Substituted pyridinium compound of the formula (I) ** ** Formula wherein X, Y are each independently O or S Z is a direct bond, O, S (O) m, NR, C (RaRaa) O, C (> = X1), C (> = X1) Y1, or Y1C (> = X1) X1 is O, S, or NR Y1 is O, S, or NRc A is C or N and wherein the two ring nitrogens pyrimidinium taken together with the carbon atom of the adjacent link and with A, A1, and A2 as shown in formula (I), form a ring system bicyclic eight to fourteen members is replaced by at least one R1 is not H, and wherein each member of the remaining ring bicyclic ring system is selected from carbon atoms and up to 4 heteroatoms independently selected from up to 2 O , up to 2 S and up to 3 N (Rc) p in each ring, wherein the ring members of the sulfur atom is independently S (> = O) m, selected in each ring may be replaced partly or completely by R1 or two R1 groups geminally bonded together may form a group selected from> = O,> = S,> = CRbRc,> = NR> = NORC, and> = NNRcRc A1, A2 are each independently C, CR1, O, S, or NR1, provided that R1 is not halogen or NR1 CN R1 is each independently H, halogen, CN, C1-C8 alkyl, C2-C8 alkenyl, C2-C8, cycloalkyl C3- C10 alkylcycloalkyl C4-C10 cycloalkylalkyl C4-C10, I cycloalkylcycloalkyl C6-C14 alkylcycloalkylalkyl C5-C10 or cycloalkenyl C3-C6 in which the groups mentioned above may be unsubstituted, partially or completely substituted by Ra, or R1 may form a three to ten carbo members or heterocyclic or a ring system from seven to eleven members, which ring or ring system may be saturated, partially unsaturated, or aromatic, and which ring or ring system may contain 1 to 4 heteroatoms selected from N (Rc) p, O, and S, where S can oxidize, and wherein the ring system or carbo or heterocyclic ring may be unsubstituted, partially or fully substituted by Ra Ra is each independently halogen, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 alkoxy, C1-C6 haloalkoxy, C2-C4 alkenyl, C2-C4 alkyl, C3-C6, CN, ORc, NRbRc, NO2, C (> = O) (O) p, OC (> = O) (O) pRe, C (> =
