Sulfonation 1,10-phenanthroline

Similarly, a water-soluble palladium complex of a sulfonated phenanthroline ligand catalyzed the highly selective aerobic oxidation of primary and secondary alcohols in an aqueous biphasic system in the absence of any organic solvent (Figure 1.8) [40]. The liquid product could be recovered by simple phase separation, and the aqueous phase, containing the catalyst, used with a fresh batch of alcohol substrate, affording a truly green method for the oxidation of alcohols. 

Using a related reaction. Sen showed that the palladium-catalyzed alternating copolymerization of CO and olefins could be carried out under aqueous conditions by using either the sulfonated chelating phosphine ligand, l,3-bis(diphenyl-phosphino)propane (dppp), or a sulfonated phenanthroline ligand, Phen-SO. Na (eq. (9)) [32]. 

The following topics have not been considered in this section metal complexes of sulfonated 2,2 -bipyridine [43] and alizarin [44], water-soluble porphyrins and cy-dopentadienyl ligands [45], and metal complexes of sulfonated phenanthroline derivatives [46], Also P,N-bidentate phosphines [47], of which coordination properties await further study, have not been discussed here. 

Aniline virtually quantitatively reacts with the corresponding anhydride in refluxing toluene in the presence of triethanolamine to form N-phenylmaleimide 189, whose oxidation with m-CPBA affords imsymme-trical sulfone in 67% yield (08CC3281). N-Substituted compounds were synthesized in a similar way starting from (2-methylbenzo[b]thiophen-3-yl)maleic anhydride and /J-alanine 190a or 5-amino-l,10-phenanthroline... 

Alper and coworkers investigated the influence of more bulky bases (2,2 -bipyridine, 1,10-phenanthroline, and 6,7-dihydro-5,8-dimethyldibenzo[b,j]-l,10-phenantroline) and para-toluene sulfonic acid (p-TsOH) as proton source (proton functions as a Lewis acid). In the presence of p-TsOH a molecular weight up to 10,000 g/mol was reported. This could be slightly increased by the use of benzylbromide instead of p-TsOH, forming PhCH2COCo(CO)4 as catalyst in situ. In this case, a molecular weight comparable to that found in Rieger s work was achieved, but the polymers remain atactic [69]. 

Isocyanates 345 react with phenanthrenequinone 346 and triphenylarsine oxide to give photochromic oxazines 347 (Equation 48) <1993PS(81)37>. The isocyanate can be replaced by a phosphinimine and the phenanthrene structure can also be replaced by the corresponding phenanthroline (Equation 49) <2003WO42195>. The /ra r-fused tetrahydrooxazine 349 was prepared from epoxide 348 and 2-aminoethyl sulfate (ethanolamine 0-sulfonic acid) (Equation 50) <1987AP625>. 

These equations show the general theoretical basis for the empirical order of rate constants given earlier for electrophilic attack on an aromatic ligand L, its metal complex ML, and its protonated form HL, one finds kt > n > hl. Conflicting reports in the literature state that coordination can both accelerate electrophilic aromatic substitution (30) and slow it down enormously (2). In the first case the rates of nitration of the diprotonated form of 0-phenanthroline and its Co(III) and Fe(III) complexes were compared. Here coordination prevents protonation in the mixed acid medium used for nitration and kML > h2l. In the second case the phenolate form of 8-hydroxyquinoline-5-sulfonic acid and its metal chelates were compared. The complexes underwent iodination much more slowly, if at all, and kL > kML ... 

Interest in the sulfonation of 1,10-phenanthrolines has stemmed principally from the desire to prepare water-soluble reagents for the estimation of metals. Following on from preliminary experiments on the sulfonation of 4,7-diphenyl-1,10-phenanthroline (batho-phenanthroline)278 and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline... 

Diphenyl-1,10-phenanthroline and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline give disulfonic acids on reaction with chloro-sulfonic acid at 25°. The position of substitution was not established, but presumably it occurs in the two phenyl rings.281 An improved method of sulfonation utilizes hot fuming sulfuric acid.282... 

Bromination of 4,7-phenanthroline in oleum gives the 5-bromo and 5,6-dibromo derivatives, along with other dibromo and tribromo products.215 Attempts to sulfonate 4,7-phenanthroline have not yet succeeded.227... 

Abbreviations DHG = Ar,Ar-di(2-hydroxyethyl)glycine NTA = nitrilotriacetic acid EDTA = ethylenediaminetetraacetic acid tiron = pyrocatechol-3,5-disulfonic acid BAL = 2,3-dimercaptopropanol unithiol = sodium 2,3-dimercaptopropane sulfonate tren — triaminatriethylamine penten = tetrakis(aminoethyl)ethylenediamine bipy = 2,2 -bipyridyl phen = 1,10-phenanthroline. 

The complexes [Rh(bipy)3]3+, [RhCl2(bipy)2]+ and [Rh(OH2)2(bipy)2]3+ also catalyze reaction (70), with the latter two being most effective. Using sulfonated bipyridyl or phenanthroline derivatives, water-soluble catalysts were prepared.444... 

Among several iron chelators used, only o-phenanthroline inhibited the soluble dehydrogenase (42). It was shown by Hateff et al. (42) that incubation of the enzyme with o-phenanthroline results in the loss of labile sulfide, while pretreatment with bathophenanthroline sulfonate, Tiron (1,2-dihydroxybenzene 3,5-disulfonate) or ethylenediamine tetraacetate protects the enzyme against the loss of labile sulfide and inhibition of activity upon subsequent incubation with o-phenanthroline. The unique destructive ability of o-phenanthroline has been demonstrated by these investigators for several iron-sulfur proteins (S5,96). 

