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采用单晶X射线衍射技术对化合物的晶体结构进行了研究. 研究结果表明,Glaucocalyxin A分子含3个六元环和1个五元环,其中六元环均为椅式构象,五元环为扭曲信封式构象. Glaucocalyxin A晶体结构属正交晶系. 采用密度函数理论和Hartree-Fock方法对该化合物晶体的键长、键角和两面角进行计算,并与X衍射测定值进行比较,结果表明理论值与实验值符合相当好. 应用规范不变原子轨道,分别在不同水平上,计算了Glaucocalyxin A的1H和13C NMR化学位移,并对理论计算值的误差 相似文献
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EPR and DFT Study of the Polycyclic Aromatic Radical Cations from Friedel-Crafts Alkylation Reactions 下载免费PDF全文
利用电子顺磁共振和电子核双共振技术在间二甲苯与氯代烷烃和对二甲苯与氯代烷烃进行付-克烷基化反应体系中分别检测到二个多核芳烃正离子自由基信号.研究结果表明,所观察到顺磁共振信号分别来自于2,6-二甲基蒽正离子和1,4,5,8-四甲基蒽自由基的贡献.提出了这二个自由基的生成是在付-克烷基化反应中生成的氯代芳基在AlCl3存在下发生Scholl缩合反应生成多核芳烃,后者发生单电子氧化转变为相应的多核芳烃正离子自由基。利用密度泛函理论计算了这两个自由基的超精细偶合常数,与实验值符合相当满意,从理论上支持了对实验超精细谱线的归属. 相似文献
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A new function called paired-permanent is defined and widely discussed, and a practicable procedure for evaluations of paired-permanents is proposed, which is similar to the Laplace method for determinants. Using the concept of paired-permanents, an efficient algorithm is presented for evaluating the Hamiltonian and overlap matrix elements in the spin-free form of valence bond (VB) theory. With the new algorithm, a spin-free wavefunction is simply written as a paired-permanent, and an overlap matrix element may be obtained by evaluating a corresponding paired-permanent. Meanwhile, the Hamiltonian matrix element is expressed in terms of the summation of the products of electronic integrals and the corresponding sub-paired-permanents 相似文献
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