دورية أكاديمية
Toward a microscopic model of light absorbing dissolved organic compounds in aqueous environments: theoretical and experimental study.
| العنوان: | Toward a microscopic model of light absorbing dissolved organic compounds in aqueous environments: theoretical and experimental study. |
|---|---|
| المؤلفون: | Karimova NV; Department of Chemistry, University of California, Irvine, CA 92697, USA. bgerber@uci.edu., Alves MR; Department of Chemistry and Biochemistry, University of California, San Diego, CA 92093, USA. vhgrassian@ucsd.edu., Luo M; Department of Chemistry and Biochemistry, University of California, San Diego, CA 92093, USA. vhgrassian@ucsd.edu., Grassian VH; Department of Chemistry and Biochemistry, University of California, San Diego, CA 92093, USA. vhgrassian@ucsd.edu and Department of Nanoengineering and Scripps Institution of Oceanography, University of California, San Diego, CA 92093, USA., Gerber RB; Department of Chemistry, University of California, Irvine, CA 92697, USA. bgerber@uci.edu and Institute of Chemistry and Fritz Haber Research Center, Hebrew University of Jerusalem, Jerusalem 91904, Israel. |
| المصدر: | Physical chemistry chemical physics : PCCP [Phys Chem Chem Phys] 2021 May 05; Vol. 23 (17), pp. 10487-10497. |
| نوع المنشور: | Journal Article |
| اللغة: | English |
| بيانات الدورية: | Publisher: Royal Society of Chemistry Country of Publication: England NLM ID: 100888160 Publication Model: Print Cited Medium: Internet ISSN: 1463-9084 (Electronic) Linking ISSN: 14639076 NLM ISO Abbreviation: Phys Chem Chem Phys Subsets: PubMed not MEDLINE; MEDLINE |
| أسماء مطبوعة: | Original Publication: Cambridge [England] : Royal Society of Chemistry, c1999- |
| مستخلص: | Water systems often contain complex macromolecular systems that absorb light. In marine environments, these light absorbing components are often at the air-water interface and can participate in the chemistry of the atmosphere in ways that are poorly understood. Understanding the photochemistry and photophysics of these systems represents a major challenge since their composition and structures are not unique. In this study, we present a successful microscopic model of this light absorbing macromolecular species termed "marine derived chromophoric dissolved organic matter" or "m-CDOM" in water. The approach taken involves molecular dynamics simulations in the ground state using on the fly Density Functional Tight-Binding (DFTB) electronic structure theory; Time Dependent DFTB (TD-DFTB) calculations of excited states, and experimental measurements of the optical absorption spectra in aqueous solution. The theoretical hydrated model shows key features seen in the experimental data for a collected m-CDOM sample. As will be discussed, insights from the model are: (i) the low-energy A-band (at 410 nm) is due to the carbon chains combined with the diol- and the oxy-groups present in the structure; (ii) the weak B-band (at 320-360 nm) appears due to the contribution of the ionized speciated form of m-CDOM; and (iii) the higher-energy C-band (at 280 nm) is due to the two fused ring system. Thus, this is a two-speciated formed model. Although a relatively simple system, these calculations represent an important step in understanding light absorbing compounds found in nature and the search for other microscopic models of related materials remains of major interest. |
| تواريخ الأحداث: | Date Created: 20210426 Latest Revision: 20210506 |
| رمز التحديث: | 20231215 |
| DOI: | 10.1039/d0cp06554d |
| PMID: | 33899856 |
| قاعدة البيانات: | MEDLINE |
كن أول من يترك تعليقا!