Of phenanthrolines

Benzoic acid and naphthoic acid are formed by the oxidative carbonylation by use of Pd(OAc)2 in AcOH. t-Bu02H and allyl chloride are used as reoxidants. Addition of phenanthroline gives a favorable effect[360], Furan and thiophene are also carbonylated selectively at the 2-position[361,362]. fndole-3-carboxylic acid is prepared by the carboxylation of 1-acetylindole using Pd(OAc)2 and peroxodisulfate (Na2S208)[362aj. Benzoic acid derivatives are obtained by the reaction of benzene derivatives with sodium palladium mal-onate in refluxing AcOH[363]. 

The electronic spectra and optical activity of phenanthroline and dipyridyl metal complexes. S. F. Mason, Inorg. Chim. Acta, Rev., 1968, 2, 89-109 (84). 

Hydrazine reduction of ferric ethylenediaminetetraacetate (denoted FeY ) gives nitrogen in high yield" In the absence of added phenanthroline the reaction, initially rapid, slows down and becomes second order in FeY . When ferrous ethylenediaminetetraacetate (FeY ) is initially present, the reaction is second-order in FeY throughout. In the presence of phenanthroline the order in FeY is one throughout. Under both sets of conditions the reaction is first-order in hydrazine. 

A chelation-assisted Pd-catalyzed Cope rearrangement was proposed in the reaction of phenanthroline to generate isoquinolinone derivatives (Eq. 12.78).177 The use of aqueous media and ligands enables a double-Heck reaction on a substrate favoring alkene insertion over (J>-hydride elimination. 

Recently, interest in copper-catalyzed carbon-heteroatom bond-forming reactions has shifted to the use of boronic acids as reactive coupling partners [133], One example of carbon-sulfur bond formation is displayed in Scheme 6.65. Lengar and Kappe have reported that, in contrast to the palladium(0)/copper(l)-mediated process described in Scheme 6.55, which leads to carbon-carbon bond formation, reaction of the same starting materials in the presence of 1 equivalent of copper(II) acetate and 2 equivalents of phenanthroline ligand furnishes the corresponding carbon-sulfur cross-coupled product [113]. Whereas the reaction at room temperature needed 4 days to reach completion, microwave irradiation at 85 °C for 45 min in 1,2-dichloroethane provided a 72% isolated yield of the product. 

A 5.00 ml sample containing iron is mixed with hydroxylamine hydrochloride to reduce the iron (III) to iron (II). The solution is then mixed with an excess of phenanthroline and the absorbance is measured and found to be 0.448. A second 5.00 ml solution of the same unknown is mixed with 1.00ml of 2.0 x 10 4M Fe2+ and is then treated the same way as the original sample. The absorbance is found to be 0.525. What is the concentration of the iron in the sample ... 

A distinctive feature of the complex is the NO group position between the two nitrogen atoms of phenanthroline skeleton, and so the complex may be regarded... 

The concentration of the Grignard reagent solution is determined by titration. An oven-dried, 10-mL flask with septum is charged with 1 mg of phenanthroline and 3.0 mL of the reaction mixture. 2-Methylpropanol is added until the red-purple color is dissipated and a yellow endpoint is reached. The yield of Grignard reagent is 0.184 mol (70%). 

The only complex of Tc containing two phenanthroline ligands is [TcOCl(phen)2] (122), which is obtained either electrochemically by controlled potential cathodic reduction or by reduction of [Tc04] with dithionite in the presence of phenanthroline. Its formulation as a mono-oxo species is suggested by the Tc=0 stretch at 895 cm in the IR. From the observation that all protons in the phenanthroline ligands are nonequivalent, chloride must be cis to the oxo group. ... 

The most common method used to synthesize the diazafluorenes is by alkaline oxidation of phenanthrolines <1996CHEC-II(7)921>. For example, Gusak a a/, have shown that compounds such as 87 can be converted into the corresponding diazafluorenones using potassium hydroxide and potassium permanganate (Equation 23) <2004RJ01322>. 

For mixtures of the two oxidation states, the contact shifts depend directly on the relative mole fractions of the two states, indicating that the system is in the limit of rapid exchange. From this and the concentrations of the two species, one can calculate that the second-order rate constant involving the electron transfer must be greater than 106 M l seer1 at 25°C. This limit applies not only to the phenanthroline iron(II)—(III) system but also the iron(II)—(III) complexes with the following methyl derivatives of phenanthroline ... 

The synthesis of a molecular knot 6 [11], olympiadane 7 [12], and many other topological molecules discussed in Sections 2.3 and 8.1 would not be possible without preorganization of substrates forcing their appropriate orientation. In this case the preorganization is accomplished by the complexation of phenanthroline fragments with a metal ion (Figure 1.2). 

Figure 1.2. Perpendicular orientation of phenanthroline fragments complexed with metal.

The coordination of phenanthroline fragments with a metal atom as depicted in Figure 1.2. In this way knots like 6 [If] and 394 [10a], a doubly-intertwined catenane 33 [3] and a mixture of [2]-, [3]-, [4]-, [5]- and [6]-catenanes 32 [14] have been synthesized by the Sauvage and Dietrich-Buchecker group. 

Scheme 13 Synthesis of Phenanthroline Alanine by Enzymatic Resolution142-431...

O-phenarUhroline complexes.—The honour of demonstrating the formation of phenanthroline (Phen) complexes of the rare earth in aqueous solution goes to Kononenko and Poltjektov [374]. Later Lobanov and Samirnova [375], and Hart and Laming [376] reported the isolation of solid complexes from ethanolic media. The following europium complexes are reported. 

Jaymen et al. [17] and other workers [18-20] found that aluminium in plant digests enhances the iron-1,10-phenanthroline colour, leading to high results in the determination of iron. Both the iron and aluminium complexes of phenanthroline exhibit identical absorption characteristics. Attempts to mask the aluminium in solution with sodium fluoride have been unsuccessful, as the fluoride ions suppress the colour formed with iron and reagent. The determination of iron after the separation of aluminium and phosphates is simple and rapid. This method is reliable and recoveries are quantitative. 

Its oxidized form (Phen)3Fe3+ is pale blue, while the reduced form (phen)3Fe2+ is red. The transition potential is about 1.11 V. Among the substituted derivatives of phenanthrolines, 5-methyl- and 5-nitro-1,10-phenanthroline complexes of iron have found wide applications in redox titrations. 

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