Chloride complex absorption spectra

The effect of peripheral substituents on absorption spectrum and in vitro PDT activity has been studied for the zinc(II) porphyrazine (5,10,15,20-tetraazaporphyrin) system.276 277 Water-soluble zinc(II) polyazaphthalocyanines have been synthesized for PDT applications.278,279 A zinc(II) bis(dimethylamino)porphyrazine is photooxidised to give the zinc(II)-,seco-porphyrazine, the reaction being autocatalytic.280 The zinc(II)-complex of a hexaalkyltexaphyrin chloride has Amax (MeOH) 732 nm and A 0.61,281 but the system does not appear to have been developed for PDT. 

Mesoionic 4-amino-l,2,3,5-thiatriazoles constitute the only class of mesoionic 1,2,3,5-thiatriazoles known. They are prepared by the reaction of l-amino-l-methyl-3-phenylguanidine with approximately 2 equivalents of thionyl chloride with pyridine as solvent (88ACS(B)63>. They are obtained as the yellow 1 1 pyridine complexes (17). The dark-violet mesoionic 1,2,3,5-thiatriazole (18) was liberated on treatment with aqueous potassium carbonate (Scheme 3). The structure is established on the basis of elemental analysis and spectroscopic data. In particular, the IR spectrum is devoid of NH absorptions. Compound (18) exhibits a long-wavelength absorption at 463 nm in methanol. When mixed with an equivalent amount of pyridinium chloride, complex (17) is formed and the absorption shifts to 350 mn. The mesoionic thiatriazoles are sensitive towards mineral acids and aqueous base and although reaction takes place with 1,3-dipolarophiles such as dimethyl acetylene-dicarboxylate, a mixture of products were obtained which were not identified. 

To 27.5 g. (0.1 mole) of crude (carbonato)bis(ethylenediamine)-cobalt(III) chloride is added 200 ml. of 1.00 N hydrochloric acid. The carbonato complex is dissolved with evolution of carbon dioxide gas and formation of a red solution consisting primarily of the corresponding cw-diaqua species. The solution is evaporated in the steam bath until an almost dry paste has been formed. The purple residue is filtered and washed with three 20-ml. portions of ice-cold water. Drying in air yields 19.5 g. of purple crystals of cu-dichlorobis(ethylenediamine)cobalt(III) chloride. The mother liquor and the washings are again evaporated almost to dryness to yield a second crop of crystals, 5.9 g. The total yield is 25.4 g. (84% based on (carbonato)bis(ethylenediamine)cobalt(III) chloride). The analysis and the visible absorption spectrum of the two fractions are identical. Anal. Calcd. for [Co(en)2Cl2 ] C1 H20 Co, 19.42 N, 18.46 C, 15.82 Cl, 35.05 H, 5.98. Found Co, 19.50 N, 18.57 C, 15.77 C1, 35.15 H, 6.01. 

Billings223 studied the absorption spectrum of a reddish orange aqueous perchlorate solution of UO2 showing a rather indistinct slope between 500 and 650 nm, and bands at 738 (e = 12) and 940 nm (s = 5.7). Cohen224 studied UOj in a saturated solution of calcium chloride and found a strong peak at 1510 nm (6660 cm-1) probably of the same origin as at 8180 cm-1 in NpOj. U(V) carbonate complexes have been studied with various experimental techniques114,224. ... 

The absorption spectrum of Po in HCl solutions reveals the presence of at least two complexes, A and B. Complex A absorbs with a maximum at 344m a. Complex B absorbs with a maximum at 418 m j,. The 418m a absorption can be used for the colorimetric determination of polonium. Although the 344m j, absorption is stronger in weakly acidic solutions, it is difficult to utilize because of chlorine formation brought about by radiation from the polonium. The absorbance of the complex at 344 m a was estimated by the use of a method involving the log absorbancy curves for the complex and for the chloride ion. 

Examples of this analysis mode are presented in Fig. 5. The slope of the log D versus log[L],i plots for the cobalt(II)-8 M HCl and the Fe(III)-6 M HCl systems indicate the formation of CoClj and FeClj, respectively, as the predominant complexes in the Dowex 1-X8 phase. These results are believed to prove the reliability of this approach, the presence of these complexes in concentrated hydrochloric acid being well documented. The chloride complex of uranium(IV), UClj, v 4iose unique absorption spectrum is shown in Fig. 6 [11], in the HCl, HCIO4 (I = 10 M)... 

A final paradox may show how difficult it is to apply the mass-action law in a consistent way. A solution of UCU in molten AUCU has an absorption spectrum corresponding to n larger than 6 76). Addition of alkali metal chlorides decreases n to 6, the typically octahedral complex being formed probably according to ... 

Triamminetrinitrocobalt(III)> tCo(N02)j(NH3)3], was first prepar in 1866 by Erdmann, later by Werner and Jorgensen, who prepared the complex by the air-oxidation of ammoniacal cobalt(II) salt solutions containing sodiiun nitrite and a large amount of ammonium chloride. In 1938, Duval examined the products obtained from several different procedures by absorption and infrared spectroscopy, refractive index of aqueous solutions, conductivity, and X-ray powder diffraction. He recognized two products in the Werner s preparation and the Jorgensen s preparation. In that year, Sueda reported an isomeric complex from the reaction of the [Co(N03)j(NH3)3] complex with sodium nitrite in a cold aqueous solution, which was assumed to be cis-cis isomer on the basis of the absorption spectrum. 

Magnanini studied the absorption spectrum and A. Speransky found that the electrical conductivity of aq. soln. shows that only a small proportion of the salt is ionized. The soln. of the violet modification conducts electricity three times better than that of the green. G. Gore electrolyzed a cone. soln. of chromic fluoride acidified with hydrofluoric and hydrochloric acids, and found that the liquid became hot no gas was liberated at the cathode, but chlorine and ozone were liberated at the platinum anode which was not corroded. C. Poulenc showed that the salt is reduced by hydrogen at dull redness. The heat of formation is 230-95 Cals, per mol—vide infra, the dichloride. Steam transforms chromic fluoride into chromic oxide. Chromic fluoride is insoluble in water, and alcohol hydrogen chloride transforms it into chromic chloride hot hydrochloric, sulphuric, and nitric acids attack chromic fluoride only a little hydrogen sulphide converts it into black sulphide and molten alkali nitrate or carbonate converts it into chromate. A. Costachescu prepared complex pyridine salts. 

The formation of a chelate compound of strontium with bromopyrogallol red and cetylpyridinium chloride serves to develop a method for the spectrophotometric determination of cetylpyridinium chloride in pharmaceutical products. This indirect procedure is based on the influence of micellar media on the absorption spectrum of the strontium(II)-bromopyrogallol red complex the formation of the ternary complex is accompanied by an observed increase in absorbance and a bathochromic shift in the maximal absorption of the complex from 555 to 627.5 nm. The optimum pH range for the reaction is 4.0-5.0 and Beer s law is obeyed over the concentration range 0.01-0.07 mg 1 ... 

Besides, the triangular gold(I) phosphine complex [Au3(p3-tppm)2Cl] (53) has also been studied [114]. X-ray crystal studies reveal a coordinating chloride ion to one of the gold atoms. Gold-gold separations of 2.9220(8) and 3.0889(8) A have been observed. Electronic absorption spectrum of the complex in acetonitrile shows intense absorption bands at 271 and 290 nm, which are assigned to [do —> Po] transitions. In addition, there are also broad absorptions at around... 

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