Tris(4-chloro­phen­yl) phosphate

Birch, J.; Hosten, E.C.; Betz, R.

doi:10.1107/S2414314624010617

organic compounds

IUCrDATA

ISSN: 2414-3146

Volume 9| Part 11| November 2024| x241061

https://doi.org/10.1107/S2414314624010617

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Tris(4-chlorophenyl) phosphate

Joshua Birch,^a Eric Cyriel Hosten ^a and Richard Betz ^a ^*

^aNelson Mandela University, Summerstrand Campus, Department of Chemistry, University Way, Summerstrand, PO Box 77000, Port Elizabeth, 6031, South Africa
^*Correspondence e-mail: Richard.Betz@mandela.ac.za

Edited by W. T. A. Harrison, University of Aberdeen, United Kingdom (Received 1 November 2024; accepted 2 November 2024; online 8 November 2024)

The title compound, C₁₈H₁₂Cl₃O₄P, is the symmetric phosphate derived from para-chlorophenol and phosphoric acid. Two of the three aromatic moieties adopt syn-orientation towards the P=O bond while the last chlorophenol ring is pointing away from this bond. In the extended structure, C—H⋯O bonds connect the individual molecules into sheets lying perpendicular to the crystallographic b axis.

Keywords: crystal structure.

CCDC reference: 2396855

Structure description

Pentacoordinate compounds of phosphorus have been an intriguing field of research for many decades, owing to their assumed importance as transition states in biological systems that see the formation and decomposition of a multitude of compounds derived from phosphoric acid encountered along the many metabolic pathways in eucaryontic cells (Stryer, 1988 ; Westheimer, 1968 ; Gerlt et al., 1975 ; Holmes, 1998 , 2004 ). An easy inroad into such derivatives stems from exploiting ligand-exchange reactions starting from already pentacoordinate precursors of this element. At the onset of a study into the chemical reactivity of this class of compound, we sought to synthesize the symmetric oxyphosphorane of para-chlorophenol, which would result in the formation of a solid reaction product of which a crystalline specimen could be subjected to diffraction studies. The results of the latter showed the presence of a defined hydrolysis product whose formation was already confirmed by means of NMR studies on the crude reaction mixture. In our ongoing interest into structural aspects of the heavier pnictogen elements such as phosphorus (Hosten et al., 2012 ; Betz & Klüfers, 2008 ; Betz, 2015 ; Betz et al., 2011a ), arsenic (Betz et al., 2007 , 2008 , 2009a ,b , 2011b ; Betz & Klüfers, 2009 ) and antimony (Betz et al., 2009b, 2010 ) and to spare future researchers the waste of valuable data-collection time on diffractometers, the outcome of our crystallographic studies is presented herein. Structural data for the thionated analogue of the title compound are apparent in the literature (Hernandez et al., 2006 ), as are data for a dinuclear diphosphazene (Allcock et al., 1994 ). Furthermore, the crystal and molecular structures of several ruthenium coordination compounds employing the trivalent phosphite ester as a ligand (Bidal et al., 2019 ) as well as two related phosphoranes in line with the actual intended oxyphosphorane have been reported (Sarma et al., 1976 ; Marczenko et al., 2019 ).

The structure solution shows the presence of the title compound, C₁₈H₁₂Cl₃O₄P, a symmetric ester of phosphoric acid derived from three equivalents of para-chlorophenol (Fig. 1). The P—O bond lengths to the three aromatic alcohol moieties cover the range 1.5678 (13)–1.5806 (14) Å while the (formal) P=O double bond is found at a value of 1.4513 (14) Å. The carbon–chlorine bonds lie between 1.7388 (18) and 1.7422 (19) Å and are, therefore, in good agreement with other aromatic C—Cl bonds whose metrical parameters have been deposited with the Cambridge Structural Database (Groom et al., 2002 ). The O—P—O angles span the range 101.50 (7)–118.37 (8)° with the largest three angles all involving the lone oxygen atom. The least-squares planes as defined by the respective carbon atoms of the C11, C21 and C31 aromatic rings enclose angles of 49.42 (8) (C11/C21), 69.83 (8) (C11/C31) and 77.48 (9)° (C21/C31). In comparison to the thionated analogue of the title compound (Hernandez et al., 2006), the P—O bonds as well as the C—Cl bonds are all found at slightly larger values in the sulfur-derivative.

Figure 1
The molecular structure of the title compound with displacement ellipsoids drawn at the 50% probability level.

