Nuclear magnetic resonance chemical shifts and

C and H Nuclear Magnetic Resonance Chemical Shifts and Coupling Constants in the Norbomyl Cation, Cyclopentyl Cation, Nortricyclene, and... 

Wishart DS, Sykes BD, Richards FM. Relationship between nuclear magnetic resonance chemical shift and protein secondary structure. J. Mol. Biol. 1991 222 311-333. 

Park, K.D., Guo, K., Adebodun, F., Chiu, M.L., Sligar, S.G., et al. Distal and proximal ligand interactions in heme proteins correlations between C-O and Fe-C vibrational liequencies, oxygen-17 and carbon-13 nuclear magnetic resonance chemical shifts, and oxygen-17 nuclear quadrupole coupling constants in C O- and CO-labeled species. Biochemistry 30, 2333-2347 (1991)... 

Muller, D., W. Gessner, A. Samoson, E. Lippmaa and G. Scheler. 1986b. Solid-state aluminium-27 nuclear magnetic resonance chemical shift and quadrupole data for condensed A104 tetrahedra./. Chem. Soc. Dalton Trans. 1277-1281. 

Given their radio-frequency electrical properties and nuclear magnetic resonance chemical shift components, solutions of reversed micelles constituted of water, AOT, and decane have been proposed as suitable systems to test and calibrate the performance of magnetic resonance imagers [68]. 

Because muscle cells are especially rich in terms of phosphorus-containing metabolites (e.g., ATP, ADP, phos-phocreatine, and orthophosphate), nuclear magnetic resonance " has proved to be a valuable noninvasive probe of metabolic changes attending muscle activity. The spectral sensitivity of P is especially high relative to other nuclei, and one can detect cellular concentrations as low as 0.5 mM as well as utilize chemical shift data to define intracellular pH and free magnesium ion concentrations. See also Nuclear Magnetic Resonance Chemical Shift... 

Nuclear magnetic resonance chemical shift differences can serve as an indicator of molecular symmetry. If two groups have the same chemical shift, they are isochronous. Isochrony is a property of homotopic groups and of enantiotopic groups under achiral conditions. Diastereotopic or constitutionally heterotopic groups will have different chemical shifts (be anisochronous), except by accidental equivalence and/or lack of sufficient resolution. 

The ground-state complex between benzene and maleic anhydride was found to have the exo configuration. Bryce-Smith and Hems [44] have measured nuclear magnetic resonance chemical shifts of the ethylenic protons of maleic an-... 

K. Bock, A. Brignole, and B. W. Sigurskjold, Conformational dependence of 13C nuclear magnetic resonance chemical shifts in oligosaccharides, J.C.S. Perkin Trans. II, (1986) 1711-1713. 

Vibrational Frequencies and Nuclear Magnetic Resonance Chemical Shift Calculations... 

Although evaluations of harmonic force constants [d E dq,dqj), elearic polarizabilities d EIdeide ), and dipole moment derivatives (d E/d ,dqj) are perhaps the most common applications of second-order properties (or, equivalently, second derivatives), other areas of interest to chemists can be treated with these techniques. One such field of application that holds great promise for the future is the calculation of nuclear magnetic resonance chemical shifts. 

Less commonly used measurement techniques include the pH dependence of partition coefficients [74], fluorescence spectra [75], nuclear magnetic resonance chemical shifts or coupling constants, HPLC or CE retention volumes [76,77], and the dependence of reaction rates for ionizable substrates on pH (also called kinetic methods). Kinetic methods were amongst the earliest methods to be used for pKg determination. In some cases, they may be the only feasible method, for example, extremely weak acids (pKa > 12) without suitable absorption spectra. The difficulty with kinetic methods is that they may not actually measure the pKg value for the substrate, but that of the reaction transition state. If the electronic configuration of the transition state is similar to that of the reactant (early transition state), then the kinetic may be quite close to the equilibrium value. However, if the transition state more nearly approximates the reaction products (late transition state), then the kinetic value may bear little resemblance to that for the reactant. This explanation might account for the lack of agreement between the first apparent kinetic pK = 4.0) and equilibrium (pK = 8.6) pKg values for hydrochlorothiazide at 60 °C [78]. Similar restrictions may be placed on the use of pKa values from the pH dependence of fluorescence spectra, as these reflect the properties of the first excited state of the molecule rather than its ground state [75]. 

Note It also includes complex inorganic phosphates (condensed phosphates) and synthetic organic phosphates commonly used in assays of phosphatase activity. Detailed information on these compounds can be found in Corbridge (2000). For solution phosphorus-31 nuclear magnetic resonance chemical shift values of these compounds, see Turner et al. (2004). 

Dale, J.A., and H.S. Mosher Nuclear Magnetic Resonance Enantiomer Reagents. Configurational Correlations via Nuclear Magnetic Resonance Chemical Shifts of Diastereomeric Mandelate, 0-Methylmandelate, and a-Methoxy-a-trifluoromethyl-phenylacetate (MTPA) Esters. J, Amer. Chem. Soc., 95, 512 (1973). 

S. Spera, A. Bax, Empirical correlation between protein backbone conformation and Cot and C(3. nuclear magnetic resonance chemical shifts, J. Am. Chem. Soc. 113 (1991) 5490-5492. 

D. B. Chesnut and C. G. Phung, /. Chem. Phys., 91, 6238 (1989). Nuclear Magnetic Resonance Chemical Shifts Using Optimized Geometries. 

Glasel, J.A., 1973, Lanthanide Ions as Nuclear Magnetic Resonance Chemical Shift Probes in Biological Systems, in Lippard, S.J., ed.. Current Research Topics in Bioinorganic Chemistry (John Wiley and Sons, New York) pp. 383-413. 

Gauss, J. and Stanton, J. F. (1995). Coupled-cluster calculations of nuclear magnetic resonance chemical shifts. J. Chem. Phys., 103, 3561-3577. 

Kussmann, J., 8c Ochsenfeld, C. (2007). Linear-scaling method for calculating nuclear magnetic resonance chemical shifts using gauge-including atomic orbitals within Hartree-Fock and density-functional theory. Journal of Chemical Physics, 127, 054103. 

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