Unbalanced racemates: solid state solutions containing enantiomeric pairs crystallizing in Sohncke space groups with (L:D) ratios other than (1:1) – illustrated with crystals of a Co(III) coordination compound
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Ivan Bernal
and
Roger A. Lalancette
Abstract
Herein we describe materials of composition [Co(NH3)4(X-leucinato)]I2·H2O in which the amino acid ligand is either L or D, and in which (a) while in pure enantiomorphic form (L), crystallizes in a Sohncke space group with Z′ = 2.0; but, whose packing closely resembles that of its racemate. Such substances are labeled a Racemic Mimic; and (b) crystals in which the L:D ratio of the amino acid ligand in the asymmetric unit is (71:29), which interestingly crystallize in the same space group and cell constants as those of the former. Moreover, the packing behavior is essentially the same in both—the difference being that the (1:1) species is fully ordered, while that with L:D (71:29) ratio has a partially disordered propyl chain. The (71:29) species we describe herein as an Unbalanced Racemate.
Acknowledgments
We acknowledge interesting conversations on this topic with colleagues at our respective institutions and to the National Science Foundation for NSF-CRIF Grant No. 0443538 for part of the purchase of the X-ray diffractometer.
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Author contributions: Ivan Bernal and Roger Lalancette wrote the manuscript and approve of its content.
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Research funding: There was no external funding for this research.
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Conflict of interest statement: The authors declare no conflicts of interest regarding this article.
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Ethical approval: All ethical guidelines have been adhered.
References
1. Fuyuhiro, A., Hibino, K., Yamanari, K. Formation of racemic solid solutions and the solubility isotherms of [Co(DL-leucinato)(NH3)4]X2 (X = Br and I). Chem. Lett. 1991, 1041–1044. JOKKAV and JOKKEZ.10.1246/cl.1991.1041Search in Google Scholar
2. Groom, C. R., Bruno, I. J., Lightfoot, M. P., Ward, S. C. Acta Cryst., 2016, B72, 171–179. https://doi.org/10.1107/s2052520616003954, CSD = Cambridge Structural Database, CCDC, Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ UK.Search in Google Scholar
3. Wood, M. R., Mikhael, S., Bernal, I., Lalancette, R. A. Erdmann’s anion – an inexpensive and useful species for the crystallization of illicit drugs after street confiscations. Memoriam Howard Flack Chem. 2021, 3, 598–611; https://doi.org/10.3390/chemistry3020042.Search in Google Scholar
4. Bernal, I. ACA Annual Meeting, Montreal, Quebec, Canada, 1995. Abstract 4a.1.e.Search in Google Scholar
5. Bernal, I., Cai, J., Myrczek, J. Models in chemistry, special issue honoring maria acs. Acta Chim. Hung. 1995, 132, 451–474. The honoring ceremony at The Technical University of Budapest occurred April 12, 1994.Search in Google Scholar
6. Bernal, I., Cai, J., Massoud, S. S., Watkins, S., Fronczek, F. R. The phenomenon of kryptoracemic crystallization. Part 1. Counterion control of crystallization pathway selection. Part 4. The crystallization behavior of (+/−)-[Co(tren)(NO2)2]Br(I), (+/−)-[Co(tren)(NO2)2]2Br(ClO4)·H2O(II), (+/(−)-[Co(tren)(NO2)2]ClO4(III) and attempts to solve the structure of (+/−)-[Co(tren)(NO2)2]NO3(IV). J. Coord. Chem. 1996, 38, 165–181; https://doi.org/10.1080/00958979608022702. NIXGIK.Search in Google Scholar
7. Morales, G. A., Fronczek, F. R. A kryptoracemic hydroperoxide. Acta Crystallogr. 1996, C52, 1266–1268; https://doi.org/10.1107/s010827019501537x. TABLUD.Search in Google Scholar
8. Bernal, I., Somoza, F., Banh, V. Kryptoracemic crystallization. Part 4. Synthesis and X-ray structure of the conglomerate [Co(en)2Ox]F 11.5H2O(I), another example of a coordination compound crystallizing as a kryptoracemate. J. Coord. Chem. 1997, 42, 1–10; https://doi.org/10.1080/00958979708045275. QADPAM.Search in Google Scholar
9. Cai, J., Myrczek, J., Chun, H., Bernal, I. The crystallization behavior of (±)-cis-α-[Co(dmtrien)(NO2)2]Cl·0.5H2O 1 and (±)-cis-α-[Co(dmtrien)(NO2)2]I 2† (dmtrien = 3, 6-dimethyl-3, 6-diazaoctane-1, 8-diamine). J. Chem. Soc. Dalton 1998, 4155–4160; https://doi.org/10.1039/a806094k. FILGIQ.Search in Google Scholar
