N-Benzyl­idene-o-(diphenyl­phosphino)­aniline

The title compound, C₂₅H₂₀NP, is a Schiff base containing triphenyl­phosphine. The mol­ecule has a trans configuration about the C=N double bond [1.266 (3) Å]. Inter­molecular π–π inter­actions (~3.61 Å) are pronounced in the crystal structure.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.047
• wR factor = 0.163
• Data-to-parameter ratio = 18.1

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S1. Comment

Schiff base ligands have various applications in the fields of synthesis and catalysis, and exhibit biological activity (Wang et al., 2005; Speiser et al., 2004). At the same time P, N ligands have attracted increasing recent attention because of their bonding versatility with a metal center and the relative ease with which the electronic and steric properties of the donor atoms can be modified (Braunstein et al., 2001; Slone et al., 1999; Helmchen et al., 2000), but few Schiff bases containing phosphorus and nitrogen have been reported (Yang et al., 2006). A Schiff base containing P, N may be expected to be a useful bidentate ligand with new properties, because triphenylphosphine is a well known ligand for coordination compounds. Here we present the title compound (I), a useful Schiff base ligand containing phosphine-imine.

In compound (I), the bond lengths of P1—C1, P1—C13, P1—C1, N1—C25 and N1—C2 are 1.830 (2), 1.831 (2), 1.830 (2), 1.266 (3) and 1.409 (3) Å, respectively. The aromatic ring 1 (C1—C6) is tilted with rings 2 (C7—C12), 3 (C13—C18) and 4 (C19—C24). The dihedral angle of ring 2 and ring 3 is 81.65 (10)°, the dihedral angles of ring 1 with rings 2, 3, 4 are 74.50 (8), 77.73 (7), and 26.61 (15)°, respectively (Fig. 1). The π-π stacking interactions support the crystal packing with distances of about 3.61 Å (Fig. 2).

Related literature

For related literature, see: Braunstein & Naud (2001); Helmchen & Pfaltz (2000); Li et al. (2005); Papathanasiou et al. (1997); Reddy et al. (2001); Slone et al. (1999); Speiser & Braunstein (2004); Wang & Jin (2005); Yang et al. (2006).

S2. Experimental

All reagents were of AR grade available commercially and used without further purification. The complex of ο-(diphenylphosphino)-N-benzaldimine was prepared by simple condensation of ο-(diphenylphosphino)-aniline (Reddy et al., 2001} with excess benzaldehyde. ο-(Diphenylphosphino)benzenamine was prepared according to the literature (Papathanasiou et al., 1997). To freshly distilled benzaldehyde (16 ml, 0.15 mol) was added ο-(diphenylphosphino)-aniline (6 g, 0.02 mol) under nitrogen, and the mixture was stirred at room temperature under nitrogen for 6–7 h. The reaction mixture was poured into cold methanol and kept at low temperature overnight. The desired ligand P, N was crystallized as a white solid. Crystals suitable for X-ray diffraction analysis were obtained by slow evaporation of ethanol solution.

S3. Refinement

H atoms were located geometrically and refined using a riding model with C—H = 0.93 Å, and U_iso(H) = 1.2 U_eq(C).

Computing details

Data collection: TEXSAN (Molecular Structure Corporation, 1998); cell refinement: TEXSAN (Molecular Structure Corporation, 1998); data reduction: TEXSAN (Molecular Structure Corporation, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXL97 (Sheldrick, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997).

Figures

	Fig. 1. View of the molecule of (I) showing the atom-labelling scheme. The molecule has a trans configuration about the C25═N1 double bond. All H atoms were omitted for clarity.
	Fig. 2. Packing diagram of (I) showing the π-π stacking along the b axis.

