Deep Blue Solution Research Articles

ChemInform Abstract: Reaction of Co(II) and Tri n‐Butyl Phosphate.

AbstractThe hexahydrate of CoCl2 (I) reacts with excess phosphate (II) yielding a deep blue solution of a tetrahedral Co(II) complex, probably (III).

Notes. Reaction between 1,3-diphenylisobenzofuran and a blue oxyhaemocyanin model compound

Deep blue species derived from the binuclear copper(I) complex with 1,4-bis[N,N-bis-(2-benzimidazolylmethyl)amino]butane (L2) and O2 exhibited high reactivity towards 1,3-diphenylisobenzofuran, an efficient singlet O2(1Δg) scavenger. This gave indirect evidence for O2-complex formation in the deep blue solution.

Reaction of Co(II) and tri n-butyl phosphate

CoCl 2·6H 2O reacts with excess tri n-butyl phosphate (TBP), neat, yielding a deep blue solution, typical of Co( II) tetrahedral complexes. Compound I, composed of two chlorides and two TBPs as ligands, is believed to be present in this medium. Removal of excess TBP at low pressure and 180 °C yielded compound II where Co(II) maintained a tetrahedral geometry and the TBPs rearranged to bidentate DBPs with the rupture of one OR bond from each TBP. Spectroscopic and physical properties of compound II were obtained and are consistent with the proposed structure.

Isolation, structure, and synthesis of hermidin, a chromogen from Mercurialis perennis L.

Hermidin has been isolated from Mercurialis perennis L. as a colourless, crystalline compound, shown by synthesis to be 5-hydroxy-4-methoxy-1-methylpyridine-2,6(1H,3H)-dione (2), which in aqueous solution exists as a dihydroxy-4-methoxy-1-methylpyridin-2(1H)-one (3) or (4). Oxidation of hermidin with nitric acid affords 4-methoxy-1-methylpyridine-2,3,6-trione (16). When equimolecular amounts of the latter and hermidin in aqueous solution are mixed an immediate deep blue solution containing an ion-radical (17) results. Oxidation of hermidin by air in methanolic solution gives 5,5′-dihydroxy-4,47′-dimethoxy-1,1′-dimethyl-3,3′-bipyridine-2,2′,6,6′-(1H,1′H,3H,3′H)-tetraone (18). and in pyridine solution 4,4′-dimethoxy-1,1′-dimethyl-3,3′-bipyridine-2,2′,5,5′,6,6′-hexaone (23). Knackmuss' conclusions on the oxidation of 3,6-dihydroxy-4-methylpyridin-2(1H)-one (26) have been re-interpreted. 3,4-Dihydroxy-5-methoxy-1-methylpyridin-2(1H)-one (7) has been synthesized.

ChemInform Abstract: PREPARATIONS AND STRUCTURES OF NN′‐ETHYLENEBIS(SALICYLIDENEIMINATO)TITANIUM(III) DERIVATIVES

AbstractDie Reduktion des Ti‐Komplexes (I) mit Zinkstaub in THF lieferte einen dimeren ionischen Komplex (II), der als Tetrachlorozinkat isoliert wurde.

Preparations and structures of NN′-ethylenebis(salicylideneiminato)-titanium(III) derivatives

Reduction of [Ti (salen) Cl2,][salen =NN′-ethylenebis(salicylideneiminate)] with zinc dust in tetrahydrofuran (thf) gives deep blue solutions from which dimeric [{Ti(salen)(thf)}2][ZnCl4] is obtained. The reduced paramagnetism (µeff 0.96 B.M., 293 K) of this complex suggests a strong electronic interaction between two metal centres. The same solution, when treated with pyridine (py), leads to the very air-sensitive [Ti(salen) Cl (py)]· thf whose magnetic moment (µeff. 1.79 B.M. at 293 K) corresponds to that expected for a d1 system. X-Ray analysis of this complex confirms the pseudo-octahedral co-ordination around titanium, with the salen unit in the equatorial plane and Cl and py trans to each other in the axial positions. The crystal structure has been solved by the heavy-atom technique and refined by anisotropic least-squares methods to a final R of 0.066. The crystals are monoclinic, space group P21/c. with a= 9.828(2), b= 19.508(5), c= 13.465(2)A, β= 109.5(4)°, U= 2 440(2)A3, and Z= 4.

