PURPOSE: To obtain a new electric active compd. which is useful for an optical modulator in an integrated optic system or optical fiber system.
CONSTITUTION: This compd. has a structure expressed by formula I and a resonant standard structure expressed by formula II. In formula I, D is D1=X- or D2=C-; D1 is an electron donating unsatd. heterocyclic a-membered org. ring; X is a trivalent atom or a substd. or unsubstd. quadrivalent atom having one pair of lone electron pair orbits; Y is C or trivalent atom having a pair of lone electron orbits; Z is a lone electron pair; A, A1 are each an electron withdrawing L group or bonded to form a substd. or unsubstd. cyclic group; R is a bivalent group having a (substd.) aromatic carbon e-membered ring or a (substd.) aromatic heterocyclic f-membered ring; D2=C- is an aromatic carbon ring or heterocyclic group. The compd. is, for example, 4-methyl-4- stylbazolium-4'-[2-(1,3-indandion-2-ide)]. A compd. expressed by formula V or VI included in the compd. above described is obtd. by the reaction of a compd. expressed by formula III and an α-H contg. carbanion expressed by formula IV.
