3-(Triphenyl­phospho­ranyl­idene)pentane-2,4-dione and dieth­yl 2-(triphenyl­phospho­ranyl­idene)malonate

The title ylides, 3-(triphenyl­phospho­ranyl­idene)pentane-2,4-dione, C₂₃H₂₁O₂P, (I), and diethyl 2-(triphenyl­phospho­ranyl­idene)malonate, C₂₅H₂₅O₄P, (II), differ in the conformations adopted by their extended ylide moieties. In (I), one carbonyl O atom is syn and the other is anti with respect to the P atom, the ylide group is nearly planar, with a maximum P-C-(C=O) angle of 18.2 (2)°, and the P-C, C-C and C=O bond lengths are consistent with electronic delocalization involving the O atoms. In (II), both carbonyl O atoms are anti and the ester groups are twisted out of the plane of the near trigonal ylide C atom, reducing delocalization, the largest P-C-(C=O) angle being 30.2 (2)°.

S1. Comment

For alkoxycarbonyl acylphosphoranes (keto esters), the conformations are similar in solution and in the solid state, with the keto and alkoxy O atoms oriented towards the phosphorus and the acyl groups in the ylide plane, thus allowing extended ylide resonance (Abell & Massy-Westropp, 1982; Abell et al., 1988, 1989). Classical structures of stabilized ylides are accordingly written with a double bond between the ylide carbon and the stabilized group (Bachrach & Nitsche, 1994). We have shown elsewhere (Castañeda, Terraza et al., 2003) that alkoxycarbonyl acylphosphoranes, Ph₃P═C(CO.R')CO₂R, can adopt a near planar preferred conformation that allows extensive electronic delocalization and favorable interactions between the cationoid P atom and the keto and alkoxy O atoms, both in the solid state and in solution. The preferred conformations result from both attractive and repulsive intramolecular interactions in solution, and possible intermolecular interactions in the solid state. Diacyl phosphorane conformations should be similar to those of the keto esters.

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# Insert Scheme

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The scheme above depicts a diacyl ylide [hereafter denoted (I)] that can adopt various conformations depending on the orientations of the carbonyl groups relative to the P atom. The methyl signal in the ¹H NMR spectrum in CHCl₃ is a sharp singlet over a wide temperature range. In ylide solutions, these groups are therefore equivalent or are equilibrating rapidly on the NMR timescale, although equilibration is slow in monoacyl ylides (Wilson & Tebby, 1972). These differences are consistent with energy barriers for equilibration from ab initio computations (Castañeda, Recabarren et al., 2003, Bachrach, 1992). Conformer (Ib), with both carbonyl O atoms syn to the P atom, has favorable interactions between anionoid O atoms and cationoid P atoms, and this structure is supported by chemical evidence (Cooke & Goswami, 1973). However, in a near planar ylide moiety there will be methyl–methyl repulsions. The anti–anti coplanar conformation, (Ic), should be electrostatically disfavored because of dipole repulsions between the carbonyl groups and possible steric repulsions between methyl and phenyl groups.

The crystal structures of two ylides are discussed here, viz. 3-(triphenylphosphoranylidene)pentane-2,4-dione, (I), and diethyl 2-(triphenylphosphoranylidene)malonate, (II), stabilized by diketo and diester groups, respectively (Figs. 1 and 2). The structural results are consistent with previous NMR, chemical and computational evidence (Castañeda, Terraza et al., 2003) regarding differences in the solid state and in solution. Selected bond lengths and angles are presented in Tables 1 and 3, with hydrogen bonds and short contacts in Tables 2 and 4.

The two ylides share a number of common features, in particular a slightly distorted tetrahedral arrangements around the P atom, as observed for stabilized keto–ester phosphorus ylides (Castañeda, Terraza et al., 2001). The P—C bonds [P1—C1 = 1.7521 (18) and 1.748 (3) Å for (I) and (II), respectively] are longer than typical double bonds, because of the ylidic resonance, and intermediate between commonly accepted values for single and double bonds (P—C = 1.80–1.83 Å and P═C = 1.66 Å; Howells et al., 1973). In both ylides, ylide atom C1is clearly sp²-hybridized, the sum of the bond angles being essentially 360° [359.9 (5) and 359.6 (5)°, respectively].

A distinctive feature that differentiates the two structures is the disposition of the C═O groups; in (I), one carbonyl O atom is syn and the other is anti with respect to the P atom, while in (II), both O atoms are positioned anti. Though neither of the two extended ylide groups is planar, the carbonyl groups in (I) deviate less from the plane defined by the nearly trigonal ylide C atom than those in (II), the maximum absolute values for the P—C_ylid—C_carbonyl—O_carbonyl torsion angles being 18.2 (2)° for (I) and 30.2 (2)° for (II). This structural disposition favours an extensive electronic delocalization in the nearly planar ylide system in (I) and the interaction of one carbonyl O atom with the cationoid P atom, and minimizes intramolecular interference involving methyl groups.

