Compounds of the formula wherein m is 0, 1 or 2; wherein when m is 0, Z is O, when m is 1, Z is N, and when m is 2, Z is C; Y is H, OH, NH2, or an organic moiety of 1-20C, optionally additionally containing 1-8 heteroatoms selected from the group consisting of N, P, O, S and halo; each l1 and l2 is independently 0-5; l3 is 0 or 1; each of R1, R2 and R3 is independently alkyl (1-6C), aryl (6-10C) or arylalkyl (7-16C) optionally containing 1-4 heteroatoms selected from the group consisting of halo, N, P, O, and S or each of R1 and R2 may independently be halo, COOR, CONR2, CF3, CN or NO2, wherein R is H or lower alkyl (1-4C) or alkyl (1-6C); n is 0 or 1; X is a linker; with the proviso that Y is not a tropolone, a coumarin, or an antioxidant containing an aromatic group and with the further proviso that if l3 is 0, and either l1 and l2 is 0 or 1 and if R1 and/or R2 represent F in the para position, Z cannot be C or N; and are useful to treat pain. Libraries of these compounds can also be used to identify antagonists for other targets.