2-Diphenyl­arsino-1-(diphenyl­phosphino)ethane

The title compound, C₂₆H₂₄PAs, has inversion symmetry as a result of the orientational disorder of the mol­ecule. The two possible positions of the As and P atoms are overlapped.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.005 Å
• Disorder in main residue
• R factor = 0.039
• wR factor = 0.096
• Data-to-parameter ratio = 18.9

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT164_ALERT_4_C Nr. of Refined C-H H-Atoms in Heavy-At Struct...          2
PLAT199_ALERT_1_C Check the Reported _cell_measurement_temperature        293 K
PLAT301_ALERT_3_C Main Residue  Disorder .........................       5.00 Perc.
PLAT366_ALERT_2_C Short? C(sp?)-C(sp?) Bond  C1     -   C2     ...       1.37 Ang.
PLAT366_ALERT_2_C Short? C(sp?)-C(sp?) Bond  C1     -   C6     ...       1.39 Ang.
PLAT366_ALERT_2_C Short? C(sp?)-C(sp?) Bond  C7     -   C8     ...       1.37 Ang.
PLAT366_ALERT_2_C Short? C(sp?)-C(sp?) Bond  C7     -   C12    ...       1.39 Ang.
PLAT711_ALERT_1_C BOND    Unknown or Inconsistent Label ..........       AS/P
                    AS/P   C13
PLAT711_ALERT_1_C BOND    Unknown or Inconsistent Label ..........       AS/P
                    AS/P   C1
PLAT711_ALERT_1_C BOND    Unknown or Inconsistent Label ..........       AS/P
                    AS/P   C7
PLAT712_ALERT_1_C ANGLE   Unknown or Inconsistent Label ..........       AS/P
                    C13    AS/P   C1
PLAT712_ALERT_1_C ANGLE   Unknown or Inconsistent Label ..........       AS/P
                    C13    AS/P   C7
PLAT712_ALERT_1_C ANGLE   Unknown or Inconsistent Label ..........       AS/P
                    C1     AS/P   C7
PLAT712_ALERT_1_C ANGLE   Unknown or Inconsistent Label ..........       AS/P
                    C2     C1     AS/P
PLAT712_ALERT_1_C ANGLE   Unknown or Inconsistent Label ..........       AS/P
                    C6     C1     AS/P
PLAT712_ALERT_1_C ANGLE   Unknown or Inconsistent Label ..........       AS/P
                    C8     C7     AS/P
PLAT712_ALERT_1_C ANGLE   Unknown or Inconsistent Label ..........       AS/P
                    C12    C7     AS/P
PLAT712_ALERT_1_C ANGLE   Unknown or Inconsistent Label ..........       AS/P
                    C13    C13    AS/P

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

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

---

S1. Comment

There have been numerous X-ray structural determinations of tertiary phosphines and also tertiary arsines which are widely used as ligands in organo-transition metal chemistry. However, X-ray structure determinations of ligands containing both P and As atoms are rare. As part of our study on the substitution of transition metal–carbonyl clusters with mixed ligand complexes, we have published several structures of triruthenium–carbonyl clusters containing mixed P/As (Shawkataly et al., 1998) or P/Sb ligands (Shawkataly et al., 2004). A search of the November 2004 release of Cambridge Structural Database (Allen, 2002) revealed only 20 structures of complexes containing the above ligands. The title compound, (I), is commercially available and has been widely used, though the crystal structure has not been reported.

The crystal structure of (I) is isomorphous with those of Ph₂P(CH₂)₂PPh₂ (Pelizzi & Pelizzi, 1979) and Ph₂As(CH₂)₂AsPh₂ (Hill et al., 2001); all these compounds have a crystallographic inversion centerat the middle of the Csp³—Csp³ bond. However, in (I), this means a positional disorder of the As and P atoms (Fig. 1). The positional disorder between the As/P atoms was also observed in Ru₃(CO)₈(Ph₂AsCH₂AsPh₂)(Ph₂PCH₂PPh₂) (Shawkataly et al., 1998).

S2. Experimental

The compound was supplied by Strem Chemicals. Single crystals of (I) were obtained by slow evaporation of an ethanol solution.

S3. Refinement

The site-occupancy factors of the As and P atoms were fixed at 1/2, and the same positional and atomic displacement parameters were assumed. The methylene H atoms were located in difference density maps and their coordinates were refined [C—H = 0.93 (3)–0.95 (3) Å]. The phenyl H atoms were placed at calculated positions and refined using a riding model, with C—H = 0.93 Å. All H-atom U_iso parameters were fixed at 1.2U_eq(C).

Computing details

Data collection: XSCANS (Siemens, 1994); cell refinement: XSCANS; data reduction: XSCANS; program(s) used to solve structure: SHELXS86 (Sheldrick, 1985); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX publication routines (Farrugia, 1999).

Figures

Fig. 1. The molecular structure of (I), showing the atom-labeling scheme. Displacement ellipsoids are drawn at the 25% probability level.

