Liquid acetonitrile at a silica surface is known to organize in a manner that, in some respects, resembles a supported lipid bilayer. Here we use broadband vibrational sum-frequency generation (VSFG) spectroscopy to study how this organization depends on temperature. We find that VSFG spectra in the methyl-stretching region of the spectrum decrease in magnitude and shift to the blue for all polarization combinations (SSP, SPS, and PPP) as the temperature is raised from 25 to 60 °C. The observed decrease in intensity with increasing temperature is unexpected and suggests that the dynamics of the second sublayer of acetonitrile molecules plays an important role in the spectral behavior of this system. We propose that the decrease in intensity with increasing temperature arises largely from the more static first sublayer becoming more disordered. This picture is supported by the observed blue shift at high temperature, which is consistent with faster reorientation-induced spectral diffusion. The rapid dynamics and average orientation of the second sublayer are biased by the first sublayer, but this bias is not influenced substantially by increasing the temperature.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.