関: crown ether、cryptate

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2017/03/14 07:01:12」(JST)

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Structure of [2.2.2]cryptand encapsulating a potassium cation (purple). At crystalline state, obtained with an X-ray diffraction.^[1]

[2.2.2]Cryptand

Cryptands are a family of synthetic bi- and polycyclic multidentate ligands for a variety of cations.^[2] The Nobel Prize for Chemistry in 1987 was given to Donald J. Cram, Jean-Marie Lehn, and Charles J. Pedersen for their efforts in discovering and determining uses of cryptands and crown ethers, thus launching the now flourishing field of supramolecular chemistry.^[3] The term cryptand implies that this ligand binds substrates in a crypt, interring the guest as in a burial. These molecules are three-dimensional analogues of crown ethers but are more selective and strong as complexes for the guest ions. The resulting complexes are lipophilic.

Structure

The most common and most important cryptand is N[CH₂CH₂OCH₂CH₂OCH₂CH₂]₃N; the formal IUPAC name for this compound is 1,10-diaza-4,7,13,16,21,24-hexaoxabicyclo[8.8.8]hexacosane. This compound is termed [2.2.2]cryptand where the numbers indicate the number of ether oxygen atoms (and hence binding sites) in each of the three bridges between the amine nitrogen "caps". Many cryptands are commercially available under the tradename "Kryptofix."^[4] All-amine cryptands exhibit particularly high affinity for alkali metal cations, which has allowed the isolation of salts of K⁻.^[5]

Properties

The 3-dimensional interior cavity of a cryptand provides a binding site – or host – for "guest" ions. The complex between the cationic guest and the cryptand is called a cryptate. Cryptands form complexes with many "hard cations" including NH+
4, lanthanoids, alkali metals, and alkaline earth metals. In contrast to crown ethers, cryptands bind the guest ions using both nitrogen and oxygen donors. This three-dimensional encapsulation mode confers some size-selectivity, enabling discrimination among alkali metal cations (e.g. Na⁺ vs. K⁺).

Uses

Cryptands are more expensive and difficult to prepare, but offer much better selectivity and strength of binding^[6] than other complexants for alkali metals, such as crown ethers. They are able to bind otherwise insoluble salts into organic solvents. They can also be used as phase transfer catalysts by transferring ions from one phase to another.^[7] Cryptands enabled the synthesis of the alkalides and electrides. They have also been used in the crystallization of Zintl ions such as Sn4−
9.

References

^ Alberto, R.; Ortner, K.; Wheatley, N.; Schibli, R.; Schubiger, A. P. (2001). "Synthesis and properties of boranocarbonate: a convenient in situ CO source for the aqueous preparation of [^99mTc(OH₂)₃(CO)₃]⁺". J. Am. Chem. Soc. 121 (13): 3135–3136. doi:10.1021/ja003932b.
^ Von Zelewsky, A. (1995). Stereochemistry of Coordination Compounds. Chichester: John Wiley. ISBN 0-471-95057-2.
^ Lehn, J. M. (1995). Supramolecular Chemistry: Concepts and Perspectives. Weinheim: VCH.
^ 23978-09-8
^ Kim, J.; Ichimura, A. S.; Huang, R. H.; Redko, M.; Phillips, R. C.; Jackson, J. E.; Dye, J. L. (1999). "Crystalline Salts of Na⁻ and K⁻ (Alkalides) that Are Stable at Room Temperature". J. Am. Chem. Soc. 121 (45): 10666–10667. doi:10.1021/ja992667v.
^ Dietrich, B. (1996). "Cryptands". In Gokel, G. W. Comprehensive Supramolecular Chemistry. 1. Oxford: Elsevier. p. 153–211. ISBN 0-08-040610-6.
^ Landini, D.; Maia, A.; Montanari, F.; Tundo, P. (1979). "Lipophilic [2.2.2]cryptands as phase-transfer catalysts. Activation and nucleophilicity of anions in aqueous-organic thirteen-phase systems and in organic solvents of low polarity". J. Am. Chem. Soc. 101 (10): 2526–2530. doi:10.1021/ja00504a004.

General reading

IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "cryptand".
Lee, J.D. (1991). Concise Inorganic Chemistry (4th ed.). New York: Chapman & Hall. pp. 306–308 & 353. ISBN 0-412-40290-4.
Krakowiak, K. E.; Bradshaw, J. S.; An, H.-Y.; Izatt, R. M. (1993). "Simple methods for the preparation of cryptands". Pure Appl. Chem. 65 (3): 511–514. doi:10.1351/pac199365030511.