2-Diphenylarsino-1-(diphenylphosphino)ethane

Crystal data

C26H24AsP	F(000) = 456
Mr = 442.34	Dx = 1.323 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 40 reflections
a = 9.1011 (6) Å	θ = 9.9–24.3°
b = 5.7856 (8) Å	µ = 1.61 mm^−1
c = 21.4502 (10) Å	T = 293 K
β = 100.557 (5)°	Prism, colorless
V = 1110.35 (18) Å^3	0.22 × 0.16 × 0.12 mm
Z = 2

Data collection

Siemens P4 diffractometer	Rint = 0.034
θ/2θ scans	θmax = 27.5°, θmin = 1.9°
Absorption correction: ψ scan (Siemens, 1994)	h = −1→11
Tmin = 0.744, Tmax = 0.826	k = −1→7
3557 measured reflections	l = −27→27
2520 independent reflections	3 standard reflections every 60 min
1579 reflections with I > 2σ(I)	intensity decay: 0.2%

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F^2 > 2σ(F^2)] = 0.039	w = 1/[σ^2(Fo^2) + (0.041P)^2] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.096	(Δ/σ)max < 0.001
S = 0.95	Δρmax = 0.29 e Å^−3
2520 reflections	Δρmin = −0.34 e Å^−3
133 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	Occ. (<1)
As	0.80176 (4)	0.21063 (7)	0.948461 (16)	0.05341 (16)	0.5
P	0.80176 (4)	0.21063 (7)	0.948461 (16)	0.05341 (16)	0.5
C1	0.6154 (3)	0.0560 (5)	0.92113 (11)	0.0539 (7)
C2	0.5766 (3)	−0.1532 (6)	0.94320 (13)	0.0701 (8)
H2	0.6474	−0.2381	0.9707	0.084*
C3	0.4318 (4)	−0.2409 (7)	0.92488 (19)	0.0958 (13)
H3	0.4061	−0.3824	0.9404	0.115*
C4	0.3272 (4)	−0.1156 (10)	0.8835 (2)	0.1104 (16)
H4	0.2309	−0.1727	0.8709	0.132*
C5	0.3659 (4)	0.0912 (9)	0.86138 (18)	0.1017 (14)
H5	0.2954	0.1745	0.8333	0.122*
C6	0.5079 (3)	0.1799 (7)	0.87987 (14)	0.0784 (10)
H6	0.5319	0.323	0.8647	0.094*
C7	0.8735 (3)	0.1948 (5)	0.87003 (11)	0.0486 (6)
C8	0.8461 (3)	0.0133 (5)	0.82838 (11)	0.0549 (7)
H8	0.7907	−0.112	0.8383	0.066*
C9	0.8992 (3)	0.0128 (6)	0.77185 (11)	0.0643 (8)
H9	0.8802	−0.1121	0.7443	0.077*
C10	0.9800 (3)	0.1984 (6)	0.75691 (13)	0.0680 (8)
H10	1.0152	0.1994	0.7189	0.082*
C11	1.0091 (3)	0.3810 (6)	0.79726 (14)	0.0700 (8)
H11	1.064	0.5061	0.7868	0.084*
C12	0.9564 (3)	0.3799 (5)	0.85405 (12)	0.0617 (7)
H12	0.9769	0.5045	0.8817	0.074*
C13	0.9184 (3)	−0.0356 (6)	0.99143 (12)	0.0542 (7)
H13A	0.877 (3)	−0.069 (5)	1.0281 (11)	0.065*
H13B	0.909 (3)	−0.172 (5)	0.9676 (13)	0.065*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
As	0.0504 (2)	0.0638 (3)	0.0447 (2)	0.0085 (2)	0.00517 (15)	−0.00239 (19)
P	0.0504 (2)	0.0638 (3)	0.0447 (2)	0.0085 (2)	0.00517 (15)	−0.00239 (19)
C1	0.0430 (14)	0.073 (2)	0.0454 (13)	0.0087 (14)	0.0074 (11)	−0.0079 (13)
C2	0.0617 (18)	0.084 (2)	0.0659 (17)	−0.0023 (17)	0.0163 (14)	−0.0133 (17)
C3	0.084 (2)	0.115 (3)	0.099 (3)	−0.031 (2)	0.046 (2)	−0.041 (2)
C4	0.050 (2)	0.180 (5)	0.105 (3)	−0.019 (3)	0.023 (2)	−0.072 (3)
C5	0.048 (2)	0.162 (4)	0.090 (2)	0.028 (3)	−0.0022 (18)	−0.029 (3)
C6	0.0561 (17)	0.111 (3)	0.0670 (17)	0.0219 (19)	0.0075 (14)	−0.0008 (18)
C7	0.0432 (13)	0.0579 (16)	0.0422 (11)	0.0057 (13)	0.0011 (10)	0.0045 (12)
C8	0.0529 (16)	0.0631 (18)	0.0475 (12)	−0.0044 (14)	0.0060 (12)	0.0005 (13)
C9	0.0596 (17)	0.087 (2)	0.0459 (13)	−0.0036 (17)	0.0085 (13)	−0.0055 (14)
C10	0.0562 (16)	0.101 (2)	0.0476 (13)	0.0117 (19)	0.0119 (12)	0.0140 (17)
C11	0.0628 (18)	0.080 (2)	0.0685 (18)	−0.0052 (17)	0.0164 (15)	0.0160 (17)
C12	0.0614 (17)	0.0577 (17)	0.0626 (16)	0.0011 (16)	0.0026 (14)	−0.0024 (14)
C13	0.0486 (15)	0.073 (2)	0.0402 (13)	0.0033 (15)	0.0061 (12)	0.0011 (13)

