Cobalt complexes oxyanions

Table 44 Rates of Aquation and Alkaline Hydrolysis of Some Cobalt(IIT)-Oxyanion Complexes...

Chemical leach tests on the bulk settled dust samples showed that the dusts are quite chemically reactive. Leach solutions have high alkali-nities, due to the rapid partial dissolution of calcium hydroxide from concrete particles. Indoor dust samples produced higher pH levels (11.8-12.4) and alkalinities (—600 mg CaCOa) than outdoor dusts (pH 8.2-10.4 alkalinity —30mgL CaCOa), indicating that outdoor dust samples had reacted with rainfall or other water prior to collection. Thurston et al (2002) found that the leachate pH of the dusts decreased with decreasing particle size. Some metals or metalloids in the dusts (aluminum, chromium, antimony, molybdenum, barium, copper, zinc, cobalt, nickel) are readily leached by deionized water many of these form oxyanion species or carbonate complexes that are most mobile at the alkaline pH s generated by the leachates. 

It has been clearly shown that ion association can markedly alter the CD of an ionic chiral solute. For example, oxyanions such as phosphate form contact ion pairs with tris(diamine)-cobalt(lll) complexes, resulting in an increase and a decrease in the sizes of the JAj lA2 and Ai - JE (Dq) components, respectively, of the - ig absorption band (17-22). This effect... 

Mass spectrometry has been used to identily complexes formed in the gas phase by reaction of oxyanions and carbanions with 1,3,5-triazine. Spectroscopic studies and DFT calculations on the species formed by reaction of ethylamine with 2,4-dinitrotoluene in DMSO indicate that transfer of a methyl proton rather than nucleophilic attack is the major interaction. Two methods for the detection of 2,4,6-trinitrotoluene (TNT) using fluorescence techniques rely on the formation of its complexes with amines. Also cobalt-doped zinc sulfide quantum dots have been used to interact with complexes formed from TNT and L-cysteine allowing detection of the nitro compound. A complex between 2,4-dinitroanisole and L-cysteine methyl ester has been identified by surface-enhanced Raman spectroscopy. ... 

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