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Über einige besonderheiten der polymerisation von 2,3‐dimethylbutadien in durch lithiumorganische verbindungen initiierten prozessen

1977; Wiley; Volume: 178; Issue: 3 Linguagem: Inglês

10.1002/macp.1977.021780315

0025-116X

Natalia Smirnowa, Vladimir Sgonnik, Karl Kalninsch, B. L. Erussalimsky,

Synthesis and characterization of novel inorganic/organometallic compounds

Abstract The polymerization of 2,3‐dimethylbutadiene (DMB) induced by butyllithium (BuLi), oligo‐2,3‐dimethylbutadienyllithium (ODMBL), and by the system ODMBL/ N , N , N ′, N ′‐tetramethylethylenediamine (TMD) was investigated in heptane at 60°C. The reaction order with respect to the organolithium compound was found to be for these cases −0,32, 0,28, and 0,56 respectively. The negative reaction order for BuLi is caused by the existence of the mixed associates (BuLi) x . (M n Li) y which follows from the negative influence of BuLi on the propagation reaction rate in the system DMB/ODMBL. Contrary to butadiene and isoprene, catalytic amounts of TMD decrease the propagation rate of DMB. This phenomenon is ascribed to a weak tendency of the complexes of the DMB‐living chains to dissociate into the monomeric form M n Li. TMD. The UV‐ and IR‐spectra of the living DMB‐chains and their complexes with TMD are studied.