Disubstituted fluoroaryloxybenzoheterodiazole compound having general formula: wherein: - Z represents sulfur, oxygen, selenium; or a NR 5 group wherein R 5 is selected from linear or branched, preferably C 1 -C 8, C 1 -C 20 alkyl groups, or optionally substituted aryl groups; - R 1, R 2 and R 3, mutually identical or different, represent a hydrogen atom; or they are selected from linear or branched, preferably C 1 -C 8, C 1 -C 20 alkyl groups, optionally containing heteroatoms, optionally substituted cycloalkyl groups, optionally substituted aryl groups, optionally substituted, linear or branched, preferably C 1 -C 8, C 1 -C 20 alkoxy groups, optionally substituted phenoxy groups, -COOR 6 groups wherein R 6 is selected from linear or branched, preferably C 1 -Cs, C 1 -C 20 alkyl groups, or is a cyano group; provided that the substituents R 1 do not both represent a hydrogen atom; - or R 1 and R 2, may optionally be bound together so as to form, together with the carbon atoms to which they are bound, a saturated, unsaturated, or aromatic, cycle or polycyclic system containing from 3 to 14 carbon atoms, preferably from 4 to 6 carbon atoms, optionally containing one or more heteroatoms such as oxygen, sulfur, nitrogen, silicon, phosphorus, selenium; - or R 2 and R 3, may be optionally linked together so as to form, together with the carbon atoms to which they are bound, a saturated, unsaturated, or aromatic, cycle or polycyclic system containing from 3 to 14 carbon atoms, preferably from 4 to 6 carbon atoms, optionally containing one or more heteroatoms such as oxygen, sulfur, nitrogen, silicon, phosphorus, selenium; - R 4 is selected from optionally substituted aryl groups. - Z represents sulfur, oxygen, selenium; or a NR 5 group wherein R 5 is selected from linear or branched, preferably C 1 -C 8, C 1 -C 20 alkyl groups, or optionally substituted aryl groups; - R 1, R 2 and R 3, mutually identical or different, represent a hydrogen atom; or they are selected from linear or branched, preferably C 1 -C 8, C 1 -C 20 alkyl groups, optionally containing heteroatoms, optionally substituted cycloalkyl groups, optionally substituted aryl groups, optionally substituted, linear or branched, preferably C 1 -C 8, C 1 -C 20 alkoxy groups, optionally substituted phenoxy groups, -COOR 6 groups wherein R 6 is selected from linear or branched, preferably C 1 -Cs, C 1 -C 20 alkyl groups, or is a cyano group; provided that the substituents R 1 do not both represent a hydrogen atom; - or R 1 and R 2, may optionally be bound together so as to form, together with the carbon atoms to which they are bound, a saturated, unsaturated, or aromatic, cycle or polycyclic system containing from 3 to 14 carbon atoms, preferably from 4 to 6 carbon atoms, optionally containing one or more heteroatoms such as oxygen, sulfur, nitrogen, silicon, phosphorus, selenium; - or R 2 and R 3, may be optionally linked together so as to form, together with the carbon atoms to which they are bound, a saturated, unsaturated, or aromatic, cycle or polycyclic system containing from 3 to 14 carbon atoms, preferably from 4 to 6 carbon atoms, optionally containing one or more heteroatoms such as oxygen, sulfur, nitrogen, silicon, phosphorus, selenium; - R 4 is selected from optionally substituted aryl groups.