Uncharacteristic quasiracemic assemblies derived from tartaramide/malamide molecular frameworks
Faculty Sponsor
kwheeler@whitworth.edu
Session Type
Poster Presentation
Research Project Abstract
Here we report the molecular recognition profiles of the quasiracemate of (-)-malamide and (+)-tartaramide. Comparing the crystal structure of this material to those of the ‘true’ malamide and tartaramide racemates reveals packing motifs described by the expected approximate inversion symmetry as well as the previously unseen pseudo glide symmetry operator. Preferred molecular associations observed in these crystal structures were investigated using Ab initio calculations via cluster analysis and group replacement methods. These results support the importance hydrogen bonds, molecular topology, and favorable molecular orientations to crystal stabilization. Further characterization was also achieved using differential scanning calorimetry and hot stage thermal microscopy to understand the structural features responsible for each crystalline phase. Recognition of quasiracemic components stems from a complex blend of both strong direction molecular contacts and more ill-defined features such as the complementarity of molecular shapes of the malamide and tartramide chemical frameworks. By systematically changing the pendant groups of the tartaramide/malamide system, calculations of these derivatives offer additional insight to the importance of the observed crystal assemblies.
Session Number
PS1
Location
HUB Multipurpose Room
Abstract Number
PS1-z
Uncharacteristic quasiracemic assemblies derived from tartaramide/malamide molecular frameworks
HUB Multipurpose Room
Here we report the molecular recognition profiles of the quasiracemate of (-)-malamide and (+)-tartaramide. Comparing the crystal structure of this material to those of the ‘true’ malamide and tartaramide racemates reveals packing motifs described by the expected approximate inversion symmetry as well as the previously unseen pseudo glide symmetry operator. Preferred molecular associations observed in these crystal structures were investigated using Ab initio calculations via cluster analysis and group replacement methods. These results support the importance hydrogen bonds, molecular topology, and favorable molecular orientations to crystal stabilization. Further characterization was also achieved using differential scanning calorimetry and hot stage thermal microscopy to understand the structural features responsible for each crystalline phase. Recognition of quasiracemic components stems from a complex blend of both strong direction molecular contacts and more ill-defined features such as the complementarity of molecular shapes of the malamide and tartramide chemical frameworks. By systematically changing the pendant groups of the tartaramide/malamide system, calculations of these derivatives offer additional insight to the importance of the observed crystal assemblies.
