INO-17

Tetrahedral vs octahedral splitting

Δt = (4/9) Δo. Same ligands, tetrahedral is a weaker field.

Reading speed

Crystal fieldLigand-field theory

Governing equation

\Delta_t=\tfrac49\Delta_o

where

\Delta_o: Octahedral Δo (cm^{-1})
\Delta_t: Tetrahedral Δt (cm^{-1})

Lecture brief

Historical brief

Pauling and Allred–Rochow electronegativity, Kapustinskii lattice energy, CFSE and Goldschmidt radii organise the periodic solid. The sheets predict bond character and crystal packing. This sheet (INO-17 — Tetrahedral vs octahedral splitting) is the form associated with Ligand-field theory. Working symbols: $\Delta_o$ $\rightarrow$ $\Delta_t$ . Point-charge crystal-field: four ligands vs six, and a different angular factor, give 4/9.

Purpose

Purpose: compute

\Delta_t

from

\Delta_o

in Inorganic chemistry via

\Delta_t=\tfrac49\Delta_o

Δt = (4/9) Δo. Same ligands, tetrahedral is a weaker field. Use it when a real inorganic chemistry question must be answered in SI before a code check.

Live realistic example

In symbols

Live case. Given

\Delta_o = 18000.000\,\mathrm{cm^-1}

, the governing relation

\Delta_t=\tfrac49\Delta_o

yields

\Delta_t = 8000\,\mathrm{cm^-1}

. Same metal, same ligand, enter Δo. Move a slider: the numbers are this situation, not a canned story.

Calculator

Inputs

Octahedral Δo \Delta_o18000 cm^{-1}

Outputs

Tetrahedral Δt \Delta_t8000 cm^{-1}

Reading speed

Watch on YouTube

Free library

Full library

Free PDF / open book

YouTube channels

00:0 / 00:08

Narration of this film

Same metal, same ligand, enter Δo.

Point-charge crystal-field: four ligands vs six, and a different angular factor, give 4/9.

Reading speed

Watch on YouTube