A LINEAR RELATIONSHIP BETWEEN13CNMR CHEMICAL SHIFT OF VINYL CARBONS AND ELECTRONIC ABSORPTION WAVELENGTH IN POLYSILYLETHYLENES

1982 ◽  
Vol 11 (8) ◽  
pp. 1251-1254 ◽  
Author(s):  
Hideki Sakurai ◽  
Hiromi Tobita ◽  
Yasuhiro Nakadaira
Keyword(s):  
Chemical Shift ◽  
Linear Relationship ◽  
Electronic Absorption ◽  
Absorption Wavelength

Solvent Effect Correlations for Acetone: IR versus NMR Data for the Carbonyl Group

1989 ◽  
Vol 43 (6) ◽  
pp. 1049-1053 ◽  
Author(s):  
R. A. Nyquist ◽  
C. L. Putzig ◽  
D. L. Hasha
Keyword(s):  
Hydrogen Bonding ◽  
Chemical Shift ◽  
Solvent Effect ◽  
Linear Relationship ◽  
Carbonyl Group ◽  
Mixed Solvent ◽  
Nmr Data ◽  
Chemical Shift Data ◽  
The Relationship ◽  
Shift Data

A linear relationship is found to exist between the carbonyl stretching frequency ( vC=O) and the carbon-13 chemical shift data [δ(13C=O)] for the carbonyl group of 0.345 mole % acetone in a mixed solvent solution ranging from 1.5 to 70.8 mole % CHCl3/CCl4. The correlation shows that as vC=O decreases in frequency δ(13C=O) increases in frequency as the concentration of CHCl3 increases in the acetone/CHCl3/CCl4 solutions. However, the relationship between vC=O and the mole % CHCl3/CCl4 and between δ(13C=O) and the mole % CHCl3/CCl4 is not linear over the concentration range studied. Both hydrogen bonding and bulk dielectric effects most likely contribute to the change in both the IR and NMR data with change in the CHCl3/CCl4 ratio.

Tri(1-cyclohepta-2,4,6-trienyl)- phosphane, P(C7H7)3, as a Tripodal Tetradentate Ligand in Cationic, Five-coordinate Complexes of Platinum(II) and Palladium(II)

2002 ◽  
Vol 57 (2) ◽  
pp. 255-258 ◽  
Author(s):  
Max Herberhold ◽  
Thomas Schmalz ◽  
Bernd Wrackmeyer
Keyword(s):  
Chemical Shift ◽  
Linear Relationship ◽  
Phosphorus Atom ◽  
Rhodium Complexes ◽  
Central Metal ◽  
Tetradentate Ligand ◽  
Nmr Data

Chloride abstraction, using AgPF6, from tri(1- cyclohepta-2,4,6-trienyl)phosphane platinum and palladium dichloride, [P]MCl2 [M = Pt (1), Pd (2)], affords the complexes {[P]MCl}PF6 [M = Pt (3), Pd (4)] in good yields. The central metal is coordinated by the chloro ligand, the phosphorus atom and by three η2-C=C units, one of each C7H7 ring. This assignment of a highly symmetrical C3v structure is based on a consistent set of NMR data (1H, 13C, 31P, 195Pt NMR), in agreement with NMR data of the corresponding known neutral iridium and rhodium complexes [P]MCl [M = Ir (5), Rh (6)]. The chemical shift δ103Rh of 6 was determined, and a nearly linear relationship δ195Pt / δ103Rh was established.

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.

A Nuclear Magnetic Resonance Study of some 4-X-Substituted-2,6-Dinitroanisoles and Related Meisenheimer 1,3- and 1,1-Complexes

1972 ◽  
Vol 50 (21) ◽  
pp. 3558-3565 ◽  
Author(s):  
M. P. Simonnin ◽  
M. J. Lecourt ◽  
F. Terrier ◽  
C. A. Dearing
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Linear Relationship ◽  
Negative Charge ◽  
Inductive Effect ◽  
Chemical Shifts ◽  
Nuclear Magnetic Resonance Study ◽  
Magnetic Resonance Study ◽  
Methoxide Ion

The structures of transient 1,3-complexes 2 and stable 1,1-complexes 3 formed by the reaction of methoxide ion with various 4-X-2,6-dinitroanisoles in DMSO-d6 are confirmed by n.m.r. spectroscopy. 13C satellites in the proton spectra of anisoles and 1,1-complexes have been used to obtain [Formula: see text] as well as 4JH–H in these symmetrical compounds.The chemical shifts of the ring protons in 1,3- and 1,1-complexes give some information concerning the influence of the substituent X on the delocalization of the negative charge. In anisoles and 1,1-complexes, [Formula: see text] of the ring protons are mainly dependent on the inductive effect of X. Furthermore, a linear relationship is observed in anisoles between the chemical shift as well as [Formula: see text] of the methoxyl protons and the Hammett σP constant of X, thus suggesting an identical geometry of these molecules at C-2,-1, and -6.

