Five-coordinated anionic tin(Ⅳ) complexes with the form [Ph 2Sn(μ 2-SCH 2COO)Cl]·[R nNH 4-n] were synthesized by the reaction of mercaptoacetic acid with diphenyltin dichloride in the presence of organic amines...Five-coordinated anionic tin(Ⅳ) complexes with the form [Ph 2Sn(μ 2-SCH 2COO)Cl]·[R nNH 4-n] were synthesized by the reaction of mercaptoacetic acid with diphenyltin dichloride in the presence of organic amines. All of the compounds synthesized were characterized by elemental analysis, IR, 1H NMR. The crystal structures of [C 5H 5NH][Ph 2Sn(μ 2-SCH 2COO)Cl](6) and [PhMeNH 2]· [Ph 2Sn(μ 2-SCH 2COO)Cl](8) were determined by X-ray diffraction. In the crystal structure, there were trigonal bipyramid geometries with five-coordinated tin atom and hydrogen-bonding interaction between anionic and cationic ions. Crystals of compound 6 were monoclinic, space group P2 1/n, a= 1.034 7(4) nm, b=1.396 8(5) nm, c=1.405 6(5) nm, β=95.366(6)°, Z=4; Crystals of compound 8 were monoclinic, space group P2 1/c, a=0.922 9(3) nm, b=1.334 5(5) nm, c= 1.838 5(7) nm, β=93.673(7)°, Z=4.展开更多
In this paper, we have disussed the internal rotation in sulfonylurea molecules,which belong to high active and low toxic herbicides and take the form of conformational iso-mers in their crystal structures. In order t...In this paper, we have disussed the internal rotation in sulfonylurea molecules,which belong to high active and low toxic herbicides and take the form of conformational iso-mers in their crystal structures. In order to understand the formation of their enantimers, weobtained a series of data of molecular energy of different conformation by using the molecularmechanics method and the stepwise rotation single-bond method. We found out the lowestinternal rotation passage and obtained the energy barrier of hindered rotation which is less 60kJ/mol. This result shows that there is a lower energy passage to exchange the conforma-tional isomers of these molecules, so exchanging the different conformational isomers is notvery difficult.展开更多
There is an increasing interest for the study of NO affinity of organic nitrite,for the biological and physiological effects of organic nitrites seem to be due to their ability releasing NO.In this paper,NO chemical a...There is an increasing interest for the study of NO affinity of organic nitrite,for the biological and physiological effects of organic nitrites seem to be due to their ability releasing NO.In this paper,NO chemical affinities of ten benzyl nitrites were determined respectively by titration calorimetry and from a thermodynamic cycle in acetonitrile solution.The results show that ΔHhet of O—NO in the O-nitroso compounds were substantially larger than the corresponding ΔHhomo of O—NO in the same compounds,suggesting that these O-nitroso compounds were much easier release NO radical by the O—NO bond homolytic cleavage.It is believed that the structural and energetic information disclosed in this work should be useful in understanding chemical and biological functions of organic nitrites.展开更多
文摘Five-coordinated anionic tin(Ⅳ) complexes with the form [Ph 2Sn(μ 2-SCH 2COO)Cl]·[R nNH 4-n] were synthesized by the reaction of mercaptoacetic acid with diphenyltin dichloride in the presence of organic amines. All of the compounds synthesized were characterized by elemental analysis, IR, 1H NMR. The crystal structures of [C 5H 5NH][Ph 2Sn(μ 2-SCH 2COO)Cl](6) and [PhMeNH 2]· [Ph 2Sn(μ 2-SCH 2COO)Cl](8) were determined by X-ray diffraction. In the crystal structure, there were trigonal bipyramid geometries with five-coordinated tin atom and hydrogen-bonding interaction between anionic and cationic ions. Crystals of compound 6 were monoclinic, space group P2 1/n, a= 1.034 7(4) nm, b=1.396 8(5) nm, c=1.405 6(5) nm, β=95.366(6)°, Z=4; Crystals of compound 8 were monoclinic, space group P2 1/c, a=0.922 9(3) nm, b=1.334 5(5) nm, c= 1.838 5(7) nm, β=93.673(7)°, Z=4.
文摘In this paper, we have disussed the internal rotation in sulfonylurea molecules,which belong to high active and low toxic herbicides and take the form of conformational iso-mers in their crystal structures. In order to understand the formation of their enantimers, weobtained a series of data of molecular energy of different conformation by using the molecularmechanics method and the stepwise rotation single-bond method. We found out the lowestinternal rotation passage and obtained the energy barrier of hindered rotation which is less 60kJ/mol. This result shows that there is a lower energy passage to exchange the conforma-tional isomers of these molecules, so exchanging the different conformational isomers is notvery difficult.
文摘There is an increasing interest for the study of NO affinity of organic nitrite,for the biological and physiological effects of organic nitrites seem to be due to their ability releasing NO.In this paper,NO chemical affinities of ten benzyl nitrites were determined respectively by titration calorimetry and from a thermodynamic cycle in acetonitrile solution.The results show that ΔHhet of O—NO in the O-nitroso compounds were substantially larger than the corresponding ΔHhomo of O—NO in the same compounds,suggesting that these O-nitroso compounds were much easier release NO radical by the O—NO bond homolytic cleavage.It is believed that the structural and energetic information disclosed in this work should be useful in understanding chemical and biological functions of organic nitrites.
