Next Article in Journal
Synthesis and Characterization of a Monoclinic Crystalline Phase of Hydroxyapatite by Synchrotron X-ray Powder Diffraction and Piezoresponse Force Microscopy
Next Article in Special Issue
Determination of the Full 207Pb Chemical Shift Tensor of Anglesite, PbSO4, and Correlation of the Isotropic Shift to Lead–Oxygen Distance in Natural Minerals
Previous Article in Journal
Selective and Recyclable Sensing of Aqueous Phase 2,4,6-Trinitrophenol (TNP) Based on Cd(II) Coordination Polymer with Zwitterionic Ligand
Previous Article in Special Issue
NMR Crystallography of the Polymorphs of Metergoline
Article Menu
Issue 12 (December) cover image

Export Article

Open AccessFeature PaperArticle
Crystals 2018, 8(12), 457; https://doi.org/10.3390/cryst8120457

Cyclodextrin-Driven Formation of Double Six-Ring (D6R) Silicate Cage: NMR Spectroscopic Characterization from Solution to Crystals

1
Institut Lavoisier de Versailles, Centre National de la Recherche Scientifique, Université de Versailles St-Quentin, Université Paris-Saclay, 45 av. des Etats-Unis, 78035 Versailles CEDEX, France
2
Centre National de la Recherche Scientifique, Conditions Extrêmes et Matériaux: Haute Température et Irradiation, Université d’Orléans, 45071 Orléans, France
*
Author to whom correspondence should be addressed.
Received: 21 November 2018 / Revised: 4 December 2018 / Accepted: 5 December 2018 / Published: 7 December 2018
(This article belongs to the Special Issue NMR Crystallography)
  |  
PDF [2922 KB, uploaded 13 December 2018]
  |  

Abstract

Identification and isolation of secondary building units (SBUs) from synthesis media of zeolites still represent a challenging task for chemists. The cage structure anion Si12O3012− known as the double six-ring (D6R) was synthesized from α-cyclodextrin (α-CD) mediated alkaline silicate solutions and conditions of its stability and reactivity in aqueous solution were studied by using nuclear magnetic resonance (NMR) spectroscopy. A single crystal X-ray diffraction (XRD) analysis revealed a novel polymorph of the hybrid complex K12Si12O30·2α-CD·nD2O (n ≈ 30–40), which crystallizes in the orthorhombic C2221 space group symmetry with a = 14.841(4) Å, b = 25.855(6) Å, and c = 41.91(1) Å. The supramolecular adduct of the silicate anion sandwiched by two α-CDs forms a perfect symmetry matching the H-bonding donor-acceptor system between the organic macrocycle and the D6R unit. The driving force of such a hybrid assembly has found to be strongly dependent on the nature of the cation present as large alkali counter ions (K+, Rb+ and Cs+), which stabilize the D6R structure acting as templates. Lastly, we provided the first 29Si MAS NMR measurement of 3Q Si in an isolated D6R unit that allows the verification of the linear correlation between the chemical shift and <SiOSi> bond angle for 3Q Si species in DnR cages (n = 3, 4, 6). View Full-Text
Keywords: crystallization; nuclear magnetic resonance spectroscopy; hydrogen-bonding; silicate oligomers; self-assembly; molecular recognition; template effect crystallization; nuclear magnetic resonance spectroscopy; hydrogen-bonding; silicate oligomers; self-assembly; molecular recognition; template effect
Figures

Graphical abstract

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Supplementary material

SciFeed

Share & Cite This Article

MDPI and ACS Style

Haouas, M.; Falaise, C.; Martineau-Corcos, C.; Cadot, E. Cyclodextrin-Driven Formation of Double Six-Ring (D6R) Silicate Cage: NMR Spectroscopic Characterization from Solution to Crystals. Crystals 2018, 8, 457.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Crystals EISSN 2073-4352 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top