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    Efficient Two Step Synthesis for Trimethylsiloxy-Functionalized New Polymers
    (Springer, 2019) Cetinkaya, Sevil; Yasar, Emine
    We have presented an efficient strategy for the synthesis of trimethylsiloxy end-functionalized new polymers using ring-opening metathesis polymerization with ruthenium initiator, [(PCy3)(2)Cl2Ru=CHPh]. The key steps for the new silicon containing end-capped polymers are: In the first step, direct end-capping is carried out by adding cis-2-butene-1,4-diol to the ring-opened norbornene dicarboximides. In the second step, the reaction of hydroxy-functionalized polymers with trimethylsilyl chloride gives trimethylsiloxy-functionalized polymers. The best results for the end group introduction are achieved by reacting the living chains with an excess of the terminating agent. The molecular and structural features of the obtained polymers were confirmed by NMR and GPC analyzes, and their thermal properties were investigated by DSC. End-functionalization efficiency values were determined by NMR spectroscopy.
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    Influence of ruthenium alkylidene complexes bearing tricyclohexylphosphine or 3-bromopyridine ligand on the properties of fluorine containing polymers
    (Springer, 2013) Cetinkaya, Sevil; Ozker, Taner; Kaya, Pembe Hulya; Yasar, Emine; Bayram, Rifat
    The catalytic performance of ruthenium alkylidene complexes bearing tricyclohexylphosphine or 3-bromopyridine ligand in the ring opening metathesis polymerization (ROMP) of fluorine containing monomers, exo-N-4-fluorophenyl-7-oxanorbornene-5,6-dicarboximide (FPhONDI) and exo-N-4-fluorophenyl-norbornene-5,6-dicarboximide (FPhNDI) was investigated. Pure monomers were subjected to ROMP with RuCl2(PCy3)(2)(CHPh) (I), RuCl2(PCy3)(H(2)IMes)(CHPh) (II), RuCl2(3-Br-py)(2)(PCy3)(CHPh) (III) and RuCl2(3-Br-py)(2)(H(2)IMes)(CHPh) (IV). The polymers were fully characterized using NMR, DSC, SEM and GPC. Catalysts I-IV displayed significant ROMP activity, allowing for the synthesis of the corresponding polymers with polydispersity indices (PDIs) in the range of 1.4-4.0. High molecular weight polymers (Mw up to 4.95 x10(5)) were prepared in yields up to 90 %, depending on the initiator and monomer used.
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    Synthesis and catalytic evaluation of a ruthenium alkylidene complex bearing methoxy-pyridine ligand
    (Elsevier Science Bv, 2013) Cetinkaya, Sevil; Yasar, Emine
    Modern well-defined ruthenium alkylidene complexes became preferred catalysts for a great variety of metathesis reactions. In this study, an air-stable new ruthenium alkylidene catalyst bearing 3-methoxypyridine has been prepared in one pot at high yields using commercially available [(PCy3)(2)Cl2Ru=CHPh] catalyst. Ruthenium based complex, (PCy3)(3-MeOPy)(2)(Cl)(2)Ru=CHPh, was characterized by a H-1 NMR doublet at 20.00 (J=11.9 Hz) for the Ru=CH proton. The catalyst was tested in model ROMP reactions and found to be very effective for ring-opening metathesis polymerization (ROMP). The optimal conditions for the polymerization of exo-N-benzylnorbornene-5,6-dicarboximide using the newly synthesized catalytic system were determined. (C) 2013 Elsevier B.V. All rights reserved.