Neutral and Cationic Octanuclear Gallium Metallamacrocycles with Two Topologically Different Connectivities

Abstract

A neutral octanuclear gallium metallamacrocycle has been synthesized using a ligand N2-cyclopentylcarbonyl-2-hydroxybenzohydrazide (H3L1) by self-assembly. The ligand connectivities in the macrocycle can be represented as -H-T-H-T-H-. Replacement of the –OH group by an –NH2 group in the above ligand - N2-cyclopentylcarbonyl-2-aminobenzohydrazide (H4L2) - leads to the formation of a cationic octanuclear gallium metallamacrocycle due to non-deprotonation of –NH2. The successive connectivities in the macrocycle can be represented as -H-H-T-T-H-H-. The structural features of the two metallamacrocycles will be discussed.