydrogen, bonded to an Sp(3) carbon, and an Sp(2) carbon is treated; the second series (4- 6) deals with the coupling between a hydrogen, bonded to an Sp3 carbon, and an Sp3 carbon. Different pulse sequences (broadband HMBC, SelJres, 1D HSQMBC, J-HMBC-2, selective J-resolved long-range experiment and IMPEACH-MBC) proved to be useful in determining the long-range (3)J(C,H) coupling constants. However, the dynamic behaviour of two of the compounds (4 and 6) led to weighted averages of the two coupling constants expected (concerning equatorial and axial positions of the corresponding hydrogens). DFT calculations proved to be useful to calculate not only the (3)J(C,H) coupling constants but also the different contributions of FC, PSO, DSO and SD terms; the calculation of the Fermi contact term (FC) was found to be sufficient for the correct estimation of (3)J(C,H) coupling constants. Copyright (C) 2004 John Wiley Sons, Ltd