On the CD2 probe infrared method for determining polymethylene chain conformation

M. Maroncelli, H. L. Strauss, R. G. Snyder

Research output: Contribution to journalArticle

39 Citations (Scopus)

Abstract

The rocking mode frequency of a CD2 group substituted in a polymethylene chain is sensitive to conformation in the immediate vicinity of the CD2 group. This sensitivity forms the basis of a commonly used infrared method for determining site-specific conformation in polymethylene systems. In the present work, the CD2 probe method has been extended and quantified with the use of infrared data on model CD2-substituted n-alkanes. The frequency of the CD2 rocking band is determined primarily by the conformation of adjoining CC bonds, i.e., by tt, gt, and gg pairs. However, we have found that there are significant frequency shifts associated with other factors. These include the conformation of the next nearest CC bonds, both with the CD2 positioned at the end and in the interior of the chain, and chain length. In addition, the ratio of the absorptivities of the tt to gt bands has been established. These results enable the method to provide new details about the conformation of the chains in polymethylene systems and reliable estimates of the concentrations of specific kinds of short conformational sequences.

Original languageEnglish (US)
Pages (from-to)4390-4395
Number of pages6
JournalJournal of physical chemistry
Volume89
Issue number20
StatePublished - Dec 1 1985

Fingerprint

Conformations
Infrared radiation
probes
Alkanes
alkanes
frequency shift
absorptivity
Chain length
Paraffins
sensitivity
estimates

All Science Journal Classification (ASJC) codes

  • Engineering(all)
  • Physical and Theoretical Chemistry

Cite this

@article{73ebc5635e634e57bc7102f1cfe1f6e8,
title = "On the CD2 probe infrared method for determining polymethylene chain conformation",
abstract = "The rocking mode frequency of a CD2 group substituted in a polymethylene chain is sensitive to conformation in the immediate vicinity of the CD2 group. This sensitivity forms the basis of a commonly used infrared method for determining site-specific conformation in polymethylene systems. In the present work, the CD2 probe method has been extended and quantified with the use of infrared data on model CD2-substituted n-alkanes. The frequency of the CD2 rocking band is determined primarily by the conformation of adjoining CC bonds, i.e., by tt, gt, and gg pairs. However, we have found that there are significant frequency shifts associated with other factors. These include the conformation of the next nearest CC bonds, both with the CD2 positioned at the end and in the interior of the chain, and chain length. In addition, the ratio of the absorptivities of the tt to gt bands has been established. These results enable the method to provide new details about the conformation of the chains in polymethylene systems and reliable estimates of the concentrations of specific kinds of short conformational sequences.",
author = "M. Maroncelli and Strauss, {H. L.} and Snyder, {R. G.}",
year = "1985",
month = "12",
day = "1",
language = "English (US)",
volume = "89",
pages = "4390--4395",
journal = "Journal of Physical Chemistry",
issn = "0022-3654",
publisher = "American Chemical Society",
number = "20",

}

On the CD2 probe infrared method for determining polymethylene chain conformation. / Maroncelli, M.; Strauss, H. L.; Snyder, R. G.

In: Journal of physical chemistry, Vol. 89, No. 20, 01.12.1985, p. 4390-4395.

Research output: Contribution to journalArticle

TY - JOUR

T1 - On the CD2 probe infrared method for determining polymethylene chain conformation

AU - Maroncelli, M.

AU - Strauss, H. L.

AU - Snyder, R. G.

PY - 1985/12/1

Y1 - 1985/12/1

N2 - The rocking mode frequency of a CD2 group substituted in a polymethylene chain is sensitive to conformation in the immediate vicinity of the CD2 group. This sensitivity forms the basis of a commonly used infrared method for determining site-specific conformation in polymethylene systems. In the present work, the CD2 probe method has been extended and quantified with the use of infrared data on model CD2-substituted n-alkanes. The frequency of the CD2 rocking band is determined primarily by the conformation of adjoining CC bonds, i.e., by tt, gt, and gg pairs. However, we have found that there are significant frequency shifts associated with other factors. These include the conformation of the next nearest CC bonds, both with the CD2 positioned at the end and in the interior of the chain, and chain length. In addition, the ratio of the absorptivities of the tt to gt bands has been established. These results enable the method to provide new details about the conformation of the chains in polymethylene systems and reliable estimates of the concentrations of specific kinds of short conformational sequences.

AB - The rocking mode frequency of a CD2 group substituted in a polymethylene chain is sensitive to conformation in the immediate vicinity of the CD2 group. This sensitivity forms the basis of a commonly used infrared method for determining site-specific conformation in polymethylene systems. In the present work, the CD2 probe method has been extended and quantified with the use of infrared data on model CD2-substituted n-alkanes. The frequency of the CD2 rocking band is determined primarily by the conformation of adjoining CC bonds, i.e., by tt, gt, and gg pairs. However, we have found that there are significant frequency shifts associated with other factors. These include the conformation of the next nearest CC bonds, both with the CD2 positioned at the end and in the interior of the chain, and chain length. In addition, the ratio of the absorptivities of the tt to gt bands has been established. These results enable the method to provide new details about the conformation of the chains in polymethylene systems and reliable estimates of the concentrations of specific kinds of short conformational sequences.

UR - http://www.scopus.com/inward/record.url?scp=0001505785&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0001505785&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0001505785

VL - 89

SP - 4390

EP - 4395

JO - Journal of Physical Chemistry

JF - Journal of Physical Chemistry

SN - 0022-3654

IS - 20

ER -