Copolymerization of cyclohexene oxide and carbon dioxide using (salen)Co(III) complexes: synthesis and characterization of syndiotactic poly(cyclohexene carbonate).

Content Provider	Semantic Scholar
Author	Cohen, Claire T. Thomas, Christophe M. Peretti, Kathryn L. Lobkovsky, Emil B. Coates, Geoffrey W.
Copyright Year	2006
Abstract	Synthetic routes to a series of new (salen-1)CoX (salen-1 = N,N'-bis(salicylidene)-1,2-diaminoalkane; X = halide or carboxylate) species are described and the X-ray crystal structures of two (salen-1)CoX (salen- = N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-diaminocyclohexane; X = Cl, I) complexes are presented. (R,R)-(salen-)CoX (X = Cl, Br, I, OAc, pentafluorobenzoate (OBzF(5))) catalysts are active for the copolymerization of cyclohexene oxide (CHO) and CO(2), yielding syndiotactic poly(cyclohexene carbonate) (PCHC), a previously unreported PCHC microstructure. Variation of the salen ligand and reaction conditions, as well as the inclusion of [PPN]Cl ([PPN]Cl = bis(triphenylphosphine)iminium chloride) cocatalysts, has dramatic effects on the polymerization rate and the resultant PCHC tacticity. Catalysts rac-(salen-)CoX (salen- = N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-diaminopropane; X = Br, OBzF(5)) have high activities for CHO/CO(2) copolymerization, yielding syndiotactic PCHCs with up to 81% r-centered tetrads. Using Bernoullian statistical methods, PCHC tetrad and triad sequences were assigned in the (13)C NMR spectra of these polymers in the carbonyl and methylene regions, respectively.
File Format	PDF HTM / HTML
DOI	10.1039/B513107C
PubMed reference number	16357982
Journal	Medline
Volume Number	1
Alternate Webpage(s)	http://www.rsc.org/suppdata/dt/b5/b513107c/b513107c.pdf
Alternate Webpage(s)	https://doi.org/10.1039/B513107C
Journal	Dalton transactions
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article