Physico‐Chemical Studies of Hinokitiol. III. A Spectrophotometric Study of Titanium Complex of Hinokitiol

A spectrophotometric study of complex formation between titanium (IV) and hinokitiol (β‐isoproyl tropolone) was made over a p H range of 1.15 to 5.60 at 25°. In a 50% dioxane‐water medium, a soluble yellow complex was formed between Ti (IV) and hinokitiol, which had two absorption maxima at 383 mμ and 335mμ. The optimum p H was 3.50 to 3.70 and the mole ratio of Ti (IV) to hinokitiol was 1 to 3. Its stability constant was found to be 8.99×10 28 at ionic strength 0.01, and the chemical formula was presumed to be [TiOH(C 10 H 11 O 2 ) 3 ] 0 . By using the wave length of 383 mμ, determination of trace amount of titanium (IV) with the sensitivity of 0.036 r/cm 2 was possible.