2,6,7-Trioxa-1-phosphabicyclo­[2.2.2]octan-4-ylmethanol 1-sulfide

Abstract

The title compound, C₅H₉O₄PS, was synthesized by the reaction of penta­erythritol with thio­phosphoryl chloride. In the crystal structure, the three six-membered rings all adopt boat conformations. Mol­ecules form chains along the c axis via inter­molecular O—H⋯O hydrogen bonds.

Related literature

For a general background to the synthesis and applications of the title compound, see: Bourbigot & Duquesne (2007 ▶); Fontaine et al. (2008 ▶); Le Bras et al. (1997 ▶); Ratz & Aweeting (1964 ▶).

Experimental

Crystal data

• C₅H₉O₄PS

• M _r = 196.16

• Orthorhombic,

• a = 11.571 (3) Å

• b = 9.724 (3) Å

• c = 7.112 (4) Å

• V = 800.2 (6) ų

• Z = 4

• Mo Kα radiation

• μ = 0.57 mm⁻¹

• T = 292 (2) K

• 0.44 × 0.40 × 0.24 mm

Data collection

• Enraf–Nonius CAD-4 diffractometer

• Absorption correction: for a sphere (Farrugia, 1999 ▶) T _min = 0.861, T _max = 0.863

• 1224 measured reflections

• 949 independent reflections

• 864 reflections with > 2s(I)

• R _int = 0.009

• 3 standard reflections every 80 reflections intensity decay: 0.3%

Refinement

• R[F ² > 2σ(F ²)] = 0.037

• wR(F ²) = 0.106

• S = 1.04

• 949 reflections

• 101 parameters

• 1 restraint

• H-atom parameters constrained

• Δρ_max = 0.45 e Å⁻³

• Δρ_min = −0.23 e Å⁻³

• Absolute structure: Flack (1983 ▶), 137 Friedel pairs

• Flack parameter: −0.04 (19)

Data collection: DIFRAC (Gabe et al., 1993 ▶); cell refinement: DIFRAC; data reduction: NRCVAX (Gabe et al., 1989 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

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

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O4—H4⋯O2i	0.82	2.20	2.886 (6)	141

Symmetry code: (i) .

supplementary crystallographic information

Comment

Intumescent flame retardant systems appear as an attractive topic and represent a wide and interesting area of research (Bourbigot & Duquesne, 2007). The use of pentaerythritol (Le Bras et al., 1997) as char former in intumescent formulations which composed of three components, i.e. an acid source, a char forming agent and a blowing agent for thermoplastics is associated with migration, water solubility and other problems. Those problems were solved by synthesis of additives that concentrate the three intumescent flame retardant elements in one molecule (Fontaine et al., 2008). The compound synthesized (Ratz & Aweeting, 1964) which has little intumescence is the intermediate product of the concentrate intumescent flame retardant.

In the molecule of the title compound (Fig.1), three six–membered rings adopt boat conformations. The bond angle of C3—C4—C5 is 112.7 (4)° which is bigger than one of sp³ hybrid, it may be the result of the co–existence of the three six–membered rings attached at C5. The torsion angles of S1/P1/O3/C3 and O1/C1/C4/C5 are -178.7 (3)° and -178.4 (4)°, respectively. Intermolecular O—H···O hydrogen bonds link the molecules with formation chains along c axis and effective stabilized the crystal structure (Table).

Experimental

A mixture of 62.6 g (0.46 mol) pentaerythritol and 77.9 g (0.46 mol) thiophosphoryl chloride was heated at 418 K in a 250 ml round–bottomed flask equipped for reflux, protected from atmospheric moisture and equipped with magnetic stirrer. Evolution of hydrogen chloride ceased after 5 h. The resulting cake was extracted with 150 ml boiling water and cooled to room temperature. During the extracting some material remained undissolved and collected as a heavy oil at the bottom of the flask. The aqueous solvent was separated from this oil by decantation through a folded filter. The product was crystallized from water and afforded white crystals (62 g, yield 68.7%, m.p. 431–433 K).

Refinement

H atoms were positioned geometrically (C—H = 0.97Å and O—H = 0.82 Å) and refined using a riding model, with U_iso(H) = 1.2U_eq(C), U_iso(H) = 1.5U_eq(O).

Figures

Fig. 1.

