Stable carbocations. CLX. Relative order of charge delocalization by phenyl, cyclopropyl, and methyl groups in carbenium ions based on carbon-13 nuclear magnetic resonance studies

1973 ◽  
Vol 95 (22) ◽  
pp. 7530-7531 ◽  
Author(s):  
George A. Olah ◽  
Philip W. Westerman
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Methyl Groups ◽  
Relative Order ◽  
Carbenium Ions ◽  
Charge Delocalization ◽  
Magnetic Resonance Studies ◽  
Nuclear Magnetic

13C Nuclear Magnetic Resonance Studies of Organometallic Compounds. V. Di- and Trimethylplatinum(IV) Derivatives

1974 ◽  
Vol 52 (10) ◽  
pp. 1973-1982 ◽  
Author(s):  
Howard Charles Clark ◽  
Leo Ernest Manzer ◽  
John Edward Henry Ward
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Organometallic Compounds ◽  
Methyl Groups ◽  
Magnetic Resonance Studies ◽  
13C Nuclear Magnetic Resonance ◽  
Cis And Trans ◽  
Nuclear Magnetic

The 13C n.m.r. parameters for thirteen di- and trimethylplatinum(IV) derivatives have been obtained. It is shown that the 13C shieldings and 1JPtC and 2JPtCH values of methyl groups both cis and trans to varied ligands consistently follow trends similar to those found for related methylplatinum(II) derivatives.

13C Nuclear Magnetic Resonance Studies of Organometallic Compounds. IV. cis-Dimethylplatinum(II) Derivatives

1974 ◽  
Vol 52 (7) ◽  
pp. 1165-1170 ◽  
Author(s):  
Howard Charles Clark ◽  
Leo Ernest Manzer ◽  
John Edward Henry Ward
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Organometallic Compounds ◽  
Methyl Groups ◽  
Magnetic Resonance Studies ◽  
Trans Influence ◽  
13C Nuclear Magnetic Resonance ◽  
Cis And Trans ◽  
Derivatives Of ◽  
Nuclear Magnetic

Data derived from the 13C n.m.r. spectra of seven neutral cis-dimethylplatinum(II) derivatives of the type cis-(CH3)2PtL2 and cis-(CH3)2Pt(L—L) (where L and L—L are neutral donors) are discussed and compared with data derived from the 1H n.m.r. spectra of the complexes. Simultaneous variations in L or L—L reveal that the n.m.r. trans-influence rather than the n.m.r. cis-influence is dominant. The suggestion that the n.m.r. cis- and trans-influences may be additive is discussed. In contrast with data obtained by other workers, it is shown that the 1JCH values of the platinum methyl groups are essentially insensitive to variations in the remaining ligands.

13C Nuclear Magnetic Resonance Studies. 32. The 13C Spectra of Several Norbornyl Derivatives

1973 ◽  
Vol 51 (17) ◽  
pp. 2893-2901 ◽  
Author(s):  
J. B. Stothers ◽  
C. T. Tan ◽  
K. C. Teo
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Dihedral Angle ◽  
Molecular Geometry ◽  
Model Systems ◽  
Methyl Groups ◽  
Nonbonded Interactions ◽  
Magnetic Resonance Studies ◽  
13C Nuclear Magnetic Resonance ◽  
Nuclear Magnetic

The 13C n.m.r. spectra of several norbornyl derivatives have been recorded to examine the variation of 13C shieldings with molecular geometry. Since it is well established that nonbonded interactions between vicinal carbon nuclei lead to pronounced upfield shifts, the so-called γ effects, series of methyl-substituted norbornanes, norbornenes, norbornan-2-ones (norcamphors), and norborn-5-en-2-ones were prepared as model systems having a variety of γ interactions between vicinal methyl groups. The observed shifts of these methyl carbons are considered in terms of the dihedral angle relating the vicinal nuclei. The use of specific deuteration for unequivocal signal assignments of carbons geminal and vicinal to the site of deuteration is illustrated.

Sign in / Sign up

Export Citation Format

Share Document