3-(1-naphthyloxy)-1,2-benzisothiazole 1,1-dioxide: Electronic effects of conjugation

The conjugation of oxygen with an aromatic ring, as in 1-naphthol, results in a C-O bond length of 1.35 Angstrom and a C-O-C bond angle of almost 120 degrees, whereas the C-O bond length in an aliphatic ether is about 1.45 Angstrom, with a C-O-C angle of about 110 degrees. The pseudo-saccharyl ether of 1-naphthol, C17H11NO3S, changes the phenolic C-O bond length to 1.422(7) Angstrom, while maintaining the C-O-C angle. The result implies that the original naphtholic O atom is no longer pi-conjugated with the naphthalene ring system, but only with the saccharyl system.