Hexanuclear manganese metallamacrocycles with tripled hydrophobic tails

A series of hexanuclear manganese(III) metallamacrocycles were synthesized using N-acylsalicylhydrazides (H(3)xshz) (where H(3)xshz = H(3)ashz, N-acet ylsalicylhydrazide; H(3)pshz, N-propionylsalicylhydrazide; H(3)hshz. N-hexa noylsalicylhydrazide; H(3)lshz, N-lauroylsalicylhydrazide), where the penta dentate ligands bridged the metal ions. The triple deprotonated N-acyisalic ylhydrazidate (xshz(3-)) could bridge the metal ions by using a hydrazide N -N group and form the hexanuclear manganese metallamacrocycle with a hole i n the center. Depending on the ligands used, the tripled hydrophobic tails of different lengths are attached at both chiral faces of the metallamacroc ycles. In the complex [Mn-6(ashz)(6)(DMF)(6)] (2), both sides of the hole a re closed by the three methyl groups of the ligands. In the complex [Mn-6(p shz)(6)(DMF)(6)] (3a), one ethyl side chain of the ligands is located insid e the hole. In complexes [Mn-6(hshz)(6)(DMF)(6)] (4) and [Mn-6(lshz)(6)(MeO H)(6)] (5), three alternating long alkyl side chains aligned at an approxim ately right angle to the plane of the metallamacrocycle in one direction, w hile the other three alkyl side chains aligned in the opposite direction. T he stability of the metallamacrocycles in the solution was addressed using H-1 NMR spectroscopy. Three phenyl protons of the bridging ligands in the m etallamacrocycles were observed in the upfield region. (C) 2000 Elsevier Sc ience Ltd. All rights reserved.