N-Benzylidene-o-(diphenylphosphino)aniline

Crystal data

C25H20NP	F(000) = 772
Mr = 366.40	Dx = 1.216 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 4416 reflections
a = 15.076 (3) Å	θ = 3.2–27.5°
b = 6.6127 (13) Å	µ = 0.15 mm^−1
c = 20.297 (4) Å	T = 293 K
β = 98.46 (3)°	Prism, colourless
V = 2001.5 (7) Å^3	0.18 × 0.12 × 0.11 mm
Z = 4

Data collection

Rigaku Weissenberg IP diffractometer	4416 independent reflections
Radiation source: fine-focus sealed tube	2664 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.054
scintillation counter scans	θmax = 27.5°, θmin = 3.2°
Absorption correction: ψ scan (North et al., 1968)	h = −19→19
Tmin = 0.979, Tmax = 0.984	k = −8→7
17296 measured reflections	l = −26→26

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.047	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.163	H-atom parameters constrained
S = 1.02	w = 1/[σ^2(Fo^2) + (0.0897P)^2] where P = (Fo^2 + 2Fc^2)/3
4416 reflections	(Δ/σ)max = 0.015
244 parameters	Δρmax = 0.21 e Å^−3
0 restraints	Δρmin = −0.21 e Å^−3

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.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

