Haptotropic rearrangements in naphthalene-chromium tricarbonyl complexes

TLDR: In this article, the magnetic properties of the isosceles (p3-oxo)triiron(III) complex with an imidazolederived ligand were examined.

Abstract: S = s/2 impurity determined from data in the range 1.7-50 K. In CD3CN solution at room temperature22 an upper bound for the magnetic moment of 1.5 pug agrees well with that in the solid state of 1.59 pB. It is clear from Table I that the antiferromagnetic coupling is independent of the Fe-O separation and the Fe-O-Fe angle-the latter has been noted previously.I6 Stronger coupling is observed for multiply bridged species (e.g., the symmetrical [ ( Bpz3) Fe( CH,C00)2( 0) Fe( Bpz,)] complex7a and unsymmetrical methemer~thrin~~ ), unsymmetrical species (this work and metHrk), and, possibly, heme species with linear FeOFe groups.* The magnetic properties of the isosceles (p3-oxo)triiron(III) cluster are different from those of the more symmetrical clusters.I2 Weaker coupling is observed for ~xyHr.~~ Earlier theoretical workz3 offers few clues for consequences of asymmetry. We intend examining in detail the proton NMR of this complex, which is the first (p-oxo)diiron(III) complex with an imidazolederived ligand, for comparison and amplification of the corresponding data for he~nerythrin.~~ We are attempting to isolate the one-electron reduced, mixed-valence compound that we observe formed in a quasi-reversible manner under cyclic voltammetry20 and to substitute other ligands at the tetrahedral site. Acknowledgment. The partial support of the Research Corporation and of the NIH-BRSG is gratefully acknowledged.