Spectral nuclear magnetic resonance

Nuclear magnetic resonance B spectral studies of BF have given a value of 9.4 1.0 ppm for the chemical shift relative to BF3 0(02113)3 as the... [Pg.159]

B. J. Zwolinski and co-workers. Selected Nuclear Magnetic Resonance Spectral Data, American Petroleum Institute Research Project 44,... [Pg.487]

The melting points, optical rotations, and uv spectral data for selected prostanoids are provided in Table 1. Additional physical properties for the primary PGs have been summarized in the Hterature and the physical methods have been reviewed (47). The molecular conformations of PGE2 and PGA have been determined in the soHd state by x-ray diffraction, and special H and nuclear magnetic resonance (nmr) spectral studies of several PGs have been reported (11,48—53). Mass spectral data have also been compiled (54) (see Mass spectrometry Spectroscopy). [Pg.153]

Nuclear Magnetic Resonance Spectroscopy. Nmr is a most valuable technique for stmeture determination in thiophene chemistry, especially because spectral interpretation is much easier in the thiophene series compared to benzene derivatives. Chemical shifts in proton nmr are well documented for thiophene (CDCl ), 6 = 7.12, 7.34, 7.34, and 7.12 ppm. Coupling constants occur in well-defined ranges J2-3 = 4.9-5.8 ... [Pg.19]

The side-chain chlorine contents of benzyl chloride, benzal chloride, and benzotrichlorides are determined by hydrolysis with methanolic sodium hydroxide followed by titration with silver nitrate. Total chlorine determination, including ring chlorine, is made by standard combustion methods (55). Several procedures for the gas chromatographic analysis of chlorotoluene mixtures have been described (56,57). Proton and nuclear magnetic resonance shifts, characteristic iafrared absorption bands, and principal mass spectral peaks have been summarized including sources of reference spectra (58). Procedures for measuring trace benzyl chloride ia air (59) and ia water (60) have been described. [Pg.61]

Infrared, nuclear magnetic resonance, ultraviolet, optical rotary dispersion and circular dichroism measurements have been used for the spectral analysis of thiiranes. A few steroidal thiiranes have been reported to possess infrared absorption in the range from 580 to 700 cm The intermediate thiocyanate derivatives (RSCN) have a strong sharp peak at 2130-2160 cm the isomeric isothiocyanate (RNCS) shows a much stronger but broad band at 2040-2180 cm. ... [Pg.42]

Bovey, F A, Jelmski, L, Mirau, P A Nuclear Magnetic Resonance Spectroscopy, 2nd ed, Acadermc Press New York, 1988 Proton and Fluorine Nuclear Magnetic Resonance Spectral Data, Vanan Instruments/Japan Halon Tokyo, 1988... [Pg.1079]

Infrared and nuclear magnetic resonance spectral evidence led Kendall and Hajos to conclude that furan-3,4-dione (37) exists as such, which is surprising since cyclic a-diketones with five-membered rings are usually monoenolized. The 2,5-dicarbethoxy derivative 38 was earlier stated to exist in the dihydroxy form. ... [Pg.8]

Snyder and his co-workers assigned structures 48 and 49 to these j6-hydroxythiophene derivatives on the basis of chemical evidence and infrared and nuclear magnetic resonance spectral data. Infrared and nuclear magnetic resonance spectra further indicate that compounds of type 49 exist as dimers, probably hydrogen bonded, when R = OC2H5 or CH3, but as monomeric enols when R = H. ... [Pg.10]

C-NUCLEAR MAGNETIC RESONANCE-SPECTRAL STUDIES OF LABELED GLYCOPHORINS... [Pg.169]

C-Nuclear Magnetic Resonance-Spectral Studies of Labeled Glycophorins... [Pg.406]

The development and reports of methods for colorless chlorophyll derivative (RCCs, FCCs, and NCCs) analysis are relatively recent and the structures of the compounds are being elucidated by deduction from their chromatographic behaviors, spectral characteristics (UV-Vis absorbance spectra), mass spectrometry, and nuclear magnetic resonance analysis. The main obstacle is that these compounds do not accumulate in appreciable quantities in situ and, moreover, there are no standards for them. The determination of the enzymatic activities of red chlorophyll catabolite reductase (RCCR) and pheophorbide a monoxygenase (PAO) also helps to monitor the appearance of colorless derivatives since they are the key enzymes responsible for the loss of green color. ... [Pg.440]

Many methods are currently available for the qualitative analysis of anthocyanins including hydrolysis procedures," evaluation of spectral characteristics, mass spectroscopy (MS), " nuclear magnetic resonance (NMR), and Fourier transform infrared (FTIR) spectroscopy. - Frequently a multi-step procedure will be used for... [Pg.486]

Infrared or nuclear magnetic resonance spectral thermodynamic AVqh. Sh 20, 21... [Pg.130]

The nuclear magnetic resonance (NMR) spectra (300MFIz) of both the compound 10 and 11 was recorded in dimethyl sulfoxide (DMSO-r4) and CDCI3. The compound 10 in its H NMR spectrum showed a singlet signal at 5 5.32 due to the two NH protons, whereas compound 11 showed the presence of two NH protons at 6 6.80 <1989JOC3062>. For information on spectral studies of the compounds 1-5, refer to CHEC-II(1996) <1996CHEC-II(8)707>. [Pg.322]

Volume 176. Nuclear Magnetic Resonance (Part A Spectral Techniques and Dynamics)... [Pg.23]

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