Synthesis And Characterization Of Main Group And Transition Metal Complexes Bearing Novel N, N, O-and N, N, N-Chelate Ligands

This thesis mainly focuses on synthesis and characterization of new types of tridentate N,N, O-chelating ligands which contain pyridyl and pyrazolyl moieties and their Ni, Pd, Zn, Al complexes and tridentate N,N,N-chelating ligands which contain pyridyl and pyrazolyl moieties as well as imine or iminophosphorane groups and their Li, Al, Zn, Sn, Pb, Yb complexes.Chapter 1 describes synthesis and characterization of two new anionic tridentate N,N,O-chelating ligands [2-{OC(Ph)₂CH₂}-6-(3,5-Me₂C₃HN₂)C₅H₃N]^- ([Ll]^-) and [2-{OC- (Ph)=CH}-6-(3,5-Me₂C₃HN₂)C₅H₃N]^- ([L2]^-), their neutral compounds H[L1] (37') and H[L2a] (38) and the metal complexes Li[L1] (37), Na[L2a] (39), [L1]PdCl (40), [L1]NiAr (41a, Ar = o-MeC₆H₄; 41b, Ar = 1-C₁₀H₇), [L2a]PdCl (42) and [L2a]NiAr (43a, Ar = o-MeC₆H₄; 43b, Ar = 1-C₁₀H₇). The structures of complexes 41b and 43a were determined by single crystal X-ray diffraction techniques. Catalytic properties of the nickel and palladium complexes toward Heck reaction and Kumada reaction were evaluated.Chapter 2 is on synthesis and characterization of Al and Zn complexes bearing L1 and L2 ligands which are reported in chapter 1. These complexes include A1R₂[L1] (31, R = Me; 32, R - Et), A1R₂[L2] (34, R = Me; 35, R = Et), ZnEt[L2a] (36), Zn[L2a]₂ (38) and Zn[L2b]₂ (39). A tetranuclear zinc complex [{ZnEt[L2a]}₂{(EtZn)₂O}] (37) was also formed in the reaction of H[L2a] with Et₂Zn due to the presence of trace moisture. The structures of complexes 35, 37 and 39 were determined by single crystal X-ray diffraction techniques.Chapter 3 presents synthesis of a new anionic tridentate N,N,N-chelating ligand and its Li, Zn complexes. The complexes synthesized include Li[L3] (113), ZnR[L3] (114, R = Cl; 115, R = Me; 116 R = Et) and A1R(Cl)[L3] (117, R = Me; 118, R = Et), Complex 116 could also be obtained by the reaction of 113 with LiBHEt₃. We also synthesized and characterized pyridyl- and pyrazolyl-containing iminophosphorane compounds [{2-{N(R)P(Ph)₂=CH}-6-(3,5-Me₂C₃HN₂)C₅H₃N}] (H[L₄]) [HL4a(120), R = Ph; HL4b (121), R = SiMe₃]. The complex of ligand L4a, ZnEt[L4a] (122) and [M₂{2-C{P(Ph₂)=N(SiMe₃)}-6-(3,5-Me₂C₃HN₂)C₅H₃N}₂] (123, M = Sn; 124, M = Pb) were further synthesized and characterized. In addition, we also synthesized pyridylcontaining diiminephosphorane compounds [2-{P(Ph)₂=N(R)}-6-{CH₂P(Ph)₂=N-(SiMe₃)}C₅H₃N] (H[L5]) (H[L5a] (130), R= 4-Me-C₆H₄; H[L5b] (131), R = SiMe₃) and prepared a series of metal complexes containing this ligand, including threecoordinatedtin complex [Sn[N(SiMe₃)₂] {2-{CHP(Ph)₂=N(SiMe₃)}-P(Ph)₂=N-(4-MeC₆H₄)}C₅H₃N}], 1,3-dimetallacyclobutanes [M₂{2-C{P(Ph₂)=N(SiMe₃)}-6-{P(Ph₂)=N(SiMe₃)}C₅H₃N}₂] (133, M = Sn; 134, M = Pb), four-coordinated ytterbium complex Yb[N(SiMe₃)₂][L5b] (135), as well as Zn and Al complexes M(Et)_n[L5b] (136, M = Zn, n = 1; 137, M = Al, n = 2)]. The structures of complexes 115, 122, 123, 124, 132, 134, 135, 136 and 137 were determined by single crystal X-ray diffraction techniques.Chapter 4 deals with the reaction of ArN₃ [Li{Si(SiMe₃)₃}(thf)₃], yielding lithium amides [Li{N(Ar)Si(SiMe3)₃}L] (22, Ar = Ph, L =(thf)₂; 23, A with r = Naphyl, L = (thf)₂; 24, Ar = Ph, L = tmeda; 25, Ar = 4-Me-C₆H₄, L = tmeda) and dilithium diamide [{Li(thf)}₂{1,2-(NSi(SiMe₃)₃)₂C₆H₄}] (26). Unexpectedly, the reaction between o-Me₃SiOC₆H₄N₃ and [Li{Si(SiMe₃)₃}(thf)₃] afforded, via 1,4- trimethylsilyl migration from oxygen to nitrogen, [Li{OC₆H₄{N(SiMe₃)Si(SiMe₃)₃}- 2}]₂ (27). Complexes 23 and 27 have been characterized by single crystal X-ray diffraction techniques.