Premium
Three Polymorphic Forms of the Co‐Crystal 4,4′‐Bipyridine/Pimelic Acid and their Structural, Thermal, and Spectroscopic Characterization
Author(s) -
Braga Dario,
Palladino Giuseppe,
Polito Marco,
Rubini Katia,
Grepioni Fabrizia,
Chierotti Michele R.,
Gobetto Roberto
Publication year - 2008
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200801051
Subject(s) - crystallography , differential scanning calorimetry , chemistry , molecule , crystal (programming language) , crystal structure , diffraction , spectroscopy , organic chemistry , physics , thermodynamics , computer science , optics , programming language , quantum mechanics
Three crystal forms of the co‐crystal 4,4′‐bipy/pimelic acid (bipy: bipyridine), [NH 4 C 5 ‐C 5 H 4 N] ⋅ [HOOC(CH 2 ) 5 COOH], have been prepared and their relationship investigated by single‐crystal X‐ray diffraction, variable‐temperature X‐ray powder diffraction, differential scanning calorimetry and solid‐state NMR spectroscopy. Both X‐ray and NMR spectroscopic results indicate that no proton transfer takes place, that is, the three crystal forms are true co‐crystals of neutral molecules. Forms I and II both convert into Form III at high temperature, Forms II and III being the thermodynamically stable forms at room and high temperature, respectively.