Density functional study of the Fe–CO bond dissociation energies of Fe(CO)5

Abstract

Fe(CO) n (n=1–5) complexes have been studied using density functional theory (DFT) methods. Several functionals have been used in the geometry optimizations, harmonic frequencies computation and calculation of the iron–carbonyl bond dissociation energies. Coupled-cluster single double (triple) bond dissociation energies have also been computed for the smaller systems. The obtained results show that DFT methods yield reasonable geometries and vibrational frequencies. Regarding the bond dissociation energies, it is shown that the validity of the results depends on whether there is a change in the atomic state of the metal during the dissociation. When the atomic state is the same for both complexes, the bond dissociation energy computed using gradient corrected functionals is within the range of the experimental values, while when the atomic state changes, DFT methods overestimate the bond dissociation energy due to a poor description of the atomic multiplets.

Computational insights into the mechanism of iron carbonyl-catalyzed ethylene hydrosilylation or dehydrogenative silylation

“…Our calculated singlet-triplet splitting energy of 1.79 kcal/ mol is close to the CCSD(T) value of 2 kcal/mol [53] and the B3PW91 value of 3.5 kcal/mol [54], although the experimental singlet-triplet splitting is unknown. The computed CO bond dissociation enthalpy (DH 298 ) leading to the most stable C 2v triplet state is 42.16 kcal/mol, in excellent agreement with the experimental value of 42 ± 2 kcal/mol [55], and other theoretical values [56][57][58]. In the liquid phase, the triplet Fe(CO) 4 has been observed as the primary photoproduct following excitation [59][60][61].…”

Combined Macro/Nanoscale Investigation of the Chemical Vapor Deposition of Fe from Fe(CO)5

“…[11,12,[17][18][19][20]30,31] The detailed description of the steps is given in the Supporting Information. The gas phase reactions with their corresponding energies are summarized in Table 1.…”

“…[5] More recently, traditional [6] and new [7] iron dissociation of Fe(CO) 5 and its intermediates [18] or by computational methods such as ab initio studies. [19,20] These studies describe the gas phase sequential decarbonylations of the pentacarbonyl precursor and the recombination reactions of the intermediate carbonyls with CO.…”

Benchmark Energetic Data in a Model System for Grubbs II Metathesis Catalysis and Their Use for the Development, Assessment, and Validation of Electronic Structure Methods

“…BP86 was chosen due to its early success in describing metal-carbonyl compounds, [33][34][35] whereas B3LYP…”