Spectroscopic studies of p-(N,N-dimethylamino) benzonitrile and ethyl p-(N,N-dimethylamino) benzoate in supercritical trifluoromethane, carbon dioxide, and ethane

Journal Article · Wed Feb 12 04:00:00 EST 1992 · Journal of the American Chemical Society

DOI:https://doi.org/10.1021/ja00030a010· OSTI ID:232075

Sun, Ya-Ping; Fox, M A; Johnston, K P ^[1]

---

1. Univ. of Texas, Austin, TX (United States)

Absorption and emission spectral maxima, bandwidths, and fractional contribution of twisted intramolecular charge transfer states to the observed emission of p-(N,N-dimethylamino) benzonitrile (DMABN) and ethyl P-(N,N-dimethylamino) benzoate (DMAAEB) in supercritical CHF{sub 3}, CO{sub 2} are presented. By examining a wide range of reduced densities from 0.05 to 2.2, the authors have discovered a characteristic density dependence in the spectral shifts in all three fluids. A model for these spectral effects is proposed, differentiating intermolecular interactions in three distinct regions; gas-phase solute-solvent clustering, clustering in the near-critical region, and {open_quotes}liquidlike{close_quotes} solvation. Even below a reduced density of 0.5, clustering of solvent about solute is already prevalent. 49 refs., 17 fig., 1 tab.

• Sponsoring Organization: USDOE
• OSTI ID: 232075
• Journal Information: Journal of the American Chemical Society, Journal Name: Journal of the American Chemical Society Journal Issue: 4 Vol. 114; ISSN JACSAT; ISSN 0002-7863
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
ABSORPTION SPECTROSCOPY
DENSITY
EMISSION SPECTROSCOPY
ESTERS
NITRILES
SUPERCRITICAL STATE