N,N-Bis(diphenyl­phosphino)ethyl­amine

In the title compound, C₂₆H₂₅NP₂, the diphenyl­phosphino groups are staggered relative to the PNP backbone, even though the ethyl substituent coordinated to the N atom is not sterically bulky. The N atom adapts an almost planar geometry with two P atoms and a C atom of the allyl group attached to it in order to accommodate the steric bulk of the phenyl groups and the alkyl group. The distortion of the trigonal-pyramidal geometry of the nitro­gen is further illustrated by the bond angles which range between 114.0 (1) and 123.7 (1)°. There are no classical inter­molecular inter­actions.

Key indicators

• Single-crystal X-ray study
• T = 101 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.038
• wR factor = 0.094
• Data-to-parameter ratio = 20.6

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT153_ALERT_1_C The su's on the Cell Axes   are Equal (x 100000)        500 Ang.
PLAT912_ALERT_4_C Missing # of FCF Reflections Above STh/L=  0.600          6

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   2 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

The crystal structure of the title compound, (I), is presented in Figure 1. All bond distances and angles in (I) are normal and fall within the range reported for similar complexes (Keat et al., 1981; Cotton et al., 1996; Fei et al., 2003; Cloete et al., 2008)]. The distance of N1 from the P1—P2—C1 plane is 0.023 (1) Å. The geometry around the phosphorous ligands are distorted from tetrahedral geometry with C—P—C angles being the most distorted (varying from 100.36 (7) to 105.6 (1)°). The P1—N1—P2 angle (123.6 (1)°) is slightly larger than that of other similar compounds quoted above which ranges between 113.3 (2) and 122.8 (3)°. There are no classical intermolecular interactions.

Two conformers are generally found for diphosphineamines and are described (Keat et al., 1981) as C_2v and C_s. In C_2v conformer, the phosphorous lone pairs are cis with respect to the N—C bond while in the C_s conformer the two lone pairs are trans relative to the N—C bond. It has been postulated (Keat et al., 1981) that the C_s conformer is usually observed for diphoshineamines with relatively bulky substituents on the nitrogen atom. The title compound (I), however has a C_s conformer in solid state even though the ethyl group is not particularly bulky.

Related literature

For similar diphosphineamine non-coordinated ligands with the P—N—P angle ranging between 113.3 (2) and 122.8 (3)°, see: Keat et al. (1981); Cotton et al. (1996); Fei et al. (2003); Cloete et al. (2008).

S2. Experimental

Ethylpropylamine (0.010 mol, 0.45 g) was dissolved in dichloromethane (30 ml) and placed on an ice bath and triethylamine (0.030 mol, 4.22 ml) was added to the solution while being stirred. Chlorodiphenylphosphine (0.020 mol, 3.62 ml) was slowly added to the reaction mixture. The ice bath was removed after 30 minutes 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. The product was recrystallized from methanol. Single colourless crystals were obtained (yield 2.439 g, 59.0%) the next day which were suitable for X-ray crystallography.

S3. Refinement

The methylene, methyl and aryl H atoms were placed in geometrically idealized positions with distances C—H = 0.99 0.98 and 0.95 Å, respectively and constrained to ride on their parent atoms, with U_iso(H) = 1.5U_eq(C-methyl) and 1.2U_eq(C-non-methyl).

Computing details

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT-Plus (Bruker, 2004); data reduction: SAINT-Plus and XPREP (Bruker, 2004); program(s) used to solve structure: SHELXL97 (Sheldrick, 2008); program(s) used to refine structure: SIR97 (Altomare et al., 1999); molecular graphics: DIAMOND (Brandenburg & Putz, 2005); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures

	Fig. 1. View of (I) (50% probability displacement ellipsoids). H-atoms were omitted for clarity.
	Fig. 2. Perspective view of the unit cell of (I) along the a axis.

