Trimethylphosphine oxide

Trimethylphosphine oxide is an organophosphorus compound with the chemical formula. It forms highly hygroscopic, white, needle-shaped crystals. It forms a dihydrate.

Synthesis

Trimethylphosphine oxide can be obtained by reaction between phosphoryl chloride and a Grignard reagent methylmagnesium chloride.
Trimethylphosphine is easily oxidized by oxygen to trimethylphosphine oxide.

Structure

Trimethylphosphine oxide molecule is Tetrahedral [molecular geometry|tetrahedral] at the phosphorus atom. It is a resonance between these two structures:
The distances between atoms are as follows:

C-H 110 pm
P-C 181 pm
P-O 148 pm

The angles between atoms are as follows:

∠C-P-O 112.3°
∠C-P-C 106.0°
∠P-C-H 109°