Fluorescence Sensing of Anions by Silanediols Bearing Substituted Naphthyl Groups.

Silanediols bearing naphthyl moieties substituted at 5-position with an electron-withdrawing cyano group and an electron-donating N,N-dimethylamino group, respectively, have been prepared and characterized. The substituents on the naphthyl moieties strongly influence the reactivity, photophysical properties, and sensing abilities for anions. The silanediol bearing 1-(5-N,N-dimethylaminonaphthyl) groups exhibited large Stokes shifts based on intramolecular charge transfer and large quantum yields in organic solvents. The silanediol showed favorable ratiometric fluorescence responses of upon the addition of biologically important anions, AcO - and H 2 PO 4 - with the association constants of 4.08×10 4 and 8.76×10 3  mol -1  dm 3 , respectively.