Ligand Field Stabilization Energies of the Hexaaqua 3+ Complexes of the First Transition Series
David A. Johnson1, Peter G. Nelson
1Department of Chemistry, University of Hull, Hull HU6 7RX, England.
Abstract:
An analysis of the ligand field stabilization energy which makes allowance for the nephelauxetic effect is shown to give satisfactory results when applied to the hydration enthalpies of the hexaaqua 3+ complexes of the first transition series. The contribution from the nephelauxetic effect is substantial, and the baseline for zero ligand field stabilization energy is displaced below the d(0) point. In these respects, the complexes show a closer resemblance to the hexafluorometalates(III) than to the hexaaqua 2+ ions. In the course of the analysis, the electronic spectra of the cesium alums of vanadium(III), manganese(III), and cobalt(III) are reexamined, and thermodynamic properties of particular complexes are calculated. These include Delta(Ti(3+),aq), E(&crclbr;)(Ti(3+)|Ti(2+)), and the relative stabilities of the high- and low-spin states of Co(3+)(aq), Mn(3+)(aq), and Cr(2+)(aq). The general influence of ligand field stabilization energies on redox potentials is also discussed.
More Related Videos
16:11Thermochemical Studies of Ni(II) and Zn(II) Ternary Complexes Using Ion Mobility-Mass Spectrometry
Published on: June 8, 2022
07:20Discovery and Synthesis Optimization of Isoreticular Al(III) Phosphonate-Based Metal-Organic Framework Compounds Using High-Throughput Methods
Published on: October 6, 2023
Related Concept Videos
02:42Valence Bond Theory
02:58Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
03:02Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
01:07Ladder Diagrams: Complexation Equilibria
The formation constant, K1, for the formation of Cd(NH3)2+ complex from cadmium and ammonia is 3.55 × 102. Log K1 (i.e. pNH3) is 2.55, and...
01:09Complexation Equilibria: Factors Influencing Stability of Complexes