Semiempirische SCF-LCAO-MO-Rechnungen als Zuordnungshilfe für 13C-chemische Verschiebungen / Semiempirical SCF-LCAO-MO-calculations as an Aid for the 13C-shift Determination

1975 ◽  
Vol 30 (9) ◽  
pp. 1185-1187 ◽  
Author(s):  
H. Sterk ◽  
H. W. Schmidt
Keyword(s):  
Charge Density ◽  
Chemical Shifts ◽  
Mo Calculations ◽  
Linear Relationships ◽  
Lcao Mo

It has been shown that charge density- and bondorder values in different linear relationships can build up a basis for the calculation of 13C-chemical shifts. This could be an aid for the assignement of different 13C signals

Versuche zur Berechnung der 13C chemischen Verschiebung in mesoionischen Verbindungen / Attempts Concerning Calculations of 13C-chemical Shifts in Mesoionic Compounds

1976 ◽  
Vol 31 (7) ◽  
pp. 793-795
Author(s):  
H. Sterk ◽  
K. Thonhofer
Keyword(s):  
Chemical Shift ◽  
Charge Density ◽  
Linear Relationship ◽  
Chemical Shifts ◽  
13C Chemical Shifts ◽  
Influence Of Substituents ◽  
Lcao Mo

Abstract The existence of a linear relationship the form Y=a x1+b x2+c between the charge density - calculated by semiempirical SCF -LCAO -MO-methods - and the 13C -chemical shifts of mesoionic compounds has been shown. An influence of substituents in pyridinium betaines on the chemical shift is not observable.

LCAO-MO Calculations on Boron Compounds

1964 ◽  
pp. 251-258 ◽  
Author(s):  
ODILON CHALVET ◽  
RAYMOND DAUDEL ◽  
JOYCE J. KAUFMAN
Keyword(s):  
Mo Calculations ◽  
Boron Compounds ◽  
Lcao Mo

Nonempirical SCF-LCAO-MO calculations for (CH)+

1970 ◽  
Vol 17 (2) ◽  
pp. 158-161 ◽  
Author(s):  
N. C. Baird ◽  
D. Lemaire
Keyword(s):  
Mo Calculations ◽  
Lcao Mo

C-13 NMR chemical shifts and visible absorption spectra of unsymmetrical fluoran dye by MO calculations

2002 ◽  
Vol 602-603 ◽  
pp. 381-388 ◽  
Author(s):  
T Hoshiba ◽  
T Ida ◽  
M Mizuno ◽  
T Otsuka ◽  
K Takaoka ◽  
...  
Keyword(s):  
Absorption Spectra ◽  
Chemical Shifts ◽  
Mo Calculations ◽  
Visible Absorption ◽  
Nmr Chemical Shifts

THE NUCLEAR MAGNETIC RESONANCE SPECTRA OF PARA-SUBSTITUTED PHENOLS

1962 ◽  
Vol 40 (11) ◽  
pp. 2122-2125 ◽  
Author(s):  
W. G. Paterson ◽  
N. R. Tipman
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Carbon Tetrachloride ◽  
Magnetic Resonance ◽  
Infinite Dilution ◽  
Chemical Shifts ◽  
Substituted Phenols ◽  
Linear Relationships ◽  
Nuclear Magnetic Resonance Spectra ◽  
Magnetic Resonance Spectra ◽  
Nuclear Magnetic

The nuclear magnetic resonance spectra of a number of para-substituted phenols have been examined. The —OH chemical shifts, extrapolated to infinite dilution in benzene and in carbon tetrachloride, were found to be almost independent of the nature of the ring substituent. Approximately linear relationships were observed between the internal chemical shift of the ring protons and other physical properties.

scholarly journals Hybrid density functional theory investigation of a series of alloxan-based thiosemicarbazones and semicarbazones

2006 ◽  
Vol 4 (4) ◽  
Author(s):  
N. Nuwan De Silva ◽  
Edward Lisic ◽  
Titus Albu
Keyword(s):  
Density Functional ◽  
Chemical Shifts ◽  
Functional Theory ◽  
1H And 13C Nmr ◽  
Hydrogen Bond Interactions ◽  
Linear Relationships ◽  
Nmr Characterization ◽  
The Relationship ◽  
Hybrid Density Functional

AbstractRecently, the synthesis and the NMR characterization of a series of eight alloxan-based thiosemicarbazones and semicarbazones were reported. These compounds exhibit a strongly hydrogenbonded hydrazinic proton that is a part of a characteristic six-membered ring. This proton is highly deshielded and resonates far downfield in the proton NMR spectra. In this report, mPW1PW91/6-31+G(d,p) calculations have been used to investigate the structure and other molecular properties of this series of eight compounds. The relationship between the 1H and 13C NMR chemical shifts and various geometric parameters was investigated, and linear relationships for proton peaks that are involved in hydrogen-bond interactions were found.

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