10476-50-3Relevant articles and documents
Preliminary characterization of four 2-chlorobenzoate-degrading anaerobic bacterial consortia
Genthner, Barbara R. Sharak
, p. 27 - 34 (2007/10/03)
Dechlorination was the initial step of 2CB biodegradation in four 2-chlorobenzoate-degrading methanogenic consortia. Selected characteristics of ortho reductive dehalogenation were examined in consortia developed from the highest actively dechlorinating dilutions of the original 2CB consortia, designated consortia M34-9, P20-9, P21-9 and M50-7. In addition to 2-chlorobenzoate, all four dilution consortia dehalogenated 4 of 32 additional halogenated aromatic substrates tested, including 2-bromobenzoate; 2,6-dichlorobenzoate; 2,4-dichlorobenzoate; and 2-chloro-5-hydroxybenzoate. Dehalogenation occurred exclusively at the ortho position. Both ortho chlorines were removed from 2,6-dichlorobenzoate. Benzoate was detected from 2-bromobenzoate and 2,6-dichlorobenzoate. 4-Chlorobenzoate and 3-hydroxybenzoate were formed from 2,4-dichlorobenzoate and 2-chloro-5-hydroxybenzoate, respectively. Only benzoate was further degraded. Slightly altering the structure of the parent "benzoate molecule" resulted in observing reductive biotransformations other than dehalogenation. 2-Chlorobenzaldehyde was reduced to 2-chlorobenzyl alcohol by all four consortia. 2-chloroanisole was O-demethoxylated by three of the four consortia forming 2-chlorophenol. GC-MS analysis indicated reduction of the double bond in the propenoic side chain of 2-chlorocinnamate forming 2-chlorohydrocinnamate. None of the reduction products was dechlorinated. The following were not dehalogenated: 3- and 4-bromobenzoate; 3- and 4-chlorobenzoate; 2-, 3-, and 4-fluorobenzoate; 2-, 3-, and 4-iodobenzoate; 2-, 3-, and 4-chlorophenol; 2-chloroaniline; 2-chloro-5-methylbenzoate; 2,3-dichlorobenzoate; 2,5-dichlorobenzoate; 2,4,5-trichlorophenoxyacetic acid; and 2,4-dichlorophenoxyacetic acid. Consortia M34-9, P20-9, P21-9, and M50-7 dechlorinated 2-chlorobenzoate at -9 followed by those of M50-7 with rates declining above 2 and 3 mm 2CB, respectively. The major physiological types of microorganisms in consortia M34-9, P20-9, P21-9, and M50-7 were sulfate-reducing and hydrogen-utilizing anaerobes.
Dissociation Constants of Weak Organic Acids in Protic Solvents Obtained from Their First Hyperpolarizabilities in Solution
Ray, Paresh Chandra,Das, Puspendu Kumar
, p. 17891 - 17895 (2007/10/03)
The first hyperpolarizabilities (β) of some weak aromatic organic acids have been measured in protic solvents by the hyper-Rayleigh scattering (HRS) technique at low concentrations.The measured hyperpolarizability (βm) varies between the two extreme limits: the hyperpolarizability of the acid form (βHA) at the lower side and that of the basic form (βA-) at the higher side.The degree of dissociation (α) of the acid in a solvent is related to the measured hyperpolarizability, βm, by the following relationship: βm2 = (1 - α)βHA2 + αβA-2.The calculated β's including solvent effects in terms of an Onsager field do not reproduce the experimentally measured hyperpolarizabilities.Other solvent-induced effects like hydrogen bonding and van der Waals interactions seem to influence the first hyperpolarizability and, thus, indirectly the extent of dissociation of these weak acids in these protic solvents.
Binary and Ternary Chelates of Scandium(III), Yttrium(III) and Lanthanum(III) with Ethyleneglycol-Bis(β-Aminoethylether)-Tetraacetic Acid as Primary and Substituted Salicylic Acids as Secondary Ligands
Pandey, Ashok Kumar,Chandra, M.,Agarwala, B. V.,Dey, A. K.
, p. 32 - 34 (2007/10/02)
Formation constants of binary and ternary complexes of the systems of the type: M-L and M-egta-L have been determined pH-metrically at 25 deg and μ=0.1 M (KNO3) in 50 percent (v/v) aqueous-ethanol medium.The order of stabilities of ternary complexes have compared with those of corresponding binary complexes, and results discussed on the basis of coulombic interactions.
