Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2019 Oct 10;20(20):5004.
doi: 10.3390/ijms20205004.

Chiral Cocrystal Solid Solutions, Molecular Complexes, and Salts of N-Triphenylacetyl-l-Tyrosine and Diamines

Agnieszka Czapik  1   2 , Maciej Jelecki  3   4 , Marcin Kwit  5   6
Affiliations

Chiral Cocrystal Solid Solutions, Molecular Complexes, and Salts of N-Triphenylacetyl-l-Tyrosine and Diamines

Agnieszka Czapik et al. Int J Mol Sci. .

Abstract

The molecular recognition process and the ability to form multicomponent supramolecular systems have been investigated for the amide of triphenylacetic acid and l-tyrosine (N-triphenylacetyl-l-tyrosine, TrCOTyr). The presence of several supramolecular synthons within the same amide molecule allows the formation of various multicomponent crystals, where TrCOTyr serves as a chiral host. Isostructural crystals of solvates with methanol and ethanol and a series of binary crystalline molecular complexes with selected organic diamines (1,5-naphthyridine, quinoxaline, 4,4'-bipyridyl, and DABCO) were obtained. The structures of the crystals were planned based on non-covalent interactions (O-H···N or N-H+···O- hydrogen bonds) present in a basic structural motif, which is a heterotrimeric building block consisting of two molecules of the host and one molecule of the guest. The complex of TrCOTyr with DABCO is an exception. The anionic dimers built off the TrCOTyr molecules form a supramolecular gutter, with trityl groups located on the edge and filled by DABCO cationic dimers. Whereas most of the racemic mixtures crystallize as racemic crystals or as conglomerates, the additional tests carried out for racemic N-triphenylacetyl-tyrosine (rac-TrCOTyr) showed that the compound crystallizes as a solid solution of enantiomers.

Keywords: amino acid; cocrystals; molecular complexes; solid solution; trityl group.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Molecular structure of the compounds under study: (a) the host N-triphenylacetyl-l-tyrosine molecule (TrCOTyr, red color); (b) the guests (blue color): 1,5-naphthyridine (NPHD), quinoxaline (QX), 4,4′-bipyridyl (BIPY), and 1,4-diazabicyclo[2.2.2]octane (DABCO).
Figure 2
Figure 2
(a) Comparison of the molecular conformation of TrCOTyr in polymorph I [42] (orange) and II (blue). Molecular packing in the crystal structure of (b) polymorph I, P212121 (view along x-axis) and (c) polymorph II, P21 (view along y-axis); (d) 1D motif observed in the crystal structure of polymorph II. The C-bound hydrogen atoms are omitted for clarity. The O and N atoms are shown as balls.
Figure 3
Figure 3
Contribution of intermolecular interactions to the Hirshfeld surface area calculated for polymorphs of TrCOTyr.
Figure 4
Figure 4
(a) The molecular structure of TrCOTyr·MeOH with displacement ellipsoids shown at the 50% probability level, hydrogen bonds are presented as dashed lines (compound crystallize as solid solution of enantiomers – model of disorder for the asymmetric molecule shown in the frame, minor position indicated by thinner bonds); (b) 1D motif via hydrogen bonds in crystal structure; (c) molecule of methanol trapped between molecules of N-triphenylacetyltyrosine.
Figure 5
Figure 5
(a) Molecular structure of centrosymmetric dimmer in crystal of rac-TrCOTyr, hydrogen bonds are presented as dashed lines (compound crystallize as solid solution of enantiomers–model of disorder for the asymmetric molecule is shown in the frame, minor position indicated by thinner bonds) and (b) molecular packing in crystal structure.
Figure 6
Figure 6
Molecular structure of building blocks in a crystal structure of (a) (TrCOTyr)2·NPHD and (b) (TrCOTyr)2·QX; hydrogen bonds are presented as dashed lines, the model of disorder is shown in the frames (minor position indicated by thinner bonds).
Figure 7
Figure 7
(a) Molecular structure of (TrCOTyr)2·BIPY (compound crystallizes as solid solution of enantiomers – model of disorder for the asymmetric molecule shown in the frame, minor position indicated by thinner bonds), displacement ellipsoids shown at the 50% probability level; (b) molecular tape stabilized by hydrogen bonds and π···π interaction. Distances are in angstroms.
Figure 8
Figure 8
(a) Molecular structure of TrCOTyr·DABCO (model of disorder for the DABCO dimer shown in the frame), (b) molecular gutter filled by DABCO cationic dimers, (c) molecular packing in crystal structure.
Figure 9
Figure 9
DSC curves of TrCOTyr·MeOH (blue), TrCOTyr·EtOH (red), rac-TrCOTyr·MeOH (green), rac-TrCOTyr·EtOH (pink). The first heating cycle is shown as dashed lines and the second heating cycle is shown as solid lines.
Figure 10
Figure 10
DSC curves of TrCOTyr·QX (red) and (TrCOTyr)2·QX (blue).
See this image and copyright information in PMC

References

    1. Steed J.W., Atwood J.L. Supramolecular Chemistry. Wiley-VCH; Weinheim, Germany: 2009.
    1. Fujita M. Molecular Self-Assembly Organic Versus Inorganic Approaches. Springer; Heidelberg, Germany: 2000.
    1. Lawrence D.S., Jiang T., Levett M. Self-Assembling Supramolecular Complexes. Chem. Rev. 1995;95:2229–2260. doi: 10.1021/cr00038a018. - DOI
    1. Lindoy L.F., Atkinson I.M. Self-Assembly in Supramolecular Systems. RSC; Cambridge, UK: 2000.
    1. MacGillivray L.R. Comprehensive Supramolecular Chemistry II. In: Atwood J.L., Gokel G.W., Barbour L.J., editors. Supramolecular Engineering: Designing The Solid State. Elsevier; Amsterdam, The Netherlands: 2017.

LinkOut - more resources