Deconjugation of cyclopent-2-enone aldols were attempted under various conditions, and the desired deconjugated product was achieved via dianion approach. Various results obtained in this study are explained by struct...Deconjugation of cyclopent-2-enone aldols were attempted under various conditions, and the desired deconjugated product was achieved via dianion approach. Various results obtained in this study are explained by structure and transition state analysis.展开更多
The struetural effect of the conjugative system(C)with carbonyl-imino bridges has been studied.The results show that:In the conjugated system(C),there is no electronic absorption peak attributable to the whole system,...The struetural effect of the conjugative system(C)with carbonyl-imino bridges has been studied.The results show that:In the conjugated system(C),there is no electronic absorption peak attributable to the whole system,but there are three π-π* bands each nt which displays chacactecistics of its own independently.These indicate that the two bridges-carbonyl-and-imino-can block the tlanSmlSSion of the conjngative polarization of the whole system,so as to form three segments,this is verified by means of chemical synthesis and degradation.展开更多
A self-consistent-field—configuration interaction(SCF-CI)procedure of studying highly excited vibrational states of bent triatomic molecules is suggested and its application to O_3 is investigated.
Recent years,many novel complexes have been prepared by using hetero-bidentate ligands.However,complexes with such ligands as 4-vinylpyridine which has two different coordinating sites have not been reported,and only ...Recent years,many novel complexes have been prepared by using hetero-bidentate ligands.However,complexes with such ligands as 4-vinylpyridine which has two different coordinating sites have not been reported,and only a few complexes of Cu(I)have been published^(1-3).The title complex Cu_2(C_5H_4N·CH=CH_2)_3Cl was prepared and characterized by elemental analyses,ICP,IR,and electronic spectra.Its conductivity,oxidation potential and reduction potential were measured.展开更多
The kinetic study of carbonylation of methanol-acetic acid mixture to acetic acid and acetic anhydride over a cis-dicarbonylrhodium complex (MVM' Rh) coordinated with the ethylene diacrylate (M') crosslinked c...The kinetic study of carbonylation of methanol-acetic acid mixture to acetic acid and acetic anhydride over a cis-dicarbonylrhodium complex (MVM' Rh) coordinated with the ethylene diacrylate (M') crosslinked copolymer of methyl acrylate (M) and 2-vinylpyddine (V)shows that the rate of reaction is zero order with respect to both reactants methanol and carbon monoxide, but first order in the concentrations of promoter methyl iodide and rhodium in the complex. Polar solvents can accelerate the reaction. Activation parameters were calculated from the experimental results, being comparable to that of the homogeneous system. A mechanism similar to that of soluble rhodium catalyst was proposed.展开更多
The distribution of calcitonin gene-related peptidergic(CGRP) nerve endings in rat rat nasal mucosa was investigated with immunocytochemical technique (ABC method).The results showed that CGRP endings had a robust loc...The distribution of calcitonin gene-related peptidergic(CGRP) nerve endings in rat rat nasal mucosa was investigated with immunocytochemical technique (ABC method).The results showed that CGRP endings had a robust localization展开更多
Hypertensive ex—perimental studies pre—vented and treated byTCM are matured re|e—rant studies of westernmedicine for reference,such as the hypotensiveeffect and elucidating itstherapeutic mechanism.Comprehension in...Hypertensive ex—perimental studies pre—vented and treated byTCM are matured re|e—rant studies of westernmedicine for reference,such as the hypotensiveeffect and elucidating itstherapeutic mechanism.Comprehension in allliteratures,most simpleherbs and compound展开更多
The application ot the sulfinatodehalogenation reaction system for the perfluoroalkylation of electron-rich aromatics is further studied.It was shown that perfluoroalkyl iodides reacted with polyhydric phenols,N,N-dia...The application ot the sulfinatodehalogenation reaction system for the perfluoroalkylation of electron-rich aromatics is further studied.It was shown that perfluoroalkyl iodides reacted with polyhydric phenols,N,N-dialkylanilines,2,5-dimethylpyrrole,N-methylpyrrole initiated by Na_2S_2O_4- NaHCO_3 gave the corresponding perfluoroalkylated products in moderate to good yields.展开更多
Reaction of aqueous solution of sodium perfluoroalkanesulfinate with cupric sulphate gave a high yield of cupric perfluoroalkanesulfinate,which decomposed slowly in the air on exposure to light to give perfluorocarbox...Reaction of aqueous solution of sodium perfluoroalkanesulfinate with cupric sulphate gave a high yield of cupric perfluoroalkanesulfinate,which decomposed slowly in the air on exposure to light to give perfluorocarboxylic acid.The reaction between cupric perfluoroalkanesulfinate and olefins in the presence of potassium iodide and excess CuSO_4 in ether at low temperature(-30 to-20℃)for- med two kinds of adducts,namely the normal adducts,R_fSO_2CH_2CHIR(2)and the adducts resulting from the loss of SO_2 moiety,R_f CH_2CHIR(3)in yields ranging from morderate to good.These results were identical with that of the addition of perfluoroalkanesulfonyl iodide to olefins.A radical reac- tion mechanism is proposed.展开更多
文摘Deconjugation of cyclopent-2-enone aldols were attempted under various conditions, and the desired deconjugated product was achieved via dianion approach. Various results obtained in this study are explained by structure and transition state analysis.
