Crystal field splitting in an octahedral complex is caused by ligand electron-metal electron repulsions. The energy separation between the higher energy eg set and lower energy t₂g set is denoted by ∆₀, with eg orbitals increasing by (3/5) ∆₀ and ...
Tiwari Academy Discussion Latest Questions
Repulsion between metal d orbitals and ligand electrons in an octahedral complex leads to the removal of degeneracy. The dx² – y² and dz² orbitals, pointing toward ligands, experience more repulsion, resulting in higher energy, while dxy, dyz, and dxz ...
The nature of the crystal field influences the pattern of splitting in d orbitals, as the asymmetry created by ligands results in distinct energy levels for the orbitals in coordination complexes.
In isolation, the d orbitals of a metal atom/ion are degenerate due to spherical symmetry. However, the presence of ligands, forming an asymmetrical negative field, leads to the lifting of d orbital degeneracy through splitting.
CFT views the metal-ligand bond as ionic, emphasizing electrostatic interactions between the metal ion and ligands. Ligands are treated as point charges for anions or point dipoles for neutral molecules in this model.
[Co(C₂O₄)₃]³⁻ is an inner orbital complex with d²sp³ hybridization, resulting in diamagnetic behavior. In contrast, [CoF₆]³⁻ is an outer orbital complex with sp³d² hybridization, leading to paramagnetism due to the presence of four unpaired electrons.
Valence Bond Theory attributes the anomalies to the formation of inner orbital and outer orbital coordination entities. Inner orbital complexes like [Mn(CN)₆]³⁻ and [Fe(CN)₆]³⁻, with d²sp³ hybridization, are paramagnetic, while outer orbital complexes like [MnCl₆]³⁻ and [FeF₆]³⁻, with sp³d² hybridization, ...
The magnetic data show anomalies in compounds like [Mn(CN)₆]³⁻ and [Fe(CN)₆]³⁻, where [Mn(CN)₆]³⁻ has a magnetic moment of two unpaired electrons, while [Fe(CN)₆]³⁻ exhibits a paramagnetic moment with five unpaired electrons.
Linkage isomerism occurs in complexes with ambidentate ligands. For instance, thiocyanate ligand (NCS⁻) can bind through nitrogen (M–NCS) or sulphur (M–SCN), illustrated by complexes like [Co(NH₃)₅(NO₂)]Cl₂.
Coordination isomerism involves the interchange of ligands between cationic and anionic entities. In [Co(NH₃)₆][Cr(CN)₆], NH₃ binds to Co³⁺ and CN⁻ to Cr³⁺. In its coordination isomer [Cr(NH₃)₆][Co(CN)₆], the ligand binding arrangement switches.