The asymmetric unit of title compound with the atom numbering scheme. Displacement ellipsoids are drawn at the 30% probability level. H atoms are presented as a small spheres of arbitrary radius.

Crystal data

C5H9O4PS	F(000) = 408
Mr = 196.16	Dx = 1.628 Mg m−3
Orthorhombic, Pna21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2c -2n	Cell parameters from 16 reflections
a = 11.571 (3) Å	θ = 4.5–7.2°
b = 9.724 (3) Å	µ = 0.57 mm−1
c = 7.112 (4) Å	T = 292 K
V = 800.2 (6) Å3	Block, colourless
Z = 4	0.44 × 0.40 × 0.24 mm

Data collection

Enraf–Nonius CAD-4 diffractometer	864 reflections with > 2s(I)
Radiation source: Fine–focus sealed tube	Rint = 0.009
Graphite	θmax = 25.5°, θmin = 2.7°
ω/2θ scans	h = −13→13
Absorption correction: for a sphere (Farrugia, 1999)	k = −11→11
Tmin = 0.861, Tmax = 0.863	l = −8→2
1224 measured reflections	3 standard reflections every 80 reflections
949 independent reflections	intensity decay: 0.3%

Refinement

Refinement on F2	Secondary atom site location: Difmap
Least-squares matrix: Full	Hydrogen site location: Geom
R[F2 > 2σ(F2)] = 0.037	H-atom parameters constrained
wR(F2) = 0.106	w = 1/[σ2(Fo2) + (0.0792P)2 + 0.1948P] where P = (Fo2 + 2Fc2)/3
S = 1.04	(Δ/σ)max < 0.001
949 reflections	Δρmax = 0.45 e Å−3
101 parameters	Δρmin = −0.23 e Å−3
1 restraint	Absolute structure: Flack (1983), 137 Friedel pairs
Primary atom site location: Direct	Flack parameter: −0.04 (19)

Special details

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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
S1	0.43219 (11)	0.07576 (14)	1.1866 (2)	0.0617 (4)
P1	0.32384 (8)	0.09916 (9)	0.98909 (19)	0.0389 (3)
O1	0.2853 (3)	−0.0370 (3)	0.8907 (5)	0.0534 (8)
O2	0.2054 (3)	0.1676 (3)	1.0501 (5)	0.0520 (8)
O3	0.3650 (2)	0.1924 (3)	0.8211 (5)	0.0509 (8)
O4	0.1030 (4)	0.0757 (5)	0.3982 (6)	0.0812 (13)
H4	0.1541	0.1153	0.3394	0.122*
C3	0.2796 (4)	0.2118 (5)	0.6721 (8)	0.0575 (12)
H3A	0.3115	0.1806	0.5534	0.069*
H3B	0.2617	0.3089	0.6603	0.069*
C1	0.1994 (4)	−0.0202 (5)	0.7394 (8)	0.0545 (11)
H1A	0.1299	−0.0711	0.7703	0.065*
H1B	0.2302	−0.0566	0.6227	0.065*
C2	0.1224 (3)	0.1837 (5)	0.8992 (7)	0.0470 (10)
H2A	0.1019	0.2801	0.8873	0.056*
H2B	0.0527	0.1329	0.9296	0.056*
C4	0.1702 (3)	0.1327 (4)	0.7147 (7)	0.0401 (9)
C5	0.0792 (4)	0.1483 (5)	0.5622 (7)	0.0557 (12)
H5A	0.0055	0.1173	0.6115	0.067*
H5B	0.0716	0.2450	0.5314	0.067*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
S1	0.0617 (7)	0.0732 (7)	0.0503 (7)	0.0055 (5)	−0.0140 (6)	0.0133 (7)
P1	0.0419 (5)	0.0398 (4)	0.0351 (5)	0.0032 (4)	0.0019 (5)	0.0075 (5)
O1	0.072 (2)	0.0367 (14)	0.0515 (19)	0.0077 (13)	−0.0097 (18)	0.0070 (16)
O2	0.0443 (14)	0.077 (2)	0.0349 (15)	0.0123 (14)	0.0007 (14)	−0.0066 (16)
O3	0.0430 (14)	0.0607 (17)	0.049 (2)	−0.0084 (13)	−0.0033 (15)	0.0200 (17)
O4	0.101 (3)	0.106 (3)	0.037 (2)	−0.015 (2)	−0.003 (2)	0.001 (2)
C3	0.052 (2)	0.074 (3)	0.047 (3)	−0.003 (2)	−0.005 (3)	0.025 (3)
C1	0.069 (3)	0.045 (2)	0.048 (3)	0.0042 (19)	−0.004 (2)	−0.003 (2)
C2	0.042 (2)	0.056 (2)	0.043 (3)	0.0064 (17)	−0.003 (2)	−0.004 (2)
C4	0.0401 (19)	0.0421 (18)	0.038 (2)	0.0000 (15)	0.0020 (18)	0.0051 (19)
C5	0.057 (3)	0.065 (3)	0.045 (3)	−0.005 (2)	−0.008 (2)	0.001 (2)

