نتایج جستجو برای: high isotactic

تعداد نتایج: 2059709  

Journal: :Dalton transactions 2015
Yangyang Sun Yaqin Cui Jiao Xiong Zhongran Dai Ning Tang Jincai Wu

Two binuclear magnesium and zinc alkoxides supported by a bis-salalen type dinucleating heptadentate Schiff base ligand were synthesized and fully characterized. The two complexes are efficient initiators for the ring-opening polymerization (ROP) of L-lactide, affording polymers with narrow polydispersities and desirable molecular weights. Interestingly, the mechanisms for the ROP of lactide ar...

Journal: :Physical chemistry chemical physics : PCCP 2010
Yuji Sasanuma Yoko Ogawa Masanao Matsumoto

Conformational characteristics and configurational properties of poly(1-methylphosphirane) (PMePP) and poly(1-phenylphosphirane) (PPhPP) have been predictively elucidated by the refined rotational isomeric state scheme coupled with ab initio molecular orbital and density functional calculations. The lone pair of the phosphorus atom adopts an sp hybrid orbital. Owing to the high s character (50%...

Journal: :Dalton transactions 2013
Konstantin Press Vincenzo Venditto Israel Goldberg Moshe Kol

The activity of dibenzylzirconium and dibenzylhafnium Salalen complexes in polymerisation of propylene with MAO as a cocatalyst is described. Three Salalen ligand precursors combining a bulky alkyl group (1-adamantyl) on the imine-side phenol and electron withdrawing halo groups of different sizes on the amine-side phenol were explored. All metal complexes were obtained as single diastereomers....

Journal: :The journal of physical chemistry. B 2006
Pascal de Sainte Claire

In fluorescence emission spectra of poly(vinylcarbazole) (PVK), two types of excimers are observed, the fully and the partially overlapped excimers, namely, excimers and exciplexes. In this work, we investigated the structural changes induced by the transition between electronic levels S(0) and S(1). Furthermore, the widely used assumption of similar potential energy surfaces in the S(0) and S(...

Journal: :Dalton transactions 2011
Frédéric Drouin Todd J J Whitehorne Frank Schaper

The reaction of N,N'-dibenzyl-2-amino-4-imino-pent-2-ene, nacnac(Bn)H, with 1 or 2 equiv. of MgnBu₂ afforded the homoleptic complex nacnac(Bn)₂Mg. The reaction of nacnac(Bn)H with Mg(N(SiMe₃)₂)₂ yielded nacnac(Bn)MgN(SiMe₃)₂, which reacted with tert-butanol to form nacnac(Bn)MgOtBu. The latter complex crystallizes as an alkoxide bridge dimer and is active in the ring-opening polymerisation of r...

Journal: :Journal of Polymer Science: Polymer Physics Edition 1975

Journal: :Bulletin of the Chemical Society of Japan 1961

Journal: :Journal of Polymer Science Part A-2: Polymer Physics 1967

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید