Two types of monoethyl α-anilino­benzyl­phosphonates: a zwitterion and a molecular compound

The crystal structures of the potential antitumour agents monoethyl (α-anilinobenzyl)­phosphonate, C₁₅H₁₈NO₃P, (I), and its 4-azo­benzene-substituted derivative monoethyl {α-[4-(phenyl­diazenyl)­anilino]­benzyl}phosphonate, C₂₁H₂₂N₃O₃P, (II), are described. A zwitterionic form of (I) and a neutral molecular form of (II) are observed, which is fully in accordance with previously reported spectroscopic studies. In both structures, hydrogen bonding induces the formation of zigzag head-to-head double layers parallel to the crystallographic b axis.

S1. Comment

There has been continued interest in the chemistry of α-aminophosphonic acids and their derivatives, since these compounds exhibit a wide range of biological properties with potential applications in the agrochemical and pharmacological fields. A number of these compounds possess herbicidal (Kafarski et al., 1995), fungicidal (Rodriguez et al., 1999), antibiotic (Du et al., 1999), antitumour (Lavielle et al., 1991) and antiviral (Krize & Stella, 1996) activity. Another interesting aspect regarding this class of compounds arises from their metal-binding properties, which enable the application of selected derivatives as catalysts, extractants, ion exchangers etc. (Ohto et al., 1997; Dzygiel et al., 2003). On the other hand, some aminophosphonate complexes of Pt-group metals have shown antitumour activity (Bloemink et al., 1999, Ćurić et al., 1996; Tušek-Božić et al., 2003).

Our interest in this field is directed to dialkyl and monoalkyl esters of aniline- and quinoline-based aminophosphonic acids, as well as to their palladium(II) and platinum(II) complexes as potential antitumour agents. In the present work, the crystal structures of monoethyl (α-anilino-N-benzyl)phosphonate, (I), and its 4-azobenzene-substituted derivative monoethyl [α-(4-benzeneazoanilino)-N-benzyl]phosphonate, (II), are described. \sch

Recent infrared and ¹H NMR spectroscopic studies on these compounds (Tušek-Božić et al., 2000; Tušek-Božić & Lyčka, 2002; Tušek-Božić, 2002) have shown that monoester (I) has inner-salt character, with the aniline group being protonated and the phosphonic group being ionized, while monoester (II) possesses a neutral structure. Thus, in the spectra of (I), the NH₂⁺ and PO₂⁻ absorptions were observed, while in (II) those associated with the NH and P—O—H groups were present. The position and complexity of these absorptions indicate hydrogen bonding in both monoesters, which is in accordance with the results obtained by single-crystal X-ray studies of these compounds. Differences in the structure of two types of anilinobenzylphosphonates could be ascribed to the relatively low basicity of the benzalaniline N atom in (II) compared with that in (I), caused by the participation of its electron pair in resonance with the adjacent azobenzene π-system. In general, a zwitterionic structure has been determined for a large number of various aminophosphonic acids and their monoesters by IR, NMR and X-ray crystallographic studies (Appleton et al., 1984; Galdecki & Wolf, 1990; Fernandez & Vega, 2003; Fernandez et al., 2003; Tušek-Božić & D'Alpaos, 1998).

The molecular structures of (I) and (II) are given in Figs. 1 and 2, respectively. The bond lengths around P1 are considerably different in these two monoesters, as a consequence of the deprotonation of the P—O—H O atom in (I). In (II), a significant difference between the bond lengths P1—O26 [1.539 (3) Å] and P1—O27 [1.479 (2) Å] suggests double-bond character for the latter. In the Cambridge Structural Database (CSD, Version 5.25, November 2003; Allen, 2002), among the 258 ethyl-phosphonate derivatives with an unspecified substituent at the remaining singly bonded O atom, the average values of the analogous P—O bonds are 1.560 (1) and 1.465 (1) Å, respectively. However, only one monoethyl-phosphonate derivative was found in the current version of the CSD having a hydroxyl group bonded to P [as in (II)] (Fang-Zhong et al., 2000).

In (I), the deprotonation induces an overall charge delocalization around P, thus equating these two bond lengths [P1—O15 1.4959 (19) Å and P1—O16 1.4895 (19) Å]. A similar situation was observed among the six monoethyl-phosphonate structures with a deprotonated hydroxyl group found in the CSD, where the average lengths of the analogous P—O bonds are 1.496 (5) and 1.489 (4) Å, respectively.

If the CSD search is extended to the 279 ethyl-phosphonate structures with unspecified P—O bond types, a bond length scattergram of P—O1 versus P—O2 shows that, in the majority of such structures, non-delocalized P—O bonds are present (Fig. 3). In the two clearly revealed clusters on the scattergram, the average values of the P—O bonds are: x (P—O1) = 1.566 (1) Å, y (P—O2)= 1.460 (1) Å in one of the clusters, and x (P—O1) = 1.482 (1) Å, y (P—O2) = 1.555 (1) Å in the other. A third, less populated, cluster reveals approximately equal average values of x and y [1.48 (1) Å] and represents the small set of ethyl-phosphonate structures with delocalized P—O bonds [as in (II), in contrast with (I)].