D-Lactate cytochrome c reductase is inhibited by p-mercuriphenyl sulfonate salts, metal chelators, and dicarboxylic acids such as oxalate and oxaloacetate (Table XVI) (312, 314, 315). According to Nygaard (314), salts (cations) inhibit at the acceptor site, and dicarboxylic acids at the substrate site. Cremona and Singer (315) have studied the inhibitions by metal chelators and by oxalate. They recognized two types of inhibition. One type of inhibition is that which is caused by EDTA or oxalate. This kind of inhibition is reversed immediately upon dilution of the enzyme-inhibitor mixture. The second is that which results from addition of o-phenanthroline. Enzyme preparations treated with o-phenanthroline bind 2 moles of the chelator per mole of Zn . This complex is stable and inactive, and does not result in the release of Zri . The inactive... 

Figure 4.46. Molecular structures of commonly used OLED/PLED materials. Shown are (a) Alq3 (tris(quinoxalinato)Al (III)) used as an electron-transport material (b) DIQA (diisoamylquinacridone) used as an emissive dopant (c) BCP (2,9-dimethyl-4,7-diphenyl-l,10-phenanthroline) used as an exciton/ hole blocking agent (d) NPB (l,4-bis(l-napthylphenyl amino)biphenyl) (e) PFO (9,9-dioctylfluorene) used as an emissive polymer in PLEDs (f) PEDOT-PSS (poly-3,4-ethylenedioxythiophene-polystyrene sulfonate) used as a hole transport material in PLEDs.

Cince Werner s early paper 19, 20) on the optical activity he postulated and discovered in coordination compounds, there have been several discoveries closely related to this work. One of these is the observation by Pfeiffer and Quehl 15) that the optical rotation of an aqueous solution containing an optically active substance (e.g., ammonium d-a-bromocamphor-TT-sulfonate, later referred to as the optically active en-vironment O be changed by adding solutions of racemic mixtures of certain coordination compounds (e.g., D,L-[Zn(o-phen)3](N03)2, where o-phen = or /io-phenanthroline). This effect has been referred to as the Tfeiffer effect in honor of its discoverer 3, 4) who first observed it during an attempted resolution of the racemic complex mentioned above 15). 

The Pfeiffer Effect in Nonaqueous Solvents. Alcohols. Because inner complexes are usually not soluble in water, and because the Pfeiffer effect has not yet been demonstrated to occur with an inner complex, the effect was studied in solvents other than water. One obvious choice is the lower alcohols because these solvents will dissolve most inner complexes and are suitable for polarimetric studies. However, Landis (11) has reported that the Pfeiffer effect does not take place in methanol with tris(l,10-phenanthroline)zinc(II) ion and d-a-bromocamphor-7r-sulfonate (BCS) as the optically active environment. He reports that the final solutions were cloudy therefore, their optical rotatory properties would be difficult to study, and the question was still open. 

Because the Pfeiffer effect is exhibited by tris(l,10-phenanthroline)-nickel(II) ion and d-a-bromocamphor-7r-sulfonate and, because the complex has an absorption band in the visible region, this system was studied using optical rotatory dispersion techniques. The study revealed that the optical rotatory dispersion curves showing Pfeiffer rotation vs. wavelength were very similar to that of the resolved complex (Figures 3 and... 

In order to test Kuhajek s relationship, two series of solutions were examined for the magnitude of the Pfeiffer effect. These solutions were composed of zinc(II) nitrate, 1,10-phenanthroline, and ammonium d-a-bromocamphor-TT-sulfonate. The first of these series had the concentration of the optically active environment held constant, while the concentration of the complex (i.e., the tris-(or /io-phenanthroline) zinc(II) ion) was varied. In the second series the concentration of the complex was held constant, while that of the environment was varied. An experiment was... 

Since the Pfeiffer rotation is linear with respect to the concentration of each of the major constituents, it follows that it would be linear with respect to the product of the concentrations of these constituents. Figure 6 shows a plot of the Pfeiffer rotation vs. the product of the molar concentration of tris(l,10-phenanthroline)zinc(II) ion and the molar concentration of ammonium d-a-bromocamphor-7r-sulfonate. As can be seen, the deviation from linearity is very slight. It should be also noted that at that high end of the curve, the relationship between the concentration of the two constituents is not so favorable as at other parts of the curve. The linearity of this plot suggests that an equation of the type utilized for the calculation of molar rotation might apply to this phenomenon also. Rewriting the specific rotation equation in standard form results in the following ... 

Bathophenanthroline disulfonate, sodium 4,7-bis(4-phenyl sulfonic acid)-1,10-phenanthroline, sodium salt 534 22.14 X 10 ... 

A useful property of a potassium permanganate solution is its intense purple color, which is sufficient to serve as an indicator for most titrations. If you add as little as 0.01 to 0.02 mL of a 0.02 M solution of permanganate to 100 itlL of water, you can perceive the purple color of the resulting solution. If the solution is very dilute, diphenylamine sulfonic acid or the 1,10-phenanthroline complex of iron(II) (see Table 19-2) provides a sharper end point. 

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