Both structures have several intra- and intermolecular non-bonding interactions. Despite being weak, they have profound effects both in the molecular and in the packing conformations. The intramolecular interactions and contacts are mainly of the C—H···π type, involving methyl H atoms and phenyl groups. In (I), methyl atom C5 interacts with a phenyl ring, with an H5B···Cg1 distance of 2.79 Å and a C5···Cg1 distance of 3.541 (3) Å (Fig. 1; Cg1 is the centroid of the C11/C21/C31/C41/C51/C61 ring). In (II), the C···π(arene) contacts involve methyl atom C7, with a C7···Cg2 distance of 3.984 (6) Å (Fig. 2; Cg2 is the centroid of the C12/C22/C32/C42/C52/C62 ring). The first of these interactions has an important effect on the molecular geometry, through the reduction of the C11—P1—C13 angle to 103.31 (8)°, sensibly smaller than expected for a strictly tetrahedral P atom, and with the concomitant opening of the C1—P1—C12 angle [114.62 (9)°; Fig. 1].

There are also several short P···O contacts of different types, as a result of conformational differences in the two structures; in (I), such contacts involve carbonyl atom O1, which is syn to P and thus favoured for this type of interaction [P1···O1 = 2.767 (2) Å]. The corresponding O atoms (O2 and O4) in (II) are oriented away from P and are therefore prohibited from this kind of contact but have a short O2···O4 intramolecular distance of 2.816 (3) Å. The syn-oriented alkoxy O atoms, O1 and O3 (relative to P), are oriented near P [P···O = 3.028 (3) and 2.775 (3) Å, respectively]. Intermolecular interactions are mainly C—H···O hydrogen bonds involving phenyl donors and carbonyl acceptors (Tables 2 and 4). However, the most important effects are those that allow (or forbid) electronic delocalization.

In (I), the distortions from planarity of the extended ylide group (as induced by non-bonding interactions) are not extremely severe; the P—C—C═O angles (Table 1) suggest some degree of coplanarity and, concomitantly, ylide resonance involving both acyl moieties. This correlates with the IR carbonyl stretching frequencies in KBr (1600 and 1557 cm⁻¹), similar to those in CHCl₃ (1601 and 1540 cm⁻¹). In (II), however, they appear to favor the out of plane geometry of the ylide and carbonyl moieties and the consequent decrease in ylide resonance. The out of plane torsion angles (Table 3) are consistent with the IR carbonyl stretching frequencies (1711 and 1632 cm⁻¹), indicating that in the solid state only one carbonyl group is sufficiently close to coplanarity with respect to the ylide moiety to participate significantly in electronic delocalization.

It is often assumed that in the search for a balance between opposing ylide resonance and non-bonding interactions it is the former that dominates conformations of stabilized phosphorus ylides, and structures are usually written with a formal double bond between the ylide and acyl C atoms. This structural assumption appears to be valid for (I) in the crystal and in solution, and for the keto esters, but it is not valid for (II). To this extent, (II) behaves differently from the other ylides stabilized by keto and ester groups, as a result of interactions in the solid state of carbonyl atoms O2 and O4 with H atoms of neighboring ylides. The presence (or absence) of such interactions is therefore a major factor controlling conformation in the crystalline state and in solution.

S2. Experimental

Compound (I) was prepared by reaction of 1-triphenylphosphoranylidene-2-propanone with acetic anhydride (Chopard et al., 1965) (yield 80%, m.p. 437–438 K from ethyl acetate/cyclohexane, 1:1). Compound (II) was prepared by Horner & Oediger (1958) from triphenylphosphine dichloride and diethyl malonate in a basic medium, with 56% yield, but we report here a simpler synthesis by transylidation. A solution of ethyl chloroformate (39 mmol) in dry benzene (10 ml) was added slowly to carboethoxymethylene triphenylphosphorane (60 mmol) in dry benzene (100 ml) under a dry atmosphere at room temperature. After 1 h, carboethoxymethyltriphenylphosphonium chloride separated from the stirred solution as a white solid. The filtered solvent was evaporated to give an oil which was crystallized from ethyl acetate (yield 85%, m.p. 379–380 K).

S3. Refinement

H atoms were placed at idealized positions (C—H = 0.93 Å for CH atoms, 0.97 Å for CH₂ atoms and 0.96 Å for CH₃), with U_iso(H) values of xU_eq(C) [x = 1.5 for methyl H atoms and x = 1.2 for the remainder]. Methyl H atoms were allowed to rotate about the C—C axis. The monoclinic character of (II) [β = 90.12 (2)°] was originally checked through the agreement between equivalents [R_int(monoclinic) = 0.027 and R_int(orthorhombic) = 0.545].

Computing details

For both compounds, data collection: P3/P4-PC (Siemens, 1991); cell refinement: P3/P4-PC; data reduction: XDISK in SHELXTL/PC (Sheldrick, 1991); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997). Program(s) used to refine structure: SHELXL97 (Sheldrick, 1997) for (I); SHELXL97 for (II). For both compounds, molecular graphics: SHELXTL/PC (Sheldrick, 1994); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. : A molecular diagram of (I), with the atomic numbering scheme, and intermolecular (single broken lines) and intramolecular (double broken lines) contacts. H atoms, except phenyl H atoms involved in hydrogen bonds, have been omitted for clarity. Displacement ellipsoids are drawn at the 30% probability level. For symmetry codes refer to Table 2.
	Fig. 2. : A molecular diagram of (II), with the atomic numbering scheme, and intermolecular (single broken lines) and intramolecular (double broken lines) contacts. H atoms, except phenyl H atoms involved in hydrogen bonds, have been omitted for clarity. Displacement ellipsoids are drawn at the 30% probability level. For symmetry codes refer to Table 4.

