To study the Fe-M interactions and their effects on 31p NMR, the structures of Fe（CO）3（EtPhPpy）2 1, Fe（CO）3（EtPhPpy）2M（NCS）2 （2： M=Zn, 3： M=Cd, 4： M=Hg） and Fe（CO）3（EtPhPpy）2CdX2 （5： X=C1, 6： X=...To study the Fe-M interactions and their effects on 31p NMR, the structures of Fe（CO）3（EtPhPpy）2 1, Fe（CO）3（EtPhPpy）2M（NCS）2 （2： M=Zn, 3： M=Cd, 4： M=Hg） and Fe（CO）3（EtPhPpy）2CdX2 （5： X=C1, 6： X=SCN） were investigated by density functional theory （DFT） PBE0 method. The stabilities S of complexes follow S（2）〉S（3）〉S（4） and S（3）,.~S（6）〉S（5）, indicating that 6 is stable and may be synthesized. The complexes with thiocyanate are more stable than that with chloride in Fe（CO）3（EtPhPpy）2CdX2. The strength I of Fe-M interactions follows I（2）≈I（3）〈I（4）. The Fe-Cd interactions of 3 and 6, which contain thiocyanate, are stronger than that of 5 with chloride. The charge-transfer, which enhances with the increasing of Fe-M interaction strength, comes from Et, Ph, py, CO groups towards P, Fe, and M atoms. Because the delocalization of thiocyanate disperses the charge of M2＋, the charge-transfer of the complexes with thiocyanate is stronger than that with chloride. There is a a-bond between Fe and Hg atoms in 4. However, in binuclear complexes except 4, the Fe-M interactions act as nFe→nM, σP-Fe→nM and σC-Fe→nM delocalization, and the N-M interactions mainly act as nN→nM delocalization. In binuclear complexes, due to the Fe→M interactions, the strong σFe--C→σ＊Fe--p or σFe-Hg→σ＊Fe--I2 delocalization and the charge-transfer, the electron density on P nucleus is increased, and thus upfield 31p chemical shifts are caused （compared with mononuclear complex 1）.展开更多
基金This work was supported by the Natural Science Foundation of Guangdong Province （No.5005938） and the Research Project of Ministry of Education and Guangdong Province （No.2007A090302046）.
文摘To study the Fe-M interactions and their effects on 31p NMR, the structures of Fe（CO）3（EtPhPpy）2 1, Fe（CO）3（EtPhPpy）2M（NCS）2 （2： M=Zn, 3： M=Cd, 4： M=Hg） and Fe（CO）3（EtPhPpy）2CdX2 （5： X=C1, 6： X=SCN） were investigated by density functional theory （DFT） PBE0 method. The stabilities S of complexes follow S（2）〉S（3）〉S（4） and S（3）,.~S（6）〉S（5）, indicating that 6 is stable and may be synthesized. The complexes with thiocyanate are more stable than that with chloride in Fe（CO）3（EtPhPpy）2CdX2. The strength I of Fe-M interactions follows I（2）≈I（3）〈I（4）. The Fe-Cd interactions of 3 and 6, which contain thiocyanate, are stronger than that of 5 with chloride. The charge-transfer, which enhances with the increasing of Fe-M interaction strength, comes from Et, Ph, py, CO groups towards P, Fe, and M atoms. Because the delocalization of thiocyanate disperses the charge of M2＋, the charge-transfer of the complexes with thiocyanate is stronger than that with chloride. There is a a-bond between Fe and Hg atoms in 4. However, in binuclear complexes except 4, the Fe-M interactions act as nFe→nM, σP-Fe→nM and σC-Fe→nM delocalization, and the N-M interactions mainly act as nN→nM delocalization. In binuclear complexes, due to the Fe→M interactions, the strong σFe--C→σ＊Fe--p or σFe-Hg→σ＊Fe--I2 delocalization and the charge-transfer, the electron density on P nucleus is increased, and thus upfield 31p chemical shifts are caused （compared with mononuclear complex 1）.
