Studies on the Interaction between Long Chain Alcohols and Alkyl Sulf ates. II. Molecular Association between Dodecyl Alcohol and Dodecyl Sulfate of Divalent Metals
Abstract
Molecular interaction between dodecyl alcohol and dodecyl sulfate of divalent metal cations such as Mg2+, Ca2+, Sr2+, Ba2+, Mn2+, Co2+, Ni2+, and Cu2+ was studied by measurement of heat of complex formation, differential thermal analysis and infrared spectroscopy. It was found that magnesium, manganese, cobalt, nickel, and copper dodecyl sulfates formed two or three kinds of complexes with dodecyl alcohol, differing in composition depending on temperature. On the other hand, no evidence of complex formation could be found by these experimental techniques for calcium, strontium and barium dodecyl sulfates, all of which are very small in solubility into water. For the former class of metal dodecyl sulfates the composition of complex was 3.5–4.0 in molar ratio of alcohol to sulfate at temperature below the melting point of alcohol, while it was 5.0–6.0 at temperature above it. The heat of complex formation above the melting point of alcohol was ?40–?44 kcal/mol-sulfate. Two or three characteristic absorption...