Complexation of planar, organic, five-membered cations with crown ethers

Kiviniemi, Sari; Nissinen, Maija; Lämsä, Markku; Jalonen, Jorma; Pursiainen, Jouni

doi:10.1039/a907608e

Cited by 37 publications

(18 citation statements)

References 8 publications

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“…1). The N7-N7 v (2 − x, y, 3/2 − z) bond length of 1.309 (3)Å is apparently shorter than some analogs which should be largely attributed to its protonated position at the 2-site, but not the generally observed 4-site (Jin et al, 2006;Ye et al, 2008;Kiviniemi et al, 2000).…”

Section: Commentmentioning

confidence: 98%

“…; Chen et al (2010); For co-crystals involved 5-sulfosaliyclic acid or triazole, see: Jin et al (2006); Kiviniemi et al (2000); Meng et al (2007Meng et al ( , 2008; Ye et al (2008 Table 1 Hydrogen-bond geometry (Å , ). Symmetry codes: (i) x À 1 2 ; y À 1 2 ; z; (ii) x À 1 2 ; y þ 1 2 ; z; (iii) x; y þ 1; z; (iv) Àx þ 1 2 ; Ày þ 1 2 ; Àz þ 1; (v) x; y À 1; z; (vi) Àx þ 1; Ày þ 1; Àz þ 1.…”

Section: Related Literaturementioning

confidence: 99%

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[Hydrogen bis(1,2,4-triazole)] 1,2,4-triazolium bis(3-carboxy-4-hydroxybenzenesulfonate) 1,2,4-triazole disolvate

Qiu

2010

Acta Cryst E

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The title compound, C2H4N3 +·[H(C2H3N3)2]+·2C7H5O6S−·2C2H3N3, consists of two types of 1,2,4-triazole monocation, one protonated at the 2-site lying across a twofold axis and the other protonated at the 4-site with the H atom disordered over a center of symmetry, a 5-sulfosalicylate anion and a neutral 1,2,4-triazole molecule. The component ions are linked into a three-dimensional network by a combination of N—H⋯O, N—H⋯N, O—H⋯O, O—H⋯N, C—H⋯O and C—H⋯N hydrogen bonds. In addition, benzene–benzene π–π interactions of 3.942 (2) Å [interplanar spacing = 3.390 (2) Å] and C—O⋯π (3.331 Å) interactions are observed.

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Section: Commentmentioning

confidence: 98%

Section: Related Literaturementioning

confidence: 99%

[Hydrogen bis(1,2,4-triazole)] 1,2,4-triazolium bis(3-carboxy-4-hydroxybenzenesulfonate) 1,2,4-triazole disolvate

Qiu

2010

Acta Cryst E

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“…Highlights include 1) the development of a new recognition template for [2]pseudorotaxane formation built around a 24membered crown ether wheel and a benzimidazolium axle with extended aromatic substituents, 2) a high yielding, modular synthesis of [2]rotaxane molecular shuttles with a compact and rigid, H-shaped molecular structure, 3) access to three distinct molecular states and corresponding molecular shuttling rates through acid-base chemistry, and 4) control of the rate of molecular shuttling through lithium ion "ferrying" between neutral binding sites. [6] The interaction of dibenzo [24]crown-8 (DB24C8) with the imidazolium (K a = 8 m À1 ) [7] or phenylbenzimidazolium, [1-H] + (K a = 5.0 10 1 m À1 ) cation is weak but this can be drastically increased by adding aromatic groups to the 4-and 7-positions of the benzimidazolium unit. The benzimidazolium salt [2-H][BF 4 ] was synthesized by reacting 4,7-dibromo-2-phenyl-1H-benzimidazole [8] with 2 equivalents of 4-fluorophenylboronic acid under Suzuki coupling conditions followed by protonation with HBF 4 (see the Supporting Information).…”