(I) 3-(Triphenylphosphoranylidene)pentane-2,4-dione

Crystal data

C23H21O2P	F(000) = 760
Mr = 360.37	Dx = 1.264 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 25 reflections
a = 14.9365 (18) Å	θ = 7.5–12.5°
b = 9.6588 (13) Å	µ = 0.16 mm^−1
c = 13.7975 (16) Å	T = 295 K
β = 107.907 (9)°	Rectangular prism, colorless
V = 1894.1 (4) Å^3	0.40 × 0.24 × 0.20 mm
Z = 4

Data collection

Siemens R3m diffractometer	Rint = 0.013
Radiation source: fine-focus sealed tube	θmax = 25.0°, θmin = 2.6°
Graphite monochromator	h = −17→16
ω/2θ scans	k = −11→0
3480 measured reflections	l = 0→16
3325 independent reflections	2 standard reflections every 98 reflections
2782 reflections with I > 2σ(I)	intensity decay: 1.5%

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)] = 0.040	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.106	H-atom parameters constrained
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0657P)^2 + 0.5296P] where P = (Fo^2 + 2Fc^2)/3
3325 reflections	(Δ/σ)max = 0.004
237 parameters	Δρmax = 0.22 e Å^−3
0 restraints	Δρmin = −0.26 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.