In the crystal of C₁₈H₁₂Cl₃O₄P, C—H⋯O contacts shorter than 0.1 Å less than the sum of the van der Waals radii are apparent. The latter are supported by one of the hydrogen atoms in the ortho-position to the chlorine atom on each of the aromatic rings and uniformly employ the (formally) double bonded oxygen atom O4 as acceptor (Table 1). In terms of graph-set analysis (Etter et al., 1990 ; Bernstein et al., 1995 ), these contacts require a C₁¹(7) C₁¹(7) C₁¹(7) descriptor on the unary level. In total, the molecules are connected into sheets lying perpendicular to the crystallographic b axis (Fig. 2). Two of the aromatic systems experience stabilization through π-stacking interactions with the shortest intercentroid distance measured at 3.7544 (10) Å.

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C15—H15⋯O4ⁱ	0.95	2.42	3.324 (2)	159
C25—H25⋯O4ⁱⁱ	0.95	2.40	3.176 (2)	139
C33—H33⋯O4ⁱⁱⁱ	0.95	2.59	3.423 (2)	147
Symmetry codes: (i) $[x+{\script{1\over 2}}, -y+{\script{3\over 2}}, z-{\script{1\over 2}}]$ ; (ii) $[x+{\script{1\over 2}}, -y+{\script{3\over 2}}, z+{\script{1\over 2}}]$ ; (iii) .

Figure 2
Intermolecular contacts viewed approximately along [010].

Synthesis and crystallization

The title compound was isolated as an accidental hydrolysis by-product upon the synthesis of the symmetric para-chlorophenoxyphosphorane from PCl₅ and para-chlorophenol according to a published procedure (Ramirez et al., 1968 ). A crystal suitable for the diffraction study was taken directly from the crystallized oily product.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2.

Table 2
Experimental details

Crystal data
Chemical formula	C₁₈H₁₂Cl₃O₄P
M_r	429.60
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	200
a, b, c (Å)	7.5771 (5), 21.1280 (14), 11.2665 (7)
β (°)	95.835 (2)
V (Å³)	1794.3 (2)
Z	4
Radiation type	Mo Kα
μ (mm⁻¹)	0.62
Crystal size (mm)	0.60 × 0.14 × 0.13

Data collection
Diffractometer	Bruker APEXII CCD
Absorption correction	Multi-scan (SADABS; Krause et al., 2015 )
T_min, T_max	0.792, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections	58447, 4427, 3920
R_int	0.036
(sin θ/λ)_max (Å⁻¹)	0.667

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.038, 0.097, 1.12
No. of reflections	4427
No. of parameters	235
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.37, −0.44
Computer programs: APEX2 and SAINT (Bruker, 2016 ), SHELXS97 (Sheldrick 2008 ), ORTEP-3 for Windows (Farrugia, 2012 ), Mercury (Macrae et al., 2020 ), SHELXL2019/3 (Sheldrick, 2015 ) and PLATON (Spek, 2020 ).

Structural data

CCDC reference: 2396855

Crystal structure: contains datablock I. DOI: https://doi.org/10.1107/S2414314624010617/hb4490sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314624010617/hb4490Isup2.hkl

Supporting information file. DOI: https://doi.org/10.1107/S2414314624010617/hb4490Isup3.cml

checkCIF report

Computing details top

Tris(4-chlorophenyl) phosphate top

Crystal data top

C₁₈H₁₂Cl₃O₄P	F(000) = 872
M_r = 429.60	D_x = 1.590 Mg m⁻³
Monoclinic, P2₁/n	Mo Kα radiation, λ = 0.71073 Å
a = 7.5771 (5) Å	Cell parameters from 9220 reflections
b = 21.1280 (14) Å	θ = 2.7–28.3°
c = 11.2665 (7) Å	µ = 0.62 mm⁻¹
β = 95.835 (2)°	T = 200 K
V = 1794.3 (2) Å³	Rod, colourless
Z = 4	0.60 × 0.14 × 0.13 mm

Data collection top

Bruker APEXII CCD diffractometer	3920 reflections with I > 2σ(I)
φ and ω scans	R_int = 0.036
Absorption correction: multi-scan (SADABS; Krause et al., 2015)	θ_max = 28.3°, θ_min = 2.1°
T_min = 0.792, T_max = 1.000	h = −10→9
58447 measured reflections	k = −28→28
4427 independent reflections	l = −15→15

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.038	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.097	H-atom parameters constrained
S = 1.12	w = 1/[σ²(F_o²) + (0.0344P)² + 1.6089P] where P = (F_o² + 2F_c²)/3
4427 reflections	(Δ/σ)_max = 0.001
235 parameters	Δρ_max = 0.37 e Å⁻³
0 restraints	Δρ_min = −0.43 e Å⁻³

Special details top

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

Refinement. The carbon-bound H atoms were placed in calculated positions (C—H = 0.95 Å) and were included in the refinement in the riding model approximation, with U_iso(H) set to 1.2U_eq(C).