文摘The struetural effect of the conjugative system(C)with carbonyl-imino bridges has been studied.The results show that:In the conjugated system(C),there is no electronic absorption peak attributable to the whole system,but there are three π-π* bands each nt which displays chacactecistics of its own independently.These indicate that the two bridges-carbonyl-and-imino-can block the tlanSmlSSion of the conjngative polarization of the whole system,so as to form three segments,this is verified by means of chemical synthesis and degradation.
文摘A self-consistent-field—configuration interaction(SCF-CI)procedure of studying highly excited vibrational states of bent triatomic molecules is suggested and its application to O_3 is investigated.
文摘Recent years,many novel complexes have been prepared by using hetero-bidentate ligands.However,complexes with such ligands as 4-vinylpyridine which has two different coordinating sites have not been reported,and only a few complexes of Cu(I)have been published^(1-3).The title complex Cu_2(C_5H_4N·CH=CH_2)_3Cl was prepared and characterized by elemental analyses,ICP,IR,and electronic spectra.Its conductivity,oxidation potential and reduction potential were measured.
基金This work was supported by a Grant from the National Natural Science Foundation of China
文摘The kinetic study of carbonylation of methanol-acetic acid mixture to acetic acid and acetic anhydride over a cis-dicarbonylrhodium complex (MVM' Rh) coordinated with the ethylene diacrylate (M') crosslinked copolymer of methyl acrylate (M) and 2-vinylpyddine (V)shows that the rate of reaction is zero order with respect to both reactants methanol and carbon monoxide, but first order in the concentrations of promoter methyl iodide and rhodium in the complex. Polar solvents can accelerate the reaction. Activation parameters were calculated from the experimental results, being comparable to that of the homogeneous system. A mechanism similar to that of soluble rhodium catalyst was proposed.
文摘The distribution of calcitonin gene-related peptidergic(CGRP) nerve endings in rat rat nasal mucosa was investigated with immunocytochemical technique (ABC method).The results showed that CGRP endings had a robust localization
文摘Hypertensive ex—perimental studies pre—vented and treated byTCM are matured re|e—rant studies of westernmedicine for reference,such as the hypotensiveeffect and elucidating itstherapeutic mechanism.Comprehension in allliteratures,most simpleherbs and compound
基金the National Natural Science Foundation of China.Part ⅩⅩⅢ in this series,see Huang,W.-Y.Zhuang,J.-L.,Chinese J.Chem.,9,270 (1991).
文摘The application ot the sulfinatodehalogenation reaction system for the perfluoroalkylation of electron-rich aromatics is further studied.It was shown that perfluoroalkyl iodides reacted with polyhydric phenols,N,N-dialkylanilines,2,5-dimethylpyrrole,N-methylpyrrole initiated by Na_2S_2O_4- NaHCO_3 gave the corresponding perfluoroalkylated products in moderate to good yields.
文摘Reaction of aqueous solution of sodium perfluoroalkanesulfinate with cupric sulphate gave a high yield of cupric perfluoroalkanesulfinate,which decomposed slowly in the air on exposure to light to give perfluorocarboxylic acid.The reaction between cupric perfluoroalkanesulfinate and olefins in the presence of potassium iodide and excess CuSO_4 in ether at low temperature(-30 to-20℃)for- med two kinds of adducts,namely the normal adducts,R_fSO_2CH_2CHIR(2)and the adducts resulting from the loss of SO_2 moiety,R_f CH_2CHIR(3)in yields ranging from morderate to good.These results were identical with that of the addition of perfluoroalkanesulfonyl iodide to olefins.A radical reac- tion mechanism is proposed.
