TY - JOUR
T1 - Synthesis, characterization, and reactivities of the polysiloxane-bridged binuclear metallocenes tetramethyldisiloxanediylbis(cyclopentadienyltitanium trichloride) and hexamethyltrisiloxanediylbis(cyclopentadienyltitanium trichloride)
AU - Noh, Seok Kyun
AU - Byun, Gyu gum
AU - Lee, Chul soo
AU - Lee, Dongho
AU - Yoon, Keun byung
AU - Kang, Kyoung Seok
PY - 1996/7/12
Y1 - 1996/7/12
N2 - The reaction of dithallium salts of tetramethyldisiloxanediylbis(cyclopentadienyl), 3, and hexamethyltrisiloxanediylbis(cyclopentadienyl), 4, with two equivalents of TiCl4 gives the title compounds tetramethyldisiloxanediylbis(cyclopentadienyltitanium trichloride), 5 and hexamethyltrisiloxanediylbis(cyclopentadienyltitanium trichloride), 6 respectively. The stoichiometric reaction of 5 and 6 with water results in the formation of new oxygen-bridged metallocenes [(TiCl2)2(μ2-O)-(η5-C5H4)2-μ2-(SiMe2)2O], 7, and [(TiCl2)2(μ2-O)-(η5-C5H4)2-μ2-(SiMe2)3O2}], 8. In addition, further reaction of 7 and 8 with another one equivalent of water or the treatment of 5 and 6 with an excess amount of water gives rise to the formation of the metallocene compounds having Ti4O4 rings [(TiCl)2(μ2-O)-(η5-C5H4)2-μ2-(SiMe2)2O]2(μ2-O)2, 9, and [(TiCl)2(μ2-O)-(η5-C5H4)2-μ2-(SiMe2)3O2]2(μ2-O)2, 10. All the new kinds of metallocenes prepared have been characterized by IR, NMR, mass spectrometry, or elemental analysis. Especially an investigation of the Δδ values in 1H NMR and a comparison between the theoretical and observed isotopic ratio in a mass spectra among the synthesized bridged compounds have been very conveniently utilized to study their structures. Polymerization experiments with the dinuclear complexes in the presence of methylaluminoxane as a cocatalyst indicate that the compounds 5 and 6 do exhibit catalytic activity for syndiotactic polymerization of styrene.
AB - The reaction of dithallium salts of tetramethyldisiloxanediylbis(cyclopentadienyl), 3, and hexamethyltrisiloxanediylbis(cyclopentadienyl), 4, with two equivalents of TiCl4 gives the title compounds tetramethyldisiloxanediylbis(cyclopentadienyltitanium trichloride), 5 and hexamethyltrisiloxanediylbis(cyclopentadienyltitanium trichloride), 6 respectively. The stoichiometric reaction of 5 and 6 with water results in the formation of new oxygen-bridged metallocenes [(TiCl2)2(μ2-O)-(η5-C5H4)2-μ2-(SiMe2)2O], 7, and [(TiCl2)2(μ2-O)-(η5-C5H4)2-μ2-(SiMe2)3O2}], 8. In addition, further reaction of 7 and 8 with another one equivalent of water or the treatment of 5 and 6 with an excess amount of water gives rise to the formation of the metallocene compounds having Ti4O4 rings [(TiCl)2(μ2-O)-(η5-C5H4)2-μ2-(SiMe2)2O]2(μ2-O)2, 9, and [(TiCl)2(μ2-O)-(η5-C5H4)2-μ2-(SiMe2)3O2]2(μ2-O)2, 10. All the new kinds of metallocenes prepared have been characterized by IR, NMR, mass spectrometry, or elemental analysis. Especially an investigation of the Δδ values in 1H NMR and a comparison between the theoretical and observed isotopic ratio in a mass spectra among the synthesized bridged compounds have been very conveniently utilized to study their structures. Polymerization experiments with the dinuclear complexes in the presence of methylaluminoxane as a cocatalyst indicate that the compounds 5 and 6 do exhibit catalytic activity for syndiotactic polymerization of styrene.
KW - Binuclear
KW - Metallocene
KW - Oxygen bridge
KW - Polysiloxane
KW - Silicon
UR - http://www.scopus.com/inward/record.url?scp=0030581032&partnerID=8YFLogxK
U2 - 10.1016/0022-328X(96)06128-1
DO - 10.1016/0022-328X(96)06128-1
M3 - Article
AN - SCOPUS:0030581032
SN - 0022-328X
VL - 518
SP - 1
EP - 6
JO - Journal of Organometallic Chemistry
JF - Journal of Organometallic Chemistry
IS - 1-2
ER -