Thioaldehydes and thioketones are candidates of new photoluminescence materials. The time-dependent density functional theory is applied to calculate the absorption and emission wavelengths of ten thiocarbonyl compoun...Thioaldehydes and thioketones are candidates of new photoluminescence materials. The time-dependent density functional theory is applied to calculate the absorption and emission wavelengths of ten thiocarbonyl compounds using both B3LYP and PBEO functionals. The theoretical results are in agreement with the measurable ones. Furthermore, it is found that the maximum absorption and emission wavelengths are linearly correlated to the C-S bond lengths.展开更多
In order to study the Fe-Cu interactions and their effects on 31p NMR, the structures of mononuclear complex Fe（CO）3fPhzPpy）a 1 and binuclear complexes Fe（CO）3（PhEPpy）z（CuXn） （2： Xn = Cl2^2-, 3： Xn = Cl-, ...In order to study the Fe-Cu interactions and their effects on 31p NMR, the structures of mononuclear complex Fe（CO）3fPhzPpy）a 1 and binuclear complexes Fe（CO）3（PhEPpy）z（CuXn） （2： Xn = Cl2^2-, 3： Xn = Cl-, 4： Xn = Br-） are calculated by density functional theory （DFT） PBE0 method. For complexes 1, 3 and 4, the 31p NMR chemical shifts calculated by PBE0-GIAO method are in good agreement with experimental results. The 31p chemical shift is 82.10 ppm in the designed complex 2. The Fe-Cu interactions （including Fe→Cu and Fe←Cu charge transfer） mainly exhibit the indirect interactions. Moreover, the Fe-Cu（I） interactions （mostly acting as σFe-p→4Scu and aFe-C→4Scu charge transfer） in complexes 3 and 4 are stronger than Fe-Cu（Ⅱ） interactions （mostly acting as σFe-p→4Scu and σFe-p←4Sc,） in complex 2. In complex 2, the stronger Fe←Cu interac- tions, acting as σFe-p←44SCu charge transfer, increase the electron density on P nucleus, which causes the upfield 31p chemical shift compared with mononuclear complex 1. For 3 and 4, although a little deshielding for P nucleus is derived from the delocalization of σFe-p→4Scu due to the Fe→Cu interactions, the stronger σFe-c→np charge-transfer finally increases the electron density on P nucleus. As a result, an upfield 31p chemical shift is observed compared with 1. The stability follows the order of 2〉3=4, indicating that Fe（CO）3（PhzPpy）2（CuCl2） is stable and could be synthesized experimentally. The N-Cu（Ⅱ） interaction plays an important role in the stability of 2. Because the delocalization of σFe-p→4SCu and σFe-c→πc-o weakens the a bonds of Fe-C and ~r bonds of CO, it is favorable for increasing the catalytic activity of binuclear complexes. Complexes 3 and 4 are expected to show higher catalytic activity compared to 2.展开更多
To study the Cu-Cu interaction and stability of the title complexes,the structures of complexes [Cu（Ph2Ppy）（CH3CN）]＋ 1,[Cu（Ph2Ppy）]＋ 2,[Cu2（Ph2Ppy）2（CH3CN）2]2＋ 3,[Cu2（Ph2Ppy）2（CH3CN）]2＋ 4,[Cu2（Ph2Pp...To study the Cu-Cu interaction and stability of the title complexes,the structures of complexes [Cu（Ph2Ppy）（CH3CN）]＋ 1,[Cu（Ph2Ppy）]＋ 2,[Cu2（Ph2Ppy）2（CH3CN）2]2＋ 3,[Cu2（Ph2Ppy）2（CH3CN）]2＋ 4,[Cu2（Ph2Ppy）2]2＋ 5 and [Cu2（Ph2Ppy）3（CH3CN）]2＋ 6 were calculated by density functional theory PBE0 method,and the following conclusions can be drawn：（1） There is no orbital overlapping between two Cu atoms,indicating no Cu-Cu orbital interaction exists in complexes 3～6.Due to a breakdown of the closed shell configuration of Cu atoms,the weak Cu-Cu interactions result from the 3dCu → 4sCu＇ charge-transfer in 4～6.The Cu-Cu interaction strength follows 5 〉 6 〉 4,implying that there are stronger Cu-Cu interactions in the complexes with fewer CH3CN or more Ph2Ppy ligands.（2） The calculated interaction energies suggest that the coordination of Cu to Ph2Ppy is stronger than that to CH3CN.In 3～6,there are weaker interactions between Cu and CH3CN or Ph2Ppy in the complexes with more CH3CN or Ph2Ppy ligands.（3） The P-Cu and N-Cu interactions are much stronger than the Cu-Cu interaction,so we mainly attribute the stabilities of the binuclear complexes to the eight-membered rings Cu2P2N2C2.展开更多
本文回顾了现代密度泛函理论的基础,着重评述了XYG3型双杂化(XYG3 type of doubly hybrid,xDH)泛函的最新进展,解析能量梯度的实现.XYG3是首个依照绝热途径理论建立的双杂化泛函,在具体实现上具有独特的构架.该类型泛函利用常用泛函(如B...本文回顾了现代密度泛函理论的基础,着重评述了XYG3型双杂化(XYG3 type of doubly hybrid,xDH)泛函的最新进展,解析能量梯度的实现.XYG3是首个依照绝热途径理论建立的双杂化泛函,在具体实现上具有独特的构架.该类型泛函利用常用泛函(如B3LYP或PBE0等)作母泛函来进行自洽计算,以期获得更好的密度和轨道,然后将所得到的轨道和密度信息带入到xDH泛函中以得到最终能量.由于自洽泛函和最终能量泛函不同,因而在计算解析能量梯度时需要求解耦合微扰Kohn-Sham方程.在此基础上,还评述了xDH泛函在能量,尤其是构型优化方面的具体表现.测试的构型集包括以共价键键合的分子和非键相互作用体系的平衡结构,以及反应过渡态结构.结果表明,xDH双杂化泛函总体上给出了比母泛函更好的能量和几何构型.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 10375030.
