Conformational analysis of coordination compounds. VIII. 1H N.M.R. study of diamagnetic five-membered amino alcohol chelate rings

1978 ◽  
Vol 31 (8) ◽  
pp. 1689 ◽  
Author(s):  
CJ Hawkins ◽  
JA Palmer
Keyword(s):  
Magnetic Resonance ◽  
Conformational Analysis ◽  
Amino Alcohol ◽  
Coordination Compounds ◽  
Proton Magnetic Resonance ◽  
Amino Alcohols ◽  
Equatorial Orientation ◽  
Amine Group ◽  
Coupling Constant ◽  
Alcohol Group

The proton magnetic resonance spectra of tetraamminecobalt(III) complexes with a series of amino alcohols have been analysed and the coupling constant data utilized to calculate the conformational populations for the various complexes. When substitution occurred at the carbon adjacent to the amine group, the equatorial orientation of the substituent was not markedly preferred over the axial. However, when substitution occurred adjacent to the alcohol group, the substituent was found to be exclusively in the equatorial orientation.

Conformational analysis of coordination compounds. VI. P.M.R. study of diamagnetic five-membered diamine chelate rings

1976 ◽  
Vol 29 (1) ◽  
pp. 33 ◽  
Author(s):  
CJ Hawkins ◽  
RM Peachey
Keyword(s):  
Magnetic Resonance ◽  
Conformational Analysis ◽  
Coordination Compounds ◽  
Proton Magnetic Resonance ◽  
Equatorial Orientation ◽  
Coupling Constant ◽  
Butyl Group ◽  
Magnetic Resonance Spectra ◽  
Chelate Rings

The proton magnetic resonance spectra of a number of coba1t(111), molybdenum(0), chromium(0), platinum(11) and palladium(11) complexes of (R)-propane-1,2-diamine, (S)-3,3-dimethylbutane-1,2- diamine, (RS)-N,N,N',N?-tetramethylpropane-1,2-dime and ethane-1,2-diamine have been analysed and the coupling constant data utilized to calculate the conformational populations for the various complexes. Necessary parameters for the conformational analysis were obtained from a study of tetracyano{(S)-3,3-dimethylbutane-1,2-diamine)cobaltate(111),in which the t-butyl group was assumed to be exclusively in the equatorial orientation. The preparation and resolution of this t-butyl substituted ethane-1,2-diamine are described.

Nuclear magnetic resonance studies of the solution chemistry of metal complexes. XIV. The aqueous chemistry of trimethyllead(IV) and its carboxylic acid complexes

1977 ◽  
Vol 55 (18) ◽  
pp. 3255-3260 ◽  
Author(s):  
T. L. Sayer ◽  
S. Backs ◽  
C. A. Evans ◽  
E. K. Millar ◽  
D. L. Rabenstein
Keyword(s):  
Carboxylic Acid ◽  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Ph Dependence ◽  
Equilibrium Constants ◽  
Formation Constants ◽  
Solution Chemistry ◽  
Resonance Spectroscopy ◽  
Coupling Constant ◽  
Proton Coupling

The aqueous solution chemistry of the trimethyllead(IV) species and the trimethyllead(IV) complexes of six carboxylic acids of pKa values ranging from 2.75 to 4.95 has been investigated by proton magnetic resonance spectroscopy. Equilibrium constants for the reaction of (CH3)3Pb+ with hydroxide ion to form (CH3)3PbOH and ((CH3)3Pb)2OH+, and the formation constants of the carboxylic acid complexes were determined from the pH dependence of the chemical shift of the methyl protons of trimethyllead. The formation constants of the complexes increase as the pKa of the ligand increases. The lead-207-proton coupling constant was found to be insensitive to complexation.

Proton magnetic resonance spectrum of 2,6-dichlorobenzaldoxime. Signs and magnitudes of long-range spin–spin couplings. Degree of nonplanarity

1969 ◽  
Vol 47 (19) ◽  
pp. 3707-3709
Author(s):  
T. Schaefer ◽  
R. Wasylishen
Keyword(s):  
Magnetic Resonance ◽  
Long Range ◽  
Proton Magnetic Resonance ◽  
Resonance Spectrum ◽  
Proton Magnetic Resonance Spectrum ◽  
Coupling Constant ◽  
Hydroxyl Proton ◽  
Ring Proton ◽  
Proton Shift

From the sign and magnitude of the coupling constant between the C—H proton in the sidechain and the para ring proton in 2,6-dichlorobenzaldoxime it is estimated that the deviation from coplanarity of the sidechain is at least 40°. The hydroxyl proton shift in dimethylsulfoxide solution of −11.7 p.p.m., relative to internal tetramethylsilane, indicates a cis arrangement of the hydroxyl and aromatic groups.

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