Kinetics and thermodynamics of solvolysis of a cationic and an anionic chlorocobalt (III) complex in water-ethanol mixtures

被引：10

作者：

El-Subruiti, GM ^{[1
]}

机构：

[1] Univ Alexandria, Fac Sci, Dept Chem, Alexandria 21321, Egypt

来源：

JOURNAL OF SOLUTION CHEMISTRY | 2002年 / 31卷 / 05期

关键词：

chlorocobalt (III) complexes; aqueous ethanol; kinetics; solvolysis; transition state; activation entropy; activation enthalpy; free-energy cycle;

D O I：

10.1023/A:1015863416229

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Rate constants and derived thermodynamic activation parameters are reported for solvolysis of trans-[Co(3Mepy)(4)Cl-2](+) and [Co(CN)(5)Cl](3)- ions in water-rich mixtures of water with ethanol at various temperatures and are analyzed by initial- and transition-state contributions. The variation of enthalpies and entropies of activation with solvent composition show extrema in composition ranges where the physical properties of the mixtures, influenced by changes in solvent structures, also show extrema. From the application of a free-energy cycle to the process of the initial state going to the transition state, it is concluded for the solvolysis of both complexes that the Co(III) species in the transition state is more stable in water + ethanol mixtures than in the initial state.

引用

页码：415 / 423

页数：9

共 25 条

[1] EFFECT OF SOLVENT ON THE REACTION OF COORDINATION-COMPLEXES .19. BASE HYDROLYSIS OF (ALPHA-BETA-S)-(O-METHOXY BENZOATO)(TETRAETHYLENEPENTAMINE)-COBALT(III) IN AQUO-ORGANIC SOLVENT MEDIA [J].

ACHARYA, AN ;

DASH, AC .

JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS, 1994, 90 (21) :3293-3299

[2] Dielectric constants of some organic solvent-water mixtures at various temperatures [J].

Akerlof, G .

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1932, 54 :4125-4139

[3] APPLICATION OF SPECTROSCOPIC AND RELAXATION TECHNIQUES TO STUDY OF T-BUTYL ALCOHOL-WATER MIXTURES [J].

BLANDAMER, MJ ;

CLARKE, DE ;

CLAXTON, TA ;

FOX, MF ;

HIDDEN, NJ ;

OAKES, J ;

SYMONS, MCR ;

VERMA, GSP ;

WOOTTEN, MJ .

CHEMICAL COMMUNICATIONS, 1967, (06) :273-+

[4] ULTRASONIC ABSORPTION PROPERTIES OF T-BUTANOL-WATER MIXTURES AT 25 DEGREES [J].

BLANDAMER, MJ ;

CLARK, DE ;

HIDDEN, NJ ;

SYMONS, MCR .

CHEMICAL COMMUNICATIONS, 1966, (11) :342-+

[5]

BLANDAMER MJ, 1980, J CHEM SOC DA, P612

[6]

BLANDAMER MJ, 1977, ADV PHYS ORG CHEM, V14, P203

[7] THE EFFECT OF SOLVENTS UPON EQUILIBRIA, SPECTRA, AND REACTION RATES [J].

BROWNSTEIN, S .

CANADIAN JOURNAL OF CHEMISTRY, 1960, 38 (09) :1590-1596

[8] AQUATION OF TRIS-(1,10-PHENANTHROLINE)IRON(2) COMPLEXES IN AQUEOUS ETHANOL AND IN AQUEOUS FORMIC ACID [J].

BURGESS, J .

JOURNAL OF THE CHEMICAL SOCIETY A -INORGANIC PHYSICAL THEORETICAL, 1969, (13) :1899-&

[9] AQUATION OF TRIS-[1,10-PHENANTHROLINE]IRON(2) COMPLEXES IN T-BUTYL ALCOHOL-WATER MIXTURES [J].

BURGESS, J .

JOURNAL OF THE CHEMICAL SOCIETY A -INORGANIC PHYSICAL THEORETICAL, 1968, (05) :1085-&

[10]

BURGESS J, 1992, Progress in Reaction Kinetics, V17, P1

← 1 2 3 →