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Šakarašvili M, Ustrnul L, Suut E, Nallaparaju JV, Mishra KA, Konrad N, Adamson J, Borovkov V, Aav R. Self-Assembly of Chiral Cyclohexanohemicucurbit[n]urils with Bis(Zn Porphyrin): Size, Shape, and Time-Dependent Binding. Molecules 2022; 27:molecules27030937. [PMID: 35164200 PMCID: PMC8839860 DOI: 10.3390/molecules27030937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 01/19/2022] [Accepted: 01/25/2022] [Indexed: 12/10/2022] Open
Abstract
In order to investigate the ability of bis(zinc octaethylporphyrin) (bis–ZnOEP) to discriminate cyclohexanohemicucurbit[n]urils (cycHC[n]) of different shapes and sizes, the self-assembly of barrel-shaped chiral cycHC[n] with bis–ZnOEP was studied by various spectroscopic methods (absorption, fluorescence, circular dichroism (CD), and NMR). While the binding of 6-membered cycHC[6] induced a tweezer-like conformation followed by the formation of anti-form of bis–ZnOEP upon further addition of cycHC[6], the interaction of 8-membered cycHC[8] is more complex and proceeds through the featured syn-to-anti conformational change of bis–ZnOEP and further intermolecular self-assembly via multiple noncovalent associations between cycHC[8] and bis–ZnOEP. Whilst bis–porphyrins are known to be effective chemical sensors able to differentiate various guests based on their chirality via induced CD, their ability to sense small differences in the shape and size of relatively large macrocycles, such as chiral cycHC[6] and cycHC[8], is scarcely examined. Both studied complexes exhibited characteristic induced CD signals in the region of porphyrin absorption upon complexation.
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Affiliation(s)
- Marko Šakarašvili
- Department of Chemistry and Biotechnology, School of Science, Tallinn University of Technology, 12618 Tallinn, Estonia; (M.Š.); (L.U.); (E.S.); (J.V.N.); (K.A.M.); (N.K.)
| | - Lukas Ustrnul
- Department of Chemistry and Biotechnology, School of Science, Tallinn University of Technology, 12618 Tallinn, Estonia; (M.Š.); (L.U.); (E.S.); (J.V.N.); (K.A.M.); (N.K.)
| | - Elina Suut
- Department of Chemistry and Biotechnology, School of Science, Tallinn University of Technology, 12618 Tallinn, Estonia; (M.Š.); (L.U.); (E.S.); (J.V.N.); (K.A.M.); (N.K.)
| | - Jagadeesh Varma Nallaparaju
- Department of Chemistry and Biotechnology, School of Science, Tallinn University of Technology, 12618 Tallinn, Estonia; (M.Š.); (L.U.); (E.S.); (J.V.N.); (K.A.M.); (N.K.)
| | - Kamini A. Mishra
- Department of Chemistry and Biotechnology, School of Science, Tallinn University of Technology, 12618 Tallinn, Estonia; (M.Š.); (L.U.); (E.S.); (J.V.N.); (K.A.M.); (N.K.)
| | - Nele Konrad
- Department of Chemistry and Biotechnology, School of Science, Tallinn University of Technology, 12618 Tallinn, Estonia; (M.Š.); (L.U.); (E.S.); (J.V.N.); (K.A.M.); (N.K.)
| | - Jasper Adamson
- Laboratory of Chemical Physics, National Institute of Chemical Physics and Biophysics, 12618 Tallinn, Estonia;
| | - Victor Borovkov
- Department of Chemistry and Biotechnology, School of Science, Tallinn University of Technology, 12618 Tallinn, Estonia; (M.Š.); (L.U.); (E.S.); (J.V.N.); (K.A.M.); (N.K.)
- Correspondence: (V.B.); (R.A.)
| | - Riina Aav
- Department of Chemistry and Biotechnology, School of Science, Tallinn University of Technology, 12618 Tallinn, Estonia; (M.Š.); (L.U.); (E.S.); (J.V.N.); (K.A.M.); (N.K.)
- Correspondence: (V.B.); (R.A.)
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Shalima T, Mishra KA, Kaabel S, Ustrnul L, Bartkova S, Tõnsuaadu K, Heinmaa I, Aav R. Cyclohexanohemicucurbit[8]uril Inclusion Complexes With Heterocycles and Selective Extraction of Sulfur Compounds From Water. Front Chem 2021; 9:786746. [PMID: 34926407 PMCID: PMC8678634 DOI: 10.3389/fchem.2021.786746] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 11/04/2021] [Indexed: 11/13/2022] Open
Abstract
Solid-phase extraction that utilizes selective macrocyclic receptors can serve as a useful tool for removal of chemical wastes. Hemicucurbiturils are known to form inclusion complexes with suitably sized anions; however, their use in selective binding of non-charged species is still very limited. In this study, we found that cyclohexanohemicucurbit[8]uril encapsulates five- and six-membered sulfur- and oxygen-containing unsubstituted heterocycles, which is investigated by single-crystal X-ray diffraction, NMR spectroscopy, isothermal titration calorimetry, and thermogravimetry. The macrocycle acts as a promising selective sorption material for the extraction of sulfur heterocycles, such as 1,3-dithiolane and α-lipoic acid, from water.
