Benzophenone derivatives of formula I R1, R2 and R3 are each independently of the others hydrogen or C1-C4alkyl, cyclopentyl or cyclohexyl; R4, R5 and R6 are each independently of the others hydrogen, C1-C4alkyl, cyclopentyl or cyclohexyl; R7 and R8 are each independently of the other hydrogen, C1-C4alkyl, cyclopentyl or cyclohexyl; with the provisos that (i) at least one radical R1, R2, R3, R4, R5, R6, R7, R8 is other than hydrogen; (ii) when all radicals R4, R5 , R6, R7 and R8 are hydrogen and only one radical R1, R2, R3 is C1-C4alkyl, that radical must be in the meta-position of the phenyl ring; and (iii) when all radicals R1, R2, R3, R7 and R8 are hydrogen and two of the radicals R4, R5 and R6 are hydrogen and the remaining radical R4, R5 or R6 is C1-C4alkyl, that alkyl radical is not bonded in the para-position on the phenyl ring; are found to be especially suitable in photocurable compositions in respect of solubility, reactivity and a low level of yellowing.