is selected from the group consisting of sulphonate so 3 carboxylate co 2 and phosphonate po 4 2 and n is 2 or 3 the cationic electron donating bridging groups b isd in polymer s and cationic electron donating bridging groups b ifd in polymer f 39 can be selected from the group consisting of str7 in which designates a point of attachment between the bridging group and a rigid connecting group r is methyl ethyl propyl hydroxyethyl or benzyl and n is 2 or 3 the anionic electron accepting bridging groups b ifa in polymer f and anionic electron accepting bridging groups b isa in polymer s 39 can be independently selected from the group consisting of str8 in which designates a point of attachment between the bridging group and a rigid connecting group x is selected from the group consisting of sulphonate so 3 carboxylate co 2 and phosphonate po 4 2 and the rigid connecting groups of the chromophore c f and c s are independently selected from the group consisting of str9 in which designates a point of attachment between the bridging group and a rigid connecting group and z can be independently chosen from thio ether s ether o or an amine nh for the case where f type or f 39 type polymer is cationic the s type or s 39 type polymer can be replaced by glucose phosphate 2 6 naphthalenedisulfonate aqueous soluble organodisulfonates aqueous soluble organodicarboxylates aqueous soluble.