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💏intro to chemistry review

$t_2$

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

$t_2$ is a term that refers to a specific type of molecular orbital in coordination compounds. It is one of the three t-type molecular orbitals that can be formed from the interaction between the central metal atom's d-orbitals and the ligand orbitals in an octahedral complex.

5 Must Know Facts For Your Next Test

  1. The $t_2$ molecular orbitals are formed from the interaction between the central metal atom's $d_{xy}$, $d_{xz}$, and $d_{yz}$ orbitals and the ligand orbitals in an octahedral complex.
  2. The $t_2$ orbitals are lower in energy than the $e_g$ orbitals, and they can accommodate up to 6 electrons in an octahedral complex.
  3. The occupancy of the $t_2$ orbitals relative to the $e_g$ orbitals determines the magnetic properties of the coordination compound, as described by the Ligand Field Theory.
  4. Transitions between the $t_2$ and $e_g$ orbitals can result in characteristic absorption bands in the visible or near-infrared region of the electromagnetic spectrum, which can be observed in the electronic spectra of coordination compounds.
  5. The splitting of the d-orbitals into $t_2$ and $e_g$ sets is a key concept in understanding the stability, reactivity, and spectroscopic properties of coordination compounds.

Review Questions

  • Explain the relationship between the $t_2$ molecular orbitals and the d-orbitals of the central metal atom in an octahedral coordination complex.
    • In an octahedral coordination complex, the central metal atom's d-orbitals split into two sets: the lower-energy $t_2$ orbitals ($d_{xy}$, $d_{xz}$, and $d_{yz}$) and the higher-energy $e_g$ orbitals ($d_{x^2-y^2}$ and $d_{z^2}$). The $t_2$ orbitals are formed by the interaction between the metal atom's $d_{xy}$, $d_{xz}$, and $d_{yz}$ orbitals and the ligand orbitals. This splitting of the d-orbitals is a key concept in Ligand Field Theory and is crucial for understanding the electronic and magnetic properties of coordination compounds.
  • Describe how the occupancy of the $t_2$ and $e_g$ orbitals affects the magnetic properties of a coordination compound.
    • The relative occupancy of the $t_2$ and $e_g$ orbitals in a coordination compound determines its magnetic properties. If the $t_2$ orbitals are fully occupied and the $e_g$ orbitals are empty, the complex will be diamagnetic (no unpaired electrons). If the $t_2$ orbitals are partially occupied, the complex will be paramagnetic (have unpaired electrons) and exhibit magnetic moments that can be measured and used to determine the electron configuration. The Ligand Field Theory provides a framework for predicting and understanding the magnetic properties of coordination compounds based on the splitting and occupancy of the $t_2$ and $e_g$ orbitals.
  • Analyze how the $t_2$ orbitals in a coordination compound can influence the compound's electronic spectra and related spectroscopic properties.
    • Transitions between the $t_2$ and $e_g$ orbitals in a coordination compound can result in characteristic absorption bands in the visible or near-infrared region of the electromagnetic spectrum. These electronic transitions are governed by the Ligand Field Theory and can provide valuable information about the complex's structure, oxidation state, and bonding. The energy and intensity of these absorption bands depend on factors such as the identity of the central metal, the nature of the ligands, and the degree of d-orbital splitting. By analyzing the electronic spectra of a coordination compound, researchers can gain insights into the electronic structure and properties of the complex, which is crucial for understanding its reactivity, stability, and potential applications in areas like catalysis, sensing, and materials science.