Geometric parameters (Å, °)

S1—P1	1.8966 (19)	C3—H3B	0.9700
P1—O1	1.562 (3)	C1—C4	1.535 (6)
P1—O3	1.573 (3)	C1—H1A	0.9700
P1—O2	1.583 (3)	C1—H1B	0.9700
O1—C1	1.474 (6)	C2—C4	1.508 (6)
O2—C2	1.449 (5)	C2—H2A	0.9700
O3—C3	1.461 (5)	C2—H2B	0.9700
O4—C5	1.390 (6)	C4—C5	1.519 (7)
O4—H4	0.8200	C5—H5A	0.9700
C3—C4	1.512 (6)	C5—H5B	0.9700
C3—H3A	0.9700
O1—P1—O3	103.55 (19)	C4—C1—H1B	109.7
O1—P1—O2	103.38 (18)	H1A—C1—H1B	108.2
O3—P1—O2	103.18 (18)	O2—C2—C4	111.4 (3)
O1—P1—S1	114.77 (13)	O2—C2—H2A	109.3
O3—P1—S1	115.56 (13)	C4—C2—H2A	109.3
O2—P1—S1	114.78 (15)	O2—C2—H2B	109.3
C1—O1—P1	115.2 (2)	C4—C2—H2B	109.3
C2—O2—P1	114.6 (3)	H2A—C2—H2B	108.0
C3—O3—P1	114.9 (2)	C2—C4—C3	108.3 (4)
C5—O4—H4	109.5	C2—C4—C5	109.5 (3)
O3—C3—C4	110.8 (4)	C3—C4—C5	112.7 (4)
O3—C3—H3A	109.5	C2—C4—C1	107.5 (4)
C4—C3—H3A	109.5	C3—C4—C1	109.3 (3)
O3—C3—H3B	109.5	C5—C4—C1	109.3 (4)
C4—C3—H3B	109.5	O4—C5—C4	114.3 (4)
H3A—C3—H3B	108.1	O4—C5—H5A	108.7
O1—C1—C4	109.9 (4)	C4—C5—H5A	108.7
O1—C1—H1A	109.7	O4—C5—H5B	108.7
C4—C1—H1A	109.7	C4—C5—H5B	108.7
O1—C1—H1B	109.7	H5A—C5—H5B	107.6
O3—P1—O1—C1	−54.2 (3)	O2—C2—C4—C3	−58.1 (5)
O2—P1—O1—C1	53.1 (3)	O2—C2—C4—C5	178.5 (4)
S1—P1—O1—C1	178.9 (3)	O2—C2—C4—C1	59.9 (4)
O1—P1—O2—C2	−53.5 (3)	O3—C3—C4—C2	59.4 (5)
O3—P1—O2—C2	54.1 (3)	O3—C3—C4—C5	−179.2 (4)
S1—P1—O2—C2	−179.3 (3)	O3—C3—C4—C1	−57.4 (5)
O1—P1—O3—C3	54.9 (3)	O1—C1—C4—C2	−59.6 (4)
O2—P1—O3—C3	−52.6 (4)	O1—C1—C4—C3	57.7 (5)
S1—P1—O3—C3	−178.7 (3)	O1—C1—C4—C5	−178.4 (4)
P1—O3—C3—C4	−1.3 (5)	C2—C4—C5—O4	−165.6 (4)
P1—O1—C1—C4	0.8 (5)	C3—C4—C5—O4	73.8 (6)
P1—O2—C2—C4	−1.0 (5)	C1—C4—C5—O4	−48.1 (5)

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
O4—H4···O2i	0.82	2.20	2.886 (6)	141

Symmetry codes: (i) x, y, z−1.