Studies on metal-ion complex formation of crown ether derivatives incorporating a photoionizable spirobenzopyran moiety by electrospray ionization mass spectrometry

Kimura, Kazuhiro; Sakamoto, Hidefumi; Kado, Shinpei; Arakawa, Ryuichi; Yokoyama, Masaaki

doi:10.1039/b002215m

Cited by 32 publications

(20 citation statements)

References 15 publications

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“…Recently, spiropyrans and spirooxazines of the indoline series 81a-e, 82, and 83a,b containing various crown ether receptors were synthesized [111][112][113][114][115][116][117][118]. The crown-containing styryl dyes 87-90, which form molecular dimers in the presence of metal ions, were described in the cycle of papers [122][123][124][125][126][127][128].…”

Section: Photoswitchable Chemosensorsmentioning

confidence: 99%

Organic chemosensors with crown-ether groups (review)

Цуканов

Дубоносов

Breń

et al. 2008

Chem Heterocycl Comp

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Recent advances in the chemistry of organic chemosensors containing crown-ether groups are reviewed.Organic chemosensors are molecules of abiotic nature capable of interacting selectively and irreversibly with a specific substrate (ion, molecule) with corresponding changes in one or more characteristics of the system. A series of reviews have described methods for the synthesis of chemosensors [1] and their use in the determination of metal cations [2-8], anions, and molecules [4, 9, 10]. Some of them treat the various types of fluorescent chemosensors [5][6][7][8] or photoswitching compounds [11][12][13][14] selectively. In this review, based exclusively on the results of recent years, sensors containing crown-ether groups are examined. Special attention is paid to the various mechanisms of action of crown-containing chemosensors, which are classified according to their electronic and photochemical characteristics.In the general case a chemosensor molecule consists of signal and receptor parts with a bridge between them although the latter may be absent. As a rule chemosensors can be subdivided into chromogenic, fluorescent, and photoswitchable.During the interaction of a chromogenic sensor with the substrate (in particular with a metal ion) a hypsochromic or bathochromic shift of the long-wave absorption band of the initial compound is observed. If the shift of the bands is significant and takes place in the visible part of the spectrum it leads to a visually discernable change in the color of the solution. Such signal systems are usually called colorimetric or "naked-eye" chemosensors.The action of fluorescent chemosensors is based both on change of the fluorescence intensity and on shift of the emission band of the initial compounds during the formation of a complex with the substrate.Photoswitchable chemosensors are capable of reversible "switching on-switching off" of their sensor characteristics under the influence of light.Among ionophore-receptors capable of combining with positively charged ions, it is possible to include chelating agents, podands, coronands (or crown ethers), cryptands, calixarenes, cyclodextrins, etc. [15].Crown ethers, discovered by Pedersen in 1962, occupy a special position among receptors and are widely used in the design of new chemosensors based on their unique ability to combine with the cations of alkali metals, their fairly high selectivity, and their accessibility. In addition to alkali metals, crown ethers are also effective complexing reagents for the cations of alkaline-earth metal, Pb 2+ , and Tl 2+ , and when nitrogen and sulfur atoms are inserted into their structure they become sensitive to Ag + , Hg 2+ , and Cd 2+ ions. The __________________________________________________________________________________________

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Section: Photoswitchable Chemosensorsmentioning

confidence: 99%

Organic chemosensors with crown-ether groups (review)

Цуканов

Дубоносов

Breń

et al. 2008

Chem Heterocycl Comp

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“…by corona discharge 14. Nevertheless, ESI‐MS has been used for the investigation of different copper(II) complexes with crown ligands,15, 16 1,10‐phenanthroline and essential amino acids17 or simple inorganic ligands,18 ethylenediaminetetraacetic acid (EDTA),19 8‐hydroxyquinoline,20 2‐(5‐bromo‐2‐pyridylazo)‐5‐diethylaminophenol (5‐Br‐PADAP)21 and small anions (Cl − , NO 3 − ) 22. Copper(I) species in jet fuel were determined;23 Cu + ion was also registered in the mass spectra of solutions containing copper(II) chloride 19, 22.…”

Section: Introductionmentioning

confidence: 99%

Atmospheric pressure chemical ionization mass spectrometric and visible spectrophotometric studies of copper(I) and copper(II) complexes with 2‐(5‐bromo‐2‐pyridylazo)‐5‐diethylaminophenol

