RADICAL CATION OF NAPHTHALENE ON H-ZSM-5 ZEOLITE AND IN CFCL3MATRIX. A THEORETICAL AND EXPERIMENTAL EPR, ENDOR, AND ESEEM STUDY
RADICAL CATION OF NAPHTHALENE ON H-ZSM-5 ZEOLITE AND IN CFCL3MATRIX. A THEORETICAL AND EXPERIMENTAL EPR, ENDOR, AND ESEEM STUDY
复制标题
H-ZSM-5 沸石和 CFCL3 基质上萘的自由基阳离子。
DOI：
10.1021/jp9631994
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发表时间：
1997
影响因子：
2.9
通讯作者：
M. Lindgren
中科院分区：
文献类型：
--
作者：
R. Erickson;N. Benetis;A. Lund;M. Lindgren
用EPR、ENDOR和ESEEM谱研究了在H-ZSM-5沸石上和在冷冻的CFCl 3溶液中，由相应的中性化合物通过UV或X射线照射产生的萘自由基阳离子。在实验误差范围内，我们确定了两种介质中的甘德环质子超精细张量。两组四个等效质子的各向同性hf耦合是|a（1）|= 16.4，|a（2）|= 4.7 MHz（分别为0.587和0.167 mT）。对各向同性和偶极高频耦合的半经验计算与实验符合得很好。用旋磁比γH/γD标度得到的萘-d8自由基阳离子的hf张量与质子化化合物的hf张量类似。ESEEM还确定了氘核的核四极相互作用（nqi）张量，这是目前nqi强度的唯一解析方法。
The naphthalene radical cation generated from the corresponding neutral compound by UV- or X-irradiation on H−ZSM-5 zeolite and in frozen CFCl3solution has been studied by EPR, ENDOR, and ESEEM spectroscopies. Thegand ring proton hyperfine (hf) tensors have been determined and are identical in the two media, within experimental error. The isotropic hf couplings of the two sets of four equivalent protons are |a(1)| = 16.4 and |a(2)| = 4.7 MHz (0.587 and 0.167 mT, respectively). Semiempirical calculations of isotropic and dipolar hf couplings are found to be in good agreement with experiment. The hf tensors obtained for the radical cation of naphthalene-d8were analogous to those of the protonated compound, scaled by the gyromagnetic ratio, γH/γD. The nuclear quadrupole interaction (nqi) tensors of the deuterium nuclei were also determined by ESEEM, being the only resolved method for the present nqi strength.