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

	x	y	z	Uiso*/Ueq
P1	0.20484 (4)	0.75168 (8)	0.17396 (3)	0.04508 (19)
N1	0.18326 (12)	1.0677 (3)	0.27147 (9)	0.0464 (4)
C2	0.10879 (14)	1.0673 (3)	0.22061 (11)	0.0426 (5)
C1	0.11152 (13)	0.9309 (3)	0.16779 (11)	0.0415 (5)
C7	0.30187 (14)	0.9120 (3)	0.16743 (11)	0.0474 (5)
C6	0.03873 (15)	0.9284 (3)	0.11698 (12)	0.0495 (5)
H6A	0.0399	0.8428	0.0808	0.059*
C13	0.18483 (14)	0.6353 (3)	0.09123 (11)	0.0460 (5)
C3	0.03371 (15)	1.1869 (3)	0.22255 (12)	0.0518 (6)
H3A	0.0318	1.2740	0.2583	0.062*
C14	0.12690 (16)	0.4726 (3)	0.08273 (13)	0.0556 (6)
H14A	0.1007	0.4263	0.1186	0.067*
C4	−0.03791 (15)	1.1780 (4)	0.17219 (13)	0.0563 (6)
H4A	−0.0882	1.2583	0.1739	0.068*
C8	0.29742 (16)	1.1050 (4)	0.14107 (14)	0.0614 (7)
H8A	0.2418	1.1607	0.1250	0.074*
C5	−0.03491 (15)	1.0496 (4)	0.11909 (13)	0.0555 (6)
H5A	−0.0828	1.0449	0.0846	0.067*
C15	0.10727 (18)	0.3773 (4)	0.02167 (14)	0.0637 (7)
H15A	0.0674	0.2691	0.0168	0.076*
C25	0.21333 (15)	1.2371 (3)	0.29366 (12)	0.0506 (5)
H25A	0.1866	1.3548	0.2752	0.061*
C19	0.28912 (15)	1.2531 (4)	0.34766 (12)	0.0541 (6)
C16	0.1455 (2)	0.4401 (4)	−0.03098 (15)	0.0702 (7)
H16A	0.1326	0.3742	−0.0718	0.084*
C12	0.38576 (16)	0.8340 (4)	0.19137 (14)	0.0639 (7)
H12A	0.3907	0.7053	0.2100	0.077*
C18	0.22344 (18)	0.6974 (4)	0.03667 (14)	0.0635 (7)
H18A	0.2634	0.8055	0.0410	0.076*
C17	0.2034 (2)	0.6011 (4)	−0.02407 (15)	0.0754 (8)
H17A	0.2292	0.6455	−0.0604	0.090*
C20	0.34628 (19)	1.0935 (4)	0.36478 (15)	0.0711 (8)
H20A	0.3392	0.9737	0.3406	0.085*
C9	0.3737 (2)	1.2162 (4)	0.13814 (16)	0.0745 (8)
H9A	0.3695	1.3458	0.1202	0.089*
C10	0.45611 (19)	1.1356 (5)	0.16167 (17)	0.0805 (9)
H10A	0.5078	1.2108	0.1598	0.097*
C24	0.30210 (18)	1.4321 (5)	0.38267 (17)	0.0818 (9)
H24A	0.2654	1.5426	0.3700	0.098*
C23	0.3692 (2)	1.4476 (6)	0.4362 (2)	0.1007 (12)
H23A	0.3772	1.5679	0.4601	0.121*
C11	0.46217 (18)	0.9470 (6)	0.18761 (18)	0.0820 (9)
H11A	0.5182	0.8925	0.2031	0.098*
C21	0.4143 (2)	1.1115 (6)	0.41809 (18)	0.0941 (11)
H21A	0.4537	1.0046	0.4295	0.113*
C22	0.4237 (3)	1.2881 (7)	0.45426 (18)	0.1019 (12)
