Perfluorocycloalkene

Perfluorocycloalkene (PFCA) is a general class of fluorocarbon compounds comprising many commercially available perfluorocyclo-olefins including hexafluorocyclobutene (or perfluorocyclobutene), octafluorocyclopentene (or perfluorocyclopentene ) and decafluorocyclohexene (or perfluorocyclohexene ) (Figure 1).[1][2] Perfluorocycloalkene is a cycloalkene with no aromatic character, and has only carbon and fluorine, but no hydrogen.

Figure 1. Structure of PFCAs

PFCAs have shown reactivity with a wide variety of nucleophiles including phenoxides, alkoxides, organometallic, amines, thiols, and azoles.[3] These small PFCA derivatives have shown a variety of applications including photochromic,[4] nonlinear optical activity,[5] lubricants,[6] etching agents,[7] fuel cells,[8] and low dielectric materials, super hydrophobic and oleophobic coatings.[9]

Derivatization of these PFCA rings via displacement of fluorine atoms with nucleophiles occurs through an addition-elimination reaction in the presence of a base. Attack of the nucleophile on the PFCA ring generates a carbanion which can eliminate a fluoride ion, resulting in vinyl substituted and allyl substituted products (Scheme 1).The ratio of vinylic to allylic products depends on the ring size, reaction conditions and nucleophile.[3][10]

Derivatization of the PFCA ring.
Scheme 1. Derivatization of the PFCA ring.

[3]

Under favorable conditions, a good nucleophile can replace all the fluorine atoms on PFCA ring (Scheme 2).[11]

Scheme 2. Multi-substitution on PFCA ring

[3][11]

PFCAs have a huge potential to be used as a monomer to produce a variety of polymers. The first time, Smith et al. showed the polycondensation of bisphenols with PFCAs. A unique class of aromatic ether polymers containing perfluorocyclopentenyl (PFCP) enchainment was prepared from the simple step growth polycondensation of commercial available bisphenols and octafluorocyclopentene (OFCP) in the presence of triethylamine (Scheme 3 and 4).[9][12]

Scheme 3. Perfluorocyclopentenyl (PFCP) aryl ether polymer synthesis

[12]

Scheme 4. Bis(heptafluorocyclopentenyl) aryl ether monomers synthesis and polymerization

[12]

Smith et al. further extended his recently published work on perfluorocyclopentenyl (PFCP) aryl ether polymers and perfuorocycloalkenyl (PFCA) aryl ether monomers, and reported the synthesis of a new class of fluoropolymers, namely, perfluorocyclohexenyl (PFCH) aryl ether polymers, via step-growth polycondensation of commercial bisphenols and decafluorocycloalkene (DFCH) in the presence of triethylamine (Scheme 5).[10][13]

Scheme 5. Perfluorocycloalkenyl (PFCA) aryl ether polymer synthesis

[10][13]

See also

References

  1. ↑ http://www.tcichemicals.com/eshop/en/us/catalog/list/search?searchWord=octafluorocyclopentene&client=default_frontend&output=xml_no_dtd&proxystylesheet=default_frontend&sort=date%3AD%3AL%3Ad1&oe=UTF-8&ie=UTF-8&ud=1&exclude_apps=1&site=en_us&mode=0
  2. ↑ http://www.synquestlabs.com/search-result.html?q=perfluorocyclohexene&st=*&commit=Search
  3. 1 2 3 4 http://www.sciencedirect.com/science/article/pii/S0040403913006825
  4. ↑ "Chiral Discrimination in Photochromic Helicenes". Journal of the American Chemical Society. 127: 7272–7273. doi:10.1021/ja050190j.
  5. ↑ "Synthesis of azo chromophores containing a perfluorocyclo-alkenyl moiety and their second-order optical nonlinearity". Journal of Fluorine Chemistry. 97: 207–212. doi:10.1016/S0022-1139(99)00050-0.
  6. ↑ http://www.freepatentsonline.com/3787461.html
  7. ↑ "Radical kinetics for polymer film deposition in fluorocarbon (C4F8, C3F6 and C5F8) plasmas". Thin Solid Films. 374: 303–310. Bibcode:2000TSF...374..303T. doi:10.1016/S0040-6090(00)01160-3.
  8. ↑ http://www.google.com/patents/US20140162173
  9. 1 2 http://pubs.rsc.org/en/Content/ArticleLanding/2013/TC/C3TC31161A#!divAbstract
  10. 1 2 3 "Triarylamine-enchained semifluorinated perfluorocycloalkenyl (PFCA) aryl ether polymers". Applied Petrochemical Research. 5: 35–45. doi:10.1007/s13203-014-0063-0.
  11. 1 2 "Azoles as Reactive Nucleophiles with Cyclic Perfluoroalkenes". Chemistry - A European Journal. 15: 10554–10562. doi:10.1002/chem.200901508.
  12. 1 2 3 "Perfluorocyclopentenyl (PFCP) Aryl Ether Polymers via Polycondensation of Octafluorocyclopentene with Bisphenols". Macromolecules. 45: 766–771. doi:10.1021/ma2024599.
  13. 1 2 "Perfluorocyclohexenyl aryl ether polymers via polycondensation of decafluorocyclohexene with bisphenols". Journal of Polymer Science Part A: Polymer Chemistry. 52: 232–238. doi:10.1002/pola.26995.
This article is issued from Wikipedia - version of the 8/30/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.