Application of singular value decomposition analysis to time-dependent powder diffraction data of anin-situphotodimerization reaction

Ahmed F Mabied,Manabu Hoshino,Ayana Tomita,Shin-Ichi Adachi,Shunsuke Nozawa,Tokushi Sato

doi:10.1107/s1600577514004366

Abstract

Singular value decomposition (SVD) analysis has important applications for time-dependent crystallographic data, extracting significant information. Herein, a successful application of SVD analysis of time-resolved powder diffraction data over the course of an in-situ photodimerization reaction of anthracene derivatives is introduced. SVD revealed significant results in the case of 9-methylanthracene and 1-chloroanthracene. The results support the formation of the 9-methylanthracene stable dimer phase and suggest the existence of an excimer state.

Highlights

The rapid development of time-resolved X-ray experiments has raised challenges regarding data analysis and the extraction of significant information
Singular value decomposition (SVD) analysis has had a variety of successful applications in crystallography; for instance, with time-resolved small-angle X-ray scattering (Okamoto & Sakurai, 2003) and timeresolved macromolecular crystallographic data (Zhao & Schmidt, 2009; Rajagopal et al, 2004)
The photodimerization experiment was carried out in-situ at the X-ray time-resolved beamline NW14A of the Photon Factory Advanced Ring (PF-AR) facility, KEK, Japan

Summary

Introduction

The rapid development of time-resolved X-ray experiments has raised challenges regarding data analysis and the extraction of significant information. SVD analysis has had a variety of successful applications in crystallography; for instance, with time-resolved small-angle X-ray scattering (Okamoto & Sakurai, 2003) and timeresolved macromolecular crystallographic data (Zhao & Schmidt, 2009; Rajagopal et al, 2004). It has been successful in many other areas such as spectroscopy (Berlich et al, 2005; Henry & Hofrichter, 1992; Henry, 1997), gene expression data (Alter et al, 2000; Wall et al, 2003), scientific computing and signal processing (Lahabar & Narayanan, 2009). The aim of this study is to find any traces of the excimer state by applying SVD analysis, which could not be observed directly using Rietveld refinement

Experimental

SVD and data treatment

Data treatment

Findings

Conclusions