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confidence: 99%

Molecular Shuttling of a Compact and Rigid H‐Shaped [2]Rotaxane

Zhu

Vukotic

2012

Angewandte Chemie

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Bistable [2]rotaxanes (molecular shuttles) are mechanically interlocked molecules (MIMs) that can be switched between different translational co-conformations in response to an external stimulus. [1] Chemical, electrochemical, and photochemical inputs have been used to control the actions of these systems in solution and some very efficient and sophisticated examples are known, including those that occupy nonequilibrium states and function using a ratchet-type mechanism. [2] Since most [2]rotaxane molecular shuttles are large, flexible molecules with multiple functional groups they operate with efficiency in solution where the interlocked components enjoy a high degree of structural and dynamic freedom. The size and flexibility of the molecular structure are rarely a problem, [3] however, these attributes make them much less practical for highly condensed phases where the size, positional orientation and degree of aggregation of the MIM components are crucial to optimum switching efficiency. [4] To incorporate efficient molecular switches into materials and devices with a high density of functional components, a compact structure with a rigid axle and short, linear track for translational motion would be most desirable. [5] We report herein a compact MIM-based switch with welldefined geometry, rigid backbone, and efficient switching characteristics for future application in highly dense media. Highlights include 1) the development of a new recognition template for [2]pseudorotaxane formation built around a 24membered crown ether wheel and a benzimidazolium axle with extended aromatic substituents, 2) a high yielding, modular synthesis of [2]rotaxane molecular shuttles with a compact and rigid, H-shaped molecular structure, 3) access to three distinct molecular states and corresponding molecular shuttling rates through acid-base chemistry, and 4) control of the rate of molecular shuttling through lithium ion "ferrying" between neutral binding sites. [6] The interaction of dibenzo[24]crown-8 (DB24C8) with the imidazolium (K a = 8 m À1 ) [7] or phenylbenzimidazolium, [1-H] + (K a = 5.0 10 1 m À1 ) cation is weak but this can be drastically increased by adding aromatic groups to the 4-and 7-positions of the benzimidazolium unit. The benzimidazolium salt [2-H][BF 4 ] was synthesized by reacting 4,7-dibromo-2-phenyl-1H-benzimidazole [8] with 2 equivalents of 4-fluorophenylboronic acid under Suzuki coupling conditions followed by protonation with HBF 4 (see the Supporting Information). The 1 H NMR spectrum of a solution comprised of equimolar amounts of [2-H] + and DB24C8 (1.0 10 À3 m, CD 3 CN, 298 K) shows the efficient formation of [2]pseudorotaxane [2-H&DB24C8] + (Figure 1). The association constant of 1.0 10 3 m À1 is two orders of magnitude larger than for simple imidazolium or benzimidazolium derivatives. Significant shifts to higher frequency were observed for the NH (+ 0.73 ppm) and proton a resonances (+ 0.37 ppm) indicating hydrogen-bonding interactions while shifts to lower frequency for peaks b and c on th...

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“…As a rule a pair of protons of the substituent takes part in bonding, and the stability of the compounds decreases in the following order: OH > NH 2 > CH 2 [4]. The crystalline supramolecular compounds of crown ethers with heterocycles are stabilized by hydrogen bonds either through one of the above-mentioned substituents in the heterocycle [5][6][7][8][9][10][11][12] or the cyclic ammonium group of the protonated heterocycle [13]. A single example of the formation of a crystalline supramolecular compound of the most effective [3,14] crown ether 1b with unsubstituted triazole is known [15].…”

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confidence: 99%

“…1302-1305, September, 2006. Original article submitted October 7, 2005. cis-anti-cis-eicosahydrodibenzo[b,k][1,4,7,10,13,16]hexaoxacyclooctadecene;(4) 1H-imidazole-4,5-dicarbonitrile; (5) 3-nitro-1,2,4-triazole; (6) 1H-tetrazole…”

mentioning

confidence: 99%

Reaction of crown ethers with five-membered heterocycles: 1H-imidazole-4,5-dicarbonitrile, 3-nitro-1,2,4-triazole, and 1H-tetrazole

Wang

Tang

Ganin

2006

Chem Heterocycl Compd

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one proton at each of the two proton-donating atoms separated by one covalent bond, it was shown that uncharged crystalline supramolecular compounds can be obtained on account of the proton-donating characteristics of the aromatic heterocycles.An indispensable condition for the formation of crystalline supramolecular compounds [1, 2] of crown ethers with organic molecules is the presence in the latter of proton-donating centers with one of the atoms C, N, or O, particularly H 2 N-, H 2 NSO 2 -, H 2 NCS-, H 2 NHNCO-, H 2 C=, H 3 C-, H 3 CO-, and similar groups or water molecules [1-3], securing stabilization of the components of the supramolecular compound by hydrogen bonds. As a rule a pair of protons of the substituent takes part in bonding, and the stability of the compounds decreases in the following order: OH > NH 2 > CH 2 [4]. The crystalline supramolecular compounds of crown ethers with heterocycles are stabilized by hydrogen bonds either through one of the above-mentioned substituents in the heterocycle [5][6][7][8][9][10][11][12] or the cyclic ammonium group of the protonated heterocycle [13]. A single example of the formation of a crystalline supramolecular compound of the most effective [3,14] crown ether 1b with unsubstituted triazole is known [15].The aim of this work was to determine the possibility of synthesizing uncharged crystalline supramolecular compounds of various crown ethers with five-membered aromatic heterocycles, containing one proton at each of two adjacent proton-donating atoms separated by one covalent bond and securing stabilization of the supramolecular compound by analogy with the data in [15].It was established that the crystalline supramolecular compounds [1b·4]-7, [2·4]-8, [3·2(4)]-9, [1a·5]-10, [1b·2(5)]-11, [2·2(5)]-12, [3·2(5)]-13, and [3·2(6)]-14 respectively are formed during spontaneous evaporation of the solvents from solutions of the crown ethers 1-3 with the respective heterocycles 4-6.

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Complexation of planar, organic, five-membered cations with crown ethers

Cited by 37 publications

References 8 publications

[Hydrogen bis(1,2,4-triazole)] 1,2,4-triazolium bis(3-carboxy-4-hydroxybenzenesulfonate) 1,2,4-triazole disolvate

[Hydrogen bis(1,2,4-triazole)] 1,2,4-triazolium bis(3-carboxy-4-hydroxybenzenesulfonate) 1,2,4-triazole disolvate

Molecular Shuttling of a Compact and Rigid H‐Shaped [2]Rotaxane

Reaction of crown ethers with five-membered heterocycles: 1H-imidazole-4,5-dicarbonitrile, 3-nitro-1,2,4-triazole, and 1H-tetrazole

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