H22A	0.4677	1.2981	0.4914	0.122*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
P1	0.0462 (3)	0.0455 (3)	0.0424 (3)	0.0021 (2)	0.0029 (2)	0.0013 (2)
N1	0.0466 (10)	0.0520 (10)	0.0405 (11)	−0.0043 (8)	0.0061 (8)	−0.0059 (8)
C2	0.0417 (10)	0.0456 (11)	0.0410 (12)	−0.0054 (9)	0.0078 (9)	−0.0008 (9)
C1	0.0407 (10)	0.0444 (11)	0.0398 (12)	−0.0050 (9)	0.0072 (9)	0.0006 (9)
C7	0.0437 (11)	0.0524 (12)	0.0447 (13)	0.0046 (10)	0.0024 (10)	−0.0068 (9)
C6	0.0490 (12)	0.0534 (12)	0.0449 (13)	0.0032 (10)	0.0025 (10)	−0.0059 (10)
C13	0.0484 (11)	0.0403 (11)	0.0485 (13)	0.0042 (10)	0.0045 (10)	0.0001 (9)
C3	0.0518 (13)	0.0522 (12)	0.0528 (15)	−0.0025 (11)	0.0122 (11)	−0.0100 (10)
C14	0.0640 (14)	0.0505 (12)	0.0506 (15)	−0.0009 (12)	0.0026 (11)	0.0040 (10)
C4	0.0463 (12)	0.0558 (13)	0.0670 (17)	0.0046 (11)	0.0091 (11)	−0.0031 (12)
C8	0.0484 (13)	0.0574 (14)	0.0785 (19)	0.0012 (11)	0.0092 (12)	0.0069 (13)
C5	0.0428 (11)	0.0609 (14)	0.0593 (16)	0.0015 (11)	−0.0038 (11)	−0.0020 (11)
C15	0.0716 (16)	0.0532 (13)	0.0629 (18)	−0.0105 (12)	−0.0016 (14)	−0.0071 (12)
C25	0.0508 (12)	0.0521 (12)	0.0485 (13)	−0.0039 (10)	0.0061 (10)	−0.0041 (10)
C19	0.0465 (12)	0.0651 (14)	0.0509 (14)	−0.0106 (11)	0.0080 (10)	−0.0114 (11)
C16	0.0850 (18)	0.0693 (16)	0.0551 (17)	−0.0018 (15)	0.0057 (15)	−0.0158 (13)
C12	0.0481 (13)	0.0698 (15)	0.0704 (18)	0.0087 (13)	−0.0032 (12)	0.0001 (14)
C18	0.0727 (16)	0.0622 (15)	0.0589 (17)	−0.0140 (13)	0.0213 (13)	−0.0094 (12)
C17	0.091 (2)	0.0811 (19)	0.0590 (18)	−0.0095 (16)	0.0285 (16)	−0.0103 (14)
C20	0.0694 (16)	0.0737 (17)	0.0652 (19)	−0.0076 (14)	−0.0066 (14)	−0.0064 (14)
C9	0.0690 (17)	0.0669 (16)	0.090 (2)	−0.0141 (14)	0.0198 (16)	0.0011 (15)
C10	0.0553 (16)	0.099 (2)	0.088 (2)	−0.0258 (17)	0.0118 (15)	−0.0127 (18)
C24	0.0542 (15)	0.089 (2)	0.100 (2)	−0.0102 (14)	0.0059 (15)	−0.0431 (18)
C23	0.074 (2)	0.125 (3)	0.100 (3)	−0.026 (2)	0.0045 (19)	−0.063 (2)
C11	0.0425 (14)	0.109 (2)	0.093 (2)	0.0000 (15)	0.0021 (14)	−0.0030 (19)
C21	0.078 (2)	0.102 (2)	0.091 (3)	−0.0088 (18)	−0.0257 (18)	0.007 (2)
C22	0.084 (2)	0.146 (3)	0.068 (2)	−0.031 (2)	−0.0172 (18)	−0.020 (2)

