PARTIAL MOLAL VOLUME OF (BU3N-(CH2)8-NBU3)BR2 A LARGE BOLAFORM ELECTROLYTE IN WATER AT 10 AND 25 DEGREES

The apparent φ2, and partial, V̄2, molal volumes were determined for octane-1,8-bis(tri-n-butylammonium) dibromide (DiBuBr2) in water at 10 and 25°. Over the concentration range studied (0.3-1.2 M), the volume behavior was similar to that observed for Bu4NBr, with φ2 and V̄2 decreasing to a minimum, φ2(min) = DiBuBr2· 100H2O, and then increasing as the concentration increased. The partial molal expansibilities, φE, of (φE - φE0) were positive, went through a maximum at the concentration where φ2 is at a minimum, and then decreased. The observed effects, including clathrate formation, all indicate that this large divalent salt affects water structure in the same manner as Bu4NBr.