N,N-Bis(diphenylphosphino)ethylamine

Crystal data

C26H25NP2	F(000) = 872
Mr = 413.44	Dx = 1.263 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71069 Å
Hall symbol: -P 2ybc	Cell parameters from 5486 reflections
a = 9.570 (5) Å	θ = 2.6–27.9°
b = 13.441 (5) Å	µ = 0.21 mm^−1
c = 16.907 (5) Å	T = 101 K
β = 91.647 (5)°	Needle, colourless
V = 2173.9 (15) Å^3	0.39 × 0.13 × 0.11 mm
Z = 4

Data collection

Bruker X8 APEXII 4K Kappa CCD diffractometer	4293 reflections with I > 2σ(I)
ω and ϕ scans	Rint = 0.046
Absorption correction: multi-scan (SADABS; Bruker, 2004)	θmax = 28.3°, θmin = 1.9°
Tmin = 0.964, Tmax = 0.975	h = −12→12
25117 measured reflections	k = −17→17
5401 independent reflections	l = −22→22

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.038	w = 1/[σ^2(Fo^2) + (0.0363P)^2 + 0.8849P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.094	(Δ/σ)max < 0.001
S = 1.06	Δρmax = 0.43 e Å^−3
5401 reflections	Δρmin = −0.26 e Å^−3
262 parameters

