Home
Resources
Publications
Thermally Induced Conformational Changes of Ca-arachidate Langmuir-Blodgett Films at Different Compression

Thermally Induced Conformational Changes of Ca-arachidate Langmuir-Blodgett Films at Different Compression

Jan Weber, Andre Beier, Eckart Hasselbrink, Thorsten Balgar

J Chem Phys. 2014 Jul 28;141(4):044912.

PMID: 25084961

Abstract:

The conformational order in Ca-arachidate Langmuir-Blodgett films on solid glass supports is investigated by means of vibrational sum-frequency generation spectroscopy (VSFG). The symmetric C-H stretching vibrations of both the terminal methyl and the methylene groups are utilized to monitor the chain conformation at various sample temperatures under ambient conditions. At room temperature the film is well-ordered consisting almost entirely of all-trans configured chains. Between 340 and 430 K we observe a marked increase in gauche-defects before oxidative degeneration starts at sample temperatures above 470 K. The temperature dependence of the data is well represented by apparent enthalpy changes for the formation of gauche-defects, sharply increasing with packing density from 29 to 62 kJ/mol; values, which are an order of magnitude larger than those of the gas phase molecule. These large apparent enthalpies do not prevent the formation of a high degree of conformational disorder at elevated temperatures.

Chemicals Related in the Paper:

Catalog Number	Product Name	Structure	CAS Number	Price
AP1120281	Methyl arachidate		1120-28-1	Price

As a specialist in analytical chemical Products, Alfa Chemistry offers consumers a wealth of raw materials and a full range of technologies and services.

QUICK LINKS

HEADQUARTERS

Tel:

Fax:

Email: