No abstract

No abstract

Tetraethylene glycol (TEG) or polyethylene glycol 200 (PEG200) was reacted with CH2Br2 in a modified Williamson synthesis to form oxymethylene‐linked chains. Analytical and preparative gel permeation chromatography plus nuclear magnetic resonance spectroscopy were used to show that the product of reaction consisted of rings with degree of condensation n = 1−15 or more (i.e. 14 to 210 or more atoms in the rings formed from TEG) and chains with molecular weights up to 106 and a wide molecular weight distribution.

Low-frequency Raman spectra were recorded for a-methy1,w-hydroxyoligo(oxyethylene)s, CIEmOH with m in the range 4-16, Le., 14-50 chain atoms. Longitudinal acoustical mode (LAM) frequencies were identified and compared with those determined previously for a-hydro,whydroxyoligo(oxyethylene)s and a-methy1,o-methoxyoligo(oxyethy1ene)s. On the basis of the linear crystal model of Minoni and Zerbi, the two most prominent bands in the low-frequency spectra were assigned to the LAM-1 and LAM-3 modes of the H-bonded dimer crystallized in a bilayer structure. ' h n t addrm: European Vinyls Corp. ((1) Campbell. C.; Viras. K.; Booth, C. J. Polym. Scl., Polym. Phys. Ed., (2) Viras, K.; Teo, H. H.; Marshall. A.; Domszy, R. C.; King, T. A,; Booth, (3) Viras, K.; King, T. A.; Booth, C. J. Polym. Sei., Polym. Phys. Ed.in press. C.Infrared absorption spectral bandshapes are examined theoretically for the OH stretching vibration in hydrogen-bonded complexes in solution. Two distinct dephasing mechanisms are considered: the indirect mechanism in which the OH vibration is coupled to one or more internal vibrations in the complex, which are in turn coupled to the solvent, and the direct mechanism in which the OH vibration is directly coupled to the solvent. Attention is focused on intramolecularly H-bonded complexes for which extensive spectral data are available for a range of solvent polarity. It is concluded for the complexes considered that the direct mechanism is dominant. In particular, good fits to the experimental data are obtained via this mechanism for spectral width features in a given solvent and as a function of solvent polarity. Some distinctions between intra-and intermolecularly H-bonded complexes are given, and some suggestions for further work are made.

No abstract