Anion–Cation Recognition Pattern, Thermal Stability and DFT-Calculations in the Crystal Structure of H2dap[Cd(HEDTA)(H2O)] Salt (H2dap = H2(N3,N7)-2,6-Diaminopurinium Cation)
Metadatos
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Belmont Sánchez, Jeannette Carolina; Ruiz González, Noelia; Matilla Hernández, Antonio; Niclos Gutiérrez, JuanEditorial
MDPI
Materia
EDTA 2,6-diaminopurine Cadmium Co-crystal H-bonding π–π stacking
Date
2020-04Referencia bibliográfica
Belmont-Sánchez, J. C., Ruiz-González, N., Frontera, A., Matilla-Hernández, A., Castiñeiras, A., & Niclós-Gutiérrez, J. (2020). Anion–Cation Recognition Pattern, Thermal Stability and DFT-Calculations in the Crystal Structure of H2dap [Cd (HEDTA)(H2O)] Salt (H2dap= H2 (N3, N7)-2, 6-Diaminopurinium Cation). Crystals, 10(4), 304. [doi:10.3390/cryst10040304]
Patrocinador
This research was funded by the Excellence Network ‘Metal Ions in Biological Systems’ MetalBio CTQ2017-90802-REDT, the Research group FQM-283 (Junta de Andalucía) and MICIU/AEI of Spain (project CTQ2017-85821-R FEDER funds).Résumé
The proton transfer between equimolar amounts of [Cd(H2EDTA)(H2O)] and
2,6-diaminopurine (Hdap) yielded crystals of the out-of-sphere metal complex H2(N3,N7)dap
[Cd(HEDTA)(H2O)]·H2O (1) that was studied by single-crystal X-ray diffraction, thermogravimetry,
FT-IR spectroscopy, density functional theory (DFT) and quantum theory of “atoms-in-molecules”
(QTAIM) methods. The crystal was mainly dominated by H-bonds, favored by the observed tautomer
of the 2,6-diaminopurinium(1+) cation. Each chelate anion was H-bonded to three neighboring
cations; two of them were also connected by a symmetry-related anti-parallel π,π-staking interaction.
Our results are in clear contrast with that previously reported for H2(N1,N9)ade [Cu(HEDTA)
(H2O)]·2H2O (EGOWIG in Cambridge Structural Database (CSD), Hade = adenine), in which H-bonds
and π,π-stacking played relevant roles in the anion–cation interaction and the recognition between
two pairs of ions, respectively. Factors contributing in such remarkable differences are discussed on
the basis of the additional presence of the exocyclic 2-amino group in 2,6-diaminopurinium(1+) ion.