Work

pH-Dependent absorption spectra of aqueous 4-imidazolecarboxaldehyde: theoretical and experimental insights into a marine chromophore proxy

Year: 2025

Type: article

Abstract: and the pH effect in its absorption features. The diol-aldehyde equilibrium of 4IC, along with the optical properties of the species involved, was also investigated in the context of daytime chemistry in the marine environment. Using theoretical and experimental techniques, we show that the protonation state of 4IC significantly affects its electronic transitions. Under acidic conditions typical of submicron SSA, 4IC exhibits low-energy absorption bands that overlap with the solar spectrum, with more intense high-energy features extending into the actinic region. As pH increases to values characteristic of the SSML, the more intense band redshifts towards the solar spectrum. Theoretical results closely match experimental trends, reproducing the redshift and accurately predicting the energies of key transitions.

Source: Physical Chemistry Chemical Physics

DOI: 10.1039/d5cp01553g

Authors: Lily J. Watson, Elizabeth Scholer, Caroline H. V. Calvert, Juan G. Navea

Institution: Skidmore College

Language: English

Topic: Atmospheric chemistry and aerosols

Subfield: Atmospheric Science

Field: Earth and Planetary Sciences

Domain: Physical Sciences

Open Access status: hybrid

Funders: National Science Foundation, Camille and Henry Dreyfus Foundation, Division of Chemistry