Synthesis and bonding analysis of pentagonal bipyramidal rhenium carboxamide oxo complexes

Noah D McMillion; Quinton J Bruch; Chun-Hsing Chen; Faraj Hasanayn; Alexander J M Miller

doi:10.1039/d3dt02617e

Synthesis and bonding analysis of pentagonal bipyramidal rhenium carboxamide oxo complexes

Dalton Trans. 2023 Oct 24;52(41):15115-15123. doi: 10.1039/d3dt02617e.

Authors

Noah D McMillion¹, Quinton J Bruch¹, Chun-Hsing Chen¹, Faraj Hasanayn², Alexander J M Miller¹

Affiliations

¹ Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, USA. ajmm@email.unc.edu.
² Department of Chemistry, American University of Beirut, Beirut 1107 2020, Lebanon. fh19@aub.edu.lb.

PMID: 37814941
DOI: 10.1039/d3dt02617e

Abstract

Seven-coordinate rhenium oxo complexes supported by a tetradentate bipyridine carboxamide/carboxamidate ligand are reported. The neutral dicarboxamide H₂^Phbpy-da ligand initially coordinates in an L₄ (ONNO) fashion to an octahedral rhenium oxo precursor, yielding a seven-coordinate rhenium oxo complex. Subsequent deprotonation generates a new oxo complex featuring the dianionic (L₂X₂) carboxamidate (NNNN) form of the ligand. Computational studies provide insight into the relative stability of possible linkage isomers upon deprotonation. Structural studies and molecular orbital theory are employed to rationalize the relative isomer stability and provide insight into the rhenium-oxo bond order.