Geometric parameters (Å, º)

As/P—C13	1.910 (3)	C7—C8	1.371 (4)
As/P—C1	1.912 (3)	C7—C12	1.389 (4)
As/P—C7	1.915 (2)	C8—C9	1.385 (3)
C1—C2	1.369 (4)	C8—H8	0.93
C1—C6	1.392 (4)	C9—C10	1.372 (4)
C2—C3	1.400 (4)	C9—H9	0.93
C2—H2	0.93	C10—C11	1.361 (4)
C3—C4	1.382 (6)	C10—H10	0.93
C3—H3	0.93	C11—C12	1.388 (4)
C4—C5	1.357 (6)	C11—H11	0.93
C4—H4	0.93	C12—H12	0.93
C5—C6	1.380 (5)	C13—C13^i	1.520 (5)
C5—H5	0.93	C13—H13A	0.95 (3)
C6—H6	0.93	C13—H13B	0.93 (3)
C13—As/P—C1	100.51 (13)	C12—C7—As/P	117.9 (2)
C13—As/P—C7	98.01 (11)	C7—C8—C9	121.4 (3)
C1—As/P—C7	97.72 (10)	C7—C8—H8	119.3
C2—C1—C6	118.7 (3)	C9—C8—H8	119.3
C2—C1—As/P	125.3 (2)	C10—C9—C8	119.4 (3)
C6—C1—As/P	115.8 (2)	C10—C9—H9	120.3
C1—C2—C3	120.8 (3)	C8—C9—H9	120.3
C1—C2—H2	119.6	C11—C10—C9	120.6 (3)
C3—C2—H2	119.6	C11—C10—H10	119.7
C4—C3—C2	119.5 (4)	C9—C10—H10	119.7
C4—C3—H3	120.3	C10—C11—C12	119.7 (3)
C2—C3—H3	120.3	C10—C11—H11	120.1
C5—C4—C3	119.7 (4)	C12—C11—H11	120.1
C5—C4—H4	120.2	C11—C12—C7	120.7 (3)
C3—C4—H4	120.2	C11—C12—H12	119.7
C4—C5—C6	121.1 (4)	C7—C12—H12	119.7
C4—C5—H5	119.4	C13^i—C13—As/P	110.3 (3)
C6—C5—H5	119.4	C13^i—C13—H13A	111.8 (15)
C5—C6—C1	120.2 (4)	As—C13—H13A	106.3 (16)
C5—C6—H6	119.9	C13^i—C13—H13B	110.6 (18)
C1—C6—H6	119.9	As—C13—H13B	112.0 (17)
C8—C7—C12	118.2 (2)	H13A—C13—H13B	106 (2)
C8—C7—As/P	123.9 (2)
C13—As—C1—C2	14.8 (3)	C1—As—C7—C8	−34.4 (2)
C7—As—C1—C2	114.4 (2)	C13—As—C7—C12	−113.6 (2)
C13—As—C1—C6	−171.4 (2)	C1—As—C7—C12	144.6 (2)
C7—As—C1—C6	−71.8 (2)	C12—C7—C8—C9	0.0 (4)
C6—C1—C2—C3	−0.2 (4)	As—C7—C8—C9	179.1 (2)
As—C1—C2—C3	173.4 (2)	C7—C8—C9—C10	−0.5 (4)
C1—C2—C3—C4	0.7 (5)	C8—C9—C10—C11	0.5 (4)
C2—C3—C4—C5	−0.3 (5)	C9—C10—C11—C12	−0.1 (4)
C3—C4—C5—C6	−0.5 (6)	C10—C11—C12—C7	−0.4 (4)
C4—C5—C6—C1	1.0 (5)	C8—C7—C12—C11	0.4 (4)
C2—C1—C6—C5	−0.6 (4)	As—C7—C12—C11	−178.7 (2)
As—C1—C6—C5	−174.8 (2)	C1—As—C13—C13^i	170.7 (2)
C13—As—C7—C8	67.4 (2)	C7—As—C13—C13^i	71.3 (3)

Symmetry code: (i) −x+2, −y, −z+2.