The reaction of the lithium tris(2-pyridyl)stannate [LiSn(2-py6OtBu)3] (py6OtBu = C5H3N-6-OtBu),1, with the element(II) amides E{N(SiMe3)2}2 (E = Sn, Pb) afforded complexes [LiE{Sn(2 py6OtBu)3}3] for E = Sn (2) and E = Pb (3), which reveal three Sn–E bonds each. Compounds 2 and 3 have been characterized by solution NMR spectroscopy and X-ray crystallographic studies. Large 1J(119Sn–119/117Sn) as well as 1J(207Pb–119/117Sn) coupling constants confirm their structural integrity in solution. However, contrary to 2, complex 3 slowly disintegrates in solution to give elemental lead and the hexaheteroarylditin [Sn(2-py6OtBu)3]2 (4).

The objective of this thesis is to examine the photophysical and structural properties of Cu(I) complexes of 2-(2’-pyridyl)benzimidazolyl based ligands and Cu(I), Pd(II) and Pt(II) complexes of 2-(2’-pyridyl)indolyl based ligands, for possible use as phosphorescent emitters in OLEDs. The discovery of the atropisomeric 3,3’-bis(2-(2’-pyridyl)indolyl based ligands led to the examination of C-C coupling reactions and the investigation of the new chiral ligands with transition metal ions. Cu(I) complexes of 2-(2’pyridyl)benzimidazolyl-benzene with varying phosphine ligands were prepared. The structures were studied with X-ray crystallography and NMR. Experimental and computational results established that steric and electronic properties of the phosphine ligands influence the photophysical properties of the Cu(I) complexes. Polynuclear Cu(I) complexes with 2-(2’-pyridyl)benzimidazolyl based ligands and two PPh3 ancillary ligands were synthesized, the photoluminescent and electroluminescent properties were examined. A series of 2-(2’-pyridyl)indolyl based ligands; 2-(2’-pyridyl)indolyl-benzene (pib), 1,4-bis[2-(2’-pyridyl)indolyl]benzene (bib) and 1,3,5-tris[2-(2’-pyridyl)indolyl]benzene) (tib) and the corresponding C-C coupled dimers bis[3,3’(2-(2’-pyridyl)indolyl-benzene)] (bpib), bis[3,3’(1,4-bis[2-(2’-pyridyl)indolyl]benzene (bbib) and bis[3,3’(1,3,5-tris[2-(2’-pyridyl)indolyl]benzene)] (btib) were synthesized in a one-pot reaction with the formation of both C-N and C-C bonds. The photophysical properties of these new molecules were investigated. The dimers display intramolecular exciplex formation. The rotation barrier around the C-C bond in the 3 position of the bis-indole was calculated using DFT which support that bpib is an atropisomeric ligand. Cu(I), Pd(II) and Pt(II) complexes were synthesized with pib and bpib. [Cu(pib)(PPh3)2]+ contains a three-coordinate Cu(I) ion and doesn’t display MLCT but rather 3π-1π phosphorescence. In Pd(pib)(acac) and Pt(pib)(DMSO)Cl the pib ligand forms C,N chelated neutral complexes that display red emission in frozen solution and in solid state. The X-ray crystal structure for [Cu(bpib)2]+ revealed a homo-chiral crystal and for Pd(bpib)Cl2 and Pt(bpib)Cl¬2 show a trans-chelating geometry around the metal centre. Frozen solutions of [Cu(bpib)2]+ and Pd(bpib)Cl2 display MCLT phosphorescence. Finally the atropisomeric ligands bpib and bbib were examined as sensors to determine the enantiomeric excess of Zn(2-bromo-3-methylbutyrate)2 by CD spectroscopy. CD and fluorescent titration experiments verified that these ligands have selective interactions with different Zn(II) carboxylates. DFT computations showed that diastereomeric excess caused by chiral discrimination leads to the CD spectral-response of the atropisomeric ligands toward chiral Zn(II) carboxylates. / Thesis (Ph.D, Chemistry) -- Queen's University, 2008-09-25 09:54:21.464

The reaction of the lithium tris(2-pyridyl)stannate [LiSn(2-py6OtBu)3] (py6OtBu = C5H3N-6-OtBu),1, with the element(II) amides E{N(SiMe3)2}2 (E = Sn, Pb) afforded complexes [LiE{Sn(2 py6OtBu)3}3] for E = Sn (2) and E = Pb (3), which reveal three Sn–E bonds each. Compounds 2 and 3 have been characterized by solution NMR spectroscopy and X-ray crystallographic studies. Large 1J(119Sn–119/117Sn) as well as 1J(207Pb–119/117Sn) coupling constants confirm their structural integrity in solution. However, contrary to 2, complex 3 slowly disintegrates in solution to give elemental lead and the hexaheteroarylditin [Sn(2-py6OtBu)3]2 (4).