Dimethylphenylphosphine

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Dimethylphenylphosphine
Dimethylphenylphosphine
Names
Preferred IUPAC name
Dimethyl(phenyl)phosphane
Other names
Dimethylphenylphosphine
Identifiers
3D model (
JSmol
)
ChEBI
ChemSpider
ECHA InfoCard
 100.010.543 Edit this at Wikidata
EC Number
  • 211-595-3
UNII
  • InChI=1S/C8H11P/c1-9(2)8-6-4-3-5-7-8/h3-7H,1-2H3 checkY
    Key: HASCQPSFPAKVEK-UHFFFAOYSA-N checkY
  • InChI=1/C8H11P/c1-9(2)8-6-4-3-5-7-8/h3-7H,1-2H3
    Key: HASCQPSFPAKVEK-UHFFFAOYAS
  • P(c1ccccc1)(C)C
Properties
C8H11P
Molar mass 138.14 g/mol
Appearance transparent light pale yellow liquid
Density 0.971 g/cm3
Melting point N/A
Boiling point 74 to 75 °C (165 to 167 °F; 347 to 348 K) at 12 mmHg
Insoluble
Structure
Pyramidal
Hazards
GHS labelling:
GHS02: FlammableGHS07: Exclamation mark
Warning
H226, H315, H319, H335
P210, P233, P240, P241, P242, P243, P261, P264, P271, P280, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P370+P378, P403+P233, P403+P235, P405, P501
Flash point 49 °C (120 °F; 322 K)
Safety data sheet (SDS) [1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

Dimethylphenylphosphine is an

metal phosphine complexes
.

Preparation

Dimethylphenylphosphine is prepared by the reaction of methylmagnesium halide with dichlorophenylphosphine.

(C6H5)Cl2P + 2CH3MgBr → (C6H5)(CH3)2P + 2MgBrCl

The phosphine is purified by distillation under reduced pressure.[1] A solution of (C6H5)(CH3)2P in CDCl3 shows

phosphorus-31 NMR spectrum shows a singlet at -45.9 ppm in CDCl3.[2]

Structure and properties

Dimethylphenylphosphine is a

methyl groups are connected to the phosphorus. The bond length and angles are the following: P-CMe: 1.844, P-CPh: 1.845 Å, C-C: 1.401 Å, C-HMe: 1.090 Å, C-HPh: 1.067 Å, C-P-C: 96.9°, C-P-C (ring): 103.4°, P-C-H: 115.2°.[3]

When attached to chiral metal centers, the P-methyl groups are

diastereotopic
, appearing as separate doublets in the 1H NMR spectrum.

Comparisons with related phosphine ligands

The νCO of IrCl(CO)(PPh3)2 and IrCl(CO)(PMe2Ph)2 are both at 1960 cm−1, whereas νCO for IrCl(CO)(PMe3)2 is at 1938 cm−1.[4][5]

In terms of basicity, dimethylphenylphosphine is intermediate between that of trialkyl- and triphenylphosphine:[6][7]

  • [HPEt3]+ = 8.7
  • [HPMe2Ph]+ = 6.8
  • [HPPh3]+ = 2.7

The ligand

cone angle
(θ) is the apex angle of a cylindrical cone, which is centered 2.28 Å from the center of the P atom. However, the cone angle of an unsymmetrical ligand cannot be determined in the same. In order to determine an effective cone angle for an unsymmetrical ligand PX1X2X3, the following equation is used:

Where θi represent the half angle.

The resulting angles for PMe3, PMe2Ph, PPh3 are: PMe3 = 118°, PMe2Ph = 122°, PPh3 = 145°. Thus, PMe2Ph is intermediate in size relative to PMe3 and PPh3.[8]

References

  1. ISBN 9780470132531
    .
  2. doi:10.1021/om800570r
    .
  3. doi:10.1007/BF00747909
  4. ISBN 978-0-7514-0413-5
  5. doi:10.1139/CJC-51-24-4145
    .
  6. doi:10.1021/ic00277a022
    .
  7. PMID 17245785
    ..
  8. doi:10.1021/cr60307a002
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