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
N1	0.35096 (13)	0.21232 (9)	0.71479 (7)	0.0155 (3)
P1	0.41307 (4)	0.09328 (3)	0.72417 (2)	0.01616 (10)
P2	0.29406 (4)	0.26318 (3)	0.62672 (2)	0.01542 (10)
C1	0.34840 (16)	0.28240 (11)	0.78268 (8)	0.0177 (3)
H1A	0.3953	0.3451	0.7678	0.021*
H1B	0.402	0.2532	0.8279	0.021*
C2	0.20138 (17)	0.30599 (14)	0.80843 (9)	0.0250 (4)
H2A	0.2059	0.3523	0.8532	0.037*
H2B	0.1551	0.2445	0.8245	0.037*
H2C	0.1483	0.3364	0.7643	0.037*
C11	0.32088 (16)	0.04094 (11)	0.80923 (9)	0.0174 (3)
C12	0.22044 (17)	−0.03189 (12)	0.79329 (9)	0.0201 (3)
H12	0.2041	−0.0532	0.7403	0.024*
C13	0.14338 (17)	−0.07416 (12)	0.85343 (10)	0.0230 (3)
H13A	0.0756	−0.1239	0.8413	0.028*
C14	0.16600 (17)	−0.04328 (12)	0.93092 (9)	0.0234 (4)
H14	0.1126	−0.0708	0.972	0.028*
C15	0.26699 (17)	0.02804 (12)	0.94820 (9)	0.0231 (4)
H15	0.2832	0.0488	1.0014	0.028*
C16	0.34485 (17)	0.06956 (12)	0.88827 (9)	0.0206 (3)
H16	0.4147	0.1176	0.901	0.025*
C21	0.58795 (16)	0.11232 (11)	0.76925 (8)	0.0169 (3)
C22	0.65088 (16)	0.03565 (12)	0.81394 (9)	0.0193 (3)
H22	0.5985	−0.0224	0.8252	0.023*
C23	0.78758 (16)	0.04296 (12)	0.84186 (9)	0.0203 (3)
H23	0.8288	−0.0104	0.8711	0.024*
C24	0.86469 (17)	0.12790 (13)	0.82738 (9)	0.0215 (3)
H24	0.958	0.1337	0.8475	0.026*
C25	0.80438 (17)	0.20455 (12)	0.78320 (9)	0.0220 (3)
H25	0.8568	0.263	0.7732	0.026*
C26	0.66815 (16)	0.19654 (12)	0.75358 (9)	0.0196 (3)
H26	0.629	0.2488	0.7223	0.024*
C31	0.13695 (15)	0.19368 (11)	0.59763 (8)	0.0167 (3)
C32	0.07951 (17)	0.20898 (13)	0.52136 (9)	0.0222 (3)
H32	0.1242	0.2531	0.4862	0.027*
C33	−0.04139 (18)	0.16056 (14)	0.49693 (10)	0.0279 (4)
H33	−0.078	0.1704	0.4447	0.034*
C34	−0.10978 (18)	0.09766 (13)	0.54801 (10)	0.0277 (4)
H34	−0.1927	0.0642	0.5309	0.033*
C35	−0.05620 (17)	0.08398 (13)	0.62401 (10)	0.0248 (4)
H35	−0.1032	0.0417	0.6595	0.03*
C36	0.06593 (16)	0.13174 (12)	0.64867 (9)	0.0196 (3)
H36	0.1015	0.122	0.7011	0.024*
C41	0.41629 (16)	0.21875 (11)	0.55304 (8)	0.0161 (3)
C42	0.52940 (16)	0.28007 (12)	0.53709 (9)	0.0205 (3)
H42	0.5438	0.3394	0.5668	0.025*
C43	0.62142 (17)	0.25524 (13)	0.47801 (10)	0.0247 (4)
H43	0.6984	0.2974	0.4676	0.03*
C44	0.60062 (17)	0.16908 (13)	0.43447 (9)	0.0234 (4)
H44	0.6631	0.1524	0.3939	0.028*
C45	0.48928 (17)	0.10702 (12)	0.44978 (9)	0.0201 (3)
