628-52-4Relevant academic research and scientific papers
Spectroscopic investigations into the binding of hydrogen sulfide to synthetic picket-fence porphyrins
Hartle, Matthew D.,Prell, James S.,Pluth, Michael D.
, p. 4843 - 4853 (2016/03/19)
The reversible binding of hydrogen sulfide (H2S) to hemeprotein sites has been attributed to several factors, likely working in concert, including the protected binding pocket environment, proximal hydrogen bond interactions, and iron ligation environment. To investigate the importance of a sterically-constrained, protected environment on sulfide reactivity with heme centers, we report here the reactivity of H2S and HS- with the picket-fence porphyrin system. Our results indicate that the picket-fence porphyrin does not bind H2S in the ferric or ferrous state. By contrast, reaction of the ferric scaffold with HS- results in reduction to the ferrous species, followed by ligation of one equivalent of HS-, as evidenced by UV-vis, NMR spectroscopy and mass spectrometry studies. Measurement of the HS- binding affinities in the picket-fence or tetraphenyl porphyrin systems revealed identical binding. Taken together, these results suggest that the protected, sterically-constrained binding pocket alone is not the primary contributor for stabilization of ferric H2S/HS- species in model systems, but that other interactions, such as hydrogen bonding, must play a critical role in facilitation of reversible interactions in ferric hemes.
Chromium(II) Complexes with Hydroxyethylidenediphosphonic Acid
Popova,Smotrina,Denisova,Aksenova
, p. 38 - 40 (2008/10/08)
The complex formation of chromium(II) with hydroxyethylidenediphosphonic acid (HEDP, H5L) in an aqueous solution is studied by spectrophotometry. The pH region is determined where the HEDP complexonates of chromium(II) are stable. The effect of pH on the complexation and the composition of the coordination sphere of the complex ions is shown. The optimum conditions for the practical application of HEDP as a stabilizing ligand are chosen. The instability constants for tetra-, tri-, di-, and monoprotonated and neutral chromium(II) hydroxyethylidenediphosphonate complexes were calculated, whose pK were found to be 1.21, 2.43, 6.87, 12.60, 19.40, respectively. A new complex of chromium(II), Na4[Cr(H2L)2 · 2H2O] · 4H2O, was isolated from a solution and characterized using elemental, IR spectroscopic, and thermographic analyses.
Catalyzed process for producing metal carboxylates for use as animal feed supplements
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, (2008/06/13)
A catalyzed process is disclosed for producing a polyvalent metal C2 -C3 carboxylate having the formula M(CH3 (CH2)x COO--)y, wherein M is the polyvalent metal cation that is manganese (Mn+2), cobalt (Co+2), or chromium (Cr+3), x is zero or 1 and y is an integer equal to the cationic charge of M. The polyvalent metal C2 -C3 carboxylate is prepared by admixing (i) a dry polyvalent metal compound that is an oxide, hydroxide or carbonate of Mn+2, Co+3 or Cr+3, (ii) an anhydrous C2 -C3 carboxylic acid, and (iii) a catalytic agent at a relative molar ratio of about 1:2-10:0.01-3 in the absence of an added solvent or other diluent to form a reaction mixture. The reaction mixture is heated to complete the reaction, remove the produced water and about 80 percent of the unreacted carboxylic acid. The product in residual carboxylic acid is solidified, ground and the product is recovered. The metal carboxylates can be used as biologically available and economical sources of trace metal ions for supplementation in animal diets.
Acid catalysed complexation of arenes with Cr(CO)6
Hrnciar, Peter,Toma, Stefan
, p. 161 - 164 (2007/10/02)
Several acids were tested as potential catalysts for complexation of arenes with Cr(CO)6 in boiling decalin.Acetic acid was found to be an efficient catalyst for complexation of acyl- and acyloxybenzenes.A mixture of butanone or cyclohexanone and acetic acid, with THF and acetic acid was found to be an efficient catalytic system or complexation of other arenes.The complex (η2-acenaphthylene)4Cr(CO)2 was isolated during an attempt on acetic acid catalysed complexation of acenaphthylene with Cr(CO)6.
Preparation of an oxy-acetyl compound
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, (2008/06/13)
This invention provides a process for producing an oxy-acetyl compound by carbonylating an oxy-methyl compound with carbon monoxide in the presence of a rhodium catalyst, an iodine compound, and a metallic accelerator, and also in the presence of at least one compound selected from the group consisting of boron compounds, bismuth compounds, and tertiary amide compounds in the reaction system. When at least one of the bismuth or boron compound is present in the reaction system, the carbonylation reaction can proceed without precipitation of any metallic accelerator.
REACTION OF CHROMOCENE WITH CARBOXYLIC ACIDS AND SOME DERIVATIVES OF ACETIC ACID
Benes, L.,Kalousova, J.,Votinsky, J.
, p. 147 - 152 (2007/10/02)
Crystalline chromocene reacts at 40 deg C with an excess of formic acid to give Cr(O2CH)3*HCOOH, cyclopentadiene and hydrogen.Aliphatic carboxylic acids CnH2n+1COOH (n = 2-4) give nearly diamagnetic chromium(II) carboxylates and cycl
Fiber-reactive 2-hydroxy-pyrid-6-on-(3)-yl azo dyestuffs
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, (2008/06/13)
Azo dyestuffs which contain an acid substituent which confers solubility in water of the formula STR1 wherein D is the radical of a sulfo substituted benzene or naphthalene diazo component; R' is alkyl of 1 to 4 carbon atoms; Z is a fiber reactive group; and N is an integer of 1 to 4 are disclosed and are useful in dyeing nitrogen containing fibers such as polyamides, polyurethanes, silk, leather and wool as well as cellulose materials, in particular cotton.
