Transfer activity coefficients between some dipolar aprotic solvents and alcohols of salts composed of various anions and potassium complexed with Bis(4,4'(5')-t-butylbenzo)-18-crown-6

1983 ◽  
Vol 36 (9) ◽  
pp. 1753 ◽  
Author(s):  
Jr MK Chantooni ◽  
IM Kolthoff ◽  
G Roland
Keyword(s):  
Dimethyl Sulfoxide ◽  
Stability Constants ◽  
Propylene Carbonate ◽  
Activity Coefficients ◽  
Isopropyl Alcohol ◽  
The Other ◽  
Aprotic Solvents ◽  
Transfer Activity ◽  
Dipolar Aprotic Solvents

Stability constants, Kf(LK+) and Kf(LKX) = [LKX]/[L][KX] at 25� in the dipolar aprotic solvents acetone (Me2CO), acetonitrile (MeCN), propylene carbonate (pc), N,N-dimethylformamide (HCONMe2), dimethyl sulfoxide (Me2SO), as well as in the alcohols, methanol (MeOH), isopropyl alcohol (Pr1OH), and butan -1-ol (BuOH) have been determined, L being bis(4,4'(5')-t-buty1benzo)-18- crown-6 (di(BuBo)-18-cr-6). This crown is considerably more lipophylic than is dibenzo-18-crown-6. Values of Kf(LKX) have been found from values of Kf(LK+), KA(KX) and KA(LKX). Transfer activity coefficients, Me2COγS, have been calculated (based on the Parker proposal that γ(Ph4As+) = γ(BPh4-) between acetone and the various solvents used of K+, Br-, ClO4-, P1- (picrate), LK+, KX, and LKX. It is found that K+ is more strongly solvated in Me2CO than in the other aprotic solvents of low donicity. The reverse is true between Me2CO and HCONMe2 or Me2SO (even after correcting for the Born effect).

Estimation of transfer activity coefficients for single ions between dipolar aprotic solvents from the E.M.F. of cells with liquid junction

1983 ◽  
Vol 36 (9) ◽  
pp. 1767 ◽  
Author(s):  
SS Goldberg ◽  
O Popovych
Keyword(s):  
Activity Coefficients ◽  
Salt Bridge ◽  
Aprotic Solvents ◽  
Liquid Junction ◽  
Transfer Activity ◽  
Novel Method ◽  
Glass Electrodes ◽  
Tetraethylammonium Perchlorate ◽  
Dipolar Aprotic Solvents ◽  
Junction Potential

Transfer activity coefficients for the sodium ion, logmγNa, between pairs of dipolar aprotic solvents were estimated from the e.m.f. of cells consisting of two sodium-selective electrodes in different solvents connected by a salt-bridge of triisoamylbutylammonium tetraphenylborate [(tab+)BPh4-], or tetraethylammonium picrate (Et4NPic), or tetraethylammonium perchlorate (Et4NclO4). The solvents were: acetonitrile (MeCN), N,N-dimethylformamide (HCONMe2), dimethyl sulfoxide (Me2SO), propylene carbonate (pcar), and N-methylformamide (HCONHMe). Values of logmγNA were estimated first by neglecting the liquid-junction potential E, and then, for some systems, by applying an Ej correction from theory. A novel method of estimating transfer activity coefficients for single ions, based on the Ej equation, was demonstrated on the (tab+) and Pic-ions. Transfer activity coefficients for the hydrogen ion between MeCN and HCONMe2 as well as MeCN and Me2SO were similarly estimated from the e.m.f. of two pH (glass) electrodes immersed in buffer media in the above pairs of solvents.

Chromium(III) complexes in dipolar aprotic solvents. VIII. Solvolysis of hexaisothiocyanatochromate(III) and solvent exchange, substitution and anation of the pentaisothiocyanato(solvento)chrornate(III) complex, [Cr(NCS)5(sol)]2-

1975 ◽  
Vol 28 (9) ◽  
pp. 1907 ◽  
Author(s):  
STD Lo ◽  
DW Watts
Keyword(s):  
Activity Coefficients ◽  
Transition States ◽  
Aprotic Solvents ◽  
Solvent Exchange ◽  
Dissociative Mechanism ◽  
Transfer Activity ◽  
Activation Data ◽  
Dipolar Aprotic Solvents ◽  
Interchange Reactions ◽  
Solvent Transfer

The displacement of the coordinated Me2SO from [Cr(NCS)5(Me2SO)]2- by NCS- and pyridine has been studied in the solvent tetramethylene sulphone (sulpholane). The results are consistent with a limiting dissociative mechanism. The solvolysis reactions: �� ��������������[Cr(NCS)6]3- + sol → [Cr(NCS)5(sol)]2- + NCS- have been studied in the solvents (sol) Me2SO, HCONMe2 and MeCONMe2. The transition states for these solvolysis reactions are compared with a dissociative model ������������������������ [Cr(NCS)5(3-)+(∂+)...NCS∂-] by means of solvent transfer activity coefficients. Kinetic and activation data are recorded for a number of solvent interchange reactions: ����������� [Cr(NCS)5(sol1)]2- + sol2 → [Cr(NCS)5(sol2)]2- + sol1

Solvation of the halide anions in dimethyl sulfoxide. Factors involved in enhanced reactivity of negative ions in dipolar aprotic solvents

1984 ◽  
Vol 106 (21) ◽  
pp. 6140-6146 ◽  
Author(s):  
Tom F. Magnera ◽  
Gary Caldwell ◽  
Jan Sunner ◽  
Sigeru Ikuta ◽  
Paul Kebarle
Keyword(s):  
Dimethyl Sulfoxide ◽  
Negative Ions ◽  
Aprotic Solvents ◽  
Halide Anions ◽  
Dipolar Aprotic Solvents

Electron-transfer reactions in non-aqueous media. VII. Reduction of CoF(NH3)52+ and Co(HCOO)(NH3)52+ by copper(I) in dimethyl sulfoxide-water mixtures

1983 ◽  
Vol 36 (10) ◽  
pp. 1923 ◽  
Author(s):  
JMB Harrowfield ◽  
L Spiccia ◽  
DW Watts
Keyword(s):  
Electron Transfer ◽  
Dimethyl Sulfoxide ◽  
Aqueous Media ◽  
Mixed Solvents ◽  
Transfer Reactions ◽  
Aprotic Solvents ◽  
Aqueous Mixtures ◽  
Electron Transfer Reactions ◽  
Dipolar Aprotic Solvents ◽  
Sphere Mechanism

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.

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