NMR spectra of cyclic formals formed during the early stage of the copolymerization of trioxane and ethylene oxide

Citation
N. Yamasaki et al., NMR spectra of cyclic formals formed during the early stage of the copolymerization of trioxane and ethylene oxide, APPL SPECTR, 54(7), 2000, pp. 1069-1074
Citations number
14
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Spectroscopy /Instrumentation/Analytical Sciences
Journal title
APPLIED SPECTROSCOPY
ISSN journal
0003-7028 → ACNP
Volume
54
Issue
7
Year of publication
2000
Pages
1069 - 1074
Database
ISI
SICI code
0003-7028(200007)54:7<1069:NSOCFF>2.0.ZU;2-F
Abstract
During the early stage of the copolymerization of trioxane and ethylene oxi de, we found the formation of three novel cyclic compounds: 1,3,5,7-tetraox acyclononane (TOCN), 1,3,5,7,10-pentaoxacyclododecane (POCD), and 1,3,5,7,1 0,13-hexaoxacyclopentadecane (HOCP). These novel cyclic compounds were new direct reaction products of 1 mole of trioxane and 1 mole of ethylene oxide , 1 mole of trioxane and 2 moles of ethylene oxide, and 1 mole of trioxane and 3 moles of ethylene oxide, respectively. We compared the H-1-NMR and C- 13-NMR spectra of each cyclic compound and precisely assigned the signals o f each spectrum using NOESY (nuclear Overhauser enhancement spectroscopy) a nd HETCOR (heteronuclear correlated spectroscopy). We also compared the H-1 -NMR spectra of POCD and HOCP with the corresponding cyclic formals with on e oxymethylene unit, diethylene glycol formal (DEGF) and triethylene glycol formal (TEGF). Interestingly, we found that DEGF and TEGF, which have only one oxymethylene unit, showed no proton splitting of the oxyethylene units , while POCD and HOCP, which have three consecutive oxymethylene units, hav e split signals for the oxyethylene units.