Bimetallic complexes based on preorganized binucleating bis(amidinate) and bis(amidoamine) ligand systems

Chapter 1. Bimetallic reactivity over the last few decades is discussed. In particular, transition metal bimetallic complexes with limited coupling between the metal centers are discussed. The properties of bis(amidinate) and bis(amidoamine) binucleating ligand systems are elucidated.; Chapter 2. Bimetallic Ti(IV) and Ti(III) species supported by preorganized bis(amidinate) ligands are described. The ligand iPr LXanH2 is utilized to form the species iPrLXanTi2Cp2Me4 along with the 2D and 13C labeled versions iPrLXanTi2Cp2(CD3) 4, and iPrLXanTi2Cp2( 13CH3)4. These species are employed in the formation of rare examples of first-row transition-metal and isotopically labeled alkyl hydrido(deuterido) species iPrLXanTi2Cp 2(mu-Me)(mu-H), iPrLXanTi2Cp 2(mu-Me)(mu-D), iPrLXanTi2Cp 2(mu-CD3)(mu-H), and iPrLXanTi 2Cp2(mu-13CH3)(mu-H) which do not undergo reductive elimination of methane. The less symmetric ligand tBu,EtLXanH2 is utilized to form the first-row transition-metal alkyl hydrido species tBu,EtL XanTi2Cp2(mu-Me)(mu-H) which was suitable for characterization by single-crystal X-ray diffraction.; Chapter 3. New dizirconium complexes prepared from preorganized binucleating bis(amidinate) ligands are reported. The previously described ligands are used to form the amido and chloride containing species iPrLXanZr2(NMe2)6, tBu,EtLXanZr2(NMe2)6 and iPrLXanZr2Cp2Cl4. iPrLXanZr2Cp2Cl4 reacts with Me2Mg and LiCH2SiMe3 to form iPrLXanZr2Cp2Me4 and iPrLXanZr2CP2(CH2SiMe 3)4. iPrLXanZr2CP 2H4, formed by the reaction of iPrLXan Zr2Cp2(CH2SiMe3)4 with H2, shows interesting fluxional behavior in solution.; Chapter 4. New dititanium complexes prepared from preorganized binucleating bis(amidinate) ligands are reported. The ligands iPrL XanH2, iPrLDBFH2, tBu,EtLXanH2, and tBu,EtL DBFH2 react with Ti(NMe2)4 to form the bimetallic species iPrLXanTi2(NMe 2)6, iPrLDBFTi2(NMe 2)6, tBu,EtLXanTi2(NMe 2)6, and tBu,EtLDBFTi2(NMe 2)6, respectively. The ligand iPrLXan H2 reacts with Ti(NMe2)2Cl2 to form the dititanium species iPrLXanTi2(NMe 2)2Cl4. This allows access to the carbamate species iPrLXanTi2(NMe2)4(O 2CNMe2)2 by reaction of iPrL XanTi2(NMe2)6 with CO2. The lithiated ligand iPrLDBFLi2 reacts with CpTiCl4 to form iPrLDBFTi2 Cp2Cl4 which can be reduced by Na/Hg amalgam to form iPrLDBFTi2Cp2Cl 2. The ligands iPrLDBFH2 and tBu,EtLDBFH2 are used to form the species iPrLDBFTi2Cp2Me4 and tBu,EtLDBFTi2Cp2Me4, which are similar to compounds described in Chapter 2.; Chapter 5. New magnesium and lithium complexes prepared from preorganized binucleating bis(ethylenediamine) ligands are reported. The ligands MeC2LH2, i PrC2LH2, and EtC3LH2 are reported. The species MeC2LH2 and i PrC2LH2 are used to form the lithium and magnesium bimetallic species MeC2LLi2, i PrC2LLi2, MeC2LMg2Me2, and iPrC2LMg2Me 2. These species represent rare examples of dimeric lithium and bridging alkyl magnesium complexes.; Chapter 6. New titanium and zirconium complexes prepared from preorganized binucleating bis(ethylenediamine) ligands are reported. The group IV bimetallic bis(amidoamine) complexes MeC2LZr 2(NMe2)6, MeC2LTi2(NMe 2)2Cl4, i PrC2LZr2(NMe2)6, and iPrC2LZr2(NMe2) 4Cl2 formed from the binucleating ligands MeC2LH 2, iPrC2LH2, and iPrC2LLi2 are reported.