
%0 Journal Article
%A Fowless, AD 
%A Lawrance, GA 
%A Stranks, DR 
%A Sullivan, TR 
%A Vanderhoek, N 
%T The Effect of Pressure on the Anation of Diaquabis(ethane-1,2-diamine)cobalt(III) by Selenate and Sulfate, and on the Isomerization of the <I>trans</I>-Aquabis(ethane-1,2-diamine)(hydrogenselenito)cobalt(III) Ion
%J Australian Journal of Chemistry
%D 1988/09/01
%V 41
%N 9
%P 1263-1273
%K 
%R https://doi.org/10.1071/CH9881263
%U https://www.publish.csiro.au/paper/CH9881263 
%X The reversible nucleophilic substitution of cis-[Co(en)2(OH2)2]3+ (en = ethane-1,2-diamine) by sulfate and selenate at pH 2.0 was studied at elevated pressure, and activation volumes (&#916;V&#8225;) for anation and solvolysis were determined. The &#916;V&#8225; values for anation by sulfate and selenate were +8.3±0.5 and +8.5±0.4 cm3 mol-1 respectively, whereas solvolysis of sulfato and selenato complexes cis -[Co(en)2(OH2)(XO4)]+ gave &#916;V&#8225; values of -2.2±0.4 and -3.3±0.7 cm3 mol-1 respectively. The trans &#8594; cis [Co(en)2(OH2)(OSeO2H)]2+ isomerization studied at pH 1.0 and elevated pressure yielded &#916;V&#8225; + 7.2±0.4 cm3 mol-1. All reactions can be interpreted in terms of dissociative mechanisms. 
