Title

ROY Revisited, Again: The Eighth Solved Structure

Document Type

Article

Publication Date

5-2-2018

Publication Title

Faraday Discussions

Volume

211

First page number:

477

Last page number:

491

Abstract

X-ray powder diffraction and crystal structure prediction (CSP) algorithms were used in synergy to establish the crystal structure of the eighth polymorph of 5-methyl-2-[(2-nitrophenyl)amino]-3-thiophenecarbonitrile (ROY), form R05. R05 crystallizes in the monoclinic space group P21 with lattice parameters a = 11.479(4) Å, b = 11.030(1) Å, c= 10.840(6) Å, β = 118.23(1)°. This is both the first acentric ROY polymorph, and the first with Z′ > 1. The torsion angles defined by the S–C–N–C atom sequence of each molecule in the asymmetric unit (R05-1 and R05-2) are 44.9° and −34.0°. These values are between those previously determined for the red and orange forms of ROY. The crystal packing and intermolecular interactions in R05 are explained herein through Hirshfeld surface analysis and an updated energy stability ranking is determined using computational methods. Although the application of CSP was critical to the structure solution of R05, energy stability rankings determined using a series of DFT van der Waals (vdW)-inclusive models substantially differ from experiment, indicating that ROY polymorphism continues to be a challenge for CSP.

Disciplines

Physics

Language

English

UNLV article access

Search your library

Share

COinS