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trans-Cyclooctanediyl-bridged [OSSO]-type ligand 4 reacts with TiCl4(thf)2 in toluene to produce the corresponding titanium(IV) dichloro complexes as an inseparable mixture of cis-α isomer 6a and cis-β isomer 6b in a ratio of 2:1, whereas treatment of dilithio salt of 4 with TiCl3(thf)3 in Et2O afforded chloride-bridged dimeric titanium(III) complex 8, which indicated the antiferromagnetic character in a nonpolar solvent solution. Di(isopropoxy) titanium(IV) complex 10 having a C2-symmetric cis-α configuration was synthesized by the reaction of 4 with Ti(OiPr)4 in toluene as yellow crystals. Moreover, the reaction of 4 with Ti(NEt2)4 in toluene resulted in the unexpected formation of [OSSO]-type bis(phenolato)-bridged dinuclear diamido titanium(IV) complex 11, which adopted a distorted tetrahedral geometry on the titanium center. These titanium complexes were characterized on the basis of their NMR spectroscopic data, and the molecular structures of complexes 8, 10, and 11 were established by single crystal X-ray diffraction. The titanium(IV) and (III) complexes 6 and 8 upon activation with a cocatalyst in toluene polymerized 1-hexene isospecifically to produce poly(1-hexene) having high molecular weight (Mw = 22,000-52,000 g mol-1) and relatively narrow polydispersity (Mw/Mn = 1.7-1.8), albeit with low activity [0.27-1.0 g mmol(cat)-1 h-1]. [ABSTRACT FROM AUTHOR]

Novel selenolato-bridged dinudear hydridoplatinum complexes, cis-[Pt2H2(μ-SetBu)2(PPh3)2] (2) and cis-[Pt2H(SetBu)(μ- SetBu)2(PPh3)2] (3) were synthesized in 30% and 57% yields, respectively, by the thermolysis of hydrido(1,1-dimethylethaneselenolato) Pt(II) complex cis-[PtH(SetBu)(PPh3)2] (1) in toluene at 80 °C for 3 h. The structures of dinuclear complexes 2 and 3 were fully characterized on the basis of their NMR and IA spectroscopic data and X-ray crystallography. The two distorted square planar Pt atoms in 2 and 3 are held together by two bridged selenolato ligands, tBu groups of which adopt a trans configuration with respect to the four-membered Pt2Se2 ring. Each central Pt2Se2 ring in 2 and 3 has a hinged arrangement due to the steric repulsion among the two PPh3 ligands and the tBu group lying between them. [ABSTRACT FROM AUTHOR]