10. Fabián, L., Brock, C. P. A list of organic kryptoracemates. Acta Crystallogr. B 2010, 66, 94–103; https://doi.org/10.1107/s0108768109053610.Search in Google Scholar
11. Bernal, I., Watkins, S. F. A list of organometallic kryptoracemates. Acta Crystallogr. 2015, C71, 216–221; https://doi.org/10.1107/s2053229615002636.Search in Google Scholar
12. Bernal, I., Lalancette, R. A. A crystalline paradise – three substances exhibiting the following crystallization modes: (1) conglomerate, kryptoracemic and unbalanced (2) conglomerate and kryptoracemic. Compt. Rendus Chem. 2015, 18, 929–934; https://doi.org/10.1016/j.crci.2015.06.005.Search in Google Scholar
13. Clevers, S., Coquerel, G. Kryptoracemic compound hunting and frequency in the Cambridge structural database. CrystEngComm 2020, 22, 7407–7419; https://doi.org/10.1039/d0ce00303d.Search in Google Scholar
14. Prelesnik, B., Andjelkovic, K., Juranic, N. Structure of [(S)-alaninato]tetraamminecobalt(III) sulfate. Acta Cryst., Sect.C: Cryst. Struct. Commun. 1992, 48, 427–429; https://doi.org/10.1107/s0108270191008946. TAPTAF.Search in Google Scholar
15. Sereda, O., Stoeckli-Evans, H. Crystal structures of {[Cu(Lpn)2] [Fe(CN)5(NO)]·H2O}n and {[Cu(Lpn)2]3[Cr(CN)6]2·5H2O}n [where Lpn = (R)-propane-1, 2-diamine]: two heterometallic chiral cyanide-bridged coordination polymers. Acta Cryst., Sect.E: Cryst. Commun. 2015, 71, 392–397; https://doi.org/10.1107/s2056989015005253. XITHIR01.Search in Google Scholar
16. Rekis, T., Berzins, A., Sarcevica, I., Kons, A., Bolodis, M., Orola, L., Lorenz, H., Actins, A. A maze of solid solutions of pimobendan enantiomers: an extraordinary case of polymorph and solvate diversity. Cryst. Growth Des. 2018, 18, 264–273; https://doi.org/10.1021/acs.cgd.7b01203.Search in Google Scholar
17. Rekis, T., d’Agostino, S., Braga, D., Grepioni, F. Designing solid solutions of enantiomers: lack of enantioselectivity of chiral naphthalimide derivatives in the solid state. Cryst. Growth Des. 2017, 17, 6477–6485; https://doi.org/10.1021/acs.cgd.7b01146.Search in Google Scholar
18. Rekis, T., Berzins, A., Orola, L., Holczbauer, T., Actins, A., Seidel-Morgenstern, A., Lorenz, H. Single enantiomer’s urge to crystallize in centrosymmetric space groups: solid solutions of phenylpiracetam. Cryst. Growth Des. 2017, 17, 1411–1418; https://doi.org/10.1021/acs.cgd.6b01867.Search in Google Scholar
19. Rekis, T. Crystallization of chiral molecular compounds: what can be learned from the Cambridge Structural Database? Acta Crystallogr. 2020, B76, 307–315; https://doi.org/10.1107/s2052520620003601.Search in Google Scholar
20. Lalancette, R. A., Arslan, E., Bernal, I., Willhelm, D., Grebowicz, J., Pluta, M. The thermochemistry of metal tris-acetylacetonates. Part 1. Al and Mn. J. Therm. Anal. Calorim. 2018, 131, 2809–2819.10.1007/s10973-017-6799-xSearch in Google Scholar
21. Lalancette, R. A., Szydek, D., Grebowitz, J., Arslan, E., Bernal, I. Thermal decomposition and analyses of MetalTris-acetylacetonates, free radical formation from Al, Cr, Mn, Fe and Co. J. Therm. Anal. Calorim. 2019, 135, 3463–3470; https://doi.org/10.1007/s10973-018-7598-8.Search in Google Scholar
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Articles in the same Issue
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Articles in the same Issue
- Frontmatter
- In this issue
- Inorganic Crystal Structures (Original Paper)
- Crystal structure and magnetic properties of some compounds with GdNi2Ga3In type structure
- Partially disordered pyrochlore: time-temperature dependence of recrystallization and dehydration
- Lu37Ru16.4In4 – coloring and vacancy formation in a new structure type closely related to a 8 × 8 × 8 bcc superstructure
- BaFe0.875Re0.125O3−δ and BaFe0.75Ta0.25O3−δ as potential cathodes for solid-oxide fuel-cells: a structural study from neutron diffraction data
- Unbalanced racemates: solid state solutions containing enantiomeric pairs crystallizing in Sohncke space groups with (L:D) ratios other than (1:1) – illustrated with crystals of a Co(III) coordination compound
- Crystal structure and specific heat of calcium lanthanide oxyborates Ca4LnO(BO3)3
- Order-disorder (OD) structures of Rb2Zn(TeO3)(CO3)·H2O and Na2Zn2Te4O11
- Na2Cu+[Cu2+3O](AsO4)2Cl and Cu3[Cu3O]2(PO4)4Cl2: two new structure types based upon chains of oxocentered tetrahedra
- Organic and Metalorganic Crystal Structures (Original Paper)
- Two isomers Ba5Mg4C54O48H114 and Pb5Mg4C54O48H114
- Layered structures based on antimony tartrate dimers
