Formation of quinol co-crystals with hydrogen-bond acceptors.
The crystal structures of eight new co-crystals of quinol with pyrazine, piperazine, morpholine, pyridine, piperidine, 4,4'-bipyridine, N-methylmorpholine and N,N'-dimethylpiperazine are reported. Quinol forms 1:1 co-crystals with pyrazine, piperazine and N,N'-dimethylpiperazine, but 1:2 co-crystals with morpholine, 4,4'-bipyridine, N-methylmorpholine, pyridine and piperidine. This difference can be rationalized in most cases by the presence of, respectively, two or one strong hydrogen-bond acceptor(s) in the guest molecule. The exception to this generalization is 4,4'-bipyridine, which forms a 1:2 co-crystal, possibly to optimize crystal packing. All structures are dominated by hydrogen bonding between quinol and the guest molecules. A doubly bridging motif, which connects pairs of quinol and guest molecules via NH...O or CH...O interactions, is present in all but the sterically hindered N,N'-dimethylpiperazine and N-methylmorpholine co-crystals.
Oswald
Iain D H
ID
School of Chemistry, The University of Edinburgh, King's Buildings, West Mains Road, Edinburgh EH9 3JJ, Scotland. i.d.h.oswald@sms.ed.ac.uk
Motherwell
W D Samuel
WD
Parsons
Simon
S
D003460:Crystallization; D003461:Crystallography; D006860:Hydrogen Bonding; D006873:Hydroquinones / Q000138:chemical synthesis / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure
D006873:Hydroquinones