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

	x	y	z	Uiso*/Ueq
P1	0.75701 (3)	0.15482 (5)	0.09982 (3)	0.03156 (14)
O1	0.74640 (10)	−0.11796 (14)	0.15677 (11)	0.0497 (4)
O2	0.51103 (10)	0.11643 (19)	0.15052 (13)	0.0656 (5)
C1	0.66098 (12)	0.08708 (19)	0.13182 (13)	0.0345 (4)
C2	0.66881 (14)	−0.0614 (2)	0.14365 (14)	0.0402 (4)
C3	0.58424 (16)	−0.1502 (2)	0.13719 (18)	0.0583 (6)
H3A	0.6014	−0.2461	0.1382	0.087*
H3B	0.5353	−0.1303	0.0750	0.087*
H3C	0.5622	−0.1309	0.1942	0.087*
C4	0.58568 (13)	0.1682 (2)	0.14904 (14)	0.0424 (5)
C5	0.59901 (17)	0.3203 (2)	0.17488 (19)	0.0598 (6)
H5A	0.5614	0.3457	0.2173	0.090*
H5B	0.5801	0.3738	0.1133	0.090*
H5C	0.6641	0.3380	0.2105	0.090*
C11	0.72720 (12)	0.32283 (18)	0.04038 (14)	0.0349 (4)
C21	0.65632 (14)	0.3268 (2)	−0.05256 (15)	0.0443 (5)
H21	0.6320	0.2444	−0.0849	0.053*
C31	0.62158 (18)	0.4514 (2)	−0.09754 (17)	0.0575 (6)
H31	0.5733	0.4527	−0.1591	0.069*
C41	0.65868 (19)	0.5737 (2)	−0.0510 (2)	0.0630 (6)
H41	0.6351	0.6578	−0.0810	0.076*
C51	0.73058 (17)	0.5720 (2)	0.0397 (2)	0.0609 (6)
H51	0.7560	0.6548	0.0704	0.073*
C61	0.76510 (14)	0.4472 (2)	0.08556 (17)	0.0479 (5)
H61	0.8138	0.4466	0.1468	0.057*
C12	0.86372 (13)	0.1740 (2)	0.20646 (15)	0.0418 (4)
C22	0.94271 (14)	0.2464 (2)	0.20004 (19)	0.0570 (6)
H22	0.9432	0.2851	0.1385	0.068*
C32	1.02105 (16)	0.2603 (3)	0.2865 (2)	0.0783 (9)
H32	1.0740	0.3079	0.2826	0.094*
C42	1.0197 (2)	0.2032 (4)	0.3777 (2)	0.0883 (10)
H42	1.0717	0.2129	0.4353	0.106*
C52	0.9420 (2)	0.1322 (3)	0.3841 (2)	0.0787 (8)
H52	0.9419	0.0936	0.4459	0.094*
C62	0.86397 (16)	0.1179 (2)	0.29932 (16)	0.0550 (6)
H62	0.8114	0.0705	0.3044	0.066*
C13	0.77789 (12)	0.04996 (18)	−0.00053 (13)	0.0340 (4)
C23	0.86351 (14)	0.0511 (2)	−0.01979 (17)	0.0523 (5)
H23	0.9135	0.1018	0.0220	0.063*
C33	0.87507 (17)	−0.0233 (3)	−0.10116 (19)	0.0648 (7)
H33	0.9327	−0.0218	−0.1138	0.078*
C43	0.80167 (17)	−0.0992 (2)	−0.16326 (17)	0.0556 (6)
H43	0.8103	−0.1518	−0.2162	0.067*
C53	0.71571 (16)	−0.0968 (2)	−0.14650 (16)	0.0508 (5)
H53	0.6654	−0.1453	−0.1898	0.061*
C63	0.70338 (14)	−0.0231 (2)	−0.06612 (14)	0.0430 (5)
H63	0.6448	−0.0222	−0.0556	0.052*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
P1	0.0274 (2)	0.0307 (2)	0.0348 (2)	0.00064 (18)	0.00714 (18)	−0.00240 (19)
O1	0.0536 (9)	0.0378 (7)	0.0550 (9)	0.0060 (6)	0.0127 (7)	0.0044 (6)
O2	0.0355 (8)	0.0869 (12)	0.0777 (11)	−0.0069 (8)	0.0221 (8)	−0.0076 (9)
C1	0.0314 (9)	0.0365 (10)	0.0352 (9)	−0.0005 (7)	0.0097 (7)	0.0008 (7)
C2	0.0444 (11)	0.0431 (11)	0.0318 (9)	−0.0048 (9)	0.0099 (8)	0.0021 (8)
C3	0.0655 (14)	0.0523 (13)	0.0612 (13)	−0.0189 (11)	0.0257 (12)	0.0016 (11)
C4	0.0327 (10)	0.0587 (13)	0.0344 (9)	0.0035 (9)	0.0084 (8)	0.0029 (9)
C5	0.0641 (14)	0.0567 (14)	0.0718 (15)	0.0148 (11)	0.0401 (13)	−0.0029 (11)
C11	0.0370 (9)	0.0310 (9)	0.0384 (9)	−0.0001 (7)	0.0143 (8)	−0.0024 (7)
C21	0.0538 (12)	0.0355 (10)	0.0405 (10)	0.0021 (9)	0.0097 (9)	−0.0023 (8)
C31	0.0745 (15)	0.0466 (12)	0.0455 (12)	0.0102 (11)	0.0097 (11)	0.0063 (10)
C41	0.0808 (17)	0.0367 (12)	0.0713 (16)	0.0082 (11)	0.0233 (14)	0.0131 (11)
C51	0.0660 (15)	0.0297 (11)	0.0866 (18)	−0.0069 (10)	0.0230 (13)	−0.0075 (11)
C61	0.0434 (11)	0.0379 (11)	0.0584 (13)	−0.0036 (9)	0.0098 (9)	−0.0081 (9)
C12	0.0330 (9)	0.0410 (10)	0.0456 (11)	0.0060 (8)	0.0035 (8)	−0.0104 (9)
C22	0.0348 (10)	0.0621 (14)	0.0699 (14)	−0.0009 (10)	0.0099 (10)	−0.0205 (12)
C32	0.0335 (12)	0.0864 (19)	0.104 (2)	0.0009 (12)	0.0050 (13)	−0.0474 (18)
C42	0.0565 (17)	0.106 (2)	0.0728 (19)	0.0290 (16)	−0.0229 (14)	−0.0377 (18)
C52	0.0765 (19)	0.088 (2)	0.0506 (14)	0.0247 (16)	−0.0109 (13)	−0.0092 (14)
C62	0.0547 (13)	0.0552 (13)	0.0447 (12)	0.0106 (10)	0.0002 (10)	−0.0033 (10)
C13	0.0338 (9)	0.0292 (9)	0.0387 (9)	0.0022 (7)	0.0106 (7)	−0.0005 (7)
C23	0.0341 (10)	0.0641 (14)	0.0590 (13)	−0.0006 (10)	0.0148 (9)	−0.0138 (11)
C33	0.0504 (13)	0.0838 (18)	0.0675 (15)	0.0118 (12)	0.0287 (12)	−0.0111 (13)
C43	0.0748 (15)	0.0496 (12)	0.0465 (12)	0.0111 (11)	0.0246 (11)	−0.0060 (10)
C53	0.0667 (14)	0.0432 (11)	0.0434 (11)	−0.0116 (10)	0.0183 (10)	−0.0090 (9)
C63	0.0433 (10)	0.0432 (11)	0.0446 (11)	−0.0099 (8)	0.0165 (9)	−0.0073 (9)

Geometric parameters (Å, º)

