✦ LIBER ✦

Quantitative 13C n.m.r. spectroscopy of a coal-derived oil and the assignment of chemical shifts

✍ Scribed by Yosuke Maekawa; Tadashi Yoshida; Yuji Yoshida

Publisher: Elsevier Science
Year: 1979
Tongue: English
Weight: 655 KB
Volume: 58
Category: Article
ISSN: 0016-2361
DOI: 10.1016/0016-2361(79)90202-3

No coin nor oath required. For personal study only.

✦ Synopsis

The conditions necessary for the recording of quantitative 13C nuclear magnetic resonance spectra of the hexane-soluble oil separated from a coal hydrogenation product have been investigated. Measured values of T1 for different signals in the spectrum were less than 1 s, and altering the pulse-repetition time beyond 2-4 s had little effect on carbon aromaticities. The nuclear Overhauser effect was suppressed by gating the proton decoupling. Assignments of chemical shifts for various signals in the spectrum of the oil were made by reference to literature spectra of polyaromatic substances and their derivatives. Determinations of different structural carbon types were internally consistent.

📜 SIMILAR VOLUMES

Aspects of quantitative 13C n.m.r.-spect

Aspects of quantitative 13C n.m.r.-spectroscopy of high boiling oil residues and coal tar pitches

✍ Herbert Dreeskamp; Thomas Potempa; Astrid Müller 📂 Article 📅 1989 🏛 Elsevier Science 🌐 English ⚖ 613 KB

Optimum conditions for high resolution 1

Optimum conditions for high resolution 13C n.m.r. of coal- and oil-derived products

✍ Herbert Dreeskamp; Heinz Kluge 📂 Article 📅 1985 🏛 Elsevier Science 🌐 English ⚖ 811 KB

Factors affecting the spin-lattice relaxation times T, of 13C resonances at 62.9 MHz were investigated for simplemixtures of tetralin, ethylbenzene, pentane and phenol and the prominent resonances of an anthracene oil and a coal-derived hydrogenation oil. Parameters varied were solvent temperature a

Characterization of coals and coal oxida

Characterization of coals and coal oxidation by magic-angle 13C n.m.r. spectroscopy

✍ John R. Havens; Jack L. Koenig; Deborah Kuehn; Carol Rhoads; Alan Davis; Paul C. 📂 Article 📅 1983 🏛 Elsevier Science 🌐 English ⚖ 651 KB

## Magic-angle 13C n.m.r. spectra have been obtained for a series of vitrinite concentrates. Proper modification of the cross-polarization pulse sequence allows separation of protonated and nonprotonated carbon resonances. This technique is used to determine the relative fraction of nonprotonated

Structural investigation of coal-tar pit

Structural investigation of coal-tar pitches and coal extracts by 13C n.m.r. spectroscopy

✍ Peter Fischer; Jürgen W. Stadelhofer; Maximilian Zander 📂 Article 📅 1978 🏛 Elsevier Science 🌐 English ⚖ 903 KB

Distribution of aliphatic and aromatic c

Distribution of aliphatic and aromatic carbons in H-Coal liquids by quantitative 13C FT-n.m.r. spectroscopy

✍ Joseph T. Joseph; John L. Wong 📂 Article 📅 1980 🏛 Elsevier Science 🌐 English ⚖ 578 KB

Three H-Coal liquids, ASO, ASB, and VSO, have been characterized by quantitative FT-n.m.r. spectroscopy. FT-parameters were chosen to allow determination of aromatic:aliphatic carbon ratios to within 1% and 2% error of the theoretical and the absolute number of aromatic and aliphatic carbons in a si

Quantitative aspects of solid state 13C

Quantitative aspects of solid state 13C n.m.r. of coals and related materials

✍ Kenneth J. Packer; Robin K. Harris; Alan M. Kenwright; Colin E. Snape 📂 Article 📅 1983 🏛 Elsevier Science 🌐 English ⚖ 480 KB

The quantitative aspects of cross-polarization (CP), which is used in conjunction with dipolar decoupling and magic-angle rotation to obtain high resolution 13C n.m.r. spectra of coals, have been studied using a bituminous coal (82 wt% C, dmmf basis) and asphaltenes from an extract of the same coal.