Low-spin 1,1'-diphosphametallocenates of chromium and iron

Samuel M Greer; Ökten Üngor; Ross J Beattie; Jaqueline L Kiplinger; Brian L Scott; Benjamin W Stein; Conrad A P Goodwin

doi:10.1039/d0cc06518h

Low-spin 1,1'-diphosphametallocenates of chromium and iron

Chem Commun (Camb). 2021 Jan 21;57(5):595-598. doi: 10.1039/d0cc06518h.

Authors

Samuel M Greer¹, Ökten Üngor², Ross J Beattie³, Jaqueline L Kiplinger³, Brian L Scott³, Benjamin W Stein³, Conrad A P Goodwin⁴

Affiliations

¹ Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA. kiplinger@lanl.gov bstein@lanl.gov cgoodwin@lanl.gov and National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA and Department of Chemistry & Biochemistry, Florida State University, Tallahassee, FL 32306, USA.
² National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA.
³ Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA. kiplinger@lanl.gov bstein@lanl.gov cgoodwin@lanl.gov.
⁴ Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA. kiplinger@lanl.gov bstein@lanl.gov cgoodwin@lanl.gov and Department of Chemistry, School of Natural Sciences, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK.

PMID: 33338086
DOI: 10.1039/d0cc06518h

Abstract

We report two anionic diphosphametallocenates, [K(2.2.2-crypt)][M(PC4Me4)2] (M = Cr, 2-Cr; Fe, 2-Fe). Both are low-spin (S = ½) by EPR spectroscopy and SQUID magnetometry. This contrasts the high-spin (S = 3/2) ferrocenate, [K(2.2.2-crypt)][Fe(C5H2-1,2,4-tBu)2] (4-Fe). Quantum chemical calculations suggest this is due to significant differences in ligand field splitting of the d-orbitals which also explain structural features in the 2-M complexes.