INO-11

18-electron count

ne = nd + 2 nL − q for MLn^{q}. Closed-shell organometallic count.

Reading speed

Organometallic18-electron rule

Governing equation

n_e=n_d+2n_L-q

$n_L \in \left[0, 8\right]$

where

n_d: Metal d count (—)
n_L: L-type ligands (—)
q: Complex charge (—)
n_e: Electron count (—)

The figure, part by part

Each numbered marker wears the color of its card. Hover a card to light the marker. Tap a marker to jump to that card. The slider walks a red point along the curve; Animate drawing traces it like a pen.

00:0 / 00:08

①

Governing law — red

n_e=n_d+2n_L-q

$n_L \in \left[0, 8\right]$

$n_L = 0$ $n_e = 8$

Along the curve

②

Domain of the variable — blue

n_L_{\min} = 0,\quad n_L_{\max} = 8

$n_L \in \left[0, 8\right]$

$n_L = 0$ $n_L = 0$

Along the curve

③

Response curve — green

n_e=n_d+2n_L-q

$n_L \in \left[0, 8\right]$

$n_L = 0$ $n_e = 8$

Along the curve

④

Rate of change — amber

\frac{\mathrm{d}n_e}{\mathrm{d}n_L}

$n_L \in \left[0, 8\right]$

$n_L = 0.05$ $n_e^{\prime} = 2$

Along the curve

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-11 — 18-electron count) is the form associated with 18-electron rule. Working symbols: $n_d$ , $n_L$ , $q$ $\rightarrow$ $n_e$ . A filled s+p+d valence set is 18. Deviations are common for early metals and π-loaded ligands.

Purpose

Purpose: compute

n_e

from

n_d

n_L

q

in Inorganic chemistry via

n_e=n_d+2n_L-q

ne = nd + 2 nL − q for MLn^{q}. Closed-shell organometallic count. 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

n_d = 8.000\,\mathrm{—}

n_L = 5.000\,\mathrm{—}

q = 0.000\,\mathrm{—}

, the governing relation

n_e=n_d+2n_L-q

yields

n_e = 18\,\mathrm{—}

. Neutral-ligand (CBC) snapshot: each L donates 2, charge q on the complex. Move a slider: the numbers are this situation, not a canned story.

Calculator

Inputs

Metal d count n_d8 —L-type ligands n_L5 —Complex charge q0 —

Outputs

Electron count n_e18 —

Reading speed

Watch on YouTube

Free library

Full library

Free PDF / open book

YouTube channels

00:0 / 00:08

Narration of this film

Neutral-ligand (CBC) snapshot: each L donates 2, charge q on the complex.

A filled s+p+d valence set is 18. Deviations are common for early metals and π-loaded ligands.

Reading speed

Watch on YouTube