Premium
Co‐Adsorption of Copper( II ) and 3‐Amino‐1,2,4‐triazole at a Water–Natural Macromolecular Compound Interface: Molecular Structure from Adsorption Isotherms Combined with X‐ray Absorption Measurements
Author(s) -
Flogeac Karine,
Guillon Emmanuel,
Aplincourt Michel
Publication year - 2005
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.200400764
Subject(s) - chemistry , adsorption , copper , aqueous solution , ternary operation , coordination sphere , inorganic chemistry , absorption (acoustics) , molecule , potentiometric titration , infrared spectroscopy , metal , crystallography , crystal structure , organic chemistry , physics , electrode , computer science , acoustics , programming language
The co‐adsorption of Cu II and amitrole at a water–natural macromolecular compound interface was studied by means of batch adsorption experiments, Fourier transform infrared, and X‐ray absorption spectroscopy. The binary systems, aqueous amitrole–Cu II complex, and amitrole and Cu II adsorbed on the surface of the solid were studied. The ternary system was investigated over the pH range 2–10 and at varying metal concentrations. The combination of macroscopic and molecular information shows that Cu II and amitrole interact directly at the water–solid interface to form ternary surface complexes. A two‐step mechanism is proposed whereby initial formation of a Cu II –amitrole aqueous complex is followed by the sorption of this complex onto the surface. The structure of the ternary complex was elucidated. Copper( II ) is bound to the surface in an inner‐sphere mode, while two amitrole ligands simultaneously bonded in a monodentate fashion to Cu II to form a six‐membered coordination sphere around the metal cation. The copper coordination sphere is completed by two water molecules. This structure and the mechanism proposed are supported by a combination of potentiometric data, IR and UV/visible spectroscopies and XAS measurements. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)