Crystal structure of 2-chloro-1,3-bis (2,6-diisopropylphenyl) -1,3,2-diazaphospholidine 2-oxide

Abstract

<p><span>The title compound, C₂₆H₃₈ClN₂OP, was synthesized by reacting phosphoryl chloride with <em>N</em>,<em>N</em>&prime;-bis(2,6-diisopropylphenyl)ethane-1,2-diamine in the presence of <em>N</em>-methylmorpholine which acted as an auxilliary base to quench the HCl released as a by-product. The resultant <em>N</em>-heterocyclic phosphine five-membered ring adopts a half-chair conformation and features a tetracoordinate P atom ligated by the chelating diamine [P&mdash;N = 1.6348 (14) and 1.6192 (14) &Aring;], one double-bonded O atom [P1&mdash;O1 = 1.4652 (12) &Aring;] and one Cl atom [P1&mdash;Cl1 = 2.0592 (7) &Aring;]. The sterically hindered 2,6-diisopropylphenyl (Dipp) groups twist away from the central heterocycle, with torsion angles of &minus;75.66 (19) and 83.39 (19)&deg; for the P&mdash;N&mdash;C_ar&mdash;C_ar links. A number of intramolecular C&mdash;H...N, C&mdash;H...O and C&mdash;H...Cl close contacts occur. In the crystal, molecules are linked by C&mdash;H...O hydrogen bonds to generate [010] chains. C&mdash;H...&pi; interactions are also observed</span></p>