Studies of multiple-chain alkylaminomethyl p-cyanophenol derivatives for Langmuir-Blodgett films

Langmuir films and Langmuir-Blodgett deposition have been studied for 2,6-dioctadecyl-aminomethyl-4-cyanophenol (CPR2R2) and 2-dioctadecyl-aminomethyl-4-cyanophenol (CPR2). Stable Langmuir films were obtainable far both compounds at high pn, but only for CPR2R2 at low ph. Molecular modelling and semiempirical MNDO calculations suggest that high pH favours stability by disrupting intramolecular hydrogen bonding, X-ray diffraction on Y-type Langmuir-Blodgett films deposited on hydrophobic glass substrates gives layer spacings of about 56 Angstrom for both compounds, indicating that the alkyl chains orient perpendicular to the substrate, Modelling and MNDO calculations suggest that analogous compounds with a single octadecyl chain on nitrogen could be stable at both low and high pH. (C) 1997 John Wiley & Sons, Ltd.