Synthesis And Structures Of Amidinate And Guanidinate Metal Complexes

In this work, the derivatives of cyclohexylamine, phenylamine,2,6-diisopropylphenylamine and2-aminopyridine (CyN(Li)SiMe3, PhN(Li)SiMe3,(Ar)N(Li)SiMe3,(2-C5H4N)N(Li)SiMe3) were used as starting materials to react with different α-hydrogen-free carbonitriles and gave amidinate and guanidinate ligands. The ligands when react with metal halides afforded the corresponding metal complexes. The structures and properties of the ligands and the metal complexes were investigated. Here ten novel metal complexes were synthesized and their structures were characterized by single crystal X-ray diffraction,1H NMR and13C NMR. The details included the following three chapters.Chapter1. The significance and background of the research were introduced in detail. It is divided into four sections:(1) the introduction of organometallic chemistry;(2) the synthesis and structures of amidinate metal complexes;(3) the synthesis and structures of guanidine metal complexes;(4) the developments and applications of amidinates and guanidinates.Chapter2. The reaction of reagent CyN(Li)SiMe3(L1) with α-hydrogen-free PhCN at the ratio of1:1led to amidinate complex2a in the presence of THF, and gave unexpected amidinate complex2b in the presence of toluene. But when Et2O was used as the solvent gave amidinate complex2c that TMEDA-solvated. The five-coordinate magnesium (Ⅱ) amidinate complex2d was synthesized from the reaction of L1with equiv of PhCN and then1/2equiv of MgBr2·2THF in Et2O. The bimeric copper (I) amidinate complex2e was synthesized in similar manner to2d but with1:1anhydrous CuCl. Treatment of CyN(Li)SiMe3(L1) with PhCN and ZrCl4yielded the complex2f (Scheme1) via unexpected hydrolysis. Their structures were characterized by single crystal X-ray diffraction,1H NMR and13C NMR. Scheme1Synthesis of complexes2a-2f Reagents and congditions:i PhCN,THF, ca,-78℃; ii PhCN, Toluene, H2O. ca,-78℃; iii PhCN, TMEDA. Et2O, ca.-78℃;iv PhCN, MgBr2-2THF, Et2O, ca,-78℃;v PhCN. CuCl, Et2O, ca,-78℃; vi PhCN, ZrCl4, Et2O, THF, ca,-78℃.Chapter3. The reaction of PhN(Li)SiMe3(L2) with α-hydrogen-free dimethyl cyanamide at ratio of1:1and then with YC13led to dimeric yttrium(Ⅲ) compound3a. The reaction of reagent (Ar)N(Li)SiMe3(L3, Ar=2,6-Pr2-C6H3) with a-hydrogen-free dimethyl cyanamide at ratio of1:2and then reacted with Cul and SnCl2·2H2O can give3b and3c, respectively. Scheme2Synthesis of complexes3a-3d Reagents and congditions:i Me2NCN, YC13, Et2O, ca,-78℃; ii Me2NCN, Cul, Et2O, ca,-78℃; iii Me2NCN, SnCl2-2H2O, Et2O, ca,-78℃; iv Me2NCN, THF, ca.-78℃The ligand backbone in compounds3b and3c both adopted W-shaped conformation. The reaction of reagent (2-C5H4N)N(Li)SiMe3(L4) with α -hydrogen-free dimethyl cyanamide at the ratio of1:1led to guanidinate ligands3d (Scheme2). Their structures were characterized by single crystal X-ray diffraction,1H NMR and13C NMR. Their structural features were analylized and compared with each other.