Structural Determination of an Unusual CuI‐Porphyrin‐π‐Bond in a Hetero‐Pacman Cu‐Zn‐Complex
Mathematisch-Naturwissenschaftliche Fakultät
The synthesis and characterization of a hetero-dinuclear compound is presented, in which a copper(I)trishistidine type coordination unit is positioned directlyabove a zinc porphyrin unit. The close distance betweenthe two coordination fragments is secured by a rigid xan-thene backbone, and a unique (intramolecular) copperporphyrin-p-bond was determined for the first time in themolecular structure. This structural motif was further ana-lyzed by temperature-dependent NMR studies: In solutionat room temperature the coordinative bond fluctuates,while it can be frozen at low temperatures. Preliminary re-activity studies revealed a reduced reactivity of the cop-per(I) moiety towards dioxygen. The results adumbratewhy nature is avoiding metal porphyrin-p-bonds by fixingreactive metal centers in a predetermined distance toeach other within multimetallic enzymatic reaction cen-ters.