Colored sulfur species in EPD-solvents

Alkali polysulfides dissolve in EPD-solvents (e.g. dimethylformamide, dimethylsulfoxide, and hexamethylphosphoramide) to give deep green, blue and carmine red solutions. Vis. and u.v. spectrophotometric as well as e.s.r. spectrometric investigations showed that normal polysulfides S x 2− with different chain length are the carriers of the yellow and red color, whereas the radical ion S 3 − is the blue species, which gives clear blue solutions or, if it is mixed with polysulfide anions with × 6, green or carmine red. U.v. and e.s.r. spectra point to the existence of two further radical ions S 2 − (yellow) and S 4 − (red) in EPD-solvents, The behaviour of polysulfides in these solvents can be understood by assuming that anions are only poorly solvated due to dipole shielding of the solvent molecules.

The Reaction of Bis(acetylacetonato)cobalt(II) with Bromine in Dichloromethane

Abstract When bis (acetylacetonato)cobalt(II) is allowed to react with twice molar quantity of bromine in dichloromethane, cobalt(II) bromide and γ-bromoacetylacetone are produced ultimately. From a deep blue solution of an equimolar reaction mixture at 0°C an intermediary product was isolated and characterized to be dimeric bromo(acetylacetonato)cobalt(II) by means of elemental analysis and molecular weight determination. The structure of this compound was inferred to be tetrahedral from absorption spectra and magnetic data. Acetylacetonate groups were supposed to act as bridging ligands on the basis of IR data in the lower frequency region. Dibromobis(acetylacetonato)dicobalt(II) was also derived from dibromo(acetylacetone)cobalt(II) by the reaction with sodium acetylacetonate in acetylacetone at 0°C.

ChemInform Abstract: ACENAPHTHO(5,6‐CD)THIAPYRAN

AbstractDurch Reduktion des Sulfoxids (I) mit Methylmagnesiumbromid in Lösungsmitteln wie Benzol, Äther und Chloroform unter Lichtausschluß und strenger Entgasung entstehen relativ stabile tiefblaue Lösungen der heterocyclischen Verbindung (II).

Acenaphtho[5,6-cd]thiapyran

An unusual sulphoxide dehydration reaction has been used to prepare deep blue solutions of the reactive nonclassical sulphur heterocycle acenaphtho[5,6-cd]-thiapyran (I).

On the nature of the blue solutions of sulfur

Deep blue solutions are formed by dissolving alkali tetrasulfides in aprotic, polar, organic solvents. Their spectra show three bands in the visible and the near UV - region at 16·2 × 10 3, 23·0 × 10 3, and 36·2 × 10 3 cm −1. The band at 16·2 × 10 3 cm −1. shows a weak, but well defined, vibrational fine structure at room temperature. The spacing between the subpeaks of 430 cm −1 is assigned to vibrations of the S 2 − ion formed by the homolytic dissociation of the S 4 2− ion. The position of the S 4 2− ⇄ 2S 2 − equilibrium has been studied in water-dimethylformamide mixtures as a function of the solvent composition and in pure DMF as a function of the ratio S:S 2−. EPR investigations suggest the presence of two further sulfur radicals. It is proposed that the color of ultra-marine is also due to S 2 − ions.

Optical Rotatory Dispersion of the Starch Iodine Complex. Part 2

Abstract The deep blue aqueous solutions of starch iodine show an abnormal rotatory dispersion with a peak near the absorption maximum. This induced Cotton effect is discussed on the basis of the known structure of the channel compound of iodine and amylose helix. The optical rotation of starch iodine solutions and also of amylose iodine solutions is very much increased with time, whereas absorption remains constant. Addition of salts or solvents to starch iodine solutions causes a shift for both the absorption maximum and the Cotton peak. Conditions that will destroy the helix or the iodine chromophore in the inner space of the helix (for example, heating, addition of urea, or detergents) cause disappearance of the induced Cotton effect.

Chemistry of indanthrone. Part XI. The reduction of the dihydrodinaphthophenazinediquinones

The reduction of two of the title compounds, viz., indanthrone and its linear isomer, with various reducing agents is described. Indanthrone with warm aqueous alkaline dithionite first forms a deep blue solution (vat), for which a structure is advanced. Treatment of indanthrone with an excess of this reagent at higher temperatures, or with hydriodic acid and red phosphorus, produces a series of “over-reduction” compounds, which are formed by the progressive reduction of the two anthraquinonoid residues to anthracene residues. The structure of these “over-reduction” products are discussed, and their properties described. A mechanism for the complete reduction of indanthrone is proposed. A comparison of the behaviour on reduction of indanthrone with that of its linear isomer clearly shows the influence of the intramolecular hydorgen-bonding in the former.

