Structure Determination from Powder X‐Ray Diffraction Data of a Hydrogen‐Bonded Molecular Solid with Competing Ferromagnetic and Antiferromagnetic Interactions: The 2‐(3,4‐Dihydroxyphenyl)‐α‐Nitronyl Nitroxide Radical

Abstract

A Single crystal was not needed for the structure determination of radical 1. This is the first time that structure of a purely organic molecule having only s and p electrons and with more than ten atoms the unit cell was obtained from powder X‐ray diffraction data. The structure is in agreement with expected from the magnetic properties of 1.

PowderSolve– a complete package for crystal structure solution from powder diffraction patterns

“…Position, orientation and conformation (degrees of freedom) of these fragments are then varied to generate`trial' crystal structures, until optimum agreement between calculated and experimental powder diffraction patterns is achieved. In the context of the directspace approach, which is the subject of the present work, a number of different algorithms to explore parameter space have been used: grid search (Reck et al, 1988;Cirujeda et al, 1995;Dinnebier et al, 1995;Hammond et al, 1997), genetic algorithms Kariuki et al, 1997;Harris, Johnston, Kariuki & Tremayne, 1998;Kariuki, Calcagno et al, 1999), and Monte Carlo/simulated annealing (Deem & Newsam, 1989Newsam et al, 1992;Harris et al, 1994;Andreev et al, 1996Andreev et al, , 1997David et al, 1998).…”

Magnetic properties of(m−MPYNN+)[Mn12Takeda1, Awaga2 1997Phys. Rev. B753272View full textAdd to dashboardCite

“…15 The materials are so stable that it is easy to produce ionic nitronylnitroxides by putting a cationic or anionic moiety on the ␣ carbon. The cation, m-or p-N-methylpyridinium nitronylnitroxide ͑abbreviated as m-or p-MPYNN ϩ , respectively͒, yields interesting spin systems, such as Kagomé antiferromagnet, 16,17 molecular spin ladder, 18 and so on 19 in combinations with various counter anions.…”

Energy landscape paving for X-ray structure determination of organic molecules

“…In such approaches, Monte Carlo methods, simulated annealing etc. (Reck et al, 1988;Harris et al, 1994;Cirujeda et al, 1995;Su, 1995a,b;Dinnebier et al, 1995;Kariuki et al, 1996;Tremayne et al, , 1997Andreev, Lightfoot & Bruce, 1997;Andreev, MacGlashan & Bruce, 1997;Andreev & Bruce, 1998;Zimmer & Su, 1998;Chen & Su, 2000) are employed and the structures are determined by minimizing the difference between the calculated and experimental diffraction patterns.…”