Mg(i)–Fe(–ii) and Mg(0)–Mg(i) covalent bonding in the Mg_nFe(CO)₄⁻ (n = 1, 2) anion complexes: an infrared photodissociation spectroscopic and theoretical study

Abstract

Heteronuclear magnesium-iron carbonyl anion complexes MgFe(CO)4- and Mg2Fe(CO)4- are produced in the gas phase and are detected by mass-selected infrared photodissociation spectroscopy in the carbonyl stretching frequency region. The geometric...

Low-Valent Transition Metalate Anions in Synthesis, Small Molecule Activation, and Catalysis

“…(21) were generated in the gas phase and their structures studied using a combination of mass-selected infrared photodissociation spectroscopy and quantum chemical calculations. 106 According to this study, the most stable structures of compounds 20 and 21 have a 2 A 1 ground state and C 3v symmetry, presenting heteronuclear Mg−Fe or Mg−Mg−Fe bonds, respectively. Theoretical calculations indicate, however, that despite having some covalent character, the interactions between magnesium and iron have a significant electrostatic component.…”

“…106 This group extended their investigations to heteronuclear magnesium−iron carbonyl cationic complexes, MgFe(CO) n + (n = 4−9) finding that for n > 5 the valence of the metal centers involved can formally be described as featuring Mg(II)−Fe(−I). 107 By reaction of the radical anion salt of fullerene [K([2. 2…”

Mg–Fe Bonding in the MgFe(CO)n+ (n = 4–9) Cation Complexes: An Infrared Photodissociation Spectroscopic and Theoretical Study

“…Both complexes are characterized to contain an electron-sharing Mg­(I)–Fe­(−II) σ bond. The Mg 2 Fe­(CO) 4 – complex involves a relatively weak covalent Mg(0)–Mg­(I) σ bond . Here we report the gas-phase generation and spectroscopic characterization of heteronuclear magnesium–iron carbonyl cation complexes MgFe­(CO) n + ( n = 4–9).…”

“…The Mg 2 Fe(CO) 4 − complex involves a relatively weak covalent Mg(0)−Mg(I) σ bond. 45 Here we report the gas-phase generation and spectroscopic characterization of heteronuclear magnesium−iron carbonyl cation complexes MgFe(CO) n + (n = 4−9). Infrared photodissociation spectroscopy combined with theoretical calculations confirm that the MgFe(CO) 9 + is a coordinatively saturated complex and each complex possesses a [(OC) n−4 Mg−Fe(CO) 4 ] + structure containing an electron-sharing Mg−Fe σ bond.…”

Gas-phase and solid-state electronic structure analysis and DFT benchmarking of HfCO

“…In general, unsaturated TM(CO) n complexes have several close-lying electronic states, which make them challenging to model accurately with computation. 14,19–23 High-level multi-reference theories provide a platform for predictions of systems with many low-lying electronic states. 24,25 The gold-standard coupled cluster level of theory can also deliver predictions with higher precision relative to most computationally tractable multi-reference (MR) methods as long as the targeted states are sufficiently single-reference (SR) in nature.…”