Behaviour of Some Copper(I) and Cobalt(III) Complexes in Acetonitrile and n-Butyronitrile at 298.15K

2003 ◽  
Vol 217 (6) ◽  
pp. 739-750 ◽  
Author(s):  
Dip Singh Gill ◽  
Vivek Pathania ◽  
Bal Krishan Vermani ◽  
Raj Pal Sharma

AbstractMolar conductances of a large number of copper(I) and cobalt(III) complexes, behaving as strong 1:1 electrolytes, have been measured in acetonitrile (AN) and n-butyronitrile (n-BTN) at 298.15K. The conductance data have been analyzed by the Shedlovsky method to evaluate Λ0 and KA values of these electrolytes. Limiting ion conductances (λi0) for various ions in AN have been calculated by using transference number data. In n-BTN, where no transference number data is available, such values have been calculated by an indirect method using Bu4NBPh4 as a reference electrolyte. The actual ionic radii (ri) for various ions in solution have been calculated using a modified form of Stokes’ law. The ionic radii (ri) for various complex ions have been compared with the ionic radii of two reference ions, Bu4N+ and Ph4B−, which are not solvated in dipolar aprotic solvents, to throw light on the solvation behaviour of these complex ions.

2009 ◽  
Vol 64 (3-4) ◽  
pp. 269-272 ◽  
Author(s):  
Dip Singh Gill ◽  
Dilbag Rana

Abstract Attempts have been made to prepare some novel copper(I) nitrate, sulfate, and perchlorate complexes. Molar conductances of these complexes have been measured in organic solvents like acetonitrile (AN), acetone (AC), methanol (MeOH), N,N-dimethylformamide (DMF), N,Ndimethylacetamide (DMA), and dimethylsulfoxide (DMSO) at 298 K. The molar conductance data have been analyzed to obtain limiting molar conductances (λ0) and ion association constants (KA) of the electrolytes. The results showed that all these complexes are strong electrolytes in all organic solvents. The limiting ionic molar conductances (λo± ) for various ions have been calculated using Bu4NBPh4 as reference electrolyte. The actual radii for copper(I) complex ions are very large and different in different solvents and indicate some solvation effects in each solvent system


1985 ◽  
Vol 50 (11) ◽  
pp. 2493-2508 ◽  
Author(s):  
Petr Kyselka ◽  
Zdeněk Havlas ◽  
Ivo Sláma

Solvation of Li+, Be2+, Na+, Mg2+, and Al3+ ions has been studied in binary mixtures with dimethyl sulphoxide, dimethylformamide, acetonitrile and water, and in ternary mixtures of the organic solvents with water. The CNDO/2 quantum chemical method was used to calculate the energies of solvation, molecular structures and charge distributions for the complexes acetonitrile...ion (1:1, 2:1, 4:1), dimethyl sulphoxide...ion (1:1), dimethylformamide...ion (1:1), and acetonitrile (dimethyl sulphoxide, dimethylformamide)...ion...water (1:1:1).


1991 ◽  
Vol 56 (10) ◽  
pp. 2160-2168 ◽  
Author(s):  
Josef Jirman

The 1H and 13C NMR spectra have been measured of six trans-azobenzenes substituted at 2 and 2’ positions with substituents favourable for complex formation with a metal (OH, NH2, NHCOCH3, COOH). From the standpoint of NMR such substituted trans-azobenzenes are present in solution in a rapid equilibrium following from rotation around the bond between C-1 of phenyl group and N atom of azo linkage. The predominant form has the substituent in the syn-position with respect to the free electron pair of the nearer azo nitrogen atom. The equilibrium is affected by dipolar aprotic solvents (such as hexadeuteriodimethyl sulfoxide) by decreasing the presence of the predominant form by 1 to 11%.


2004 ◽  
Vol 59 (9) ◽  
pp. 615-620 ◽  
Author(s):  
Dip Singh Gill ◽  
Hardeep Anand ◽  
J. K. Puri

Viscosity and molar conductance of Bu4NBPh4, Bu4NClO4, [Cu(CH3CN)4]ClO4, NaClO4 and NaBPh4 have been measured in the concentration ranges 0.02 - 0.5 mol dm−3 and 0.0005 - 0.0065 mol dm−3 at 298.15 K in AN + DMF mixtures containing 0, 10, 20, 40, 60, 75, 80, 90, and 100 mol % DMF. The viscosity data have been analyzed by the extended form of the Jones-Dole equation in the form: (η/η0) = 1+AC1/2+BC+DC2 to evaluate B and D parameters and the conductance data by the Shedlovsky equation to evaluate Λo and KA values of the salts. Ionic viscosity B-coefficients (B±) and ionic molar conductances (λ◦ i) have been calculated by using Bu4NBPh4 as a reference electrolyte. Solvated radii (ri) for Na+, Cu+ and ClO4 − have been estimated by using Gill’s modification of Stokes’ law. The variation of B± and ri as a function of mol % DMF shows that both Na+ and Cu+ are highly solvated in AN + DMF mixtures over the entire composition region. The solvation passes through a maximum between 40 to 80 mol % DMF. Both Na+ and Cu+ are more strongly solvated between 40 to 80 mol % DMF. Cu+ is relatively more strongly solvated than Na+ in AN + DMF mixtures. ClO4 − shows poor solvation in AN + DMF mixtures.


1983 ◽  
Vol 36 (10) ◽  
pp. 1923 ◽  
Author(s):  
JMB Harrowfield ◽  
L Spiccia ◽  
DW Watts

Previous work on the reduction of a series of cobalt(III) complexes by iron(II) in dipolar aprotic solvents and in aqueous mixtures has been extended to reduction by copper(I). The greater stability of copper(I) to disproportionation in these media has permitted the study of the reduction of CoF(NH3)52+ and Co(HCOO)(NH3)52+ in range of solvents over a number of temperatures with a precision not possible in previous studies in water. The results are consistent with an inner-sphere mechanism in which the copper(I) reductant is preferentially solvated by dimethyl sulfoxide to the exclusion of water in mixed solvents.


1990 ◽  
Vol 55 (9) ◽  
pp. 2131-2137
Author(s):  
Mahboob Mohammad ◽  
Ather Yaseen Khan ◽  
Tariq Mahmood ◽  
Ismat Fatima ◽  
Riffat Shaheen ◽  
...  

The 1H NMR spectra of the charge-transfer complex of 1-ethyl-4-methoxycarbonylpyridinium iodide have been recorded in various dipolar aprotic solvents. An attempt is made to interpret the chemical shifts in terms of Buckingham's reaction field equation for spherical cavities. A linear dependence has been found between the δ(2,6) values and the square of dielectric function for a spherical cavity, which confirms the validity of the Buckingham equation for this class of compounds.


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