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
Cl1	0.17450 (8)	0.67130 (3)	0.25722 (4)	0.04555 (15)
Cl2	0.15619 (7)	0.96171 (2)	1.13729 (5)	0.04071 (14)
Cl3	0.96260 (7)	0.50899 (3)	1.16357 (5)	0.03942 (14)
P1	0.23268 (6)	0.67194 (2)	0.87255 (4)	0.02265 (11)
O1	0.31794 (18)	0.63308 (6)	0.77432 (11)	0.0272 (3)
O2	0.34438 (17)	0.73521 (6)	0.87549 (12)	0.0277 (3)
O3	0.29349 (17)	0.63395 (6)	0.98911 (11)	0.0269 (3)
O4	0.04172 (17)	0.68072 (6)	0.85985 (12)	0.0298 (3)
C11	0.2781 (2)	0.64485 (8)	0.65109 (15)	0.0227 (3)
C12	0.1892 (2)	0.59829 (8)	0.58403 (16)	0.0262 (4)
H12	0.150962	0.560988	0.620952	0.031*
C13	0.1561 (2)	0.60655 (9)	0.46160 (17)	0.0280 (4)
H13	0.094852	0.575032	0.413415	0.034*
C14	0.2138 (2)	0.66143 (9)	0.41085 (16)	0.0276 (4)
C15	0.3042 (3)	0.70793 (9)	0.47845 (18)	0.0298 (4)
H15	0.343241	0.745139	0.441633	0.036*
C16	0.3373 (2)	0.69956 (9)	0.60092 (17)	0.0273 (4)
H16	0.399366	0.730840	0.649255	0.033*
C21	0.2917 (2)	0.78820 (8)	0.93942 (16)	0.0237 (3)
C22	0.2113 (3)	0.83806 (9)	0.87600 (16)	0.0288 (4)
H22	0.186261	0.835618	0.791773	0.035*
C23	0.1678 (3)	0.89184 (9)	0.93736 (17)	0.0292 (4)
H23	0.112444	0.926854	0.895784	0.035*
C24	0.2060 (2)	0.89370 (9)	1.05993 (17)	0.0269 (4)
C25	0.2854 (2)	0.84366 (9)	1.12328 (16)	0.0279 (4)
H25	0.309330	0.845798	1.207611	0.033*
C26	0.3298 (2)	0.79007 (9)	1.06137 (16)	0.0264 (4)
H26	0.385733	0.755121	1.102768	0.032*
C31	0.4588 (2)	0.60700 (8)	1.02654 (15)	0.0229 (3)
C32	0.6164 (3)	0.62701 (9)	0.98716 (17)	0.0300 (4)
H32	0.617447	0.660803	0.931603	0.036*
C33	0.7737 (3)	0.59701 (10)	1.03000 (18)	0.0315 (4)
H33	0.883513	0.610130	1.004259	0.038*
C34	0.7679 (2)	0.54797 (9)	1.11032 (16)	0.0260 (4)
C35	0.6100 (2)	0.52804 (8)	1.14972 (15)	0.0256 (4)
H35	0.608753	0.494033	1.204801	0.031*
C36	0.4536 (2)	0.55828 (8)	1.10788 (15)	0.0244 (3)
H36	0.344168	0.545645	1.134817	0.029*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Cl1	0.0594 (4)	0.0555 (3)	0.0228 (2)	0.0116 (3)	0.0091 (2)	0.0070 (2)
Cl2	0.0412 (3)	0.0326 (2)	0.0492 (3)	−0.0024 (2)	0.0087 (2)	−0.0158 (2)
Cl3	0.0279 (2)	0.0446 (3)	0.0451 (3)	0.0055 (2)	0.0005 (2)	0.0124 (2)
P1	0.0239 (2)	0.0231 (2)	0.0209 (2)	0.00231 (16)	0.00230 (16)	−0.00020 (16)
O1	0.0338 (7)	0.0262 (6)	0.0214 (6)	0.0082 (5)	0.0025 (5)	0.0001 (5)
O2	0.0298 (7)	0.0248 (6)	0.0298 (6)	−0.0003 (5)	0.0088 (5)	−0.0018 (5)
O3	0.0248 (6)	0.0327 (7)	0.0231 (6)	0.0027 (5)	0.0031 (5)	0.0053 (5)
O4	0.0249 (6)	0.0321 (7)	0.0319 (7)	0.0031 (5)	0.0009 (5)	−0.0025 (5)
C11	0.0233 (8)	0.0246 (8)	0.0206 (8)	0.0071 (6)	0.0044 (6)	0.0004 (6)
C12	0.0290 (9)	0.0227 (8)	0.0274 (9)	0.0032 (7)	0.0058 (7)	0.0025 (7)
C13	0.0286 (9)	0.0284 (9)	0.0269 (9)	0.0032 (7)	0.0021 (7)	−0.0036 (7)
C14	0.0285 (9)	0.0350 (9)	0.0205 (8)	0.0103 (7)	0.0076 (7)	0.0038 (7)
C15	0.0295 (9)	0.0283 (9)	0.0334 (9)	0.0033 (7)	0.0117 (8)	0.0064 (7)
C16	0.0247 (8)	0.0264 (9)	0.0316 (9)	−0.0002 (7)	0.0065 (7)	−0.0013 (7)
C21	0.0222 (8)	0.0228 (8)	0.0265 (8)	−0.0021 (6)	0.0048 (6)	−0.0010 (6)
C22	0.0338 (10)	0.0303 (9)	0.0218 (8)	0.0008 (7)	0.0010 (7)	0.0019 (7)
C23	0.0310 (9)	0.0268 (9)	0.0293 (9)	0.0036 (7)	0.0010 (7)	0.0046 (7)
C24	0.0239 (8)	0.0254 (8)	0.0321 (9)	−0.0040 (7)	0.0064 (7)	−0.0056 (7)
C25	0.0262 (9)	0.0350 (10)	0.0219 (8)	−0.0045 (7)	0.0007 (7)	−0.0002 (7)
C26	0.0253 (8)	0.0272 (8)	0.0261 (8)	0.0004 (7)	0.0004 (7)	0.0059 (7)
C31	0.0253 (8)	0.0252 (8)	0.0182 (7)	0.0012 (6)	0.0018 (6)	−0.0008 (6)
C32	0.0286 (9)	0.0308 (9)	0.0306 (9)	−0.0035 (7)	0.0034 (7)	0.0104 (7)
C33	0.0256 (9)	0.0361 (10)	0.0330 (10)	−0.0044 (7)	0.0046 (7)	0.0070 (8)
C34	0.0252 (8)	0.0277 (9)	0.0243 (8)	0.0013 (7)	−0.0010 (7)	0.0005 (7)
C35	0.0310 (9)	0.0247 (8)	0.0213 (8)	−0.0011 (7)	0.0045 (7)	0.0032 (6)
C36	0.0263 (8)	0.0265 (8)	0.0213 (8)	−0.0018 (7)	0.0064 (6)	0.0009 (6)

