Synthesis and X-ray crystal structure of novel tetramethylphosphonium dichlorodimethylaluminate

Abstract

The reaction of tris(trimethylsilyl)phosphine with dimethylaluminum chloride in 1,2-dimethoxyethane (monoglyme) displays an important role as building blocks that results in the production of novel tetramethyl phosphonium dichlorodimethylaluminate and the already known dimer compound (bis(2,2-methoxy-ethanolato-O,O′)-tetramethyl-di-aluminum). The newly formed tetramethyl phosphonium dichlorodimethylaluminate [(CH₃)₄P]⁺[(CH₃)₂AlCl₂]⁻ crystallizes in the monoclinic space group P2₁/c, having unit cell with lattice constants a = 7.522, b = 11.644, c = 14.841 Å, and β = 99.32° includes four formula units. The mean values of the bond lengths are P-C 1.787 Å, Al-Cl 2.224 Å, and Al-C 1.966 Å. Both phosphorus and aluminum are tetrahedrally surrounded in organophosphonium-based cations and organoaluminium-based anions. The geometry of the dichlorodimethylaluminate anion shows a distorted tetrahedron.

KEYWORDS:

• Phosphine
• phosphonium
• aluminate
• monoglyme
• crystal structure

Ethical statement

All ethical guidelines have adhered.

Conflict of interest

The author declares that he has no conflict of interest.

Additional information

Funding

The author extends his appreciation to the Deanship of Scientific Research at King Khalid University, Abha, Saudi Arabia for funding this work through the General Research Project under grant number G.R.P-87-40.