H45	0.4755	0.0477	0.42	0.024*
C46	0.39761 (16)	0.13181 (12)	0.50904 (9)	0.0184 (3)
H46	0.3214	0.089	0.5196	0.022*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0194 (6)	0.0161 (6)	0.0110 (6)	0.0014 (5)	−0.0010 (5)	−0.0018 (5)
P1	0.0210 (2)	0.01536 (19)	0.01218 (18)	−0.00001 (16)	0.00139 (15)	−0.00045 (14)
P2	0.0176 (2)	0.0164 (2)	0.01224 (18)	0.00027 (15)	0.00057 (15)	−0.00007 (14)
C1	0.0223 (8)	0.0177 (7)	0.0130 (7)	0.0001 (6)	−0.0008 (6)	−0.0030 (6)
C2	0.0246 (9)	0.0316 (9)	0.0187 (8)	0.0050 (7)	0.0009 (7)	−0.0062 (7)
C11	0.0200 (8)	0.0170 (7)	0.0152 (7)	0.0025 (6)	0.0012 (6)	0.0014 (6)
C12	0.0239 (8)	0.0180 (8)	0.0185 (7)	0.0004 (6)	−0.0001 (6)	−0.0010 (6)
C13	0.0209 (8)	0.0202 (8)	0.0280 (8)	−0.0029 (7)	0.0021 (7)	0.0012 (7)
C14	0.0227 (8)	0.0242 (8)	0.0238 (8)	0.0040 (7)	0.0080 (7)	0.0053 (7)
C15	0.0288 (9)	0.0249 (9)	0.0159 (7)	0.0021 (7)	0.0045 (7)	0.0009 (6)
C16	0.0245 (8)	0.0207 (8)	0.0165 (7)	−0.0019 (7)	0.0004 (6)	0.0002 (6)
C21	0.0197 (8)	0.0190 (7)	0.0122 (7)	0.0023 (6)	0.0042 (6)	−0.0009 (6)
C22	0.0236 (8)	0.0170 (8)	0.0176 (7)	0.0008 (6)	0.0046 (6)	0.0004 (6)
C23	0.0226 (8)	0.0223 (8)	0.0161 (7)	0.0062 (7)	0.0047 (6)	0.0030 (6)
C24	0.0166 (8)	0.0264 (8)	0.0217 (8)	0.0028 (7)	0.0031 (6)	0.0004 (7)
C25	0.0203 (8)	0.0205 (8)	0.0254 (8)	−0.0004 (6)	0.0068 (7)	0.0029 (7)
C26	0.0211 (8)	0.0198 (8)	0.0183 (7)	0.0037 (6)	0.0050 (6)	0.0035 (6)
C31	0.0162 (7)	0.0191 (7)	0.0148 (7)	0.0029 (6)	0.0003 (6)	−0.0018 (6)
C32	0.0198 (8)	0.0309 (9)	0.0159 (7)	0.0022 (7)	0.0006 (6)	0.0031 (6)
C33	0.0218 (9)	0.0420 (11)	0.0197 (8)	0.0015 (8)	−0.0055 (7)	−0.0016 (7)
C34	0.0195 (8)	0.0311 (10)	0.0323 (9)	−0.0035 (7)	−0.0039 (7)	−0.0043 (8)
C35	0.0221 (8)	0.0249 (9)	0.0274 (9)	−0.0031 (7)	0.0025 (7)	0.0013 (7)
C36	0.0184 (8)	0.0235 (8)	0.0169 (7)	0.0018 (6)	−0.0005 (6)	−0.0004 (6)
C41	0.0173 (7)	0.0195 (7)	0.0114 (6)	0.0021 (6)	−0.0006 (6)	0.0024 (6)
C42	0.0191 (8)	0.0228 (8)	0.0193 (7)	−0.0019 (6)	−0.0012 (6)	0.0011 (6)
C43	0.0180 (8)	0.0301 (9)	0.0262 (8)	−0.0014 (7)	0.0049 (7)	0.0053 (7)
C44	0.0198 (8)	0.0344 (10)	0.0159 (7)	0.0093 (7)	0.0031 (6)	0.0063 (7)
C45	0.0236 (8)	0.0235 (8)	0.0132 (7)	0.0073 (7)	−0.0007 (6)	−0.0007 (6)
C46	0.0186 (8)	0.0203 (8)	0.0164 (7)	−0.0002 (6)	0.0012 (6)	0.0017 (6)