Geometric parameters (Å, º) top

Cl1—C14	1.7388 (18)	C21—C26	1.376 (3)
Cl2—C24	1.7418 (19)	C21—C22	1.379 (3)
Cl3—C34	1.7422 (19)	C22—C23	1.387 (3)
P1—O4	1.4513 (14)	C22—H22	0.9500
P1—O3	1.5678 (13)	C23—C24	1.382 (3)
P1—O1	1.5690 (13)	C23—H23	0.9500
P1—O2	1.5806 (14)	C24—C25	1.379 (3)
O1—C11	1.413 (2)	C25—C26	1.389 (3)
O2—C21	1.411 (2)	C25—H25	0.9500
O3—C31	1.401 (2)	C26—H26	0.9500
C11—C12	1.374 (3)	C31—C36	1.381 (2)
C11—C16	1.381 (3)	C31—C32	1.382 (3)
C12—C13	1.388 (3)	C32—C33	1.392 (3)
C12—H12	0.9500	C32—H32	0.9500
C13—C14	1.383 (3)	C33—C34	1.379 (3)
C13—H13	0.9500	C33—H33	0.9500
C14—C15	1.381 (3)	C34—C35	1.383 (3)
C15—C16	1.388 (3)	C35—C36	1.386 (3)
C15—H15	0.9500	C35—H35	0.9500
C16—H16	0.9500	C36—H36	0.9500

