Phosphine oxides

Structure of tertiary phosphine oxides with the phosphine oxide group marked in blue . R ¹ to R ³ are organyl radicals (alkyl radical, aryl radical, alkylaryl radical, etc.). - In the primary phosphine oxides, R ² = R ³ = H.

Triphenylphosphine oxide, a phosphine oxide with three identical groups.

In chemistry, phosphine oxides , also called tertiary phosphine oxides, are a class of compounds with organically bound phosphorus and oxygen of the general structure R ¹ R ² R ³ P = O, where R ¹ , R ² and R ^{3 are} organic radicals . An older name for this group of substances is phosphine oxides. Compounds with the general formula R ¹ P (= O) H ₂ are called primary phosphine oxides (older name: phosphine oxides).

Chirality

Phosphine oxides with three different organic radicals R ¹ to R ³ are chiral .

Manufacturing

To synthesize the phosphine oxides, the corresponding phosphines (R ¹ R ² R ³ P) are oxidized, e.g. B. with peroxides:

R ₃ P + 1/2 O ₂ → R ₃ PO

In the Wittig reaction of alkenes , a phosphine oxide is also formed from the phosphorylide:

R ₃ PCR ' ₂ + R " ₂ CO → R ₃ PO + R' ₂ C = CR" ₂

The chemical reaction of phosphorus oxide halides with Grignard compounds also gives phosphorus oxides.

use

Trioctylphosphine oxide is used as an extractant, especially for uranium from phosphoric acid . Other metals (including gold, chromium, molybdenum and tin) can be extracted in the same way.

Individual evidence

1. ^ Siegfried Hauptmann : Organic Chemistry , 2nd revised edition, VEB Deutscher Verlag für Grundstoffindindustrie, Leipzig, 1985, p. 540, ISBN 3-342-00280-8 .
2. ^ Siegfried Hauptmann: Organic Chemistry , 2nd reviewed edition, VEB Deutscher Verlag für Grundstoffindindustrie, Leipzig, 1985, p. 96, ISBN 3-342-00280-8 .
3. ^ Siegfried Hauptmann: Organic chemistry . 2nd revised edition, VEB Deutscher Verlag für Grundstoffindustrie, Leipzig 1985, pp. 541-542, ISBN 3-342-00280-8 .
4. ↑ Otto-Albrecht Neumüller (Ed.): Römpps Chemie-Lexikon. Volume 4: M-Pk. 8th revised and expanded edition. Franckh'sche Verlagshandlung, Stuttgart 1985, ISBN 3-440-04514-5 , p. 3157.