TRANSITION-METALS AS ASSEMBLING AND TEMPLATING SPECIES - FROM CATENANES AND KNOTS TO ORGANIZED MULTI-PORPHYRINS ARRAYS

New dicopper(I) knots have been synthesized as well as their face-to-f ace isomers. The knots range from 80 to 90-membered rings and their pr eparation yields depend crucially on structural parameters such as num ber of methylene fragments linking the two chelating units and length of the polyethyleneoxy unit used in the cyclization reaction. The best yield was obtained for an 84-membered knotted ring with a -(CH2)6- co nnector: this relartively long fragment allows pronounced winding of t he double helix precursor and is thus favorable to the knotting reacti on. The X-ray structures of two dicopper trefoil knots are also presen ted and discussed. The transition metal-directed threading of a molecu lar fragment containing a central chelate and an end-attached gold(III ) porphyrin into a presynthesized coordinating ring affords a general precursor to a rotaxane-type structures. After threading, construction of the second porphyrin acting as an efficient stopper affords a copp er(I) complexed [2]-rotaxane as well as a novel compartmental [3]-rota xane.