1.10- phenanthroline nitration

Classic A/-heterocychc ligands, eg, bipyridyl (bipy), terpyridyl, imidazole, pyrazine, phenanthroline, piperazine (including alkyl- and aryl-substituted derivatives), and polypyrazol-l-yl-borates (bis, tris, and tetra), have all been found to coordinate Th(IV) chlorides, perchlorates, and nitrates. The tripodal hydrotris(pyrazolyl)borates, HBPz, have been used to stabilize organometaHic complexes (31). Bis-porphyrin Th(IV) "sandwich" complexes have been... 

Procedure. Prepare a standard solution of lead nitrate (0.05M), a 0.05 per cent aqueous solution of xylenol orange indicator, and a 1,10-phenanthroline solution (0.05M) by dissolving 0.90 g of pure 1,10-phenanthroline in 1.5 mL of concentrated nitric acid and 100 mL of water. 

To determine the cadmium content, add 20-25 mL of the 1,10-phenanthroline solution and titrate the liberated EDTA with the 0.05M lead nitrate solution until the colour change from yellow to red-violet occurs — a little practice is required to discern the end point precisely. Introduce further 2-5 mL portions of the 1,10-phenanthroline solution and note whether the indicator colour changes if so, continue the titration with the lead nitrate solution. The consumption of lead nitrate solution corresponds to the cadmium content. 

The AOM has recently been used in the analysis of the polarized crystal spectrum of aquobis(l,10-phenanthroline)coppei(II) nitrate (127), where the coordination geometry is trigonal bipyramidal. The water molecule occupies an equatorial position, so that the appropriate point group is C2 although C2v is a reasonable approximation. However, it was found impossible to fit the spectrum with AOM parameters which could be regarded as chemically meaningful. 

Trihydrazinecobalt(II) nitrate, 4205 Trihydrazinenickel(II) nitrate, 4592 Tris(2,2/-bipyridine)chromium(II) perchlorate, 3874 Tris(2,2/-bipyridine)silver(II) perchlorate, 3873 Tris(2,3-diaminobutane)nickel(II) nitrate, 3589 Tris(l,2-diaminoethane)chromium(III) perchlorate, 2619 Tris(l,2-diaminoethane)cobalt(III) nitrate, 2622 Tris(l,2-diaminoethane)ruthenium(III) perchlorate, 2621 Tris(4-methoxy-2,2/bipyridine)ruthenium(II) perchlorate, 3886 Tris(3-methylpyrazole)zinc sulfate, 3540 Tris(l,10-phenanthroline)cobalt(III) perchlorate, 3890 Tris(l,10-phenanthroline)ruthenium(II) perchlorate, 3889... 

Sterically hindered, mesityl-substituted, stable enols 72 have been examined with regard to one-electron oxidation. Using two equivalents of a one-electron oxidant such as triarylaminium salts, iron(III)phenanthroline, thianthrenium perchlorate or ceric ammonium nitrate in acetonitrile-benzofurans 73 are obtained in good yields within a few seconds [111]. 

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 ... 

Murray et al. (2) prepared permeable membranes for selectively removing phosphate, nitrate, and ferric cations by polymerizing and crosslinking with the modified matrix monomer, (bis-acrylamindo-phenanthroline)dinitrate, (IV), to produce an ion permeability substrate. Kulkami et al. (3) selectively removed cobalt cations from solution using 2-hydroxy ethyl methacrylate copolymers,... 

Phenanthroline is oxidized by alkaline potassium permanganate to 2,4 -bipyridyl-3,3 -dicarboxylic acid14 and to l,8-phenanthroline-5,6-dione in 28% yield by nitric-sulfuric acid mixtures.252 The latter reaction also yielded some nitrated products and 2,5-diazafluorenone. 

Nitration of 1,7-phenanthroline with fuming nitric acid and sulfuric acid at higher temperatures than used hitherto has improved252 the yield of 6-nitro-1,7-phenanthroline to 28%. 1,5-Diazafluorenone (3%) is a byproduct. Bromination of 1,7-phenanthroline in oleum gives either 6-bromo-l,7-phenanthroline or the 5,6-dibromo derivative, depending on reaction conditions.275... 

