Compounds having Formula (A): wherein Q is N L is any bivalent organic radical capable of covalently linking each Q R 1 - R 6 , independently of one another, are selected from the group consisting of H, -(CH 2 ) p -D-Z, an alkyl, an alkenyl, an aryl, and an alkyl or alkyl ether optionally substituted by one or more of an alcohol, an aminoalcohol, an amine, an amide, an ether, a polyether, a polyamide, an ester, a mercaptan, an alkylthio, a urea, a thiourea, a guanidyl, or a carbamoyl group, and wherein at least one of R 1 , R 3 , R 4 and R 6 is a straight chain or branched, cyclic, alkyl, alkenyl, alkynyl or aryl group and R 1 and R 4 or R 3 and R 6 are covalently linked with each other, with L when L is C or CH to form a cyclic moiety Z is selected from the group consisting of amine, spermiyl, carboxyspermiyl, guanidyl, spermidinyl, putricinyl, diaminoalkyl, pyridyl, piperidinyl, pyrrolidinyl, polyamine, amino acid, peptide, and protein D is Q or a bond A 1 and A 2 , independently of one another, are selected from the group consisting of CH 2 O, CH 2 S, CH 2 NH, C(O), C(NH), C(S) and (CH 2 ) 1 X is a physiologically acceptable anion m, n, r, s, u, v, w and y are 0 or 1, with the proviso that when both m and n are 0 at least one of r, s, u and y is other than 0 p and t are integers from 0 to about 100 q is an integer from 1 to about 1000 and a is the number of positive charge divided by the valence of the anion,
