| | 1 | Author
| Takeshi Kyan, Hamagawa, Takahiro Isono, Masao Hashimoto | Requires cookie* | | | Title
| Hiroshi  | | | | Abstract
| The crystal structure of cyclohexylhemiacetal (cycHx-CH) was determined at 296 K: monoclinic, space group P2 Jc, a =1028.7 (9), b = 609.5 (1), c = 1811.9 (4) pm, and ß = 99.79 (3)°, Z -4, R = 0.0552. The three 5s Cl NQR lines in cycHx-CH, T., T2, and T2*, were measured by a pulsed method at 80-300 K. Below 200 K Tf 1 obeyed the T law well, indicating that the spin lattice relaxation is governed by lattice vibrations. The reorientation of CC13 seems to be responsible for the sharp T: drop observed above 250 K. Shoulders in the T { vs. 1/T curves indicate the presence of Ti minima at about 240 K. A fluctuation of the EFG due to a dynamic disorder of hydrogen atoms in the OH groups is assumed to explain the T x minima. | | | |
Reference
| Z. Naturforsch. 47a, 299 (1992); received July 25 1991 | | | |
Published
| 1992 | | | |
Keywords
| Chlorine NQR, Spin-lattice relaxation, Hydrogen bond, Crystal structure | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_A/47/ZNA-1992-47a-0299.pdf | | | | Identifier
| ZNA-1992-47a-0299 | | | | Volume
| 47 | |
| 2 | Author
| Masao Hashimoto, Takahiro Isono, Noriko Yomesaka, Haruo Niki, Hiroshi Kyan, Takeshi Hamagawa | Requires cookie* | | | Title
| Reorientation of the CC1 3 Group in Chloral 4-Chlorobenzyl- hemiacetal. A Pulsed 35 C1 NQR and X-ray Study | | | | Abstract
| The crystal structure of the title compound was determined at 291 K: monoclinic, space group C^h-P21/n, Z = 4, a = 1693.2(1), 6 = 579.3(1), c = 1232.5(1) pm, and ß = 107.21 (1)°, R = 0.0415. A sharp decrease of of Cl NQR found at T> 270 K for the CC13 group is attributed to the reorientation of the group over a potential barrier of ca. 50 kJ/mol. Intermolecular interactions between the CC13 and the neighboring atoms seem to dominate the magnitude of the potential barrier. T{~ 1 of the 35 C1 NQR of the Cl atom on the benzene ring obeyed the T 2 law well in the range 80 < T/K <270, while at T>280 K it deviated from the T 2 law. | | | |
Reference
| Z. Naturforsch. 47a, 293—298 (1992); received July 25 1991 | | | |
Published
| 1992 | | | |
Keywords
| Crystal structure, Hydrogen bond, Chlorine NQR, Spin lattice relaxation, Atom-atom potential method | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_A/47/ZNA-1992-47a-0293.pdf | | | | Identifier
| ZNA-1992-47a-0293 | | | | Volume
| 47 | |
| 4 | Author
| K. P. Ramesh, J. Ramakrishna, K. S. Suresh, C.Raghavendra Rao | Requires cookie* | | | Title
| Pressure Dependence of the Chlorine NQR in Chloro Pyridines | | | | Abstract
| The "CI NQR frequency (VQ) and spin lattice relaxation time) in 2,6-dichloropyridine, 2 amino 3,5-dichloropyridine and 6 chloro 2-pyridinol have been measured as a function of pressure up to 5.1 kbar at 300 K, and the data have been analysed to estimate the temperature coefficients of the NQR frequency at constant volume. All the three compounds show a non linear variation of the NQR frequen-cy with pressure which can be described by a 2 nd order polynomial in pressure. The rate of change of the NQR frequency with pressure is positive and decreases with increasing pressure. The spin lattice re-laxation time 7, in all the three compounds shows a small increase with pressure, indicating that the re-laxation is mainly due to the torsional motions. | | | |
Reference
| Z. Naturforsch. 55a, 111—116 (2000); received August 25 1999 | | | |
Published
| 2000 | | | |
Keywords
| Chlorine NQR, Spin-Lattice Relaxation Time, Pressure Dependence, 2,6 dichloropyridine, 2-amino 3,5-dichloropyrine, 6-chloro 2-pyridinol | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_A/55/ZNA-2000-55a-0111.pdf | | | | Identifier
| ZNA-2000-55a-0111 | | | | Volume
| 55 | |
|
