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Attention Score in Context
| Title |
Propagation and termination steps in Rh-mediated carbene polymerisation using diazomethane
|
|---|---|
| Published in |
Dalton Transactions: An International Journal of Inorganic Chemistry, January 2013
|
| DOI | 10.1039/c2dt32584e |
| Pubmed ID | |
| Authors |
Nicole M. G. Franssen, Markus Finger, Joost N. H. Reek, Bas de Bruin |
| Abstract |
Rh-mediated carbene (co)polymerisation of diazomethane works best in the presence of Rh(III) catalyst precursors, the use of which leads to a significant increase in polymer yield and molecular weight. Chain termination via β-hydride elimination is severely suppressed for these species, although this process does still occur leading to unsaturated chain ends. Subsequent chain walking leading to the formation of branched polymers seems not to occur. Computational studies describing pathways for both chain propagation and chain termination using a (cycloocta-2,5-dien-1-yl)Rh(III)(alkyl) species as a representative model for the active species revealed that chain propagation is favoured for these species, although β-hydride elimination is still viable at the applied reaction temperatures. The computational studies are in excellent agreement with all experimental results, and further reveal that chain propagation via carbene insertion (leading to linear poly-methylene) occurs with a much lower energy barrier than insertion of 1-alkenes into either the Rh-H bond after β-hydride elimination or into the Rh-C bond of the growing polymer chain (leading to branched polymers). These energetic differences conveniently explain why experimentally the formation of branches is not observed in (co)polymerisation reactions employing diazomethane. The formation of substantial amounts of low-M(w) oligomers and dimers in the experimental reactions can be ascribed to the presence of (1,5-cyclooctadiene)Rh(I) species in the reaction mixture, for which chain termination via β-hydride elimination is clearly favoured over chain propagation. These two species stem from a non-selective catalyst activation process during which the catalyst precursors are in situ activated towards carbene polymerisation, and as such the results in this paper might contribute to further improvements of this reaction. |
X Demographics
The data shown below were collected from the profile of 1 X user who shared this research output. Click here to find out more about how the information was compiled.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Unknown | 1 | 100% |
Demographic breakdown
| Type | Count | As % |
|---|---|---|
| Scientists | 1 | 100% |
Mendeley readers
The data shown below were compiled from readership statistics for 15 Mendeley readers of this research output. Click here to see the associated Mendeley record.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Japan | 1 | 7% |
| Germany | 1 | 7% |
| Saudi Arabia | 1 | 7% |
| Unknown | 12 | 80% |
Demographic breakdown
| Readers by professional status | Count | As % |
|---|---|---|
| Student > Master | 4 | 27% |
| Researcher | 3 | 20% |
| Student > Ph. D. Student | 3 | 20% |
| Professor > Associate Professor | 2 | 13% |
| Student > Doctoral Student | 1 | 7% |
| Other | 2 | 13% |
| Readers by discipline | Count | As % |
|---|---|---|
| Chemistry | 13 | 87% |
| Materials Science | 1 | 7% |
| Economics, Econometrics and Finance | 1 | 7% |
Attention Score in Context
This research output has an Altmetric Attention Score of 1. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 26 February 2013.
All research outputs
#22,760,732
of 25,374,917 outputs
Outputs from Dalton Transactions: An International Journal of Inorganic Chemistry
#12,352
of 21,062 outputs
Outputs of similar age
#258,419
of 289,007 outputs
Outputs of similar age from Dalton Transactions: An International Journal of Inorganic Chemistry
#483
of 1,212 outputs
Altmetric has tracked 25,374,917 research outputs across all sources so far. This one is in the 1st percentile – i.e., 1% of other outputs scored the same or lower than it.
So far Altmetric has tracked 21,062 research outputs from this source. They receive a mean Attention Score of 1.8. This one is in the 1st percentile – i.e., 1% of its peers scored the same or lower than it.
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We're also able to compare this research output to 1,212 others from the same source and published within six weeks on either side of this one. This one is in the 1st percentile – i.e., 1% of its contemporaries scored the same or lower than it.