Triethanolamine , complex with

Hydrogen Peroxide Analysis. Luminol has been used for hydrogen peroxide analysis at concentrations as low as 10 M using the cobalt(III) triethanolamine complex (280) or ferricyanide (281) as promoter. With the latter, chemiluminescence is linear with peroxide concentration from... 

After dissolution of the alloy in a mixture of concentrated nitric and hydrochloric acids the iron is masked with triethanolamine in an alkaline medium, and the manganese titrated with standard EDTA solution using thymolphthalexone as indicator. The amount of iron(III) present must not exceed 25 mg per 100 mL of solution, otherwise the colour of the iron(III)-triethanolamine complex is so intense that the colour change of the indicator is obscured. Consequently, the procedure can only be used for samples of ferro-manganese containing more than about 40 per cent manganese. 

Nickel may be determined in the presence of a large excess of iron(III) in weakly acidic solution by adding EDTA and triethanolamine the intense brown precipitate dissolves upon the addition of aqueous sodium hydroxide to yield a colourless solution. The iron(III) is present as the triethanolamine complex and only the nickel is complexed by the EDTA. The excess of EDTA is back-titrated with standard calcium chloride solution in the presence of thymolphthalexone indicator. The colour change is from colourless or very pale blue to an intense blue. The nickel-EDTA complex has a faint blue colour the solution should contain less than 35 mg of nickel per 100 mL. 

Discussion. Minute amounts of beryllium may be readily determined spectrophotometrically by reaction under alkaline conditions with 4-nitrobenzeneazo-orcinol. The reagent is yellow in a basic medium in the presence of beryllium the colour changes to reddish-brown. The zone of optimum alkalinity is rather critical and narrow buffering with boric acid increases the reproducibility. Aluminium, up to about 240 mg per 25 mL, has little influence provided an excess of 1 mole of sodium hydroxide is added for each mole of aluminium present. Other elements which might interfere are removed by preliminary treatment with sodium hydroxide solution, but the possible co-precipitation of beryllium must be considered. Zinc interferes very slightly but can be removed by precipitation as sulphide. Copper interferes seriously, even in such small amounts as are soluble in sodium hydroxide solution. The interference of small amounts of copper, nickel, iron and calcium can be prevented by complexing with EDTA and triethanolamine. 

One-phase titration methods have also been developed. These methods are not truly one-phase titrations but the term is used to indicate the absence of a second organic phase. One of these methods, applied to the analysis of sodium and triethanolamine lauryl sulfates and lauryl ether sulfates, use a quaternary amine as a titrant and cobalt(II) thiocyanate as indicator. Centrimide was found to avoid the use of chloroform which was not possible with other titrants examined, such as domiphen bromide and oxyphenonium bromide. The pink color of the indicator changes to violet as an excess of titrant forms a complex with the indicator [238]. 

In the next step of the sequence, the authors sought to introduce a hydroxy-methylene substituent at the unsubstituted 7-position of the enone. This bond construction can be carried out by conducting a Baylis-Hillman reaction with formaldehyde. In this instance, the authors used a modification of the Baylis-Hillman reaction which involves the use of a Lewis acid to activate the enone [26]. Under these conditions, the enone 42 is treated with excess paraformaldehyde in the presence of triethylphosphine (1 equiv), lanthanum triflate (5 mol%), and triethanolamine (50 mol%). It is proposed that the lanthanum triflate forms a complex with the triethanolamine. This complex is able to activate the enone toward 1,4-addition of the nucleophilic catalysts (here, triethylphosphine). In the absence of triethanolamine, the Lewis acid catalyst undergoes nonproductive complexation with the nucleophilic catalyst, leading to diminution of catalysis. Under these conditions, the hydroxymethylene derivative 37 was formed in 70 % yield. In the next step of the sequence, the authors sought to conduct a stereoselective epoxidation of the allylic... 

CdSe, CdTe. CdSe films have been grown from complexed (with tartaric acid and triethanolamine) cadmium acetate or cadmium sulfate solutions and sodium selenosullale.1272 81 84 The films were amorphous or nanocrystalline with an average crystallite size of 6nm. The optical band gap was 1.8-2.1 eV, and the electrical resistivity was of the order 104-106Qcm. 

The lead precursor in PbSe film deposition was lead acetate complexed with triethanolamine. The growth rate for PbSe was 0.18-0.16nm/cycle. The films were polycrystalline (i.e., cubic) without preferred orientation. The stoichiometry of SILAR-grown PbSe was found to be 1 1 within the limits of the RBS technique. Impurities detected were 5 at.% of oxygen and 8 at.% of hydrogen.103... 

CuS and Cu2S. Copper(II) sulfate complexed with triethanolamine... 

Bi2S3, Bi2Se3. Bismuth nitrate complexed with triethanolamine or EDTA and thioacetamide, with the addition of hydrazine hydrate, have been... 

Triethanolamine complexes of chromium(iii) have been reported and characterized in i.r. spectra and thermal-decomposition studies. The chromium(iii) nitrilotriacetato-complex [CrL(H20)2] [L = N(CH2C02)3 ] complexes with thallium(iii) to give [ CrL3(0H)(H20) gTl] with a formation constant of 9 3 X 10 at 25 The hydrolysis and dimerization of [CrLlOHljV ... 

