Abstract Since the 2017 REACH restrictions on hexavalent chromium, aeronautics industries have been seeking substitute processes for chromium plating. So far, use of trivalent chromium-based precursors seems to be best solution in terms process adaptation. The development such requires a better understanding plating bath chemistry. More specifically, there is need characterize complexation mech...

Treatment of CrCl3 with sodium octahydrotriborate, NaB3H8, affords a thermally unstable purple liquid thought to be a chromium(III) hydride of stoichiometry CrH(B3H8)2. This hydride converts rapidly at room temperature to the chromium(II) complex Cr(B3H8)2, which adopts a square-planar structure in which four hydrogen atoms form the coordination sphere of the chromium atom. This chromium(II) sp...

BACKGROUND: The amino acid composition of a low molecular weight chromium binding peptide (LMWCr), isolated from bovine liver, is reportedly E:G:C:D::4:2:2:2, though its sequence has not been discovered. There is some controversy surrounding the exact biochemical forms and the action of Cr(III) in biological systems; the topic has been the subject of many experimental reports and continues to b...

The effects of vitamin E and vitamin B2 on DNA damage and cellular reduction of chromium(VI) were investigated using Chinese hamster V-79 cells. Pretreatment with alpha-tocopherol succinate (vitamin E) resulted in a decrease of DNA single-strand breaks produced by Na2CrO4, while similar treatment with riboflavin (vitamin B2) enhanced levels of DNA breaks. In contrast, levels of DNA-protein cros...

In the present study, the influence of chromium(III) complexes (acetate, chloride, glycinate, histidinate, lactate and propionate) on insulin binding and signal transduction [phosphorylation of tyrosine and serine in the insulin receptor substrate (IRS)-1] was investigated in vitro using three experimental models: isolated rat liver membranes and cultured mouse C2C12 myoblasts or 3T3-L1 preadip...

A method for the preconcentration and speciation of chromium in seawater was developed. On-line preconcentration and determination were carried out by using inductively coupled plasma atomic emission spectrometry (ICP-AES) with dual mini-columns containing a chelating resin. In this system, Cr(III) was collected on the first column. The effluent containing residual chromium from the first colum...

Low-molecular-weight organic chromium complexes such as chromium picolinate are often used as dietary supplements to improve insulin sensitivity and to correct dyslipidemia. However, toxicity associated with such chromium compounds has compromised their therapeutic value. The aim of this study was to evaluate the impact of a newly synthesized complex of chromium with phenylalanine, Cr(pa)3 on i...

The two common chromium oxidation states, Cr(III) and Cr(VI), differ greatly in their impacts on the environment and human health. Cr(III) in most common forms in the environment is normally not a major concern to public health because it is not very soluble and therefore poorly adsorbed by the body. In contrast, Cr(VI) in the form of chromates is usually readily soluble and, because of its oxi...

Tris(3-bromo-acetylacetonato) chromium(III) as an inert and very stable complex with a good leaving group was synthesized using as-prepared Cr(acetylacetonate)3. Highly ordered nanoporous silica (LUS-1), with some great features, was functionalized with 3-aminopropyltriethoxysilane. Then the as-prepared product was modified with tris(3-bromo-acetylacetonato) chromium(III) under mild reaction co...