With the increasing power and sophistication of experimental and theoretical methods for assigning chemical structures, it seems almost incredible that the structure of any reasonably stable organic entity with a small number of carbons could remain enigmatic for very long. Nonetheless, this is true of...
The effects of solvent and anion (X) changes on the NMR parameters are generally minor. The major factor influencing J(Tl-C) and J(Tl-H) is the number of R groups attached to thallium and the ratios of analogous couplings in TlR 2X and TlRX 2 are generally close to the value of 1...
the tautomeric equilibria of some β-ketobutanamides in solution were investigated by proton and carbon-13 Nuclear Magnetic Resonance (NMR) Spectroscopy. Their chemical shifts were compared with those of related β-hydroxybutanamides. Equilibrium populations of the keto and enol forms were measured. ...
10). The study found that the reaction is remarkably sensitive to the pattern of substitution on the carbon-carbon double bond. In addition, it revealed that the rates of hydrolysis of the studied dialkyl-N-methylmaleamic acids range over more than ten powers of ten, and the “effective ...
New analyses of baryon spectra in proton-proton and proton-carbon collisions at \(\sqrt{s}_\mathrm {_{NN}}=17.3\) GeV, made in the framework of two phenomenological models are presented. The first model in question is the classic Dual Parton Model by Capella and Tran Thanh Van, the sec...
The calculated ionization energies are in the range of 8-10.5 eV and they decrease as the number of carbon atoms increases. Computational results and ion mobility spectrometry study confirm that some alkanolamines lose a water molecule due to protonation at oxygen site and form cationic cyclic ...
Negative spin densities arising from [sgrave]-spin polarization on-NH-and-NH2 protons give rise to large upfield contact shifts whereas positive spin densities are found for protons on carbon atoms adjacent to nitrogen. The electronic spectra of solutions of Ni(Cyhx-dtp)2 in amines are ...
Gas-phase proton affinities (PAs) and hydride affinities (HAs) of organic bases possessing an allene moiety and substituted with methyl, dimethylamino, cyano, and vinyl substituents were examined with the B3LYP/6-311+G(2df, p)//B3LYP/6- 31G(d) model. It was shown that a number of super...
Introduction of the trivalent cations results in the reduction of the molar number of oxygen from the stoichiometric three due to charge neutrality, and increasing the generation of oxide-ion vacancies (Uchida, 1983; Uchida et al., 1989a, b; Iwahara and Yajima, 1992; Yajima and Iwahara, 1992...
The Proton-Proton and Proton-Carbon-13 Spin-Spin Coupling Constants in 1,3-Dioxoleand Bis-1,3-dioxolyl. Conformational Dependence TEDSCHAEFERK, ALVINCHUMD, AVIDMCKINNONA, ND M. S. CHAUHAN Department of Chemistry, University of Manitoba, ... Ted Schaefer,Kalvin Chum,David McKinnon,... - ...