Α-diimine Ligand Drilling Metal Organic Compounds In The Study Of Reactivity

In recent years, organometallic complexes with low-valent, low-coordinate metal ions have attracted much interest owing to their excellent characteristics in many catalytic reactions and interesting reactivities with a variety of small molecules. The activation of small molecules have become a hot topic in chemical field. The noninnocent ligands of a-diimine have been proved to have the ability to stabilize complexes with low-valent, low-coordinate metal atoms owing to the electronic and steric effect tuning abilities. The late-transition-metal compounds coordinated with a-diimine ligands have important application value in catalytic chemistry. Especially the cobalt complexes with a-Diimine ligands have been widely applied in catalytic chemistry attribute to its inexpensive cost and efficient catalytic properties. On the strength of the advantages of cobalt organometallic compounds coordinated with a-diimine, designing the reactions towards small molecules and finding out some regularities will be profound. In this work, we designed the reactions of the cobalt complex, [L·-Co]2 (1, L= [(2,6-/Pr2C6H3)NC(Me)]2), with polyarenes and some other molecules, and reported the synthesis and characterization of nine cobalt organometallic compounds. Through a combination of crystal structure analysis, EPR spectroscopy, magnetic susceptibility measurement, and DFT computations, the electronic configurations of the complexes were studied.This thesis consists of three parts:1. The development of organometallic compounds with a-diimine, and the reaction properties of the typical complexes with small molecules are summarized.2. Reactions of the cobalt complex. [L·-Co]2 (1, L=[(2,6-/Pr2C6H3)NC(Me)]2) reacted with polyarenes affording a series of mononuclear and dinuclear complexes, [LCo(η4-anthracene)] (2), [LCo(μ-η4:η4-naphthalene)CoL] (3), and phenanthrene)CoL] (4). The pyrene complexes [{Na2(Et2O)2}{LCo(μ-η3:η3-pyrene)CoL}] (5) and [{Na2(Et2O)3}{LCo(73-pyrene)}] (6) were obtained by treating precursor 1 with pyrene followed by reduction with Na metal. Notably, these complexes contain three potential redox active centers:the cobalt metal, the a-diimine and polyarene ligands. Their electronic structures were elucidated by experimental and theoretical methods.3. Reactions of the cobalt complex, [L*-Co]2 (1, L= [(2,6-iPr2C6H3)NC(Me)]2), with some other small molecules which have unsaturated bond afforded a series of mononuclear and dinuclear complexes, LCo(η2-Ph-C=C-Ph) (7)、 [{(L*-)Co(μ-O)}2] (8)、[(L*-)Co(μ-η1-N3)2Co(L*-] (9)、LCo(η/4-C4-AcrH) (10). These complexes have been investigated by using X-ray diffraction and elemental analysis.