(CH_3OCH_2CH_2C_5H_4)_2LnI(Ln=La,Nd)complexes have been synthesized by the reaction between NaI and[(CH_3OCH_2CH_2C_5H_4)_2LnCl]2 in THF;A single crystal X-ray study has shown that the lanthanum complex is an unsolvat...(CH_3OCH_2CH_2C_5H_4)_2LnI(Ln=La,Nd)complexes have been synthesized by the reaction between NaI and[(CH_3OCH_2CH_2C_5H_4)_2LnCl]2 in THF;A single crystal X-ray study has shown that the lanthanum complex is an unsolvated monomer with lanthanum(Ⅲ)in a trigonal bipyramidal coordination geometry if the cyclopentadienyl ring is regarded as occupying a single polyhedral vertex.展开更多
The mode selectivity of the H+CH_(3)D→H_(2)+CH_(2)D reaction was studied using a recently developed ten-dimensional time-dependent wave packet method.The reaction dynamics are studied for the reactant CH_(3)D initial...The mode selectivity of the H+CH_(3)D→H_(2)+CH_(2)D reaction was studied using a recently developed ten-dimensional time-dependent wave packet method.The reaction dynamics are studied for the reactant CH_(3)D initially from the ground state,the CH_(3) symmetry and asymmetry stretching excitation,the CD stretching excitation and the fundamental and the first overtone of the CH_(3) bending mode.The calculated reaction probabilities show that exciting either of the CH_(3) stretching modes enhances the reactivity in the collision energy range below 1.0 eV,while the CD stretching excitation does not obviously prompt the reaction.Fundamental CH_(3) bending excitation has nearly no effect on promoting reactivity.However,a significant enhancement is observed for the first overtone excitation of the CH_(3) bending mode,resulting from the Fermi resonance between the fundamental state of the CH_(3) symmetry stretching mode and the first overtone state of the CH_(3) bending mode.展开更多
An efficient method is described for the synthesis of 2-substituted quinolino[7＇,8＇：5~6]pyrano[2,3-d] pyrimidin-4（3H）-ones（6） via a tandem aza-Wittig annulation process. The iminophosphorane（3） reacted with a...An efficient method is described for the synthesis of 2-substituted quinolino[7＇,8＇：5~6]pyrano[2,3-d] pyrimidin-4（3H）-ones（6） via a tandem aza-Wittig annulation process. The iminophosphorane（3） reacted with aromatic isocyanates, followed by heterocyclization on the addition of secondary amines, phenols or alcohols to give the corresponding guanidine intermediates（5）, which were cyclized in the presence of a catalytic amount of a base to tetracyclic compounds 6 in good yields. The corresponding carbodiimide（4） and guanidine-type intermediate compounds 5 need not be isolated.展开更多
Fourteen unreported 2-amino-4H-imidazol-4-ones 4 were rapidly synthesized by a new parallel synthetic method, which included aza-Wittig reaction of iminophosphorane 1 with phenyl isocynate to give carbodiimide 2 and s...Fourteen unreported 2-amino-4H-imidazol-4-ones 4 were rapidly synthesized by a new parallel synthetic method, which included aza-Wittig reaction of iminophosphorane 1 with phenyl isocynate to give carbodiimide 2 and subsequent reaction of 2 with various amines in a parallel fashion. The structure of compound 4 was confirmed by means of 1H NMR, MS and IR. The configuration of compound 4b was determined as in Z form since the coupling constant 3J( 13C, 1H) between the carbonyl carbon and the olefinic hydrogen was 5.6 Hz.展开更多
文摘(CH_3OCH_2CH_2C_5H_4)_2LnI(Ln=La,Nd)complexes have been synthesized by the reaction between NaI and[(CH_3OCH_2CH_2C_5H_4)_2LnCl]2 in THF;A single crystal X-ray study has shown that the lanthanum complex is an unsolvated monomer with lanthanum(Ⅲ)in a trigonal bipyramidal coordination geometry if the cyclopentadienyl ring is regarded as occupying a single polyhedral vertex.
基金supported by the National Natural Science Foundation of China(No.21773297,No.21973108,and No.21921004 to Minghui Yang,No.21973109 to Hongwei Song)。
文摘The mode selectivity of the H+CH_(3)D→H_(2)+CH_(2)D reaction was studied using a recently developed ten-dimensional time-dependent wave packet method.The reaction dynamics are studied for the reactant CH_(3)D initially from the ground state,the CH_(3) symmetry and asymmetry stretching excitation,the CD stretching excitation and the fundamental and the first overtone of the CH_(3) bending mode.The calculated reaction probabilities show that exciting either of the CH_(3) stretching modes enhances the reactivity in the collision energy range below 1.0 eV,while the CD stretching excitation does not obviously prompt the reaction.Fundamental CH_(3) bending excitation has nearly no effect on promoting reactivity.However,a significant enhancement is observed for the first overtone excitation of the CH_(3) bending mode,resulting from the Fermi resonance between the fundamental state of the CH_(3) symmetry stretching mode and the first overtone state of the CH_(3) bending mode.
基金Supported by the Mid-young Scholar's Science and Technology Program of the Education Department of Hubei Province,China(No.Q20082202)
文摘An efficient method is described for the synthesis of 2-substituted quinolino[7＇,8＇：5~6]pyrano[2,3-d] pyrimidin-4（3H）-ones（6） via a tandem aza-Wittig annulation process. The iminophosphorane（3） reacted with aromatic isocyanates, followed by heterocyclization on the addition of secondary amines, phenols or alcohols to give the corresponding guanidine intermediates（5）, which were cyclized in the presence of a catalytic amount of a base to tetracyclic compounds 6 in good yields. The corresponding carbodiimide（4） and guanidine-type intermediate compounds 5 need not be isolated.
文摘Fourteen unreported 2-amino-4H-imidazol-4-ones 4 were rapidly synthesized by a new parallel synthetic method, which included aza-Wittig reaction of iminophosphorane 1 with phenyl isocynate to give carbodiimide 2 and subsequent reaction of 2 with various amines in a parallel fashion. The structure of compound 4 was confirmed by means of 1H NMR, MS and IR. The configuration of compound 4b was determined as in Z form since the coupling constant 3J( 13C, 1H) between the carbonyl carbon and the olefinic hydrogen was 5.6 Hz.