Geometric parameters (Å, º)

P1—C7	1.827 (2)	C25—C19	1.466 (3)
P1—C13	1.831 (2)	C25—H25A	0.9300
P1—C1	1.830 (2)	C19—C20	1.375 (4)
N1—C25	1.266 (3)	C19—C24	1.379 (3)
N1—C2	1.409 (3)	C16—C17	1.370 (4)
C2—C3	1.386 (3)	C16—H16A	0.9300
C2—C1	1.406 (3)	C12—C11	1.384 (4)
C1—C6	1.391 (3)	C12—H12A	0.9300
C7—C8	1.382 (3)	C18—C17	1.381 (4)
C7—C12	1.386 (3)	C18—H18A	0.9300
C6—C5	1.375 (3)	C17—H17A	0.9300
C6—H6A	0.9300	C20—C21	1.382 (4)
C13—C14	1.381 (3)	C20—H20A	0.9300
C13—C18	1.387 (3)	C9—C10	1.371 (4)
C3—C4	1.374 (3)	C9—H9A	0.9300
C3—H3A	0.9300	C10—C11	1.352 (4)
C14—C15	1.383 (3)	C10—H10A	0.9300
C14—H14A	0.9300	C24—C23	1.375 (4)
C4—C5	1.378 (3)	C24—H24A	0.9300
C4—H4A	0.9300	C23—C22	1.353 (5)
C8—C9	1.374 (4)	C23—H23A	0.9300
C8—H8A	0.9300	C11—H11A	0.9300
C5—H5A	0.9300	C21—C22	1.376 (5)
C15—C16	1.352 (4)	C21—H21A	0.9300
C15—H15A	0.9300	C22—H22A	0.9300
C7—P1—C13	101.71 (10)	C20—C19—C24	119.5 (3)
C7—P1—C1	103.59 (10)	C20—C19—C25	121.6 (2)
C13—P1—C1	100.85 (10)	C24—C19—C25	118.9 (2)
C25—N1—C2	117.86 (19)	C15—C16—C17	119.8 (3)
C3—C2—N1	123.0 (2)	C15—C16—H16A	120.1
C3—C2—C1	120.2 (2)	C17—C16—H16A	120.1
N1—C2—C1	116.76 (18)	C11—C12—C7	120.3 (3)
C6—C1—C2	117.67 (19)	C11—C12—H12A	119.9
C6—C1—P1	123.90 (16)	C7—C12—H12A	119.9
C2—C1—P1	118.15 (16)	C17—C18—C13	120.9 (2)
C8—C7—C12	118.0 (2)	C17—C18—H18A	119.6
C8—C7—P1	124.76 (17)	C13—C18—H18A	119.6
C12—C7—P1	117.25 (18)	C16—C17—C18	120.1 (3)
C5—C6—C1	121.5 (2)	C16—C17—H17A	119.9
C5—C6—H6A	119.3	C18—C17—H17A	119.9
C1—C6—H6A	119.3	C19—C20—C21	119.8 (3)
C14—C13—C18	117.6 (2)	C19—C20—H20A	120.1
C14—C13—P1	117.25 (18)	C21—C20—H20A	120.1
C18—C13—P1	125.15 (18)	C10—C9—C8	119.9 (3)
C4—C3—C2	120.7 (2)	C10—C9—H9A	120.0
C4—C3—H3A	119.7	C8—C9—H9A	120.0
C2—C3—H3A	119.7	C11—C10—C9	120.0 (3)
C15—C14—C13	121.0 (2)	C11—C10—H10A	120.0
C15—C14—H14A	119.5	C9—C10—H10A	120.0
C13—C14—H14A	119.5	C19—C24—C23	120.2 (3)
C5—C4—C3	119.7 (2)	C19—C24—H24A	119.9
C5—C4—H4A	120.2	C23—C24—H24A	119.9
C3—C4—H4A	120.2	C22—C23—C24	120.2 (3)
C9—C8—C7	121.2 (2)	C22—C23—H23A	119.9
C9—C8—H8A	119.4	C24—C23—H23A	119.9
C7—C8—H8A	119.4	C10—C11—C12	120.7 (3)
C4—C5—C6	120.2 (2)	C10—C11—H11A	119.7
C4—C5—H5A	119.9	C12—C11—H11A	119.7
C6—C5—H5A	119.9	C22—C21—C20	119.8 (3)
C16—C15—C14	120.6 (2)	C22—C21—H21A	120.1
C16—C15—H15A	119.7	C20—C21—H21A	120.1
C14—C15—H15A	119.7	C23—C22—C21	120.4 (3)
N1—C25—C19	121.9 (2)	C23—C22—H22A	119.8
N1—C25—H25A	119.0	C21—C22—H22A	119.8
C19—C25—H25A	119.0
C25—N1—C2—C3	−45.7 (3)	P1—C7—C8—C9	179.8 (2)
C25—N1—C2—C1	137.2 (2)	C3—C4—C5—C6	1.1 (4)
C3—C2—C1—C6	3.0 (3)	C1—C6—C5—C4	0.2 (4)
N1—C2—C1—C6	−179.87 (19)	C13—C14—C15—C16	0.9 (4)
C3—C2—C1—P1	−171.27 (16)	C2—N1—C25—C19	178.46 (19)
N1—C2—C1—P1	5.9 (2)	N1—C25—C19—C20	17.8 (4)
C7—P1—C1—C6	117.68 (19)	N1—C25—C19—C24	−161.1 (3)
C13—P1—C1—C6	12.7 (2)	C14—C15—C16—C17	−0.8 (4)
C7—P1—C1—C2	−68.48 (18)	C8—C7—C12—C11	−1.0 (4)
C13—P1—C1—C2	−173.49 (16)	P1—C7—C12—C11	179.6 (2)
C13—P1—C7—C8	84.7 (2)	C14—C13—C18—C17	0.9 (4)
C1—P1—C7—C8	−19.7 (2)	P1—C13—C18—C17	−179.3 (2)
C13—P1—C7—C12	−96.0 (2)	C15—C16—C17—C18	0.8 (5)
C1—P1—C7—C12	159.66 (19)	C13—C18—C17—C16	−0.8 (4)
C2—C1—C6—C5	−2.2 (3)	C24—C19—C20—C21	2.0 (4)
P1—C1—C6—C5	171.66 (18)	C25—C19—C20—C21	−176.9 (3)
C7—P1—C13—C14	167.16 (17)	C7—C8—C9—C10	0.0 (5)
C1—P1—C13—C14	−86.34 (18)	C8—C9—C10—C11	0.1 (5)
C7—P1—C13—C18	−12.6 (2)	C20—C19—C24—C23	−2.9 (5)
C1—P1—C13—C18	93.9 (2)	C25—C19—C24—C23	176.0 (3)
N1—C2—C3—C4	−178.8 (2)	C19—C24—C23—C22	0.9 (6)
C1—C2—C3—C4	−1.8 (3)	C9—C10—C11—C12	−0.7 (5)
C18—C13—C14—C15	−0.9 (4)	C7—C12—C11—C10	1.1 (5)
P1—C13—C14—C15	179.26 (19)	C19—C20—C21—C22	0.9 (5)
C2—C3—C4—C5	−0.3 (4)	C24—C23—C22—C21	2.1 (6)
C12—C7—C8—C9	0.5 (4)	C20—C21—C22—C23	−3.0 (6)