Title: Determination of a Complex Crystal Structure in the Absence of Single Crystals: Analysis of Powder X-ray Diffraction Data, Guided by Solid-State NMR and Periodic DFT Calculations, Reveals A New 2'-Deoxyguanosine Structural Motif

Citation
Hughes CE, Reddy GNM, Masiero S, et al. (2017). Determination of a Complex Crystal Structure in the Absence of Single Crystals: Analysis of Powder X-ray Diffraction Data, Guided by Solid-State NMR and Periodic DFT Calculations, Reveals A New 2'-Deoxyguanosine Structural Motif. Cardiff University. https://doi.org/10.17035/d.2017.0031643370

Dataset Details

Publisher: Cardiff University

Date (year) of data becoming publicly available: 2017

Data format: .raw, .cpi, .magres

Software Required: The .raw file may be viewed using the Bruker software "EVA". The corresponding .cpi file is ascii and may be opened by various free software for PXRD data.
The .magres files may be viewed at www.ccpnc.ac.uk/magresview/magresview/magres_view.html.

Estimated total storage size of dataset: Less than 100 megabytes

Number of Files In Dataset: 3

DOI : 10.17035/d.2017.0031643370

DOI URL: http://doi.org/10.17035/d.2017.0031643370

Description

Derivatives of guanine exhibit diverse supramolecular chemistry, with a variety of distinct hydrogen-bonding motifs reported in the solid state, including ribbons and quartets, which resemble the G-quadruplex found in nucleic acids with sequences rich in guanine. Reflecting this diversity, the solid-state structural properties of 3',5'-bis-O-decanoyl-2'-deoxyguanosine, reported in this paper, reveal a hydrogen-bonded guanine ribbon motif that has not been observed previously for 2'‑deoxyguanosine derivatives. In this case, structure determination was carried out directly from powder X-ray diffraction (XRD) data, representing one of the most challenging organic molecular structures (a 90-atom molecule) that has been solved to date by this technique. While specific challenges were encountered in the structure determination process, a successful outcome was achieved by augmenting the powder XRD analysis with information derived from solid-state NMR data and with dispersion-corrected periodic density functional theory (DFT) calculations for structure optimization. The synergy of experimental and computational methodologies demonstrated in the present work is likely to be an essential feature of strategies to further expand the application of powder XRD as a technique for structure determination of organic molecular materials of even greater complexity in the future.

The dataset consists of the powder XRD data, with data provided in both the raw format, as generated by the Bruker D8 Diffractometer, and in the cpi format, together with three magres files generated by the program CASTEP when calculating NMR parameters from our crystal structure.

Research results based upon these data are published at http://doi.org/10.1039/C7SC00587C