Oxazine als azidobasische Indikatoren XV. Untersuchung der Protonisierungsgleichgewichte der Benzo[a]phenoxazoniumderivate

Stužka, V.; Šimánek, V.

doi:10.1135/cccc19730194

Cited by 8 publications

(4 citation statements)

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“…It is important to point out that R6G and NR present mobilities that are virtually identical, indicating that they experience similar interactions. This occurs even though R6G has an expected positive charge and NR (p K a = 1.00 ± 0.05) is neutral . There can be seen a slight but noticeable increase in the percentage of tumbling molecules when cationic R6G and neutral NR are compared to anionic ORG.…”

Section: Resultsmentioning

confidence: 94%

“…This occurs even though R6G has an expected positive charge and NR (pK a ) 1.00 ( 0.05) is neutral. 64 There can be seen a slight but noticeable increase in the percentage of tumbling molecules when cationic R6G and neutral NR are compared to anionic ORG. A larger decrease in the percentage of fixed molecules for ORG relative to R6G and NR is also observed.…”

Section: Resultsmentioning

confidence: 98%

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Comparative Study of Guest Charge−Charge Interactions within Silica Sol−Gel

2005

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We investigated the effect of charge-charge interactions on the mobilities of rhodamine 6G (R6G), Nile Red, sulforhodamine B, and Oregon Green 514 (ORG) guest molecules within a silica sol-gel host as the guest charge progressed from positive to neutral to negative. Through classification of the mobility as fixed, tumbling, or intermediate behavior, we were able to distinguish differences in surface attraction as the guest charge was varied. On the basis of our results, an attractive charge (as tested by cationic R6G) does not contribute significantly to mobility within dry films. However, an increase in the cationic influence is observed in water-equilibrated environments. A comparison of ORG in dry and water- and phosphate-buffer-equilibrated films indicates that charge repulsion does significantly increase dye rotational mobility (to a maximum of 24 +/- 3% tumbling molecules). However, in view of the percentage of tumbling molecules found, charge-charge interactions do not appear to be the dominant force controlling guest mobility.

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Section: Resultsmentioning

confidence: 94%

Section: Resultsmentioning

confidence: 98%

Comparative Study of Guest Charge−Charge Interactions within Silica Sol−Gel

2005

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“…24 The phenoxazine dye 9-diethylamino-5H-benzo [R]-phenoxazin-5-one, NR (Figure 1), in contrast, is an efficient laser dye with high photochemical stability. 25 The synthesis of NR in acid solutions and its low basicity (pk a ∼ 1) 26 indicates stability toward an acid environment. 27 NR is an uncharged polarity probe and exhibits one of the largest known bathochromic shifts with increase in solvent polarity.…”

Section: Introductionmentioning

confidence: 99%

“…The phenoxazine dye 9-diethylamino-5 H -benzo [α]-phenoxazin-5-one, NR (Figure ), in contrast, is an efficient laser dye with high photochemical stability . The synthesis of NR in acid solutions and its low basicity (p k a ∼ 1) indicates stability toward an acid environment . NR is an uncharged polarity probe and exhibits one of the largest known bathochromic shifts with increase in solvent polarity. , Absorbance maximum of NR does not appear to shift significantly when subjected to hydrogen bonding; however, the protonated form of NR can be formed in acidic environment, and the spectral behavior will be useful to complete the environment information.…”

Section: Introductionmentioning

confidence: 99%

Role of the Comonomer GLYMO in ORMOSILs As Reflected by Nile Red Spectroscopy

Moreno

Lévy

2000

Chem. Mater.

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The spectroscopy of nile red (NR) was reported when incorporated in organically modified silicates (ORMOSILs), obtained by the copolymerization of (glycidoxypropyl)trimethoxysilane and tetramethoxysilane in various proportions. An increase of the fluorescence intensity, a gradual blue spectral shift by 43 nm in absorption and 45 nm in emission, and a change in the lifetime from 2.6 to 4.4 ns of the dye were observed as a response to the change of the polarity and the structure of the ORMOSILs caused by the addition of (glycidoxypropyl)trimethoxysilane. The decrease of the nonradiative H + -NR form was observed as one of the consequence of addition of (glycidoxypropyl)trimethoxysilane. Absorption spectral shifts of the NR were used for the determination of a polarity empirical scale (E NR ) of the ORMOSIL. The value of E NR (r 0/100 ) ) 48.70 kcal/mol for NR in silica xerogels prepared from tetramethoxysilane and E NR (r 100/0 ) ) 52.55 kcal/mol for NR in ORMOSILs prepared from (glycidoxypropyl)trimethoxysilane showed the high polarity of the inorganic matrixes in contrast to ORMOSILs. A study in solution was performed in order to make a concluding comparison of the NR behavior in terms of the restricted environment around the NR molecule ORMOSILs.

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ChemInform Abstract: OXAZUNE ALS AZIDOBASISCHE INDIKATOREN 15. MITT. PROTONIERUNGSGLEICHGEWICHTE DER BENZO(A)PHENOXAZONIUMDERIVATE

Stužka¹,

Šimánek²

1973

Chemischer Informationsdienst

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Oxazine als azidobasische Indikatoren XV. Untersuchung der Protonisierungsgleichgewichte der Benzo[a]phenoxazoniumderivate

Cited by 8 publications

References 0 publications

Comparative Study of Guest Charge−Charge Interactions within Silica Sol−Gel

Comparative Study of Guest Charge−Charge Interactions within Silica Sol−Gel

Role of the Comonomer GLYMO in ORMOSILs As Reflected by Nile Red Spectroscopy

ChemInform Abstract: OXAZUNE ALS AZIDOBASISCHE INDIKATOREN 15. MITT. PROTONIERUNGSGLEICHGEWICHTE DER BENZO(A)PHENOXAZONIUMDERIVATE

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