English Journal

Anionic Guests in Prismatic Cavities Generated by Enneanuclear Nickel Metallacycles.

Esteban J, Font-Bardia M, Escuer A.Author information Departament de Química Inorgànica, Universitat de Barcelona , Av. Diagonal 645, 08028 Barcelona, Spain.AbstractThe combination of polydentate aminated ligands with the 2-pyridyloxime-nickel-azide system leads to series of clusters with unprecedented topologies. Among them, a remarkable family of {Ni9} metallacycles that are capable of selective encapsulation of azide/halide anions in a cryptand-like cavity through hydrogen-bond interactions has been characterized.
Inorganic chemistry.Inorg Chem.2013 Dec 30. [Epub ahead of print]
The combination of polydentate aminated ligands with the 2-pyridyloxime-nickel-azide system leads to series of clusters with unprecedented topologies. Among them, a remarkable family of {Ni9} metallacycles that are capable of selective encapsulation of azide/halide anions in a cryptand-like cavity t
PMID 24377425

Thermodynamic studies of aqueous solutions of 2,2,2-cryptand at 298.15 k: enthalpy-entropy compensation, partial entropies, and complexation with k(+) ions.

Shaikh VR, Terdale SS, Ahamad A, Gupta GR, Dagade DH, Hundiwale DG, Patil KJ.Author information School of Chemical Sciences, North Maharashtra University , Jalgaon-425001, India.AbstractThe osmotic coefficient measurements for binary aqueous solutions of 2,2,2-cryptand (4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8] hexacosane) in the concentration range of ∼0.009 to ∼0.24 mol·kg(-1) and in ternary aqueous solutions containing a fixed concentration of 2,2,2-cryptand of ∼0.1 mol·kg(-1) with varying concentration of KBr (∼0.06 to ∼0.16 mol·kg(-1)) have been reported at 298.15 K. The diamine gets hydrolyzed in aqueous solutions and needs proper approach to obtain meaningful thermodynamic properties. The measured osmotic coefficient values are corrected for hydrolysis and are used to determine the solvent activity and mean ionic activity coefficients of solute as a function of concentration. Strong ion-pair formation is observed, and the ion-pair dissociation constant for the species [CrptH](+)[OH(-)] is reported. The excess and mixing thermodynamic properties (Gibbs free energy, enthalpy, and entropy changes) have been obtained using the activity data from this study and the heat data reported in the literature. Further, the data are utilized to compute the partial molal entropies of solvent and solute at finite as well as infinite dilution of 2,2,2-cryptand in water. The concentration dependent non-linear enthalpy-entropy compensation effect has been observed for the studied system, and the compensation temperature along with entropic parameter are reported. Using solute activity coefficient data in ternary solutions, the transfer Gibbs free energies for transfer of the cryptand from water to aqueous KBr as well as transfer of KBr from water to aqueous cryptand were obtained and utilized to obtain the salting constant (ks) and thermodynamic equilibrium constant (log K) values for the complex (2,2,2-cryptand:K(+)) at 298.15 K. The value of log K = 5.8 ± 0.1 obtained in this work is found to be in good agreement with that reported by Lehn and Sauvage. The standard molar entropy for complexation is also estimated for the 2,2,2-cryptand-KBr complex in aqueous medium.
The journal of physical chemistry. B.J Phys Chem B.2013 Dec 19;117(50):16249-59. doi: 10.1021/jp410814w. Epub 2013 Nov 26.
The osmotic coefficient measurements for binary aqueous solutions of 2,2,2-cryptand (4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8] hexacosane) in the concentration range of ∼0.009 to ∼0.24 mol·kg(-1) and in ternary aqueous solutions containing a fixed concentration of 2,2,2-cryptand of ∼0.
PMID 24251447

Triamidetriamine Bearing Macrobicyclic and Macrotricyclic Ligands: Potential Applications in the Development of Copper-64 Radiopharmaceuticals.

