Standard electrode potential of Br<img src='/image/spc_char/3_bar.gif' border=0>/Br^-, Br₂/ Br<img src='/image/spc_char/3_bar.gif' border=0> and B₂/Br redox couples and related formation constants of Br<img src='/image/spc_char/3_bar.gif' border=0> in some dipolar aprotic solvents

Abstract

Standard potentials of Br<img src='/image/spc_char/3_bar.gif' border=0>/Br^-, Br₂/ Br<img src='/image/spc_char/3_bar.gif' border=0> and B₂/Br redox couples have been determined in dipolar aprotic solvents like acetonitrile (AN), N,N-dimethylformamide (DMF) and propylene carbonate (PC) at 25ᵒC by potentiometric method, The standard potentials of the redox couple Br₂/Br^- as well as the related formation constants (<em>K</em>_f) of Br<img src='/image/spc_char/3_bar.gif' border=0> in the solvents have also been derived thereof. These values help derive transfer free energies, <img src='http://www.niscair.res.in/jinfo/delta.gif' border=0>G<img src='http://www.niscair.res.in/jinfo/zerov.gif' border=0>, Br<img src='/image/spc_char/3_bar.gif' border=0> and Br₂ from water to the solvents, as the corresponding values of Br^- based on TATB reference electrolyte are already known in the literature. <img src='http://www.niscair.res.in/jinfo/delta.gif' border=0>G<img src='http://www.niscair.res.in/jinfo/zerot.gif' border=0> values of different Br-species have also been examined in the light of various types of interactions, such as cavity, Born, ion-dipole, ion-induced dipole and the rest 'chemical' as guided chiefly by dispersion-type soft-soft interactions.