Geometric parameters (Å, º)

N1—C1	1.4856 (18)	C23—H23	0.95
N1—P1	1.7127 (14)	C24—C25	1.388 (2)
N1—P2	1.7130 (13)	C24—H24	0.95
P1—C21	1.8369 (18)	C25—C26	1.387 (2)
P1—C11	1.8478 (15)	C25—H25	0.95
P2—C31	1.8255 (17)	C26—H26	0.95
P2—C41	1.8331 (16)	C31—C36	1.391 (2)
C1—C2	1.518 (2)	C31—C32	1.402 (2)
C1—H1A	0.99	C32—C33	1.380 (2)
C1—H1B	0.99	C32—H32	0.95
C2—H2A	0.98	C33—C34	1.386 (2)
C2—H2B	0.98	C33—H33	0.95
C2—H2C	0.98	C34—C35	1.382 (2)
C11—C12	1.393 (2)	C34—H34	0.95
C11—C16	1.403 (2)	C35—C36	1.387 (2)
C12—C13	1.394 (2)	C35—H35	0.95
C12—H12	0.95	C36—H36	0.95
C13—C14	1.385 (2)	C41—C42	1.393 (2)
C13—H13A	0.95	C41—C46	1.394 (2)
C14—C15	1.386 (2)	C42—C43	1.391 (2)
C14—H14	0.95	C42—H42	0.95
C15—C16	1.392 (2)	C43—C44	1.384 (2)
C15—H15	0.95	C43—H43	0.95
C16—H16	0.95	C44—C45	1.383 (2)
C21—C26	1.397 (2)	C44—H44	0.95
C21—C22	1.403 (2)	C45—C46	1.391 (2)
C22—C23	1.382 (2)	C45—H45	0.95
C22—H22	0.95	C46—H46	0.95
C23—C24	1.385 (2)
C1—N1—P1	122.29 (10)	C24—C23—H23	119.9
C1—N1—P2	114.00 (10)	C23—C24—C25	119.44 (16)
P1—N1—P2	123.65 (7)	C23—C24—H24	120.3
N1—P1—C21	102.58 (7)	C25—C24—H24	120.3
N1—P1—C11	104.81 (7)	C26—C25—C24	120.55 (15)
C21—P1—C11	100.36 (7)	C26—C25—H25	119.7
N1—P2—C31	105.59 (7)	C24—C25—H25	119.7
N1—P2—C41	105.52 (7)	C25—C26—C21	120.67 (15)
C31—P2—C41	100.78 (7)	C25—C26—H26	119.7
N1—C1—C2	112.95 (13)	C21—C26—H26	119.7
N1—C1—H1A	109	C36—C31—C32	118.21 (15)
C2—C1—H1A	109	C36—C31—P2	123.55 (12)
N1—C1—H1B	109	C32—C31—P2	118.08 (12)
C2—C1—H1B	109	C33—C32—C31	120.61 (15)
H1A—C1—H1B	107.8	C33—C32—H32	119.7
C1—C2—H2A	109.5	C31—C32—H32	119.7
C1—C2—H2B	109.5	C32—C33—C34	120.51 (16)
H2A—C2—H2B	109.5	C32—C33—H33	119.7
C1—C2—H2C	109.5	C34—C33—H33	119.7
H2A—C2—H2C	109.5	C35—C34—C33	119.42 (16)
H2B—C2—H2C	109.5	C35—C34—H34	120.3
C12—C11—C16	118.04 (14)	C33—C34—H34	120.3
C12—C11—P1	117.34 (11)	C34—C35—C36	120.32 (15)
C16—C11—P1	124.63 (12)	C34—C35—H35	119.8
C11—C12—C13	121.46 (14)	C36—C35—H35	119.8
C11—C12—H12	119.3	C35—C36—C31	120.88 (15)
C13—C12—H12	119.3	C35—C36—H36	119.6
C14—C13—C12	119.74 (15)	C31—C36—H36	119.6
C14—C13—H13A	120.1	C42—C41—C46	118.76 (14)
C12—C13—H13A	120.1	C42—C41—P2	116.96 (12)
C13—C14—C15	119.70 (14)	C46—C41—P2	124.14 (12)
C13—C14—H14	120.2	C43—C42—C41	120.57 (15)
C15—C14—H14	120.2	C43—C42—H42	119.7
C14—C15—C16	120.56 (15)	C41—C42—H42	119.7
C14—C15—H15	119.7	C44—C43—C42	119.90 (15)
C16—C15—H15	119.7	C44—C43—H43	120.1
C15—C16—C11	120.48 (15)	C42—C43—H43	120.1
C15—C16—H16	119.8	C45—C44—C43	120.33 (14)
C11—C16—H16	119.8	C45—C44—H44	119.8
C26—C21—C22	117.87 (15)	C43—C44—H44	119.8
C26—C21—P1	122.22 (12)	C44—C45—C46	119.69 (15)
C22—C21—P1	119.53 (12)	C44—C45—H45	120.2
C23—C22—C21	121.29 (15)	C46—C45—H45	120.2
C23—C22—H22	119.4	C45—C46—C41	120.75 (14)
C21—C22—H22	119.4	C45—C46—H46	119.6
C22—C23—C24	120.15 (15)	C41—C46—H46	119.6
C22—C23—H23	119.9
C1—N1—P1—C21	−53.54 (12)	C22—C23—C24—C25	−1.4 (2)
P2—N1—P1—C21	123.41 (9)	C23—C24—C25—C26	−0.1 (2)
C1—N1—P1—C11	50.91 (13)	C24—C25—C26—C21	1.6 (2)
P2—N1—P1—C11	−132.13 (9)	C22—C21—C26—C25	−1.6 (2)
C1—N1—P2—C31	−116.42 (11)	P1—C21—C26—C25	−174.42 (11)
P1—N1—P2—C31	66.40 (10)	N1—P2—C31—C36	14.23 (15)
C1—N1—P2—C41	137.38 (10)	C41—P2—C31—C36	123.86 (13)
P1—N1—P2—C41	−39.80 (11)	N1—P2—C31—C32	−170.32 (12)
P1—N1—C1—C2	−111.26 (14)	C41—P2—C31—C32	−60.70 (13)
P2—N1—C1—C2	71.52 (15)	C36—C31—C32—C33	−2.5 (2)
N1—P1—C11—C12	109.42 (13)	P2—C31—C32—C33	−178.19 (13)
C21—P1—C11—C12	−144.47 (12)	C31—C32—C33—C34	1.4 (3)
N1—P1—C11—C16	−70.44 (15)	C32—C33—C34—C35	0.3 (3)
C21—P1—C11—C16	35.67 (15)	C33—C34—C35—C36	−0.8 (3)
C16—C11—C12—C13	1.3 (2)	C34—C35—C36—C31	−0.3 (2)
P1—C11—C12—C13	−178.59 (12)	C32—C31—C36—C35	1.9 (2)
C11—C12—C13—C14	0.3 (2)	P2—C31—C36—C35	177.36 (12)
C12—C13—C14—C15	−1.2 (2)	N1—P2—C41—C42	−93.59 (13)
C13—C14—C15—C16	0.6 (2)	C31—P2—C41—C42	156.74 (12)
C14—C15—C16—C11	1.0 (2)	N1—P2—C41—C46	90.85 (14)
C12—C11—C16—C15	−1.9 (2)	C31—P2—C41—C46	−18.82 (14)
P1—C11—C16—C15	177.98 (12)	C46—C41—C42—C43	0.4 (2)
N1—P1—C21—C26	−32.09 (13)	P2—C41—C42—C43	−175.41 (12)
C11—P1—C21—C26	−139.97 (12)	C41—C42—C43—C44	0.1 (2)
N1—P1—C21—C22	155.21 (11)	C42—C43—C44—C45	−0.5 (2)
C11—P1—C21—C22	47.33 (13)	C43—C44—C45—C46	0.3 (2)
C26—C21—C22—C23	0.2 (2)	C44—C45—C46—C41	0.3 (2)
P1—C21—C22—C23	173.18 (11)	C42—C41—C46—C45	−0.6 (2)
C21—C22—C23—C24	1.3 (2)	P2—C41—C46—C45	174.89 (12)