N,N-Bis(diphenyl­phosphan­yl)cyclo­butanamine

Ilana Engelbrecht; Hendrik G Visser; Andreas Roodt

doi:10.1107/S1600536811027656

. 2011 Jul 16;67(Pt 8):o2041–o2042. doi: 10.1107/S1600536811027656

N,N-Bis(diphenylphosphanyl)cyclobutanamine

Ilana Engelbrecht ^a,^*, Hendrik G Visser ^a, Andreas Roodt ^a

PMCID: PMC3213490 PMID: 22091069

Abstract

In the title compound, C₂₈H₂₇NP₂, the N atom adopts an almost planar geometry with the two P atoms and the C atom attached to it, with a distance of 0.066 (2) Å between the N atom and the C/P/P plane. The distorted trigonal–pyramidal geometry of the N atom is further illustrated by bond angles ranging between 115.22 (11) and 123.53 (8)°. Bond angles varying from 99.99 (9) to 108.07 (9) ° are indicative of the distorted pyramidal environment around the P atoms. An intramolecular C—H⋯P hydrogen bond occurs. In the crystal, intermolecular C—H⋯π interactions link the molecules into a supramolecular network.

Related literature

For similar structures, see: Keat et al. (1981 ▶); Cotton et al. (1996 ▶); Fei et al. (2003 ▶); Cloete et al. (2008 ▶, 2009 ▶, 2010 ▶); Engelbrecht et al. (2010a ▶,b ▶). For diphosphinoamine (PNP) and other P-donor ligands, see: Muller et al. (2008 ▶); Purcell et al. (1995 ▶); Otto & Roodt (2001 ▶); Otto et al. (2005 ▶). For their use in catalytic olefin transformation reactions, see: Haumann et al. (2004 ▶); Crous et al. (2005 ▶); Booyens et al. (2007 ▶); Cloete et al. (2011 ▶); Ferreira et al. (2007 ▶).

Experimental

Crystal data

C₂₈H₂₇NP₂
M _r = 439.45
Monoclinic,
a = 9.414 (5) Å
b = 9.664 (5) Å
c = 12.644 (4) Å
β = 94.245 (5)°
V = 1147.2 (10) Å³
Z = 2
Mo Kα radiation
μ = 0.21 mm⁻¹
T = 100 K
0.32 × 0.12 × 0.04 mm

Data collection

Bruker X8 APEXII 4K KappaCCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2004 ▶) T _min = 0.937, T _max = 0.992
20748 measured reflections
3035 independent reflections
2930 reflections with I > 2σ(I)
R _int = 0.027

Refinement

R[F ² > 2σ(F ²)] = 0.024
wR(F ²) = 0.064
S = 1.04
3035 reflections
281 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.25 e Å⁻³
Δρ_min = −0.18 e Å⁻³

Data collection: APEX2 (Bruker, 2010 ▶); cell refinement: SAINT-Plus (Bruker, 2004 ▶); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Brandenburg & Putz, 2005 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811027656/go2019sup1.cif

e-67-o2041-sup1.cif^{(22.6KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811027656/go2019Isup2.hkl

e-67-o2041-Isup2.hkl^{(145.9KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

Cg1 and Cg2 are the centroids of the C11–C16 and C21–C26 rings, respectively.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C32—H32⋯P1	0.95	2.8	3.452 (2)	127
C43—H43⋯Cg1ⁱ	0.95	2.87	3.686 (7)	144
C44—H44⋯Cg2ⁱⁱ	0.95	2.81	3.614 (6)	143

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

Financial assistance from the Department of Science and Technology (DST) of South Africa, the South African National Research Foundation (NRF), the DST–NRF centre of excellence (c*change), the University of the Free State and the INKABA funding project are gratefully acknowledged.

supplementary crystallographic information

Comment

Diphosphinoamine (PNP) and other P donor ligands (Muller et al., 2008; Purcell et al., 1995; Otto et al., 2005; Otto & Roodt, 2001) with various substituents on both the P and N atoms form part of ongoing research in different catalytic olefin transformation reactions such as hydroformylation (Haumann et al., 2004; Crous et al., 2005), metathesis (Booyens et al.) methoxycarbonylation (Ferreira et al., 2007) and tetramerization (Cloete et al., 2011). In the title compound, C₂₉H₂₉NP₂, Fig.1, all bond distances and angles fall within the range for similar complexes (Keat et al., 1981; Cotton et al., 1996; Fei et al., 2003; Cloete et al., 2008, 2009, 2010; Engelbrecht et al., 2010a, 2010b).

The N(P₂C) group is almost planar, with the central N displaced by -0.066 (2) Å from the P1—P2—C1 plane. The distorted trigonal-pyramidal geometry around the N atom is evident by the bond angles ranging between 115.22 (11) and 123.53 (8) °. The distorted triangular pyramidal geometry around the phosphorous atoms is indicated by C—P—C angles varying from 99.99 (9) - 108.07 (9) ° and N—P—C angles from 102.24 (8) - 108.07 (9) °. The phosphorous lone pairs are trans with respect to the N—C bond, therefore the title compound has a C_s conformer in the solid state. The crystal packing is stabilized by a C—H···P intramolecular hydrogen bond (Table 1) and intermolecular C—H···π interactions resulting in a three-dimensional network (Table 1, Figure 2).

Experimental

Cyclobutylamine (0.010 mol, 854 µl) was dissolved in dichloromethane (30 ml) after which the solution was placed on an ice bath. Triethylamine (0.030 mol, 4.21 ml) was added to the solution while stirring. Chlorodiphenylphosphine (0.020 mol, 3.70 ml) was slowly added to the reaction mixture. The ice bath was removed after 1 h and the reaction mixture was allowed to stir at room temperature for a further 12 h. The dichloromethane was removed under reduced pressure. A mixture of hexane (20 ml) and toluene (2 ml) was added to the remaining white powder and was passed through a column containing neutral activated alumina (35 g). The solvent of the eluent was removed under reduced pressure and the white precipitate was collected. Single colourless crystals suitable for X-ray crystallography were obtained from recrystallization from methanol. (yield: 2.100 g, 48%)