“…Recently, a series of bis-(azobenzocrown)s (compounds 41 – 48 , Scheme 4 ) based on the skeleton of parent 13- and 16-membered crowns 22 and 23 (Fig. 16 a) linked by α,ω-dioxaalkane chains between two macrocycles have been obtained [ 162 ]. Bis-crowns were synthesized from the respective hydroxyazobenzocrowns obtained in reaction analogous to Wallach rearrangement elaborated by Luboch [ 161 ].…”
Section: Crown Ethers With Azobenzene Moiety(-ies)mentioning
confidence: 99%
“… Scheme 4 Synthetic route for preparation of bis-(azobenzocrown)s 41 – 48 from hydroxyazobenzocrowns as substrates [ 162 ] …”
Section: Crown Ethers With Azobenzene Moiety(-ies)mentioning
confidence: 99%
“…The unique structure of intermolecular of 2:2 stoichiometry sandwich-type complex of bis-(azobenzocrown) 41 with sodium iodide was obtained [ 162 ]. It is presented in Fig.…”
Section: Crown Ethers With Azobenzene Moiety(-ies)mentioning
Azobenzene derivatives due to their photo- and electroactive properties are an important group of compounds finding applications in diverse fields. Due to the possibility of controlling the trans–cis isomerization, azo-bearing structures are ideal building blocks for development of e.g. nanomaterials, smart polymers, molecular containers, photoswitches, and sensors. Important role play also macrocyclic compounds well known for their interesting binding properties. In this article selected macrocyclic compounds bearing azo group(s) are comprehensively described. Here, the relationship between compounds’ structure and their properties (as e.g. ability to guest complexation, supramolecular structure formation, switching and motion) is reviewed.
“…Recently, a series of bis-(azobenzocrown)s (compounds 41 – 48 , Scheme 4 ) based on the skeleton of parent 13- and 16-membered crowns 22 and 23 (Fig. 16 a) linked by α,ω-dioxaalkane chains between two macrocycles have been obtained [ 162 ]. Bis-crowns were synthesized from the respective hydroxyazobenzocrowns obtained in reaction analogous to Wallach rearrangement elaborated by Luboch [ 161 ].…”
Section: Crown Ethers With Azobenzene Moiety(-ies)mentioning
confidence: 99%
“… Scheme 4 Synthetic route for preparation of bis-(azobenzocrown)s 41 – 48 from hydroxyazobenzocrowns as substrates [ 162 ] …”
Section: Crown Ethers With Azobenzene Moiety(-ies)mentioning
confidence: 99%
“…The unique structure of intermolecular of 2:2 stoichiometry sandwich-type complex of bis-(azobenzocrown) 41 with sodium iodide was obtained [ 162 ]. It is presented in Fig.…”
Section: Crown Ethers With Azobenzene Moiety(-ies)mentioning
Azobenzene derivatives due to their photo- and electroactive properties are an important group of compounds finding applications in diverse fields. Due to the possibility of controlling the trans–cis isomerization, azo-bearing structures are ideal building blocks for development of e.g. nanomaterials, smart polymers, molecular containers, photoswitches, and sensors. Important role play also macrocyclic compounds well known for their interesting binding properties. In this article selected macrocyclic compounds bearing azo group(s) are comprehensively described. Here, the relationship between compounds’ structure and their properties (as e.g. ability to guest complexation, supramolecular structure formation, switching and motion) is reviewed.
“…In particular cases, a 2:2 (biscrown:ion) stoichiometry is possible, with two cations being shared by two ligand molecules [18, 19]. Such is the case, for example, in bis(azobenzocrown) with a short, dioxyethylene linker that forms an intermolecular sandwich-type complex of 2:2 stoichiometry with sodium ions [3]. …”
Novel biscrowns 1 and 2 were synthesized from 13-membered azobenzocrown ethers containing bromoalkylenoxy chains in para position relative to the azo group. The synthesized diester molecules are dodecylmethylmalonic acid derivatives differing by the linker length. The synthesized compounds have the potential of being used as sodium ionophores in ion-selective electrodes. They were characterized and used as ionophores in classic and miniature, solid contact (screen-printed and glassy carbon) membrane ion-selective electrodes. Compound 3, a similar monoester derivative of 13-membered azobenzocrown, was synthesized and used in membrane electrodes for comparison. Lipophilicity of new ionophores was determined by TLC. Lipophilicity of bis(azobenzocrown)s was found to be within the range of logPTLC = 12–13. It was observed that the particularly important selectivity coefficients logK
Na,K determined for new electrodes, being logK
Na,K = −2.5 and −2.6 (SSM, 0.1 M), are better than those of the electrodes featuring seven out of the nine commercially available sodium ionophores. It was concluded that the ionophore 1 creates, in acetone, with sodium iodide, complex of 1:1 stoichiometry (sandwich complex) with stability constant (logK) ca. 3.0.
“…Azobenzocrowns with peripheral hydroxyl groups are universal substrates for further modifications. They may be used as starting compounds in the synthesis of, e.g., lariat azobenzocrowns and bisazobenzocrowns [ 56 , 62 , 63 ].…”
The article presents the synthesis of novel 13- and 16-membered azobenzocrown derivatives with peripheral thiol moieties and preliminary studies assessing their possible application in plasmonic sensors based on gold nanoparticles. The effect of the length of the chain connecting the macrocycle with the thiol group and the effect of the presence of the additional functional compound, i.e. lipoic acid, on the sensor response was analyzed. Colloidal gold nanoparticles modified with a 16-membered crown with a thiol group on oxyethylene (compound 12) or oxybutylene (compound 13) linker was found to have good properties, allowing for detection of potassium ions in aqueous solutions at concentrations 8-20 mM for bifunctionalized nanogold and 4-26 mM for less stable, colloidal gold modified only with thiol derivatives of azobenzocrowns. The response towards potassium cations of bifunctionalized nanogold modified with compound 13 was more stable in time than for the system incorporating compound 12. Compound 13, obtained with the highest yield among all presented thiol derivatives of azobenzocrowns, was selected for further, more detailed, studies.
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