Unlike 1,7-, 1,10-, and 4,7-phenanthrolines, which give nitrated products, the predominant product of the reaction of 1,8-phenanthroline (2) with mixed nitric and sulfuric acids is the 5,6-dione (59) (28%). Both the 5-nitro- (60) and 6-nitro-1,8-phenanthrolines (61) are formed, but in much lower yield ( 6-7%). 2,5-Diazafluorenone (62) is also present (6%).252 Bromination of 1,8-phenanthroline affords the 5- and 6-bromo derivatives and the 5,6-dibromo analog.275... 

Reports of further studies of the nitration of 1,10-phenanthroline have appeared. Nitration with fuming nitric acid and concentrated sulfuric acid at 160°-170° gives 5-nitro-1,10-phenanthroline (75%) and 4,5-diazafluorenone (13%).252... 

A much milder route to 5-nitro-1,10-phenanthroline involves nitration of the tris-phenanthroline complex of cobalt(III) which is readily nitrated in concentrated sulfuric acid at 80°. The free 5-nitro-l,10-phenanthroline can be isolated in 70% yield from the nitrated complex.276... 

The first nitration of 1,10-phenanthroline in one of the pyridine rings has been accomplished by the use of fuming nitric acid in acetic anhydride.252 In this way 3-nitro-1,10-phenanthroline was obtained in very low yield. The mechanism proposed for the nitration is the same as that previously proposed for the similar nitration of quinoline.277 4,5-Diazafluorenone was again a coproduct. 

The nitration of l,4-dihydro-5-methoxy-2-trifluoromethyl-4-oxo-l,10-phenanthroline gives a nitrated product, presumably the 6-nitro derivative, along with the corresponding 5,6-dione.38... 

Nitration of 4,7-phenanthroline has been accomplished,252 thus disproving old statements that it cannot be so substituted. By using mixed nitric and sulfuric acids at 170°, a 17% yield of 5-nitro-4,7-phen-anthroline was obtained. If nitric acid in acetic anhydride is used as the nitrating medium, 2-nitro-4,7-phenanthroline is the product, albeit in low yield. 

The product obtained by Kaufmann and Radosevic283 by nitrating 3,4-dihydro-4-methyl-3-oxo-4,7-phenanthroline (63). with mixed nitric and sulfuric acids has been shown231 to be the 2-nitro derivative (64) and not the 5-nitro derivative as previously supposed. 

The first coordination compound of this type was the aniline complex Hg(PhNH2)2(N03)2,96 but later research revealed that up to six ligands are coordinated to Hg2(N03)2. The first X-ray crystal structure determination of this type of coordination compound was published in 1967 for Hg2(phen)(N03)2.98 In this complex one Hg atom of the Hg+—Hg+ ion is bonded to both N atoms of 1,10-phenanthroline the other Hg atom is coordinated to oxygen atoms of the nitrate ions.98 More recently X-ray structure determinations have been made with complexes of Hg2(N03)2 with either 1,4-diazine (10)99 or quinoline (11).100... 

NMO NMP Nu PPA PCC PDC phen Phth PPE PPTS Red-Al SEM Sia2BH TAS TBAF TBDMS TBDMS-C1 TBHP TCE TCNE TES Tf TFA TFAA THF THP TIPBS-C1 TIPS-C1 TMEDA TMS TMS-C1 TMS-CN Tol TosMIC TPP Tr Ts TTFA TTN N-methylmorpholine N-oxide jV-methyl-2-pyrrolidone nucleophile polyphosphoric acid pyridinium chlorochromate pyridinium dichromate 1,10-phenanthroline phthaloyl polyphosphate ester pyridinium p-toluenesulfonate sodium bis(methoxyethoxy)aluminum dihydride (3-trimethylsilylethoxy methyl disiamylborane tris(diethylamino)sulfonium tetra-n-butylammonium fluoride f-butyldimethylsilyl f-butyldimethylsilyl chloride f-butyl hydroperoxide 2,2,2-trichloroethanol tetracyanoethylene triethylsilyl triflyl (trifluoromethanesulfonyl) trifluoroacetic acid trifluoroacetic anhydride tetrahydrofuran tetrahydropyranyl 2,4,6-triisopropylbenzenesulfonyl chloride 1,3-dichloro-1,1,3,3-tetraisopropyldisiloxane tetramethylethylenediamine [ 1,2-bis(dimethylamino)ethane] trimethylsilyl trimethylsilyl chloride trimethylsilyl cyanide tolyl tosylmethyl isocyanide meso-tetraphenylporphyrin trityl (triphenylmethyl) tosyl (p-toluenesulfonyl) thallium trifluoroacetate thallium(III) nitrate... 

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