O4—P1—O3	110.68 (8)	C23—C22—H22	120.6
O4—P1—O1	118.37 (8)	C24—C23—C22	119.00 (17)
O3—P1—O1	102.47 (7)	C24—C23—H23	120.5
O4—P1—O2	114.86 (8)	C22—C23—H23	120.5
O3—P1—O2	107.72 (7)	C25—C24—C23	122.09 (17)
O1—P1—O2	101.50 (7)	C25—C24—Cl2	118.61 (15)
C11—O1—P1	122.62 (11)	C23—C24—Cl2	119.29 (15)
C21—O2—P1	120.20 (11)	C24—C25—C26	118.69 (17)
C31—O3—P1	129.62 (11)	C24—C25—H25	120.7
C12—C11—C16	122.37 (16)	C26—C25—H25	120.7
C12—C11—O1	117.26 (15)	C21—C26—C25	119.23 (17)
C16—C11—O1	120.24 (16)	C21—C26—H26	120.4
C11—C12—C13	119.02 (17)	C25—C26—H26	120.4
C11—C12—H12	120.5	C36—C31—C32	121.64 (17)
C13—C12—H12	120.5	C36—C31—O3	114.70 (15)
C14—C13—C12	118.92 (17)	C32—C31—O3	123.66 (16)
C14—C13—H13	120.5	C31—C32—C33	119.12 (17)
C12—C13—H13	120.5	C31—C32—H32	120.4
C15—C14—C13	121.88 (17)	C33—C32—H32	120.4
C15—C14—Cl1	119.26 (15)	C34—C33—C32	119.09 (17)
C13—C14—Cl1	118.85 (15)	C34—C33—H33	120.5
C14—C15—C16	119.12 (17)	C32—C33—H33	120.5
C14—C15—H15	120.4	C33—C34—C35	121.70 (17)
C16—C15—H15	120.4	C33—C34—Cl3	119.91 (15)
C11—C16—C15	118.68 (17)	C35—C34—Cl3	118.38 (14)
C11—C16—H16	120.7	C34—C35—C36	119.20 (16)
C15—C16—H16	120.7	C34—C35—H35	120.4
C26—C21—C22	122.15 (17)	C36—C35—H35	120.4
C26—C21—O2	119.43 (16)	C31—C36—C35	119.24 (16)
C22—C21—O2	118.33 (16)	C31—C36—H36	120.4
C21—C22—C23	118.83 (17)	C35—C36—H36	120.4
C21—C22—H22	120.6

O4—P1—O1—C11	48.94 (16)	C26—C21—C22—C23	0.1 (3)
O3—P1—O1—C11	170.98 (13)	O2—C21—C22—C23	−176.51 (16)
O2—P1—O1—C11	−77.74 (14)	C21—C22—C23—C24	−0.1 (3)
O4—P1—O2—C21	40.80 (15)	C22—C23—C24—C25	−0.3 (3)
O3—P1—O2—C21	−83.02 (14)	C22—C23—C24—Cl2	178.60 (15)
O1—P1—O2—C21	169.75 (13)	C23—C24—C25—C26	0.7 (3)
O4—P1—O3—C31	169.27 (14)	Cl2—C24—C25—C26	−178.23 (14)
O1—P1—O3—C31	42.15 (16)	C22—C21—C26—C25	0.3 (3)
O2—P1—O3—C31	−64.41 (16)	O2—C21—C26—C25	176.86 (16)
P1—O1—C11—C12	−113.75 (16)	C24—C25—C26—C21	−0.7 (3)
P1—O1—C11—C16	70.2 (2)	P1—O3—C31—C36	−157.17 (13)
C16—C11—C12—C13	−0.5 (3)	P1—O3—C31—C32	23.3 (3)
O1—C11—C12—C13	−176.52 (15)	C36—C31—C32—C33	0.4 (3)
C11—C12—C13—C14	0.0 (3)	O3—C31—C32—C33	179.97 (17)
C12—C13—C14—C15	0.4 (3)	C31—C32—C33—C34	0.2 (3)
C12—C13—C14—Cl1	179.27 (14)	C32—C33—C34—C35	−0.3 (3)
C13—C14—C15—C16	−0.4 (3)	C32—C33—C34—Cl3	179.11 (15)
Cl1—C14—C15—C16	−179.23 (14)	C33—C34—C35—C36	−0.3 (3)
C12—C11—C16—C15	0.6 (3)	Cl3—C34—C35—C36	−179.68 (14)
O1—C11—C16—C15	176.44 (15)	C32—C31—C36—C35	−1.0 (3)
C14—C15—C16—C11	−0.1 (3)	O3—C31—C36—C35	179.43 (15)
P1—O2—C21—C26	78.94 (19)	C34—C35—C36—C31	0.9 (3)
P1—O2—C21—C22	−104.39 (17)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C15—H15···O4ⁱ	0.95	2.42	3.324 (2)	159
C25—H25···O4ⁱⁱ	0.95	2.40	3.176 (2)	139
C33—H33···O4ⁱⁱⁱ	0.95	2.59	3.423 (2)	147

Symmetry codes: (i) x+1/2, −y+3/2, z−1/2; (ii) x+1/2, −y+3/2, z+1/2; (iii) x+1, y, z.

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