THE SYNTHESIS AND CHARACTERIZATION OF THE COORDINATION COMPOUNDS OF Pt(Ⅱ)AND Ir(Ⅲ)WITH 2-MERCAPTOPYRIDINE-1-OXIDE AND ITS METHYL DERIVATIVES

Six coordination compounds of Pt(Ⅱ)L_2 and Ir(Ⅲ)L_3 type(where L is PT^-, 3Me-PT^-or 4Me-PT^-)are reported here.Four coordination compounds of the latter two ligands have never been reported before,while PT^-'s were synthesized with H_2PtCl_6 and(NH_4)_3IrCl_6 respectively,which were different from the methods of Davidson et al.~1 and Sterinbrech^2.They were characterized by elemental analysis, UV,IR,~1HNMR and molar conductance.Their structural formulas have been determined,and the mechanism of synthetic reaction has been discussed.

THE SYNTHESIS AND CHARACTERISTICS OF THE COORDINATION COMPOUNDS OF 2-MERCAPTOPYRIDINE-1-OXIDE WITH THE FIPST TRANSITION SERIES METALS

The stability of the coordination compounds of the first transition series metal ions(Mn(Ⅱ),Co(Ⅱ),Ni(Ⅱ),Cu(Ⅱ)and Zn(Ⅱ))with 2-mercaptopyridine-1- oxide is reported.A coordination compound CoL_2 is synthesized and characterized for the first time.

STUDY ON THE COORDINATION COMPOUNDS OF RARE EARTHS WITH DIPEPTIDE-COORDINATION OF RARE EARTHS WITH DL-ALANYL-ALANINE

In this paper protonation constants of the title lisand and stability constants of its coordination compounds with rare earths have been determined by potentiometric titration at 25±0.1℃ and ionic strength of 0.10mol.dm^(-3)NaClO_4. The coordination of rare earths with DL-alanyl-alanine has been discussed. The stability of the coordination compound shows 'tetrad effect'. The position for yttrium shifts from its usual Bo-Er region to the vicinity of Tb.

DETERMINATION OF STABILITY CONSTANTS OF THE COORDINATION COMPOUNDS OF Au(Ⅲ)-2-MERCAPTOPYRIDINE-1-OXIDE AND METHYL DERIVATIVES——METHOD OF DUAL-WAVELENGTH CORRESPONDING SOLUTIONS

In this paper,we report the deductive formula used for the method of dual-wavelength corresponding solutions under condition of having ligand interference and the stability constants of three new coordination compounds [AuL_2]^+determined with this method.The stability of the three compounds,the necessity of controlling pH in experimental systems and the advantage of this method are discussed in detail.

Selective flotation of chalcopyrite from pyrite via seawater oxidation pretreatment

The flotation separation of chalcopyrite from pyrite has attracted increasing attention due to the consumption of vast water resources and depressants.This study proposed the seawater oxidation pretreatment for non-depressant flotation separation of chalcopyrite from pyrite,as an effective and environmentally friendly strategy.Without the addition of depressants,seawater oxidation for 3 d effectively depressed pyrite flotation,with the highest recovery difference greater than 70%and a selectivity index greater than 6 between chalcopyrite and pyrite.The surface investigation showed that pyrite surface was more readily oxidized to form hydrophilic Fe oxidants/oxyhydroxides,as compared to that of chalcopyrite.Further UV-visible spectrophotometer and Fourier transform infrared spectrum(FTIR)results indicated that xanthate was less adsorbed onto the treated pyrite surface,resulting in un-floatable particles.Chalcopyrite surface was changed slightly due to seawater oxidation,thereby insignificantly affecting its flotation.The coordination theory was further used to reveal the combination mechanisms between xanthate and pyrite or chalcopyrite.This study therefore provides a promising strategy to effectively separate chalcopyrite from pyrite,especially in the freshwater-deficient area.