Relationship between oxygen-17 nuclear magnetic resonance chemical shifts and Π-bonding to oxygen in the dichromate ion

1967 ◽  
Vol 45 (6) ◽  
pp. 605-608 ◽  
Author(s):  
R. G. Kidd
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Linear Relationship ◽  
Chemical Shifts ◽  
Chromium Vi ◽  
Nuclear Magnetic

A linear relationship between 17O chemical shift and degree of π-bonding from oxygen to chromium in a number of chromium(VI) compounds is reported. The basis for this relationship is presented in terms of chemical shift theory. The 17O chemical shift values for the two types of oxygen in the Cr2O72− ion are shown to be consistent with an angular rather than a linear Cr—O—Cr arrangement.

Synthesis and electronic properties of meso-tetra(3,4,5-trimethoxy)phenyl-porphyrin and -tetrabenzoporphyrin and their phosphorus complexes

2020 ◽  
Vol 24 (01n03) ◽  
pp. 105-111
Author(s):  
Taniyuki Furuyama ◽  
Yuichi Takahashi ◽  
Tomoteru Fukumura ◽  
Ana C. C. Bacilla ◽  
Nagao Kobayashi
Keyword(s):  
Chemical Shift ◽  
Molecular Orbital ◽  
Electronic Absorption ◽  
Current Density ◽  
Magnetic Circular Dichroism ◽  
Induced Current ◽  
Mo Calculations ◽  
Metal Free ◽  
Nucleus Independent Chemical Shift ◽  
Td Dft

meso-Tetra(3,4,5-trimethoxy)phenyl-porphyrin and -tetrabenzoporphyrin and their phosphorus complexes were synthesized and their electronic absorption and magnetic circular dichroism (MCD) spectra discussed based on TD-DFT molecular orbital (MO) calculations. Nucleus-independent chemical shift (NICS) and anisotropy of the induced current density (ACID) calculations were also carried out for metal-free (and phosphorus) tetrabenzoporphyrins in order to discuss the aromaticity and flow of electrons in the molecule.

Investigating the Interaction of Ninhydrin with Amino Acids and Polypeptide

2014 ◽  
Vol 955-959 ◽  
pp. 395-398
Author(s):  
Shu Yuan Hu ◽  
Hui Qing Li ◽  
Lian Wei Yu ◽  
Fu Li Tian
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Detection Limit ◽  
Linear Relationship ◽  
Maximum Absorption ◽  
Good Linear ◽  
Good Linear Relationship ◽  
Ninhydrin Reaction ◽  
Maximum Absorption Wavelength ◽  
Absorption Wavelength

Ninhydrin chromogenic reactions are widely used to analyze and characterize amino acids, peptides, and proteins. In this study, the spectroscopy behavior of ninhydrin reaction with mercapto amino acid and polypeptide has been investigated. The maximum absorption wavelength of glutathione reaction with ninhydrin was 568 nm; the maximum absorption wavelength of cysteine reaction with ninhydrin was 457 nm. Under the optimized wavelength condition, glutathione and cysteine in the certain concentration range exhibt good linear relationship and low detection limit.

31P-NMR-spektroskopische Untersuchungen an A4B3-Molekülen/ 31P NMR Spectroscopical Investigations of A4B3 Molecules

1984 ◽  
Vol 39 (8) ◽  
pp. 1135-1138 ◽  
Author(s):  
R. Blachnik ◽  
U . Wickelund ◽  
P. Schmitt
Keyword(s):  
Chemical Shift ◽  
Linear Relationship ◽  
31P Nmr ◽  
Bond Angle ◽  
Chalcogen Atom ◽  
Basal Ring ◽  
Bond Angles ◽  
Reference Molecule ◽  
Common Structure ◽  
Nmr Data

Abstract31P NMR data of sixteen molecules in the series P4SxSe3-x (x = 0 - 3), PyAs4-yS3, and PyAs4-ySe3 (y = 0 - 4), resp., are given. All molecules have a common structure, in which a basal ring of three V b-atom s is connected by three chalcogen atom bridges to an apical V b-atom . The dependence of the data on bond angles and electronegativities is discussed. A linear relationship was found betw een chemical shift and an angle increment I=11.3 (∢ endo - 60°) + 5.5 (∢ exo -103°), which describes the bond angle deviations from the reference molecule P4S3.

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