The geometric configurations of binuclear Zinc( complex Zn2[(n-Bu)2NCSS]4 and the ligand Na[(n-Bu)2 NCSS] have been optimized by B3LYP quantum chemical method. The electronic structures have been performed by density ...The geometric configurations of binuclear Zinc( complex Zn2[(n-Bu)2NCSS]4 and the ligand Na[(n-Bu)2 NCSS] have been optimized by B3LYP quantum chemical method. The electronic structures have been performed by density functional theory at B3LYP/6-31G* level. The electronic spectrums of the complex and ligand were calculated by ZINDO/S-CIS method. It is indicated from the calculation that: (1) The coordination effect of bridging ligand is bigger than that of chelating one, and the bridging ligands also translate more charge to Zn than the chelating one. (2) The calculated results about electronic spectrums are similarly to experimental measurement, and farther explain that absorption band at λ=267 nm of complex is assigned to two n → π* transitions :one arising from the bridging ligands and the another mainly arising from the chelating ligands;but absorption band at λ=236 nm of complex is assigned to π → π* transition which the electron mainly translates from the bridging ligands to the chelating ligands. (3) By consideration of delocalization and polar effects in coordination, the charge transfer from ligand to metal decreases the π-π and p-π conjugation effects in the chromophore group NCS2 and to increase the energy needed for the π → π* and n → π* transitions, and results in the absorption bands shifting towards the short wavelength direction.展开更多
本文报导了对较普遍的水田和旱田杂草有不同活性的两个化合物除草剂,讨论了它们的结构与活性的关系,两个化合物的晶胞参数a_(Ⅰ)=21.422Å、b_(Ⅰ)=14.645Å,C_(Ⅰ)=8.769Å;a_(Ⅱ)=22.191Å、b_(Ⅱ)=12.355Å、c_(...本文报导了对较普遍的水田和旱田杂草有不同活性的两个化合物除草剂,讨论了它们的结构与活性的关系,两个化合物的晶胞参数a_(Ⅰ)=21.422Å、b_(Ⅰ)=14.645Å,C_(Ⅰ)=8.769Å;a_(Ⅱ)=22.191Å、b_(Ⅱ)=12.355Å、c_(Ⅱ)=9.404Å,空间群均为P_(b c a)、Z=8,分别用MuLTAN和RANTAN测定其结构,用块对角线最小二乘法修正,最冶R_(Ⅰ)=0.092、R_(Ⅱ)=0.108。展开更多
文摘The geometric configurations of binuclear Zinc( complex Zn2[(n-Bu)2NCSS]4 and the ligand Na[(n-Bu)2 NCSS] have been optimized by B3LYP quantum chemical method. The electronic structures have been performed by density functional theory at B3LYP/6-31G* level. The electronic spectrums of the complex and ligand were calculated by ZINDO/S-CIS method. It is indicated from the calculation that: (1) The coordination effect of bridging ligand is bigger than that of chelating one, and the bridging ligands also translate more charge to Zn than the chelating one. (2) The calculated results about electronic spectrums are similarly to experimental measurement, and farther explain that absorption band at λ=267 nm of complex is assigned to two n → π* transitions :one arising from the bridging ligands and the another mainly arising from the chelating ligands;but absorption band at λ=236 nm of complex is assigned to π → π* transition which the electron mainly translates from the bridging ligands to the chelating ligands. (3) By consideration of delocalization and polar effects in coordination, the charge transfer from ligand to metal decreases the π-π and p-π conjugation effects in the chromophore group NCS2 and to increase the energy needed for the π → π* and n → π* transitions, and results in the absorption bands shifting towards the short wavelength direction.
文摘本文报导了对较普遍的水田和旱田杂草有不同活性的两个化合物除草剂,讨论了它们的结构与活性的关系,两个化合物的晶胞参数a_(Ⅰ)=21.422Å、b_(Ⅰ)=14.645Å,C_(Ⅰ)=8.769Å;a_(Ⅱ)=22.191Å、b_(Ⅱ)=12.355Å、c_(Ⅱ)=9.404Å,空间群均为P_(b c a)、Z=8,分别用MuLTAN和RANTAN测定其结构,用块对角线最小二乘法修正,最冶R_(Ⅰ)=0.092、R_(Ⅱ)=0.108。
