On the Electronic Structure of Cu Chlorophyllin and Its Breakdown Products: A Carbon K-Edge X-ray Absorption Spectroscopy Study

J Phys Chem B. 2018 Feb 15;122(6):1846-1851. doi: 10.1021/acs.jpcb.7b12108. Epub 2018 Feb 1.

Abstract

Using near-edge X-ray absorption fine structure (NEXAFS) spectroscopy, the carbon backbone of sodium copper chlorophyllin (SCC), a widely used chlorophyll derivative, and its breakdown products are analyzed to elucidate their electronic structure and physicochemical properties. Using various sample preparation methods and complementary spectroscopic methods (including UV/Vis, X-ray photoelectron spectroscopy), a comprehensive insight into the SCC breakdown process is presented. The experimental results are supported by density functional theory calculations, allowing a detailed assignment of characteristic NEXAFS features to specific C bonds. SCC can be seen as a model system for the large group of porphyrins; thus, this work provides a novel and detailed description of the electronic structure of the carbon backbone of those molecules and their breakdown products. The achieved results also promise prospective optical pump/X-ray probe investigations of dynamic processes in chlorophyll-containing photosynthetic complexes to be analyzed more precisely.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chlorophyll / chemistry*
  • Copper / chemistry*
  • Electrons
  • Molecular Structure
  • Quantum Theory
  • X-Ray Absorption Spectroscopy*

Substances

  • Chlorophyll
  • Copper