The Formation of Crystal Violet by the Reaction of N,N-Dimethylaniline with Aluminum Chloride

Abstract The reaction of N,N-dimethylaniline with aluminum chloride in vacuo has given a deep blue solution. This blue solution turns violet because of moisture or the added methanol. The electronic spectra of these solutions seem to be identical with that of crystal violet. The finding that transient green species appear when the vacuum cell system is opened to air can be interpreted in terms of the color of crystal violet dissolved in hydrochloric acid. From these findings the formation of crystal violet has been concluded.

The structure of chromium azide: Its instability constant in aqueous solutions

A spectrophotometric study of chromium(III) azide solutions has shown that the intense green colour formed from the violet chromium(III) nitrate and sodium azide in dilute solutions, is due to a mono-azido-chromium(III) complex with two absorbancy maxima at wavelengths 442 and 605 mμ. The slope ratio method was applied and suggested the presence of such a complex. The results were confirmed by the continuous variation method. The molar ratio method was also applied for the determination of the instability constant of the 1:1 complex. It was found to be (2·14 ± 0·136) × 10 −2. There is a tendency for a stepwise formation of azide-rich complexes upon gradual increases in azide concentration. A deep blue solution, with absorbancy maxima at wavelengths 480 and 650 mμ, was formed in solutions containing a large excess of azide. Migration experiments proved the existence of positively and negatively charged complex ions in the green and the deep blue solutions respectively.

Oxidation of Chromium(II) Amines by Water

AN interest in reactive reducing agents has led us to investigate aqueous solutions of chromium(II) containing excess of polyamines. We have observed that, in the absence of oxygen, these deep blue solutions (pH > 9) evolve hydrogen in accordance with the reaction : Although the reaction is quite slow when the amine is ethylenediamine or diethylenetriamine1, with purified triethylenetetramine or tris(β-aminoethyl)amine2 the reaction is sufficiently rapid to be studied conveniently. It is apparently autocatalytic with excess of the linear tetramine, and first-order in chromium(II) when the branched amine is present.

A Giemsa Stain of Quite Constant Composition and Performance, Made in the Laboratory from Eosin and Methylene Blue

When the eosinate formula (1) for compounding Giemsa stain from dyes of American manufacture was worked out, it was hoped that this would solve the problem of duplicating stains satisfactorily. However, continued experience with successive commercial lots from several American mnanufacturers indicated that commercial azure A, azure B, and azure I were quite variable substances and that considerable study and adjustment of proportions was necessary each time a new lot of Giemsa stain was offered. On spectroscopic examination of various lots of the azures and methylene blue anid their eosinates, the reason for this variability became apparent, as may be seen from table 1. Considering the relative constancy of the spectroscopic data for methylene blue chloride, it seems that the variation in the azures is probably inherent in their mode of nmanufacture from methylene blue. If the traditional method of chloroform extraction of the base from weakly alkaline aqueous solution of polychrome methylene blue is employed, the composition of the product will depend to some extenit on that of the polychrome methylene blue from which it is prepared. Not only azure I or B and methylene violet appear in the chloroform extract, but also, though in less amounts, azure A and azure C, and the three azures are all reextracted from chloroform solution by weak acetic acid. Consequently, if methiylene blue polychromed by an alkali process is employed as a source of azures, a mixed product will be obtained, since alkali polychroming engenders simultaneously a wide variety of the decomposition products of methylene blue. The method of formaldebyde remethylation of crude azure A made by the acid oxidation process does not stop at trimethylthionin as was supposed, but may go on to methylene blue. Experimental extraction of some commercial azure B solutions with chloroform until no more red color was produced in the chloroform has left a deep blue solution with the spectral characteristics of methylene blue and as much as 20 to 25 percent of the color density of the original solution. Having shown that the acid oxidation process (2) produced polychrome methylene blues of quite constant spectroscopic characteristics when the same ratio of K,Cr207 to methylene blue was used, and that after a certain time interval varying with temperature, further heating was without effect, and that the same product was produced at varying temperatures, it was believed that this process might prof-