To produce a new compound useful as an anion excluder for a sol-gel sensitive membrane for measuring the ionic activity, excellent in durability, nontoxic and nonirritating to living bodies and suitable as an ion sensitive membrane capable of indwelling in vivo over a long period.
This compound is represented by formula I {R1 is a 1-6C alkyl; (x) and (y) are each an integer satisfying 1≤(x)≤3; 1≤(y)≤3 and [(x)+(y)] is 4; R2 is a (substituted)aromatic group; M is a metal ion; and (n) is 1-6}, e.g. sodium [4-(triethoxysilylpropyloxy)phenyl]-triphenylborate. The compound represented by formula I is obtained by reacting a chlorosilane represented by formula II (preferably trichlorosilane) with a boric salt derivative such as a compound represented by formula III in the presence of a catalyst (preferably platinum) in an anhydrous solvent (preferably benzene), distilling off the solvent, then reacting the resultant chlorosilylated boric salt derivative with an anhydrous alcohol (preferably ethanol) and then distilling off the solvent.
YAMADA SATOSHI
HAYASHI AKIO
KIMURA KEIICHI