Meldola

The so-called self-diazotization was developed by Sihlbohm (1951, 1953 a, 1953 b). It is based on the observation that several nitroaniline derivatives, on treatment with hydrochloric acid in acetic acid solution, form the corresponding chlorobenzenedi-azonium ions. 2,5-Dinitroaniline will serve as an example (Scheme 2-37). This reaction had already been discovered in principle by Meldola and Eyre in 1901. The method did not become important. 

FIGURE 6-6 Chemical stmcture of some common redox mediators (a) dimethyl ferrocene (b) tetrathiafidvalene (c) tetracyanoquinodimethane (cl) Meldola Blue. 

NADH. Immobilized redox mediators, such as the phenoxazine Meldola Blue or phenothiazine compoimds, have been particularly useful for this purpose (20) (see also Figure 4-12). Such mediation should be useful for many other dehydrogenase-based biosensors. High sensitivity and speed are indicated from the flow-injection response of Figure 3-21. The challenges of NADH detection and the development of dehydrogenase biosensors have been reviewed (21). Alcohol biosensing can also be accomplished in the presence of alcohol oxidase, based on measurements of the liberated peroxide product. 

Macrocyclic compounds, 155 Magnesium, 155 Mass measurements, 52 Mass transport, 4, 5 Mechanism, 33, 36, 40 Mediator, 177, 178 Meldola Blue, 121, 179... 

Stacey s success brought him many honors and he was the recipient of awards both from the United Kingdom and abroad. The Meldola Medal, awarded to him at the early age of 26, and the Inaugural Haworth Medal in 1970 were especially gratifying to him. He gave many prestigious lectures and served on numerous scientific committees and boards of governors. He was vice-president of the Chemical Society on four occasions and president of its Perkin Division. He was elected F.R.S. in 1950 and appointed C.B.E. in 1966. 

Stem nuclei. Morpholine, 5. Hydroxy compounds Scopolamine, 99. Carbonyl compoimds, 135 Saccharin, 169. Carboxylic acids, 313. Sulphonio acids, 355. Amines, 361 Meldola s blue, 383. 

Bindschedler s Green (6.204) can be made by condensing p-nitroso-N,N-dimethylaniline with N,N- dimethyl aniline. A similar condensation with 2-naphthol gives Meldola s Blue (6.209 Cl Basic Blue 6), the first oxazine dye, discovered in 1879. The symmetrical Cl Basic Blue 3 (6.210) is of more commercial significance. It is synthesised by nitrosation of N,N-diethybrn-anisidine followed by condensation with N,N-diethybm-aminophenol, and is used for dyeing acrylic fibres. This dye is now classified by ETAD as toxic [73]. 

An optode based on Meldola Blue immobilized in tetramethyl orthosUicate gel can be used to evaluate the concentration of H2O2 in the pH range from 5 to 12, in the dynamic... 

The valency Of chlorine, bromine, and iodine.—Compounds are known in which the three halogens act as uni-, ter-, quinque-, or septa-valent elements. Usually, however, these elements are univalent. In chlorine dioxide, C102, the chlorine is bi- or quadri-valent.19 In M. Berthelot s hydrogen perchloride, HC13, the chlorine is probably tervalent, and R. Meldola (1888) showed that the oxygen in the hydrochloride of methyl oxide is best regarded as quadrivalent, the chlorine tervalent thus, (CH3)2 0 Cl.H. Iodine also appears to be tervalent in the so-called iodonium compounds. 

HO.C6H4.N]2.Crp7 N 12.23% yel crysts mp - expl ca 134° was prepd by Me ldola 8e Eynon (Ref 2) on diazotizing p-aminophenol with Na nitrite in sulfuric acid, followed by treatment with Na dichromate Refs 1) Beil - not found 2) R. Meldola ... 

---