Interactions of organic molecules at grain boundaries in ice: A solvatochromic analysis

HEGER, Dominik and Petr KLÁN. Interactions of organic molecules at grain boundaries in ice: A solvatochromic analysis. Journal of Photochemistry and Photobiology A: Chemistry. Amsterdam, The Netherlands: Elsevier Science, 2007, vol. 187, 2-3, p. 275-284, 9 pp. ISSN 1010-6030.

Basic information

• Original name: Interactions of organic molecules at grain boundaries in ice: A solvatochromic analysis
• Name in Czech: Interakce organických molekul na hranicích zrn ledu: Solvatochromní analýza
• Authors: HEGER, Dominik (203 Czech Republic) and Petr KLÁN (203 Czech Republic, guarantor).
• Edition: Journal of Photochemistry and Photobiology A: Chemistry, Amsterdam, The Netherlands, Elsevier Science, 2007, 1010-6030.

Other information

• Original language: English
• Type of outcome: Article in a journal
• Field of Study: 10401 Organic chemistry
• Country of publisher: Netherlands
• Confidentiality degree: is not subject to a state or trade secret
• Impact factor: Impact factor: 1.911
• RIV identification code: RIV/00216224:14310/07:00020320
• Organization unit: Faculty of Science
• UT WoS: 000245882900019
• Keywords in English: Photochemistry; Ice; Solvatochromic
• Tags: ice, Photochemistry, Solvatochromic
• Tags: International impact, Reviewed

Abstract

Empirical solvent polarity parameters were used to evaluate the nature and magnitude of the intermolecular interactions of eight dipolar organic solvatochromic indicators in aqueous solutions frozen at 253 or 77 K, using the concept that is generally employed to study the polarity of liquid solvents or solid surfaces. ET(30), ET(33), and as well as alpha, acceptor number (AN) (hydrogen-bond donation ability), beta (hydrogen-bond acceptor ability), and pi* (polarity/polarizability) parameters were obtained by measuring the differences in the shifts of the absorption spectra of the probes. It was found that hydrogen-bond and electron pair donating interactions were significant contributors to the polarity of a probe environment in ice and, at the same time, they were found to be substantially larger than those measured in liquid aqueous solutions and relatively insensitive to the sample temperature. While the former interaction type is attributed rather to the presence of water in a close vicinity of the probe molecules, the latter is evidently connected with the interprobe interactions within the self-assembled molecular aggregations in conjunction with the water probe interactions. The solvatochromic analysis revealed very weak dipole dipole interactions (pi*) but the results are inconclusive. The data are consistent with a model according to which, upon freezing the aqueous solutions, the organic solute molecules are ejected to the grain boundaries to form highly concentrated liquid or frozen mixtures of organic and water molecules, having a high degree of complexity and exhibiting specific intermolecular interactions. Evaluation of the intermolecular polar interactions at the grain boundaries in ice should be of a great value in advancing our understanding of physical and chemical processes occurring in natural ice and snow.

Abstract (in Czech)

Empirical solvent polarity parameters were used to evaluate the nature and magnitude of the intermolecular interactions of eight dipolar organic solvatochromic indicators in aqueous solutions frozen at 253 or 77 K, using the concept that is generally employed to study the polarity of liquid solvents or solid surfaces. ET(30), ET(33), and as well as alpha, acceptor number (AN) (hydrogen-bond donation ability), beta (hydrogen-bond acceptor ability), and pi* (polarity/polarizability) parameters were obtained by measuring the differences in the shifts of the absorption spectra of the probes. It was found that hydrogen-bond and electron pair donating interactions were significant contributors to the polarity of a probe environment in ice and, at the same time, they were found to be substantially larger than those measured in liquid aqueous solutions and relatively insensitive to the sample temperature. While the former interaction type is attributed rather to the presence of water in a close vicinity of the probe molecules, the latter is evidently connected with the interprobe interactions within the self-assembled molecular aggregations in conjunction with the water probe interactions. The solvatochromic analysis revealed very weak dipole dipole interactions (pi*) but the results are inconclusive. The data are consistent with a model according to which, upon freezing the aqueous solutions, the organic solute molecules are ejected to the grain boundaries to form highly concentrated liquid or frozen mixtures of organic and water molecules, having a high degree of complexity and exhibiting specific intermolecular interactions. Evaluation of the intermolecular polar interactions at the grain boundaries in ice should be of a great value in advancing our understanding of physical and chemical processes occurring in natural ice and snow.

Links

• GA205/05/0819, research and development project: Name: Environmentální důsledky fotochemických transformací v ledu a sněhu

Investor: Czech Science Foundation, Enviromental consequences of photochemical processes in ice and snow

• MSM0021622412, plan (intention): Name: Interakce mezi chemickými látkami, prostředím a biologickými systémy a jejich důsledky na globální, regionální a lokální úrovni (INCHEMBIOL) (Acronym: INCHEMBIOL)

Investor: Ministry of Education, Youth and Sports of the CR, Interactions among the chemicals, environment and biological systems and their consequences on the global, regional and local scales (INCHEMBIOL)