P1—C1	1.7521 (18)	C51—H51	0.9300
P1—C11	1.8109 (18)	C61—H61	0.9300
P1—C12	1.8159 (18)	C12—C62	1.390 (3)
P1—C13	1.8182 (18)	C12—C22	1.397 (3)
O1—C2	1.243 (2)	C22—C32	1.397 (3)
O2—C4	1.228 (2)	C22—H22	0.9300
C1—C2	1.444 (3)	C32—C42	1.380 (4)
C1—C4	1.449 (3)	C32—H32	0.9300
C2—C3	1.507 (3)	C42—C52	1.374 (4)
C3—H3A	0.9600	C42—H42	0.9300
C3—H3B	0.9600	C52—C62	1.381 (3)
C3—H3C	0.9600	C52—H52	0.9300
C4—C5	1.511 (3)	C62—H62	0.9300
C5—H5A	0.9600	C13—C23	1.384 (3)
C5—H5B	0.9600	C13—C63	1.391 (3)
C5—H5C	0.9600	C23—C33	1.387 (3)
C11—C21	1.390 (3)	C23—H23	0.9300
C11—C61	1.391 (3)	C33—C43	1.377 (3)
C21—C31	1.380 (3)	C33—H33	0.9300
C21—H21	0.9300	C43—C53	1.373 (3)
C31—C41	1.377 (3)	C43—H43	0.9300
C31—H31	0.9300	C53—C63	1.377 (3)
C41—C51	1.376 (3)	C53—H53	0.9300
C41—H41	0.9300	C63—H63	0.9300
C51—C61	1.385 (3)
C1—P1—C11	110.03 (8)	C61—C51—H51	119.9
C1—P1—C12	114.62 (9)	C51—C61—C11	120.26 (19)
C1—P1—C13	109.22 (8)	C51—C61—H61	119.9
C11—P1—C12	107.92 (9)	C11—C61—H61	119.9
C11—P1—C13	103.31 (8)	C62—C12—C22	119.36 (19)
C12—P1—C13	111.14 (8)	C62—C12—P1	117.38 (16)
C2—C1—P1	110.80 (13)	C22—C12—P1	123.21 (17)
C4—C1—P1	125.20 (14)	C12—C22—C32	119.7 (3)
C2—C1—C4	123.94 (17)	C12—C22—H22	120.1
O1—C2—C1	119.51 (17)	C32—C22—H22	120.1
O1—C2—C3	119.03 (18)	C42—C32—C22	119.8 (3)
C1—C2—C3	121.43 (18)	C42—C32—H32	120.1
C2—C3—H3A	109.5	C22—C32—H32	120.1
C2—C3—H3B	109.5	C52—C42—C32	120.5 (2)
H3A—C3—H3B	109.5	C52—C42—H42	119.7
C2—C3—H3C	109.5	C32—C42—H42	119.7
H3A—C3—H3C	109.5	C42—C52—C62	120.3 (3)
H3B—C3—H3C	109.5	C42—C52—H52	119.8
O2—C4—C1	122.5 (2)	C62—C52—H52	119.8
O2—C4—C5	116.51 (18)	C52—C62—C12	120.3 (2)
C1—C4—C5	120.79 (17)	C52—C62—H62	119.9
C4—C5—H5A	109.5	C12—C62—H62	119.9
C4—C5—H5B	109.5	C23—C13—C63	118.71 (17)
H5A—C5—H5B	109.5	C23—C13—P1	121.80 (14)
C4—C5—H5C	109.5	C63—C13—P1	119.19 (13)
H5A—C5—H5C	109.5	C13—C23—C33	120.3 (2)
H5B—C5—H5C	109.5	C13—C23—H23	119.9
C21—C11—C61	118.63 (17)	C33—C23—H23	119.9
C21—C11—P1	117.00 (13)	C43—C33—C23	120.4 (2)
C61—C11—P1	124.16 (14)	C43—C33—H33	119.8
C31—C21—C11	120.89 (18)	C23—C33—H33	119.8
C31—C21—H21	119.6	C53—C43—C33	119.5 (2)
C11—C21—H21	119.6	C53—C43—H43	120.2
C41—C31—C21	119.8 (2)	C33—C43—H43	120.2
C41—C31—H31	120.1	C43—C53—C63	120.5 (2)
C21—C31—H31	120.1	C43—C53—H53	119.7
C51—C41—C31	120.2 (2)	C63—C53—H53	119.7
C51—C41—H41	119.9	C53—C63—C13	120.51 (18)
C31—C41—H41	119.9	C53—C63—H63	119.7
C41—C51—C61	120.2 (2)	C13—C63—H63	119.7
C41—C51—H51	119.9
P1—C1—C2—O1	18.2 (2)	P1—C1—C4—O2	164.61 (16)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C31—H31···O2^i	0.93	2.59	3.422 (3)	149
C63—H63···O2^ii	0.93	2.47	3.183 (2)	134
C51—H51···O1^iii	0.93	2.52	3.376 (3)	153

Symmetry codes: (i) x, −y+1/2, z−1/2; (ii) −x+1, −y, −z; (iii) x, y+1, z.

