Dynamic properties of the guest molecules in the pyrazine/α-zirconium phosphate intercalation compound:: A multinuclear solid-state NMR study

被引:7
作者
Bach-Vergés, M
Kitchin, SJ
Hix, GB
Harris, KDM [1 ]
Aliev, AE
机构
[1] Univ Birmingham, Sch Chem, Birmingham B15 2TT, W Midlands, England
[2] UCL, Dept Chem, London WC1H 0AH, England
关键词
D O I
10.1021/cm0117329
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
Dynamic properties of perdeuterated pyrazine (pyrazine-d(4)) guest molecules in the layered a-zirconium phosphate host structure have been established from solid-state (2)H NMR lineshape analysis and (2)H NMR spin-lattice relaxation time measurements. Both techniques indicate that the intercalation compound contains two different types of pyrazine-d(4) guest molecules, which undergo different dynamic processes. The relative proportions of the two types of pyrazine-d(4) guest molecules are approximately 30% (component A) and 70% (component B). The pyrazine-d(4) molecules representing component B undergo two-site 180degrees jumps about the N...N axis of the molecule, whereas the pyrazine-d(4) molecules representing component A undergo an effectively isotropic motion. The activation energy for the two-site 180degrees motion of component B is estimated to be 39 kJ mol(-1) from the (2)H NMR spin-lattice relaxation time measurements and 49 kJ mol(-1) from the (2)H NMR line-shape analysis. Structurally, it may be inferred that component B comprises guest molecules for which the N...N axis has a restricted orientation in space, presumably because of direct interactions with the alpha-zirconium phosphate host structure, whereas component A comprises guest molecules that are held rather weakly in the host structure (or on its external surfaces) such that their reorientation is relatively unestricted. Thermogravimetric analysis provides direct evidence for the existence of two different types of pyrazine guest molecules in the alpha-zirconium phosphate host structure, with different strengths of binding and with populations in the approximate ratio 30:70. High-resolution solid-state (15)N NMR and (13)C NMR spectra provide further support for the existence of two different types of pyrazine guest species within the alpha-zirconium phosphate host structure and provide direct evidence that the pyrazine guest molecules of component B are N-protonated (from the host structure).
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页码:2656 / 2663
页数:8
相关论文
共 26 条
[11]   NATURE OF THE PROTONIC SPECIES AND THE GEL CRYSTAL TRANSITION IN HYDRATED ZIRCONIUM-PHOSPHATE [J].
COLOMBAN, P ;
NOVAK, A .
JOURNAL OF MOLECULAR STRUCTURE, 1989, 198 :277-295
[12]   QUADRUPOLAR ECHO DEUTERON MAGNETIC-RESONANCE SPECTROSCOPY IN ORDERED HYDROCARBON CHAINS [J].
DAVIS, JH ;
JEFFREY, KR ;
BLOOM, M ;
VALIC, MI ;
HIGGS, TP .
CHEMICAL PHYSICS LETTERS, 1976, 42 (02) :390-394
[13]  
DEWITH G, 1976, ACTA CRYSTALLOGR B, V32, P3178, DOI 10.1107/S0567740876006924
[14]   DEUTERIUM QUADRUPOLE-ECHO NMR-SPECTROSCOPY .3. PRACTICAL ASPECTS OF LINESHAPE CALCULATIONS FOR MULTIAXIS ROTATIONAL PROCESSES [J].
GREENFIELD, MS ;
RONEMUS, AD ;
VOLD, RL ;
VOLD, RR ;
ELLIS, PD ;
RAIDY, TE .
JOURNAL OF MAGNETIC RESONANCE, 1987, 72 (01) :89-107
[15]  
Hix GB, 1997, EUR J SOL STATE INOR, V34, P589
[16]  
Hoatson G.L., 1994, NMR BASIC PRINCIPLES, V32, P3
[17]  
JELINSKI LW, 1985, ANNU REV MATER SCI, V15, P359
[18]  
Levy G. C., 1979, NITROGEN 15 NUCL MAG
[19]  
Look D. C., 1970, Review of Scientific Instruments, V41, P250, DOI 10.1063/1.1684482
[20]  
RALEIGH DP, 1989, J MAGN RESON, V81, P445