Coordination reactions of 2-pyridinecarboxaldehyde-phenylhydrazonatolithium with selected transition metal (Zn, Sn, Fe, Co, Ni and Zr) chlorides and its coupling reaction with dichloromethane.
The reactions of 2-pyridinecarboxaldehyde-phenylhydrazonatolithium C5H4Npy-CH[double bond, length as m-dash]Ni-NaLi(Ph) (abbreviated as Li) with a 1/2 equivalent of anhydrous metal (Zn, Sn, Fe and Co) chlorides or NiCl2(DME) (DME = 1, 2-dimethoxyethane) produced the corresponding mononuclear metal(ii) complexes ( and ), in which each ligand acts as a bidentate ligand and the coordination geometries around the metals are shown to be tetrahedral within the complexes , , and , respectively, and a tetragonal pyramid in the complex . The reaction of Li successively with sodium tert-butoxide and anhydrous ZrCl4 afforded the unanticipated bizirconium complex , in which each monoanionic ligand behaves as a tridentate bridge. Whereas treatment of Li with NiCl2 and then CH2Cl2 led to an interesting methylene-bridged bis(2-pyridyl-phenylhydrazone) compound in moderate yield; a comparative experiment showed that when the Li reacted with CH2Cl2, the coupling compound was also obtained but in very low yield. A plausible mechanism of compound formation was also proposed and supported by the density functional theory (DFT) calculations. All the synthesized compounds were characterized by single-crystal X-ray diffraction.
School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan, 030006, P. R. China. duanxe@sxu.edu.cn.
Xin-E
XE
Duan
Institute of Applied Chemistry, Shanxi University, Taiyuan 030006, P. R. China. dsliu@sxu.edu.cn.
Hong-Bo
HB
Tong
School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan, 030006, P. R. China. duanxe@sxu.edu.cn.
Xue-Hong
XH
Wei
School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan, 030006, P. R. China. duanxe@sxu.edu.cn.
He-Ping
HP
Shi
Institute of Applied Chemistry, Shanxi University, Taiyuan 030006, P. R. China. dsliu@sxu.edu.cn.
Sheng-Di
SD
Bai
School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan, 030006, P. R. China. duanxe@sxu.edu.cn.
Tao
T
Bai
Institute of Applied Chemistry, Shanxi University, Taiyuan 030006, P. R. China. dsliu@sxu.edu.cn.
Jing
J
Zhang
Institute of Applied Chemistry, Shanxi University, Taiyuan 030006, P. R. China. dsliu@sxu.edu.cn.
Yong-Bin
YB
Zhang
Institute of Applied Chemistry, Shanxi University, Taiyuan 030006, P. R. China. dsliu@sxu.edu.cn.
Dian-Sheng
DS
Liu