The most active system to date for the Cu-catalyzed oxidation of cyclohexane has only recently been reported. Reaction of triethanolamine with Cu(N03)2 in the presence of NaOH and different types of aromatic carboxy-lates, NaNs or NaBp4 yielded a family of multinuclear copper complexes with different structural characteristics, including 6 and 7. These systems showed... 

Only one group has reported CD of SbiSes. The solution used was potassium an-timonyl tartrate, complexed with triethanolamine and ammonia. Selenosulphate was used as the Se source. No XRD pattern was found, as for the sulphide deposited under equivalent conditions. The bandgap was 1.88 eV, and resistivity O-cm [13,14]. Continued study of this deposition showed the effect of various parameters on deposition rate and film thickness (the latter typically reaching 1 p.m) [15]. This study also described some photoelectrochemical behavior of these films (Chap. 9). 

MnS was deposited from a room-temperature solution of Mn(II) acetate complexed with triethanolamine and buffered with NH4CI [73]. Thioacetamide was used as a sulphur source, and hydrazine was also used (it was not specified whether the reaction proceeded in its absence). No XRD pattern was seen in the as-deposited (grey-pink) film annealing at 500°C in an inert atmosphere gave a pattern corresponding to MnS. A bandgap (indirect) of 3.25 was measured from the optical spectrum. The film was p-type with a resistivity of ca. 10 O-cm. 

TlSe was also deposited from a solution of TI2SO4 complexed with triethanolamine and ammonia and selenosulphate at 30°C [49]. Tetragonal TlSe was identified by XRD. The bandgap was estimated at 1.12 eV however, the absorption spectrum appears to show two transitions—one (possibly indirect) at > 0.9 eV and another at = 1.3 eV. The films were p-type, with a resistivity of Kl O-cm. Considering the high carrier concentration measured (almost 10 ° cm ), this resistivity value appears unusually high. 

Only one example of Sn-Se has been reported [110]. Films were deposited from a room-temperature selenosulphate solution of SnCli complexed with triethanolamine and added NaOH. Polyvinylpyrollidone (PVP) was also added and in general slowed down the deposition. At an optimum concentration of PVP, a maximum terminal thickness was obtained (although no comparison with films deposited from PVP-free solutions was given). No XRD pattern was observed for the as-deposited films heating in an inert atmophere at ca. 330°C gave the pattern of SnSe. The bandgap was 0.95 eV (indirect). The films were n-type, with a resistivity of ca. 10 O-cm... 

From solutions of Bi and Pb nitrates, complexed with triethanolamine and ammonia, mixed sulphides were deposited with thiourea on glass at pH values between 9.5 and 11 and at 100°C (initially) followed by slow cooling in the solution [35]. Elemental analyses showed the presence of both metals in the films. It is not clear whether solid solution formation occurred in the as-deposited films, although the lattice parameters did vary non-monotonicaUy, depending on composition. 

In this case, thioacetamide was used as the sulphur source, instead of thiourea as for the previous mixed sulphides-selenides (selenosulphate, as before, was used as the Se source) [56]. Bi(N03)3 was complexed with triethanolamine and the pH adjusted with ammonia to 8.2. The deposition was carried out at 55°C. The composition was varied by varying the thioacetamide/selenosulphate ratio. Although it is not clear what the elemental compositions of the various films were, from the limited XRD data given, it seems that solid solution did occur. The crystal sizes increased from 6 nm (pure sulphide) to 13 nm (pure selenide), and bandgap values decreased over the same range from ca. 1.9 to 1.0 eV. 

This type of ligand can afford charge balanced, 1 1 complexes with lanthanide elements in their most stable oxidation state III (Table 13). Alkoxide complexes of the triethanolamine ligand were reported as insoluble, high melting ( > 360 °C) oligomerized materials [91-93], Substituted atrane complexes did... 

TAM, spectrophotometrie determination of vanadium photometric determination of niobium in the presence of triethanolamine spectrophotometrie determination of bismuth in the presence of 1,3-diphenylguanidinc spectrophotometrie determination of yttrium in the presence of 7.ephiramine formation constants of complexes with Infill) measured... 

The electrochemical data indicate that both triethanolamine and diethanolamine form stable bis complexes with Mn(II) and Mn(III) and transiently stable bis complexes with Mn(IV). The latter have sufficiently positive reduction potentials to oxidize mercury and to attack the ligand. These complexes appear to be mononuclear and not to be involved in equilibria as represented by Reaction 9. 

The solid-state and solution chemistry of triethanolamine complexes has been investigated. While the solid-state structure was maintained in organic solvent (38), a different structure was observed in aqueous solution.262 170 NMR spectroscopy was used to demonstrate that the two oxo groups were different and in combination with H and 13C NMR data, defined the structure as (39).262 Speciation studies and a detailed characterization of this class of compounds were important because the ligand is a commonly used buffer in biology and the complexes are model systems for interactions with proteins.61,263 The thermodynamic parameters were determined for several derivatized diethanolamine ligand-vanadium(V) complexes, and represent some of the few vanadium complexes for which such parameters are known.62 The structure of (nitrilotriacetato)dioxovanadate was reinvestigated.2 4... 

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