o-Hydroxybenzophenone (Hbp) chromophores were immobilized on 3-aminopropyl silicagel (SiO 2 -NH 2 ) by a reaction of succinimidyl 4-(4-benzoyl-3-hydroxyphenoxy)butanoate (2a) and -undecanoate (2b) with SiO 2 -NH 2 to produce microbeads 1a and 1b in 25 and 21% yield, respectively. The bond formation was confirmed by appearance of an absorption at 1550 cm -1 due to the N-H bending of the amide bond