Endeavor toward Redox-Responsive Transition Metal Contrast Agents Based on the Cross-Bridge Cyclam Platform.

ABSTRACT: We present the synthesis and characterization of a series of Mn(III), Co(III), and Ni(II) complexes with cross-bridge cyclam derivatives (CB-cyclam = 1,4,8,11-tetraazabicyclo[6.6.2]hexadecane) containing acetamide or acetic acid pendant arms. The X-ray structures of [Ni(CB-TE2AM)]Cl₂·2H₂O and [Mn(CB-TE1AM)(OH)](PF₆)₂ evidence the octahedral coordination of the ligands around the Ni(II) and Mn(III) metal ions, with a terminal hydroxide ligand being coordinated to Mn(III). Cyclic voltammetry studies on solutions of the [Mn(CB-TE1AM)(OH)]²⁺ and [Mn(CB-TE1A)(OH)]⁺ complexes (0.15 M NaCl) show an intricate redox behavior with waves due to the Mn^III/Mn^IV and Mn^II/Mn^III pairs. The Co(III)

SUBMITTER: Uzal-Varela R 

PROVIDER: S-EPMC10806912 | biostudies-literature | 2024 Jan

REPOSITORIES: biostudies-literature