SUM COMBINATION HARMONICS IN 4-PULSE ESEEM SPECTRA - STUDY OF THE LIGAND GEOMETRY IN AQUA VANADYL COMPLEXES IN POLYCRYSTALLINE AND GLASS MATRICES

被引:68
作者
TYRYSHKIN, AM [1 ]
DIKANOV, SA [1 ]
GOLDFARB, D [1 ]
机构
[1] WEIZMANN INST SCI,DEPT CHEM PHYS,IL-76100 REHOVOT,ISRAEL
关键词
D O I
10.1006/jmra.1993.1281
中图分类号
O64 [物理化学(理论化学)、化学物理学]; O56 [分子物理学、原子物理学];
学科分类号
070203 ; 070304 ; 081704 ; 1406 ;
摘要
Structural differences in the vanadyl pentaaqua complex in two different matrices, a frozen glassy water solution and a polycrystalline Tutton salt, were investigated using the recently designed one dimensional four-pulse electron spin-echo envelope modulation (ESEEM) experiment. The four-pulse ESEEM spectrum consists of the basic nuclear frequencies, να and νβ, of the ligands′ protons along with their sum combination harmonics, (να + νβ). This particular example demonstrates the potential of this new experiment which lies in the generation of highly resolved combination harmonics from which information regarding the hyperfine and quadrupole interactions can be derived. While the combination lines in the two-pulse ESEEM spectra of the polycrystalline sample suffered from low resolution due to a relatively short T2, highly resolved peaks were observed in the four-pulse ESEEM spectra since in this experiment T1 dominates the echo decay rather than T2. Orientation-selective four-pulse ESEEM experiments were performed under conditions that optimize the intensities of the sum combination harmonics. Aqua complexes with H2O and D2O were studied and clear differences in the Fourier transform ESEEM spectra of the two matrices, not detected previously by electron-nuclear double-resonance spectroscopy or two-pulse ESEEM, were evident. The analysis of the spectra was done by simulating the FT-ESEEM spectra of both the H2O and the D2O complexes. For this purpose, an analytical expression describing the four-pulse ESEEM for I = 1 was derived, taking into account the 2H quadrupole interaction as a first-order correction to the nuclear frequencies. The simulations showed that the positions and orientations of the ligands in VO2+(H2O)5 and VO2+(D2O)5 are somewhat different in the frozen glassy solution and in the crystalline matrix of the Tutton salt. © 1993 by Academic Press, Inc.
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页码:271 / 283
页数:13
相关论文
共 22 条
[1]   HYPERFINE INTERACTIONS OF DEUTERIUM NUCLEI IN THE NEAREST SURROUNDINGS OF TRAPPED ELECTRONS IN ALKALINE GLASS [J].
ASTASHKIN, AV ;
DIKANOV, SA ;
TSVETKOV, YD .
CHEMICAL PHYSICS LETTERS, 1988, 144 (03) :258-264
[2]   THE STRUCTURE OF THE NEAREST SURROUNDINGS OF SILVER ATOMS STABILIZED IN GAMMA-IRRADIATED AGNO3/D2O ICE, BASED ON ESE DATA [J].
ASTASHKIN, AV ;
DIKANOV, SA ;
TYRYSHKIN, AM ;
TSVETKOV, YD .
CHEMICAL PHYSICS LETTERS, 1989, 164 (2-3) :299-306
[3]   PROTON ENDOR OF VO(H2O)52+ IN MG(NH4)2(SO4)26H2O [J].
ATHERTON, NM ;
SHACKLETON, JF .
MOLECULAR PHYSICS, 1980, 39 (06) :1471-1485
[4]   ELIMINATION OF THE MATRIX CONTRIBUTION TO ELECTRON-SPIN ECHO MODULATION [J].
DIKANOV, SA ;
ASTASHKIN, AV ;
TSVETKOV, YD .
CHEMICAL PHYSICS LETTERS, 1988, 144 (03) :251-257
[5]   ELECTRON SPIN-ECHO ENVELOPE MODULATION (ESEEM) STUDIES OF THE TYROSYL RADICAL D. OF PLANT PHOTOSYSTEM-II [J].
EVELO, RG ;
DIKANOV, SA ;
HOFF, AJ .
CHEMICAL PHYSICS LETTERS, 1989, 157 (1-2) :25-30
[6]   ABSORPTION SPECTRA OF VANADIUM(III) AND VANADIUM(IV) IONS IN COMPLEXING AND NON-COMPLEXING MEDIA [J].
FURMAN, SC ;
GARNER, CS .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1950, 72 (04) :1785-1789
[7]   PHASE CYCLING IN PULSE EPR [J].
GEMPERLE, C ;
AEBLI, G ;
SCHWEIGER, A ;
ERNST, RR .
JOURNAL OF MAGNETIC RESONANCE, 1990, 88 (02) :241-256
[8]   STUDY OF CU(II) BINDING TO CHIRAL TRIPODAL LIGANDS BY ELECTRON-SPIN ECHO SPECTROSCOPY [J].
GOLDFARB, D ;
FAUTH, JM ;
TOR, Y ;
SHANZER, A .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1991, 113 (06) :1941-1948
[9]   HYPERFINE SUBLEVEL CORRELATION (HYSCORE) SPECTROSCOPY - A 2D ELECTRON-SPIN-RESONANCE INVESTIGATION OF THE SQUARIC ACID RADICAL [J].
HOFER, P ;
GRUPP, A ;
NEBENFUHR, H ;
MEHRING, M .
CHEMICAL PHYSICS LETTERS, 1986, 132 (03) :279-282
[10]  
HOFER P, 1991, ELECTRON MAGNETIC RE, P1