Polymer p. 3202 - 3211 (2014)
Update date:2022-08-17
Topics:
Gibson, Harry W.
Shen, Ya Xi
Bheda, Mukesh C.
Gong, Caiguo
Reaction of di(p-isocyanatophenyl)methane (MDI, 4) with N,N′-di(2-hydroxyethyl)- (1b) or N,N′-di[2-(2′-hydroxyethoxy) ethyl]-4,4′-bipyridinium di(hexafluorophosphate) (1e) and other diols [oligo(ethylene glycol)s and poly(tetramethylene oxide)s] in the presence of bis(p-phenylene)-34-crown-10 (2) afforded polyurethane (pseudo)rotaxanes as statistical (7P or 7R) and segmented analogs 10P (P = pseudorotaxane, R = rotaxane). In 7R a bulky alcohol was incorporated at the chain ends and in 13R a bulky diol as in-chain units to form polyrotaxanes and preclude the possibility of dethreading. The crown ether 2 in 10P and 13R was shown by 1H NMR spectroscopy to be shuttling between the viologen (paraquat) and urethane sites; in DMSO the crown ether prefers the urethane site, probably because of H-bonding with the N-H moieties and complexation of the pyridinium site by the dipolar solvent, while in acetone at low temperatures the viologen site is preferred by the crown ether, with ΔH = -6.91 kcal/mol and ΔS = -22.9 eu for 13R.
View MoreHuangshi Meifeng Chemical Co.,ltd.
Contact:+86-714-6516706
Address:1941-4-3#,Hubin Avenue,Huangshi,Hubei,China
Contact:+49-9398-993127
Address:Untertorstr. 27
Binzhou Holly Pharmaceutical Co.,Ltd.
Contact:74517
Address:No.15 Dapu Road,Huangpu District Shanghai,P.R.China
Taimai Sanluck Pharmaceutical Co.,Ltd
Contact:86-592-7662921
Address:8D,No.186,Huarong Road,Huli,Xiamen,China
website:http://www.fwdchem.com
Contact:86-21-54450828
Address:Room 802,Lotus Tower ,159 Tianzhou Road,Xuhui District,Shanghai
Doi:10.1016/j.molstruc.2014.08.042
(2014)Doi:10.1246/bcsj.61.575
(1988)Doi:10.1021/ic0607585
(2006)Doi:10.1039/c2cc37271a
(2013)Doi:10.1002/ejoc.202100251
(2021)Doi:10.1021/nl5048972
(2015)