| Autor: |
Zhukhovitskiy AV; Department of Chemistry , University of California , Berkeley , California 94720 , United States., Kobylianskii IJ; Department of Chemistry , University of California , Berkeley , California 94720 , United States., Thomas AA; Roger Adams Laboratory, Department of Chemistry , University of Illinois , Urbana , Illinois 61801 , United States., Evans AM; Department of Chemistry , Northwestern University , Evanston , Illinois 60208 , United States., Delaney CP; Roger Adams Laboratory, Department of Chemistry , University of Illinois , Urbana , Illinois 61801 , United States., Flanders NC; Department of Chemistry , Northwestern University , Evanston , Illinois 60208 , United States., Denmark SE; Roger Adams Laboratory, Department of Chemistry , University of Illinois , Urbana , Illinois 61801 , United States., Dichtel WR; Department of Chemistry , Northwestern University , Evanston , Illinois 60208 , United States., Toste FD; Department of Chemistry , University of California , Berkeley , California 94720 , United States. |
| Abstrakt: |
Carbene polymerization provides polyolefins that cannot be readily prepared from olefin monomers; however, controlled and living carbene polymerization has been a long-standing challenge. Here we report a new class of initiators, (π-allyl)palladium carboxylate dimers, which polymerize ethyl diazoacetate, a carbene precursor in a controlled and quasi-living manner, with nearly quantitative yields, degrees of polymerization >100, molecular weight dispersities 1.2-1.4, and well-defined, diversifiable chain ends. This method also provides block copolycarbenes that undergo microphase segregation. Experimental and theoretical mechanistic analysis supports a new dinuclear mechanism for this process. |