文摘Thioaldehydes and thioketones are candidates of new photoluminescence materials. The time-dependent density functional theory is applied to calculate the absorption and emission wavelengths of ten thiocarbonyl compounds using both B3LYP and PBEO functionals. The theoretical results are in agreement with the measurable ones. Furthermore, it is found that the maximum absorption and emission wavelengths are linearly correlated to the C-S bond lengths.
基金Supported by the Natural Science Foundation of Guangdong Province (No. 5005938)
文摘In order to study the Fe-Cu interactions and their effects on 31p NMR, the structures of mononuclear complex Fe（CO）3fPhzPpy）a 1 and binuclear complexes Fe（CO）3（PhEPpy）z（CuXn） （2： Xn = Cl2^2-, 3： Xn = Cl-, 4： Xn = Br-） are calculated by density functional theory （DFT） PBE0 method. For complexes 1, 3 and 4, the 31p NMR chemical shifts calculated by PBE0-GIAO method are in good agreement with experimental results. The 31p chemical shift is 82.10 ppm in the designed complex 2. The Fe-Cu interactions （including Fe→Cu and Fe←Cu charge transfer） mainly exhibit the indirect interactions. Moreover, the Fe-Cu（I） interactions （mostly acting as σFe-p→4Scu and aFe-C→4Scu charge transfer） in complexes 3 and 4 are stronger than Fe-Cu（Ⅱ） interactions （mostly acting as σFe-p→4Scu and σFe-p←4Sc,） in complex 2. In complex 2, the stronger Fe←Cu interac- tions, acting as σFe-p←44SCu charge transfer, increase the electron density on P nucleus, which causes the upfield 31p chemical shift compared with mononuclear complex 1. For 3 and 4, although a little deshielding for P nucleus is derived from the delocalization of σFe-p→4Scu due to the Fe→Cu interactions, the stronger σFe-c→np charge-transfer finally increases the electron density on P nucleus. As a result, an upfield 31p chemical shift is observed compared with 1. The stability follows the order of 2〉3=4, indicating that Fe（CO）3（PhzPpy）2（CuCl2） is stable and could be synthesized experimentally. The N-Cu（Ⅱ） interaction plays an important role in the stability of 2. Because the delocalization of σFe-p→4SCu and σFe-c→πc-o weakens the a bonds of Fe-C and ~r bonds of CO, it is favorable for increasing the catalytic activity of binuclear complexes. Complexes 3 and 4 are expected to show higher catalytic activity compared to 2.
基金Supported by the Natural Science Foundation of Guangdong Province (No. 5005938)Research Project of Ministry of Education and Guangdong Province,China (2007A090302046)
文摘To study the Cu-Cu interaction and stability of the title complexes,the structures of complexes [Cu（Ph2Ppy）（CH3CN）]＋ 1,[Cu（Ph2Ppy）]＋ 2,[Cu2（Ph2Ppy）2（CH3CN）2]2＋ 3,[Cu2（Ph2Ppy）2（CH3CN）]2＋ 4,[Cu2（Ph2Ppy）2]2＋ 5 and [Cu2（Ph2Ppy）3（CH3CN）]2＋ 6 were calculated by density functional theory PBE0 method,and the following conclusions can be drawn：（1） There is no orbital overlapping between two Cu atoms,indicating no Cu-Cu orbital interaction exists in complexes 3～6.Due to a breakdown of the closed shell configuration of Cu atoms,the weak Cu-Cu interactions result from the 3dCu → 4sCu＇ charge-transfer in 4～6.The Cu-Cu interaction strength follows 5 〉 6 〉 4,implying that there are stronger Cu-Cu interactions in the complexes with fewer CH3CN or more Ph2Ppy ligands.（2） The calculated interaction energies suggest that the coordination of Cu to Ph2Ppy is stronger than that to CH3CN.In 3～6,there are weaker interactions between Cu and CH3CN or Ph2Ppy in the complexes with more CH3CN or Ph2Ppy ligands.（3） The P-Cu and N-Cu interactions are much stronger than the Cu-Cu interaction,so we mainly attribute the stabilities of the binuclear complexes to the eight-membered rings Cu2P2N2C2.
文摘本文回顾了现代密度泛函理论的基础,着重评述了XYG3型双杂化(XYG3 type of doubly hybrid,xDH)泛函的最新进展,解析能量梯度的实现.XYG3是首个依照绝热途径理论建立的双杂化泛函,在具体实现上具有独特的构架.该类型泛函利用常用泛函(如B3LYP或PBE0等)作母泛函来进行自洽计算,以期获得更好的密度和轨道,然后将所得到的轨道和密度信息带入到xDH泛函中以得到最终能量.由于自洽泛函和最终能量泛函不同,因而在计算解析能量梯度时需要求解耦合微扰Kohn-Sham方程.在此基础上,还评述了xDH泛函在能量,尤其是构型优化方面的具体表现.测试的构型集包括以共价键键合的分子和非键相互作用体系的平衡结构,以及反应过渡态结构.结果表明,xDH双杂化泛函总体上给出了比母泛函更好的能量和几何构型.
