Preparation and Characterization of (1-Me-indenyl)Ni(PR₃)(CC−Ph) (R = Cy, Ph) and Alkyne Polymerization Catalysis

Abstract

The complexes (1-Me-Ind)(PR3)Ni−CC−Ph (R = Ph and Cy) have been prepared and characterized spectroscopically and by means of single-crystal structural analyses. These compounds are inert toward the insertion of alkynes, but when combined with methylaluminoxane (MAO), they form active catalysts for the homogeneous polymerization of phenylacetylene. cis-Poly(Ph−CC−H) is thus obtained with M w values in the range of 104 and relatively narrow polydispersities. The combination of the corresponding Ni−Cl complexes with MAO gives similar results with Ph−CC−H and also polymerizes 1-hexyne and 3-hexyne, but the degree of polymerization is much lower. Optimization studies have shown that the polymerization reactions give the best results with THF as solvent and a 1:10 ratio of Ni to MAO. Evidence is presented for the involvement in the catalytic cycle of bimetallic species with a Ni(μ-X)(μ-Me)Al core.

Thermal, optical, electrochemical properties and conductivity of trans- and cis-poly(1-ethynylpyrene): a comparative investigation

“…However, to get a deeper insight into the effect of the stacking, we studied three new geometrically different di (1-ethynylpyrene) derivatives by UV-vis and Fluorescence spectroscopy for comparison with their respective polymers [37]. In the other studies, we also carried out the polymerization of EP using the catalytic system developed by Zargarian and co-workers: (1-Me-Indenyl)(PPh 3 )NiCbC-Ph and methylaluminoxane (MAO), (named here NiC/MAO) [35]. This method provided the formation of soluble cis-transoidal polymers (cis-PEPs, Fig.…”

Indenyl nickel complexes: synthesis, characterization and styrene polymerization catalysis

“…; X 0/halide, alkyl, alkynyl, imidate, thiolate, etc.) [3 Á/6] can act as effective precatalysts in a number of reactions, such as the oligomerizations or polymerizations of ethylene [4], styrene [5] and phenylacetylene [6], the dehydrogenative oligomerization and polymerization of phenylsilane [7] etc. Preliminary studies have implied that the in situ generated cationic species [Ind(PPh 3 )Ni] ' might be the active centers for these reactions and the Ind substituents have a major influence on the course of the catalysis, the later is in evidence by comparison the analogous styrene reactions catalyzed by in situ generated cations from (1-Me Á/Ind)(PPh 3 )Ni Á/Cl and (h 3 , h 0 -Ind Á/CH 2 CH 2 NMe 2 )(PPh 3 )Ni Á/Cl [5].…”

Synthesis of Conducting Organic Polymeric Materials Mediated by Metals: How the Organic Chemists Make Some of the Most Advanced Polymeric Materials

“…The catalyst that results from the mixture of [Ni(1-Me-indenyl)(PPh 3 )(C CPh)] 20 and methylaluminoxane has been used for the polymerization of the bulky acetylene 1-ethynylpyrene, affording cis-transoidal poly(1-ethynylpyrene) [42] in low to good yields (20 to 80 %, mainly depending on the temperature) with moderate molecular weight (1.4 to 2.4 10 4 D). The details of the mechanism were studied using phenylacetylene as model [43]. Other systems that incorporate acetylide ligands are [Ni (PR 3 ) 2 (C CC 6 H 5 ) 2 ] 21 and [Co(PR 3 ) 2 (C CC 6 H 5 ) 2 ] 22 (where R = Ph or Bu).…”