Carbohydrate Research p. 127 - 135 (2000)
Update date:2022-08-11
Topics:
Signorella, Sandra
Lafarga, Rubén
Daier, Verónica
Sala, Luis F.
The reduction of Cr(VI) by α-D-glucose and β-D-glucose was studied in dimethyl sulfoxide in the presence of pyridinium p-toluensulfonate, a medium where mutarotation is slower than the redox reaction. The two anomers reduce Cr(VI) by formation of an intermediate Cr(VI) ester precursor of the slow redox step. The equilibrium constant for the formation of the intermediate chromic ester and the rate of the redox steps are different for each anomer. α-D-Glucose forms the Cr(VI)-Glc ester with a higher equilibrium constant than β-D-glucose, but the electron transfer within this complex is slower than for the β anomer. The difference is attributed to the better chelating ability of the 1,2-cis-diolate moiety of the α anomer. The Cr(V) species, generated in the reaction mixture, reacts with the two anomers at a rate comparable with that of Cr(VI). The EPR spectra show that the α anomer forms several linkage isomers of the five-coordinate Cr(V) bis-chelate, while β-D- glucose affords a mixture of six-coordinate Cr(V) mono-chelate and five- coordinate Cr(V) bis-chelate. The conversion of the Cr(V) mono- to bis- chelate is discussed in terms of the ability of the 1,2-cis- versus 1,2- trans-diolate moieties of the glucose anomers to bind Cr(V). (C) 2000 Elsevier Science Ltd.
View Morewebsite:http://www.simagchem.com
Contact:+86-592-2680277
Address:21/F Hualong Office Building,No.6 Hubin East Road, Xiamen,China
Shanghai Massive Chemical Technology Co., Ltd.
website:http://www.massivechem.com/
Contact:+86 21 34943721
Address:Room 435, 4th floor, Building 9, No. 2568 Gudai Road,Minhang District, Shanghai,
Hangzhou Gangjin Chemical Co.,Ltd.
Contact:+86-571-85109780
Address:707 Zhejiang Minhang Bldg., No.290 Zhongshan North Road, Hangzhou 310003, China
WUHAN CHEMPROSPECT PHARMTECH CO., LTD
website:http://www.chemprospect.com
Contact:+86--27-84984898
Address:No. 2, Road, East Lake Hi-tech Development Zone, Wuhan, China
Shenyang NovPharm Technology Co., Ltd.
Contact:.+86-24-24165786
Address:Room 306, Hongjin Mansion, No. 36-1, Wanliutang Rd., Shenhe District, Shenyang, Liaoning, P.R.C.
Doi:10.1016/j.abb.2011.11.013
(2012)Doi:10.1002/chem.201801908
(2018)Doi:10.1021/acs.organomet.6b00336
(2016)Doi:10.1021/acs.joc.6b00655
(2016)Doi:10.1111/cbdd.13902
(2021)Doi:10.1002/chem.201904651
(2019)