Descriptors for ferrocene and some substituted ferrocenes

We have used literature data on solubilities in 58 solvents to obtain Abraham (Absolv) descriptors for ferrocene. The required descriptor E was obtained through known measurements of molar refraction, and the V descriptor was obtained through comparison of partial molal volumes with McGowan volumes, Vx, for 58 compounds. Ferrocene is quite hydrophobic, with our calculated water-octanol partition coefficient as 3.70 (log Ps), it has no hydrogen bond acidity, only a small hydrogen bond basicity, but a significant dipolarity. Descriptors for a number of derivatives of ferrocene were also obtained from solubility data; these derivatives were acetylferrocene, diacetylferrocene, acetoacetylferrcene and diacetoacetylferocene. In addition, descriptors for alkylferrocenes were estimated by comparison. Substituent effects on ferrocene are very similar to substituent effects on purely organic compounds, and could be used to estimate descriptors for a variety of monosubstituted ferrocenes.