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
Synthesis and crystal structure of the title molecule was reported here. The crystal is monoclinic, belonging to space group P21/n, with unit cell parameters a = 0. 786 1 (3)nm, b=0. 580 9(2) nm, c=3. 272 9(6) nm, β=...Synthesis and crystal structure of the title molecule was reported here. The crystal is monoclinic, belonging to space group P21/n, with unit cell parameters a = 0. 786 1 (3)nm, b=0. 580 9(2) nm, c=3. 272 9(6) nm, β=93. 25°, V=1. 492(1) nm3, D.=1. 568 g/cm3, μ=2. 441 cm-1, F(0 0 0) =728 for 1 084 reflections. R=0. 046, R.=0. 046. Molecular structure was discussed. There are three different planes in the molecule, with a conjugated system in each. The conformation difference between this molecule and other sulfonylure a molecule which has a different bioactivity was compared.展开更多
基金National Natural Science Foundation of China(No.30800757)the key project of Fujian Provincial Science & Technology Foundation(No.2008N0107)by the Xiamen Municipal Science & Technology Project(No.3502Z20081137)
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Synthesis and crystal structure of the title molecule was reported here. The crystal is monoclinic, belonging to space group P21/n, with unit cell parameters a = 0. 786 1 (3)nm, b=0. 580 9(2) nm, c=3. 272 9(6) nm, β=93. 25°, V=1. 492(1) nm3, D.=1. 568 g/cm3, μ=2. 441 cm-1, F(0 0 0) =728 for 1 084 reflections. R=0. 046, R.=0. 046. Molecular structure was discussed. There are three different planes in the molecule, with a conjugated system in each. The conformation difference between this molecule and other sulfonylure a molecule which has a different bioactivity was compared.