(II) diethyl 2-(triphenylphosphoranylidene)malonate

Crystal data

C25H25O4P	F(000) = 888
Mr = 420.42	Dx = 1.261 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 25 reflections
a = 12.572 (14) Å	θ = 7.5–12.5°
b = 9.022 (12) Å	µ = 0.15 mm^−1
c = 19.52 (2) Å	T = 295 K
β = 90.12 (2)°	Rectangular prism, colorless
V = 2214 (4) Å^3	0.35 × 0.20 × 0.15 mm
Z = 4

Data collection

Siemens R3m diffractometer	Rint = 0.027
Radiation source: fine-focus sealed tube	θmax = 25.1°, θmin = 1.6°
Graphite monochromator	h = 0→14
ω/2θ scans	k = −10→0
4069 measured reflections	l = −23→23
3880 independent reflections	2 standard reflections every 98 reflections
3138 reflections with I > 2σ(I)	intensity decay: 1.8%

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.047	H-atom parameters constrained
wR(F^2) = 0.129	w = 1/[σ^2(Fo^2) + (0.059P)^2 + 1.0148P] where P = (Fo^2 + 2Fc^2)/3
S = 1.10	(Δ/σ)max = 0.003
3880 reflections	Δρmax = 0.43 e Å^−3
272 parameters	Δρmin = −0.22 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0202 (15)

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 on F² for ALL reflections except for 5 with very negative F² or flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The observed criterion of F² > σ(F²) is used only for calculating _R_factor_obs 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	0.28278 (4)	0.23787 (6)	0.08714 (3)	0.03604 (19)
O1	0.40889 (15)	0.4986 (2)	0.14144 (9)	0.0605 (5)
O2	0.32989 (18)	0.4985 (2)	0.24457 (9)	0.0771 (6)
O3	0.08152 (12)	0.26462 (18)	0.14410 (8)	0.0482 (4)
O4	0.11500 (16)	0.4132 (2)	0.23439 (10)	0.0740 (6)
C1	0.25214 (18)	0.3599 (2)	0.15379 (11)	0.0402 (5)
C2	0.3306 (2)	0.4563 (3)	0.18550 (12)	0.0497 (6)
C3	0.5072 (3)	0.5619 (4)	0.17161 (18)	0.0800 (9)
H3A	0.5203	0.5168	0.2159	0.096*
H3B	0.5671	0.5394	0.1422	0.096*
C4	0.4980 (3)	0.7229 (4)	0.1797 (2)	0.0944 (11)
H4A	0.5625	0.7613	0.1993	0.142*
H4B	0.4394	0.7452	0.2094	0.142*
H4C	0.4861	0.7678	0.1358	0.142*
C5	0.14746 (19)	0.3514 (3)	0.18333 (11)	0.0451 (6)
C6	−0.0166 (2)	0.2190 (4)	0.17536 (15)	0.0691 (8)
H6A	−0.0587	0.3056	0.1869	0.083*
H6B	−0.0017	0.1651	0.2173	0.083*
C7	−0.0765 (2)	0.1240 (4)	0.12803 (19)	0.0892 (11)
H7A	−0.1420	0.0942	0.1491	0.134*
H7B	−0.0351	0.0378	0.1172	0.134*
H7C	−0.0917	0.1780	0.0867	0.134*
C11	0.23707 (19)	0.0525 (3)	0.11073 (12)	0.0480 (6)
C21	0.2530 (2)	0.0054 (3)	0.17789 (15)	0.0645 (8)
H21	0.2865	0.0674	0.2093	0.077*
C31	0.2184 (3)	−0.1356 (4)	0.1979 (2)	0.0878 (12)
H31	0.2302	−0.1680	0.2425	0.105*
C41	0.1674 (3)	−0.2260 (3)	0.1521 (2)	0.0973 (14)
H41	0.1443	−0.3194	0.1657	0.117*
C51	0.1504 (3)	−0.1793 (4)	0.0865 (2)	0.1018 (14)
H51	0.1156	−0.2413	0.0556	0.122*
C61	0.1846 (3)	−0.0396 (3)	0.06506 (16)	0.0738 (9)
H61	0.1723	−0.0085	0.0203	0.089*
C12	0.22621 (17)	0.2862 (2)	0.00423 (11)	0.0390 (5)
C22	0.2505 (2)	0.2050 (3)	−0.05516 (12)	0.0513 (6)
H22	0.2972	0.1253	−0.0526	0.062*
C32	0.2052 (2)	0.2430 (3)	−0.11772 (13)	0.0637 (8)
H32	0.2206	0.1880	−0.1567	0.076*
