МОНООКСИД БИС(ДИФЕНИЛФОСФИНО) МЕТАНА

Identification

Bis(diphenylphosphino)methane monoxide is a derivative of the classical bidentate phosphine ligand dppm, in which one of the two phosphorus atoms is oxidized to phosphine oxide. English name Bis(diphenylphosphino)methane monooxide, CAS 23176-18-3, formula C25H22OP2. Synonyms: diphenylphosphinomethyldiphenylphosphine oxide; (diphenylphosphino)(diphenylphosphinyl)methane; diphenyl(diphenylphosphinomethyl)phosphine oxide.

Basic Attributes

• CAS No.: 23176-18-3
• Chemical formula: C25H22OP2
• Molecular Weight: 400.39
• Exact weight: 400.115
• NSC Number: 193781
• DSSTox ID: DTXSID10307678
• HS code: 2902909090
• PSA specifications: 40.47
• XLogP3: 5.0909

Physico-chemical characteristics

• Melting point: 187–191 °C (lit.)
• Boiling point: 517.1 °C at 760 mm Hg. Art.
• Flash point: 266.6 °C

Substance class and purpose

A heterodifunctional ligand of the mixed P,P=O type - one phosphorus atom remains a trivalent donor (phosphine), the other is oxidized to a phosphinyl oxide group (P=O), which can be coordinated through oxygen. This asymmetry of coordination capabilities distinguishes the compound from symmetric bis(diphenylphosphino)methane (dppm), where both phosphorus atoms are identical.

Applications

• heteroditopic P,O-type ligand in the coordination chemistry of transition metals - capable of binding one metal center through phosphorus, and another (or the same one in a different geometry) through oxygen of the phosphine oxide group
• reagent for the preparation of unsymmetrical bimetallic and heteroligand complexes
• intermediate in the partial oxidation of dppm, used as a marker of the completeness and regioselectivity of the oxidation reaction of bidentate diphosphines
• object of study of coordination chemistry of mixed P,O-donor ligands

Safety Information

• Transport codes: NONH for all modes of transport
• WGK Germany: 3

The source does not provide detailed hazard class codes, safety instructions and precautionary phrases for this position.

Storage and transportation

Store in a tightly closed container in a cool, dry place. High melting points (187–191 °C) and flash points (266.6 °C) indicate thermal stability of the solid under normal storage conditions. Transport code NONH: not classified as dangerous goods for standard transport.

Comparison with symmetric dppm

The initial symmetrical ligand bis(diphenylphosphino)methane, from which this compound is obtained by partial oxidation, melts lower (159–161 °C) and boils lower (497.2 °C at 760 mmHg). The introduction of a polar phosphinyl oxide group P=O on one of the two phosphorus atoms increases the melting point and boiling point of the monoxide derivative due to the enhancement of intermolecular dipole-dipole interactions in the solid and liquid phases.

Practical meaning of asymmetry

The presence of soft (phosphine) and hard (phosphine oxide) donor centers in one molecule makes the compound a convenient tool for the design of heterobimetallic complexes, where two metal centers of different nature are coordinated to different donor atoms of the same ligand.