Degree Name

Master of Science (MS)

Semester of Degree Completion


Thesis Director

David W. Ebdon


A new compound, 1,3,5-triphenylbenzene-4' ,4",4"'-trisulfonic acid, was synthesized by treating triphenylbenzene in 1,2-dichloroethane with chlorosulfonic acid. The reaction appears to be quantitative. Conductance measurements were then made on the sodium, potassium, and lanthanum salts of this new acid and of 1,3,5-benzenetrisulfonic acid.

The choice of these acids was based on two factors: 1) the desire to prepare a 3-3 symmetrical unassociated electrolyte which would allow the determination of a more reliable equivalent ionic conductance value for La3+ and 2) an interest in using the Murphy-Cohen equation to determine solute parameters such as association constants if association is present.

Conductance measurements were done in water at 25°C using the weight dilution technique and phoreograms of each salt were drawn. From the phoreograms of the sodium, potassium, and lanthanum salts of 1,3,5-triphenylbenzene-4' ,4",4"'-trisulfonic acid values of ⋀ found are 99.35 (ohm-1-cm2-equiv-1), 122.65 (ohm-1-cm2-equiv-1), and 119.25 (ohm-1-cm2-equiv-1), respectively. The value of the limiting equivalent ionic conductance, λ-, of 1,3,5-triphenylbenzene-4' ,4",4"'-trisulfonate ion found is 49.25 ± 0.1 (ohm-1-cm2-equiv-1). A value of λ+ for La3+ as determined from λ- is 70.0 (ohm-1-cm2-equiv-1).

Similarly, ⋀'s for the sodium and potassium salts of 1,3,5-benzenetrisulfonic acid were found to be 80.69 (ohm-1-cm2-equiv) and 80.88 (ohm-1-cm2-equiv-1) respectively. The value of λ- for 1,3,5-benzenetrisulfonate ion was found to be 80.78 ± .1 (ohm-1-cm2-equiv-1).

The Murphy-Cohen equation qualitatively shows these salts to be associated; however, there is a real possibility of very slight association.