C42	0.1374 (2)	0.3626 (4)	−0.12168 (14)	0.0702 (9)
H42	0.1074	0.3886	−0.1636	0.084*
C52	0.1137 (2)	0.4444 (4)	−0.06362 (15)	0.0670 (8)
H52	0.0678	0.5250	−0.0668	0.080*
C62	0.15799 (19)	0.4070 (3)	−0.00085 (12)	0.0490 (6)
H62	0.1420	0.4627	0.0379	0.059*
C13	0.42517 (18)	0.2246 (2)	0.07359 (11)	0.0415 (5)
C23	0.47419 (19)	0.3002 (3)	0.01996 (13)	0.0560 (7)
H23	0.4329	0.3523	−0.0114	0.067*
C33	0.5831 (2)	0.2986 (4)	0.01300 (14)	0.0667 (8)
H33	0.6148	0.3483	−0.0233	0.080*
C43	0.6452 (2)	0.2234 (4)	0.05986 (14)	0.0654 (8)
H43	0.7188	0.2231	0.0552	0.078*
C53	0.5985 (2)	0.1489 (3)	0.11338 (14)	0.0654 (8)
H53	0.6405	0.0994	0.1453	0.079*
C63	0.4889 (2)	0.1475 (3)	0.11966 (12)	0.0539 (6)
H63	0.4575	0.0945	0.1551	0.065*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
P1	0.0417 (3)	0.0315 (3)	0.0349 (3)	−0.0003 (2)	0.0024 (2)	0.0019 (2)
O1	0.0688 (11)	0.0599 (11)	0.0528 (10)	−0.0242 (9)	0.0006 (8)	−0.0031 (9)
O2	0.1037 (16)	0.0869 (15)	0.0405 (10)	−0.0356 (13)	−0.0072 (10)	−0.0102 (10)
O3	0.0432 (9)	0.0550 (10)	0.0464 (9)	−0.0047 (8)	0.0061 (7)	−0.0064 (8)
O4	0.0808 (14)	0.0834 (14)	0.0577 (11)	−0.0053 (11)	0.0214 (10)	−0.0272 (11)
C1	0.0477 (13)	0.0381 (12)	0.0349 (11)	−0.0021 (10)	−0.0017 (9)	−0.0013 (9)
C2	0.0674 (16)	0.0436 (13)	0.0379 (13)	−0.0069 (12)	−0.0079 (11)	0.0015 (10)
C3	0.0791 (19)	0.080 (2)	0.081 (2)	−0.0296 (17)	−0.0041 (15)	−0.0161 (17)
C4	0.098 (3)	0.079 (2)	0.107 (3)	−0.021 (2)	0.008 (2)	−0.018 (2)
C5	0.0560 (14)	0.0422 (13)	0.0371 (12)	0.0033 (11)	0.0038 (10)	−0.0005 (10)
C6	0.0541 (16)	0.087 (2)	0.0662 (18)	−0.0107 (15)	0.0133 (13)	0.0106 (16)
C7	0.0614 (19)	0.102 (3)	0.104 (3)	−0.0271 (19)	−0.0111 (18)	0.019 (2)
C11	0.0524 (14)	0.0346 (12)	0.0572 (14)	0.0032 (10)	0.0202 (11)	0.0052 (11)
C21	0.0569 (16)	0.0626 (17)	0.0739 (18)	0.0000 (14)	0.0100 (13)	0.0274 (15)
C31	0.073 (2)	0.074 (2)	0.116 (3)	0.0150 (18)	0.036 (2)	0.054 (2)
C41	0.113 (3)	0.0350 (16)	0.144 (4)	0.0023 (18)	0.071 (3)	0.014 (2)
C51	0.146 (4)	0.0480 (18)	0.112 (3)	−0.035 (2)	0.063 (3)	−0.0222 (19)
C61	0.107 (2)	0.0421 (15)	0.0720 (19)	−0.0198 (15)	0.0313 (17)	−0.0116 (14)
C12	0.0431 (12)	0.0370 (11)	0.0368 (11)	−0.0053 (9)	−0.0008 (9)	0.0002 (9)
C22	0.0636 (16)	0.0459 (13)	0.0446 (13)	−0.0043 (12)	0.0050 (11)	−0.0049 (11)
C32	0.0789 (19)	0.0735 (19)	0.0388 (14)	−0.0228 (16)	−0.0001 (12)	−0.0062 (13)
C42	0.0677 (19)	0.097 (2)	0.0456 (15)	−0.0143 (17)	−0.0134 (13)	0.0141 (16)
C52	0.0599 (17)	0.076 (2)	0.0648 (18)	0.0116 (15)	−0.0065 (13)	0.0189 (15)
C62	0.0522 (14)	0.0484 (14)	0.0464 (13)	0.0044 (11)	0.0007 (11)	0.0046 (11)
C13	0.0444 (12)	0.0409 (12)	0.0391 (12)	0.0042 (10)	0.0027 (9)	0.0049 (9)
C23	0.0472 (14)	0.0700 (17)	0.0508 (14)	0.0038 (13)	0.0008 (11)	0.0244 (13)
C33	0.0522 (15)	0.089 (2)	0.0584 (16)	0.0015 (15)	0.0114 (12)	0.0263 (15)
C43	0.0436 (14)	0.091 (2)	0.0612 (16)	0.0120 (14)	0.0073 (12)	0.0124 (16)
C53	0.0568 (16)	0.082 (2)	0.0580 (16)	0.0215 (15)	0.0005 (13)	0.0223 (15)
C63	0.0548 (15)	0.0609 (16)	0.0459 (13)	0.0097 (12)	0.0080 (11)	0.0175 (12)

