SOLID-STATE MO-95 NMR-STUDY OF (ARYLDIAZENIDO)POLYOXOMOLYBDATES AND (ORGANOHYDRAZIDO)POLYOXOMOLYBDATES - INVESTIGATION OF MODEL COMPOUNDS OF CATALYTIC MOLYBDENUM ENVIRONMENTS

被引:23
作者
EDWARDS, JC
ZUBIETA, J
SHAIKH, SN
CHEN, Q
BANK, S
ELLIS, PD
机构
[1] UNIV S CAROLINA,DEPT CHEM,COLUMBIA,SC 29208
[2] SUNY ALBANY,DEPT CHEM,ALBANY,NY 12222
关键词
D O I
10.1021/ic00343a024
中图分类号
O61 [无机化学];
学科分类号
070301 ; 081704 ;
摘要
The 95Mo static powder and magic angle spinning NMR spectra of the central ±1/2 transition of a number of (aryldiazenido)- polyoxomolybdates, (organohydrazido)polyoxomolybdates, and unsubstituted polyoxomolybdates were obtained. The spectra clearly demonstrated the existence of octahedral and tetrahedral sites within these compounds by the contrast between the respective line widths and the dependence under MAS conditions of the resonances from these sites. Variation of ligand coordination was also seen to yield a visible chemical shift to the octahedral molybdenum sites in selected complexes. An interactive graphics curve-fitting program was used to estimate the quadrupolar coupling constants, asymmetry parameters of the electric field gradients, the three principal elements of the shielding tensor, and the Euler angles relating the quadrupole and chemical shielding principal axis systems for the molybdenum sites from the static powder spectra. Assignments of the line shape components was made to the different molybdenum sites present in these species. The method of assignment, based on degree of distortion at the site, was vindicated by MO calculations carried out on a simple [MoO6]6− model species. These MO calculations demonstrate the increase in the magnitude of the electric field gradient (and hence the value of Aoc) was one distorts the octahedral environment by a combination of bond length and angular variations. The effectiveness of the 95Mo NMR technique to obtain these data from Mo(VI) compounds was thus demonstrated and has laid a foundation from which future solid-state 95Mo NMR studies of biological and catalytic molybdenum systems can benefit by comparison of the results obtained with those obtained for these model compounds. © 1990, American Chemical Society. All rights reserved.
引用
收藏
页码:3381 / 3393
页数:13
相关论文
共 49 条
[1]   CRYSTAL AND MOLECULAR-STRUCTURE OF A NEW HEXAMOLYBDATE-CYCLOPHOSPHAZENE COMPLEX .16. [J].
ALLCOCK, HR ;
BISSELL, EC ;
SHAWL, ET .
INORGANIC CHEMISTRY, 1973, 12 (12) :2963-2968
[2]   MO-95 NMR-STUDIES OF (ARYLDIAZENIDO)MOLYBDATES AND (ORGANOHYDRAZIDO)MOLYBDATES - CRYSTAL AND MOLECULAR-STRUCTURE OF [NORMAL-BU4N]3[MO6O18(NNC6F5)] [J].
BANK, S ;
LIU, SC ;
SHAIKH, SN ;
SUN, X ;
ZUBIETA, J ;
ELLIS, PD .
INORGANIC CHEMISTRY, 1988, 27 (20) :3535-3543
[3]   NUCLEAR MAGNETIC RESONANCE POWDER PATTERNS IN PRESENCE OF COMPLETELY ASYMMETRIC QUADRUPOLE AND CHEMICAL SHIFT EFFECTS - APPLICATION TO METAVANADATES [J].
BAUGHER, JF ;
TAYLOR, PC ;
OJA, T ;
BRAY, PJ .
JOURNAL OF CHEMICAL PHYSICS, 1969, 50 (11) :4914-&
[4]  
BONERA G, 1968, PHYS REV, V165, P171
[5]  
BOWDEN FL, 1975, TECHNIQUES TOPICS 3, P205
[6]  
Bray R. C., 1972, STRUCT BOND, V11, P107
[7]   CRYSTAL-STRUCTURE AND SPECTROSCOPIC STUDIES OF [MOO2(L-CYSOME)2] [J].
BUCHANAN, I ;
MINELLI, M ;
ASHBY, MT ;
KING, TJ ;
ENEMARK, JH ;
GARNER, CD .
INORGANIC CHEMISTRY, 1984, 23 (04) :495-500
[8]  
CHEN Q, 1989, INORG CHIM ACTA, V162, P163
[9]   STRUCTURAL CHARACTERIZATION OF THE PENTAMOLYBDATE ANION, [(MOO4)2(MO3O8(OME))]3-, AND ISOLATION OF THE [MO3O8(OME)]+ TRINUCLEAR CORE IN THE SQUARATE COMPLEX [(MO3O8(OME))(C4O4)2]3- [J].
CHEN, Q ;
MA, L ;
LIU, S ;
ZUBIETA, J .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1989, 111 (15) :5944-5946
[10]  
CHEN Q, IN PRESS INORG CHIM