ZfN: Search Results

1	Author	Takahiro Iijima, Motohiro Mizuno, Masahiko Suhara	Requires cookie*
	Title	H NMR Study of Molecular and Electron Spin Dynamics in Paramagnetic [Co(H 2 0) 6 ][SiF 6 ]
	Abstract	The temperature dependences of 2 H NMR spectra and the spin-lattice relaxation time T\ were measured for [Co(H20)f,][SiF6]. The variation of the spectrum above room temperature can be explained by the reorientation of [Co(H20)fi] 2+ about the C3 axis. The activation energy E a and the jumping rate at infinite temperature fco for the three site jump of [Co(H20)6] 2+ were obtained as 82 kJmol -1 and 2x 10 17 s~ 1 from the spectral simulation. Below room temperature, the spectral line shape was dominated by the 180° flip of the water molecule. The minimum of T\ caused by the 180° flip of the water molecule was observed at ca. 260 K. The jumping rate of the 180° flip of the water molecule was estimated from the 2 H NMR T\ and the spectral simulation. E* = 38 kJmol -1 and fco = 6x 10 l5 s -1 for the 180° flip of the water molecule were obtained from T\.
	Reference	Z. Naturforsch. 55a, 173—177 (2000); received August 23 1999
	Published	2000
	Keywords	Phase Transition, 2 H NMR, Nuclear Quadrupole Interaction, Paramagnetic Shift, Molecular Dynamics
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	TEI-XML for	default:Reihe_A/55/ZNA-2000-55a-0173.pdf
	Identifier	ZNA-2000-55a-0173
	Volume	55

2	Author	Motohiro Mizuno, Takahiro Iijima, Kengo Orii, Masahiko Suhara	Requires cookie*
	Title	Water Molecular Motion and Hydrogen Bond in Paramagnetic [Cu(H 2 0) 6 ][PtCl 6 ] as Studied by Single Crystal 2 H NMR
	Abstract	The temperature and angular dependences of the 2 H NMR spectrum were measured for single crystal [Cu(H 2 0) 6 ] [PtCl 6 ]. (e 2 Qq/h, r?) = (132 kHz, 0.72) were obtained for the D nucleus averaged by the fast 180° flip of the water molecule at 297 K. D,(236 kHz, 0.10) and D 2 (246 kHz, 0.09) were obtained for two unequal D nuclei of the water molecule at 133 K. Below T c , at least three nonequivalent waters were found to exist. The jumping rate for the 180° flip of the water molecule (k) was obtained from the simulation of 2 H NMR spectra at //o\|\|[l 11] direction. The activation energy E d and the jumping rate at infinite temperature were estimated from the temperature dependence of k to be 24kJmol _1 and 1 x 10 13 s -1 .
	Reference	Z. Naturforsch. 55a, 178—182 (2000); received August 23 1999
	Published	2000
	Keywords	Phase Transition, 2 H NMR, Nuclear Quadrupole Interaction, Paramagnetic Shift, Molecular Dynamics
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	TEI-XML for	default:Reihe_A/55/ZNA-2000-55a-0178.pdf
	Identifier	ZNA-2000-55a-0178
	Volume	55