Tan KV, Pellegrini PA, Skelton BW, Hogan CF, Greguric I, Barnard PJ.Author information Department of Chemistry, La Trobe Institute for Molecular Science, La Trobe University , Victoria 3086, Australia.AbstractA versatile and straightforward synthetic approach is described for the preparation of triamide bearing analogues of sarcophagine hexaazamacrobicyclic cage ligands without the need for a templating metal ion. Reaction of 1,1,1-tris(aminoethyl)ethane (tame) with 3 equiv of 2-chloroacetyl chloride, yields the tris(α-chloroamide) synthetic intermediate 6, which when treated with either 1,1,1-tris(aminoethyl)ethane or 1,4,7-triazacyclononane furnished two novel triamidetriamine cryptand ligands (7 and 8 respectively). The Co(III) and Cu(II) complexes of cryptand 7 were prepared; however, cryptand 8 could not be metalated. The cryptands and the Co(III) complex 9 have been characterized by elemental analysis, 1H and 13C NMR spectroscopy, and X-ray crystallography. These studies confirm that the Co(III) complex 9 adopts an octahedral geometry with three facial deprotonated amido-donors and three facial amine donor groups. The Cu(II) complex 10 was characterized by elemental analysis, single crystal X-ray crystallography, cyclic voltammetry, and UV-visible absorption spectroscopy. In contrast to the Co(III) complex (9), the Cu(II) center adopts a square planar coordination geometry, with two amine and two deprotonated amido donor groups. Compound 10 exhibited a quasi-reversible, one-electron oxidation, which is assigned to the Cu2+/3+ redox couple. These cryptands represent interesting ligands for radiopharmaceutical applications, and 7 has been labeled with 64Cu to give 64Cu-10. This complex showed good stability when subjected to l-cysteine challenge whereas low levels of decomplexation were evident in the presence of l-histidine.
Inorganic chemistry.Inorg Chem.2013 Dec 16. [Epub ahead of print]
A versatile and straightforward synthetic approach is described for the preparation of triamide bearing analogues of sarcophagine hexaazamacrobicyclic cage ligands without the need for a templating metal ion. Reaction of 1,1,1-tris(aminoethyl)ethane (tame) with 3 equiv of 2-chloroacetyl chloride, yi
PMID 24341386

Japanese Journal

クリプタンドを輪分子に用いる擬ロタキサンの合成と物性

村岡雅弘,大田司,中辻洋司
基礎有機化学討論会要旨集（基礎有機化学連合討論会予稿集） 2010(0), 3P85-3P85, 2011
クリプタンド型ロタキサンの合成を目的に二つの芳香環を有するクリプタンドを輪分子に用いたビピリジニウム塩誘導体の捕捉能について検討した。等モル量のクリプタンドとビピリジニウム塩誘導体を重アセトン中で混合し<SUP>1</SUP>H NMRスペクトルを測定したところ、クリプタンドの芳香環のシグナルの高磁場シフトが観察された。また、UV-Vis測定より電荷移動に関する吸収が観察さ …
NAID 130004729302

ピリジン含有環状テトラピロールとそのメソ付加誘導体の合成と性質

大和恭平,瀬恒潤一郎
基礎有機化学討論会要旨集（基礎有機化学連合討論会予稿集） 2010(0), 1P37-1P37, 2011
2,6-ジピリルピリジンとホルムアルデヒドを用いて三フッ化ホウ素エーテル錯体を酸触媒とするローズムント型縮合反応を行うことにより、メソ位が無置換のピリジン含有環状テトラピロールを合成した。この化合物はアルコール、アミンなどと室温下で混合するだけで容易に反応し、メソ位に種々の官能基が付加することがわかった。他のメソ付加誘導体も合成したので、それらはまとめて報告する。
NAID 130004729092

２個の銀食い分子を導入した円筒状クリプタンドの合成：　架橋鎖長に依存するアロステリック特性

二瓶祐太郎,桑原俊介,幅田揚一
基礎有機化学討論会要旨集（基礎有機化学連合討論会予稿集） 2011(0), 420-420, 2011
２個の銀食い分子（テトラアームドサイクレン）を２本のエチレンオキシド鎖で架橋した円筒状クリプタンドを合成した．この円筒状クリプタンドは２個の銀イオンと錯形成すると架橋鎖長に依存してアロステリック特性を示すことが<SUP>1</SUP>H NMRとUV-Visスペクトルを用いた滴定実験で明らかになった。また，各サイクレン部位に銀イオンを捕捉した錯体の構造をX線結晶構造解析によ …
NAID 130004645946