| Attributs | Valeurs |
|---|
| type
| |
| Is Part Of
| |
| Subject
| |
| Title
| - Structures, Metal−Ligand Bond Strength, and BondingAnalysis of Ferrocene Derivatives with Group-15Heteroligands Fe(η5-E5)2 and FeCp(η5-E5) (E = N, P, As,Sb). A Theoretical Study
|
| has manifestation of work
| |
| related by
| |
| Author
| |
| Abstract
| - We report quantum chemical DFT calculations of the homoleptic and heteroleptic title compounds which have π-heterocyclic ligands E5. Theoreticlly predicted equilibrium geometries and bond dissociation energies are given. The metal−ligand bonding has been analyzed with an energy decomposition method, which gives the contributions by electrostatic and covalent attraction and the strength of the orbital interactions.
- Quantum chemical DFT calculations using B3LYP and BP86 functionals have been carriedout for the title compounds. The equilibrium geometries and bond dissociation energies arereported. The metal−ligand bonding was analyzed with an energy partitioning method. Thestrongest bonded homoleptic complex with a heterocyclic ligand is Fe(η5-P5)2. The bonddissociation energy yielding the Fe atom and two cyclo-P5 ligands (Do = 128.3 kcal/mol) isnearly the same as for ferrocene (Do = 131.3 kcal/mol). The nitrogen, arsenic, and antimonyanalogues of Fe(η5-E5)2 have significantly weaker metal−ligand bonds, which, however,should still be strong enough to make them isolable under appropriate conditions. Thecalculated heats of formation show also that the phosphorus complex is the most stablespecies of the heterocyclic Fe(η5-E5)2 series. The Fe−(η5-E5) bonding in the mixed sandwichcomplexes FeCp(η5-E5) is much stronger compared to the homoleptic molecules. Theheterocyclic ligands cyclo-E5 in the mixed complexes FeCp(η5-E5) bind as strongly or in caseof phosphorus even stronger than one Cp ligand does in FeCp2 except for E = Sb. The metalfragments Fe(η5-E5)+ have a pyramidal geometry except for E = Sb, which is predicted to bea planar ion with D5h symmetry. The energy partitioning shows that the binding interactionsbetween the closed shell cyclo-E5- ligand and the Fe(η5-E5)+ fragment do not change verymuch for the different ligand atoms E in the homoleptic and heteroleptic complexes. Thebonding comes from 53%−58% electrostatic attraction, while 42%−47% come from covalentinteractions. The latter contribution comes mainly from the donation of the occupied e1 (π)orbital of the ligand into the empty orbital of the metal fragment.
|
| article type
| |
| is part of this journal
| |