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Affiliation(s)
- Tatsiana Shalima
- Department of Chemistry and Biotechnology, School of Science, Tallinn University of Technology, Tallinn, Estonia
| | - Kamini A Mishra
- Department of Chemistry and Biotechnology, School of Science, Tallinn University of Technology, Tallinn, Estonia
| | - Sandra Kaabel
- Department of Chemistry, McGill University, Montreal, QC, Canada
| | - Lukas Ustrnul
- Department of Chemistry and Biotechnology, School of Science, Tallinn University of Technology, Tallinn, Estonia
| | - Simona Bartkova
- Department of Chemistry and Biotechnology, School of Science, Tallinn University of Technology, Tallinn, Estonia
| | - Kaia Tõnsuaadu
- Laboratory of Inorganic Materials, School of Engineering, Institute of Materials and Environmental Technology, Tallinn University of Technology, Tallinn, Estonia
| | - Ivo Heinmaa
- Laboratory of Chemical Physics, National Institute of Chemical Physics and Biophysics, Tallinn, Estonia
| | - Riina Aav
- Department of Chemistry and Biotechnology, School of Science, Tallinn University of Technology, Tallinn, Estonia
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Ustrnul L, Burankova T, Öeren M, Juhhimenko K, Ilmarinen J, Siilak K, Mishra KA, Aav R. Binding Between Cyclohexanohemicucurbit[ n]urils and Polar Organic Guests. Front Chem 2021; 9:701028. [PMID: 34262895 PMCID: PMC8273652 DOI: 10.3389/fchem.2021.701028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 06/07/2021] [Indexed: 11/13/2022] Open
Abstract
Inherently chiral, barrel-shaped, macrocyclic hosts such as cyclohexanohemicucurbit[n]urils (cycHC[n]) bind zinc porphyrins and trifluoroacetic acid externally in halogenated solvents. In the current study, we tested a set of eighteen organic guests with various functional groups and polarity, namely, thiophenols, phenols, and carboxylic and sulfonic acids, to identify a preference toward hydrogen bond–donating molecules for homologous cycHC[6] and cycHC[8]. Guests were characterized by Hirshfeld partial charges on acidic hydrogens and their binding by 1H and 19F NMR titrations. Evaluation of association constants revealed the complexity of the system and indirectly proved an external binding with stoichiometry over 2:1 for both homologs. It was found that overall binding strength is influenced by the stoichiometry of the formed complexes, the partial atomic charge on the hydrogen atom of the hydrogen bond donor, and the bulkiness of the guest. Additionally, a study on the formation of complexes with halogen anions (Cl− and Br−) in methanol and chloroform, analyzed by 1H NMR, did not confirm complexation. The current study widens the scope of potential applications for host molecules by demonstrating the formation of hydrogen-bonded complexes with multisite hydrogen bond acceptors such as cycHC[6] and cycHC[8].
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Affiliation(s)
- Lukas Ustrnul
- Department of Chemistry and Biotechnology, School of Science, Tallinn University of Technology, Tallinn, Estonia
| | | | - Mario Öeren
- Optibrium Limited, Cambridge, United Kingdom
| | - Kristina Juhhimenko
- Department of Chemistry and Biotechnology, School of Science, Tallinn University of Technology, Tallinn, Estonia
| | - Jenni Ilmarinen
- Department of Chemistry and Biotechnology, School of Science, Tallinn University of Technology, Tallinn, Estonia
| | - Kristjan Siilak
- Department of Chemistry and Biotechnology, School of Science, Tallinn University of Technology, Tallinn, Estonia
| | - Kamini A Mishra
- Department of Chemistry and Biotechnology, School of Science, Tallinn University of Technology, Tallinn, Estonia
| | - Riina Aav
- Department of Chemistry and Biotechnology, School of Science, Tallinn University of Technology, Tallinn, Estonia
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Mishra KA, Adamson J, Öeren M, Kaabel S, Fomitšenko M, Aav R. Dynamic chiral cyclohexanohemicucurbit[12]uril. Chem Commun (Camb) 2020; 56:14645-14648. [PMID: 33155596 DOI: 10.1039/d0cc06817a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
NMR spectroscopy and DFT modeling studies of chiral cyclohexanohemicucurbit[12]uril indicate that the macrocycle adopts a concave octagonal shape with two distinct conformational flexibilities in solution. Methylene bridge flipping occurs at temperatures above 265 K, while urea monomers rotate at temperatures above 308 K, resulting in the loss of confined space within the macrocycle.
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Affiliation(s)
- Kamini A Mishra
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia.
| | - Jasper Adamson
- Chemical Physics Laboratory, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, 12618 Tallinn, Estonia
| | - Mario Öeren
- Optibrium Limited, F5-6 Blenheim House, Denny End Road, Cambridge, CB25 9PB, UK
| | - Sandra Kaabel
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia. and Department of Chemistry, McGill University, 801 Sherbrooke Street West, H3A 0B8, Montreal, Quebec, Canada
| | - Maria Fomitšenko
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia.
| | - Riina Aav
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia.
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Ustrnul L, Kaabel S, Burankova T, Martõnova J, Adamson J, Konrad N, Burk P, Borovkov V, Aav R. Supramolecular chirogenesis in zinc porphyrins by enantiopure hemicucurbit[n]urils (n = 6, 8). Chem Commun (Camb) 2019; 55:14434-14437. [PMID: 31737875 DOI: 10.1039/c9cc07150d] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Chiral cyclohexanohemicucurbit[n]urils (n = 6, 8) (cycHCs) are able to bind guests through multiple "outer surface interactions", which in the case of planar zinc porphyrins leads to induction of chirality. Crystal structures of complexes of complementary sized hosts revealed social self-sorting, while in the solution phase one cycHC can accommodate up to three porphyrin molecules with log Ktotal 9.
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Affiliation(s)
- Lukas Ustrnul
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia.
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