2001

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Complexes of copper(II) with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) formed in aqueous methanol in a wide range of pH (from acidic to alkaline) as well as copper(I)-5-Br-PADAP species formed in methanolic solutions were investigated by spectrophotometry and mass spectrometry. Pseudomolecular and fragment ions created in the atmospheric pressure chemical ionization (APCI) source confirmed the molecular masses of the complexes existing in the solvents and their structures. The structure of the Cu(II) complex with 5-Br-PADAP formed in acidic medium was proposed as CuR(R - H) (where R is the undissociated molecule of the reagent). The binding sites of the two bound reagent molecules were different: in one of them the oxygen atom of the dissociated phenolic group and the nitrogen atom from the azo (-N=N-) group took part in complex formation, whereas in the other only nitrogen atoms from the pyridyl ring and azo group were involved. The complex was stable and could not be reduced to Cu(I) species by use of standard reducing agents (ascorbic acid, hydroxylamine). In alkaline solutions the complex tended to polymerize and precipitated in media containing less than 80% of methanol. The copper(I)-5-Br-PADAP complex was extremely unstable and could be obtained (as a mixture with Cu(II) species) in media free of water or oxygen. For this complex, CuR(2) was proposed as the most probable structure. According to this proposal copper(I) reacted exclusively with nitrogen-containing binding sites and the undissociated phenolic group was not engaged in complex formation. In this system Cu(I)/Cu(II) electron transfer is very rapid, accelerated by a polar environment, e.g. in the presence of water molecules or dissolved oxygen.

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“…4,5 Crowned spirobenzopyrans can be isomerized from their spiropyran form to the corresponding merocyanine form by metal ion complexation even under dark conditions. [6][7][8][9][10][11][12] The metal-ion complexing ability of a crowned spirobenzopyran is drastically increased as compared to that of its parent crown ether moiety due to the interaction between the phenolate anion of the merocyanine moiety and a metal ion. Therefore, many studies about how to control the metal-ion complexing ability based on the isomerization of the spirobenzopyran have been carried out.…”

Section: Introductionmentioning

confidence: 99%

Molecular Design of Tetraazamacrocyclic Derivatives Bearing a Spirobenzopyran and Three Carboxymethyl Moieties and Their Metal-Ion Complexing Behavior

et al. 2008

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Tetraazacyclododecane and tetraazacyclotetradecane derivatives bearing a spirobenzopyran and three carboxymethyl moieties, 1 and 2, and a diethylenetriamine derivative bearing a spirobenzopyran and four carboxymethyl moieties 3 were synthesized. The isomerization behaviors based on the spirobenzopyran moiety of these ligands were studied by UVvisible spectrophotometry in aqueous solutions containing various metal ions at neutral pH. These ligands formed stable 1:1 complexes with lanthanide ions, while the spirobenzopyran moiety was isomerized to its corresponding merocyanine form even under dark conditions. In aqueous solutions containing a lanthanide ion, the absorption spectra of 1 or 2 showed remarkable blue shifts, while absorbances at the maximum absorption wavelengths in the visible region were enhanced; such changes are attributable to the isomerization to the merocyanine form of the spirobenzopyran moiety. These results suggest that the phenolate anion of the merocyanine moiety interacts very strongly with a lanthanide ion bound by the complexing moiety because of the high charge density of lanthanide ions. In contrast, the absorbance of merocyanine form was decreased by the complexation of the macrocyclic ligand with transition metal ions, such as Cu . This result indicates that macrocyclic ligands, 1 and 2, formed complexes with transition metal ions only by the aminocarboxylate moieties, and the phenolate ion of merocyanine moiety was not able to participate in the complexation. This conclusion was also demonstrated by density functional theory calculations.

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Studies on metal-ion complex formation of crown ether derivatives incorporating a photoionizable spirobenzopyran moiety by electrospray ionization mass spectrometry

Cited by 32 publications

References 15 publications

Organic chemosensors with crown-ether groups (review)

Organic chemosensors with crown-ether groups (review)

Atmospheric pressure chemical ionization mass spectrometric and visible spectrophotometric studies of copper(I) and copper(II) complexes with 2‐(5‐bromo‐2‐pyridylazo)‐5‐diethylaminophenol

Molecular Design of Tetraazamacrocyclic Derivatives Bearing a Spirobenzopyran and Three Carboxymethyl Moieties and Their Metal-Ion Complexing Behavior

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