Synthesis and Chgraoterization of Different Ion-pairs [ co(py) 4Cl2 ] +X- and measurement of assooiation and aquation rate constants
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Date
1988-06
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Addis Ababa Universty
Abstract
The dichlorotetrapyridineCobalt(lll) complexes ~co(PY)4C12 ~ X(X = Cl- ,
N~-, 01°
4
-, 1°
4
-, SCN-, N~-) were synthesized and oharacterized by using
elemental analysis and speotroscopio techniques. The spectral data for
complexes in the UV, Vis ("'"
~.../ J- I
), and IR ( \t (Co-Cl), V(Co-N»
regions have been determined.
From conduotivity measurement equivalent conductivity at infinite dilution
( ~) and association constants (KA) were estimated in various solvents.
"
Non-linear oorrelation of the association conetant of the medium has been
shown. Larger assooiation constants for 104- and SCN-, whereas lower
association constants for NO~- and Cl- salts were found.
Rates of aquation of the complexes were measured in water as a function
of Co-solvents (50:50); (v/v), and with the different composition of ethanol;
and faster rate of aquations were Observed for SCN- and NO~- and slower for
104- oounter ions.
The nuoleophilic order of the oounter ions of the complexes was also
established. The increasing order of the nuoleophilicity of the oounterions
was found as follows:SON- < No-3 < CI< CIO4 –C<N-3
Description
Keywords
Co(py) 4Cl2