Geometric parameters (Å, º)

P1—C1	1.748 (3)	C31—H31	0.9300
P1—C11	1.828 (3)	C41—C51	1.364 (6)
P1—C12	1.819 (4)	C41—H41	0.9300
P1—C13	1.814 (3)	C51—C61	1.396 (4)
O1—C2	1.363 (3)	C51—H51	0.9300
O1—C3	1.482 (4)	C61—H61	0.9300
O2—C2	1.214 (4)	C12—C62	1.390 (3)
O3—C5	1.372 (3)	C12—C22	1.405 (4)
O3—C6	1.438 (3)	C22—C32	1.389 (4)
O4—C5	1.214 (3)	C22—H22	0.9300
C1—C2	1.453 (3)	C32—C42	1.377 (5)
C1—C5	1.440 (4)	C32—H32	0.9300
C3—C4	1.466 (5)	C42—C52	1.386 (5)
C3—H3A	0.9700	C42—H42	0.9300
C3—H3B	0.9700	C52—C62	1.386 (4)
C4—H4A	0.9600	C52—H52	0.9300
C4—H4B	0.9600	C62—H62	0.9300
C4—H4C	0.9600	C13—C63	1.389 (4)
C6—C7	1.467 (5)	C13—C23	1.394 (4)
C6—H6A	0.9700	C23—C33	1.376 (4)
C6—H6B	0.9700	C23—H23	0.9300
C7—H7A	0.9600	C33—C43	1.380 (4)
C7—H7B	0.9600	C33—H33	0.9300
C7—H7C	0.9600	C43—C53	1.375 (4)
C11—C61	1.384 (4)	C43—H43	0.9300
C11—C21	1.392 (5)	C53—C63	1.384 (4)
C21—C31	1.400 (4)	C53—H53	0.9300
C21—H21	0.9300	C63—H63	0.9300
C31—C41	1.369 (6)
C1—P1—C11	108.60 (15)	C41—C31—H31	119.8
C1—P1—C12	115.14 (16)	C21—C31—H31	119.8
C1—P1—C13	111.66 (11)	C51—C41—C31	120.1 (3)
C11—P1—C12	108.71 (12)	C51—C41—H41	120.0
C11—P1—C13	106.69 (11)	C31—C41—H41	120.0
C12—P1—C13	105.68 (13)	C41—C51—C61	120.8 (4)
C2—O1—C3	117.4 (2)	C41—C51—H51	119.6
C5—O3—C6	116.4 (2)	C61—C51—H51	119.6
P1—C1—C2	122.95 (19)	C11—C61—C51	119.7 (3)
P1—C1—C5	117.87 (17)	C11—C61—H61	120.1
C2—C1—C5	118.8 (2)	C51—C61—H61	120.1
O1—C2—O2	121.2 (2)	C62—C12—C22	119.0 (2)
O1—C2—C1	112.9 (2)	C62—C12—P1	119.42 (18)
O2—C2—C1	125.9 (2)	C22—C12—P1	121.6 (2)
C4—C3—O1	111.0 (3)	C32—C22—C12	120.5 (3)
C4—C3—H3A	109.4	C32—C22—H22	119.8
O1—C3—H3A	109.4	C12—C22—H22	119.8
C4—C3—H3B	109.4	C42—C32—C22	119.7 (3)
O1—C3—H3B	109.4	C42—C32—H32	120.2
H3A—C3—H3B	108.0	C22—C32—H32	120.2
C3—C4—H4A	109.5	C32—C42—C52	120.4 (3)
C3—C4—H4B	109.5	C32—C42—H42	119.8
H4A—C4—H4B	109.5	C52—C42—H42	119.8
C3—C4—H4C	109.5	C42—C52—C62	120.4 (3)
H4A—C4—H4C	109.5	C42—C52—H52	119.8
H4B—C4—H4C	109.5	C62—C52—H52	119.8
O4—C5—O3	121.1 (2)	C52—C62—C12	120.1 (2)
O4—C5—C1	127.8 (2)	C52—C62—H62	120.0
O3—C5—C1	111.0 (2)	C12—C62—H62	120.0
O3—C6—C7	109.9 (3)	C63—C13—C23	118.4 (2)
O3—C6—H6A	109.7	C63—C13—P1	120.42 (19)
C7—C6—H6A	109.7	C23—C13—P1	120.99 (17)
O3—C6—H6B	109.7	C33—C23—C13	120.7 (2)
C7—C6—H6B	109.7	C33—C23—H23	119.7
H6A—C6—H6B	108.2	C13—C23—H23	119.7
C6—C7—H7A	109.5	C23—C33—C43	120.1 (3)
C6—C7—H7B	109.5	C23—C33—H33	120.0
H7A—C7—H7B	109.5	C43—C33—H33	120.0
C6—C7—H7C	109.5	C53—C43—C33	120.2 (3)
H7A—C7—H7C	109.5	C53—C43—H43	119.9
H7B—C7—H7C	109.5	C33—C43—H43	119.9
C61—C11—C21	119.4 (3)	C43—C53—C63	119.9 (2)
C61—C11—P1	122.4 (2)	C43—C53—H53	120.1
C21—C11—P1	118.1 (2)	C63—C53—H53	120.1
C11—C21—C31	119.7 (3)	C53—C63—C13	120.7 (2)
C11—C21—H21	120.2	C53—C63—H63	119.6
C31—C21—H21	120.2	C13—C63—H63	119.6
C41—C31—C21	120.3 (4)
P1—C1—C2—O2	−149.8 (2)	O4—C5—C1—C2	−2.3 (4)
P1—C1—C5—O4	170.8 (2)	C5—C1—C2—O2	22.9 (4)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C53—H53···O2^i	0.93	2.36	3.213 (6)	152

Symmetry code: (i) −x+1, y−1/2, −z+1/2.