title: Resolution of 2-chloromandelic acid with (R)-(+)-N-benzyl-1-phenylethylamine: chiral discrimination mechanism.
abstract: During the resolution of 2-chloromandelic acid with (R)-(+)-N-benzyl-1-phenylethylamine, the crystals of the less soluble salt were grown, and their structure were determined and presented. The chiral discrimination mechanism was investigated by examining the weak intermolecular interactions (such as hydrogen bond, CH/π, and van der Waals interactions) and molecular packing mode in crystal structure of the less soluble diastereomeric salt. A one-dimensional double-chain hydrogen-bonding network and a "lock-and-key" supramolecular packing mode are disclosed. The investigation demonstrates that hydrophobic layers with corrugated surfaces can fit into the grooves of one another to realize a compact packing, when the molecular structure of resolving agent is much larger than that of the racemate. This "lock-and-key" assembly is recognized to be another characteristic of molecular packing contributing to the chiral discrimination, in addition to the well-known sandwich-like packing by hydrophobic layers with planar boundary surfaces.
authors.affiliation: Department of Chemical Engineering, East China University of Science and Technology, Shanghai, China.
authors.forename: Yangfeng
authors.initials: Y
authors.lastname: Peng
authors.forename: Quan
authors.initials: Q
authors.lastname: He
authors.forename: Sohrab
authors.initials: S
authors.lastname: Rohani
authors.forename: Hilary
authors.initials: H
authors.lastname: Jenkins
mesh_terms: D001593:Benzyl Compounds / Q000737:chemistry*; D018360:Crystallography, X-Ray; D005021:Ethylamines / Q000737:chemistry*; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D008333:Mandelic Acids / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D010627:Phenethylamines / Q000737:chemistry; D012995:Solubility; D013237:Stereoisomerism; D044366:Transition Temperature
chemical_list: C541344:2-chloromandelic acid; D001593:Benzyl Compounds; D005021:Ethylamines; D008333:Mandelic Acids; C576079:N-benzyl-1-phenylethylamine; D010627:Phenethylamines