The P1—C and the P1—O_ether bonds are considerably longer in (I) [1.844 (3) and 1.588 (2) Å, respectively] than in (II) [1.805 (3) and 1.558 (3) Å, respectively]. The set of 258 CSD ethyl-phosphonate structures reveals average values for these bonds of 1.797 (1) and 1.563 (1) Å, respectively. These values are comparable with those of (II). If, however, we analyse the set of six deprotonated structures, then the values for the analogous bonds are 1.841 (1) and 1.591 (4) Å, respectively, which are close to the corresponding values revealed by the structure of (I).

The atom1-P1-atom2 bond angles reveal that the atoms attached to P1 form an almost perfect tetrahedron in both (I) and (II). An unusually short Csp³—Csp³ contact was observed for the terminal ethyl group in (II) [1.393 (6) Å], as a consequence of the disorder of this part of the molecule. It was not possible to resolve the disordered positions of the terminal ethyl group. In (I), the analogue bond has an expected value [1.504 (5) Å].

The interplanar angle between the aniline moiety and the phenyl ring bonded to the stereogenic centre C6 in (I) is 68.2 (1)°. The same angle in (II) is 85.7 (2)° and the angle between the phenyl ring attached to the stereogenic centre C16 and the least-squares plane calculated through 15 atoms of the benzeneazoaniline moiety in (II) is 84.4 (2)° [maximum deviation from this least-squares plane 0.096 (3) Å for atom N15]. The difference in the values of these two analoguous interplanar angles is due to the N—C_chiral single-bond free rotation [torsion angle C9—C8—N7—C1 in (I) 53.9 (3)° and C17—C16—N15—C12 in (II) −72.0 (4)°] (Figs. 1 and 2). The torsion angles around the C_Ph—C_chiral bond [45.0 (3)° in (I) and −45.3 (4)° in (II)] suggest that the phenyl moiety has a particular preferred orientation with respect to the remaining part of the molecule, which is maintained in both structures.

In both structures, the molecular chains formed by intermolecular hydrogen bonding are parallel to the b axis and coincide with the four P2₁ screw axes perpendicular to the monoclinic plane. In (I), atom N7 engages both of its H atoms in intermolecular hydrogen bonding, connecting the parent molecule to two of its neighbours via atoms O16ⁱ and O15ⁱⁱ (Fig. 4; symmetry codes as in Fig. 4). At the same time, atom O15 of the parent molecule is the acceptor in the N7ⁱ—H···O15 hydrogen bond, and atom O16 is the acceptor in the N7ⁱⁱ—H···O16 hydrogen bond. The molecules are thus connected into doubly bonded zigzag chains parallel to the b axis. The elongation of the a axis in (II) relative to (I) is caused by the orientation of the bulky benzeneazoaniline moiety along this axis. In the structure of (II), the O atoms play a major role in the intermolecular hydrogen bonding (Fig. 5). Molecules are oriented head-to-head and intermolecular O26—H···O27ⁱ hydrogen bonds are observed creating molecular zigzag chains along the four twofold screw axes which are perpendicular to the ac plane (Fig. 5). In addition, there is an intramolecular N15—H···O26 hydrogen bond, making atom O26 a donor and an acceptor at the same time.

S2. Experimental

Compounds (I) and (II) were prepared by an acidification reaction from the corresponding sodium monoalkyl phosphonates, according to published methods (Jagodić, 1960; Jagodić & Tušek, 1972). Both monoesters were purified by repeated recrystallization from absolute ethanol and dried by heating to about 323 K under high vacuum. Crystals suitable for X-ray diffraction were obtained by slow evaporation from concentrated solutions in absolute ethanol, at 293 K for (I) and at 315 K for (II).

S3. Refinement

H atoms involved in hydrogen bonding were located directly from the Fourier map and refined freely. The positions of the remaining H atoms were determined in accordance with the relevant geometry and refined as a riding model, with C—H distances in the range 0.93–0.98 Å and with U_iso(H) = 1.2U_eq(C). Please check added text and correct as necessary.

Computing details

For both compounds, data collection: CAD-4 EXPRESS (Enraf-Nonius, 1994); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995). Program(s) used to solve structure: SIR2002 (Burla et al., 2003) for (I); SIR97 (Altomare et al., 1997) for (II). For both compounds, 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 (Farrugia, 1999).

Figures

	Fig. 1. A view of (I), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii.
	Fig. 2. A view of (II), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii.
	Fig. 3. A scattergram of P—O1 versus P—O2 bond lengths in 279 ethyl-phosphonate derivative structures found in the CSD (Version 5.25, November, 2003).
	Fig. 4. A crystal-packing diagram for (I) [symmetry codes: (i) 3/2 − x, y + 1/2, 1/2 − z; (ii) 3/2 − x, y − 1/2, 1/2 − z]
	Fig. 5. A crystal-packing diagram for (II), viewed down the b axis [symmetry code: (i) 1/2 − x, y − 1/2, 1/2 − z].

(I) Monoethyl [α-(phenylaminio)benzyl]phosphonate

Crystal data

C15H18NO3P	F(000) = 1232
Mr = 291.29	Dx = 1.329 Mg m^−3
Monoclinic, C2/c	Cu Kα radiation, λ = 1.54179 Å
Hall symbol: -C 2yc	Cell parameters from 25 reflections
a = 23.448 (2) Å	θ = 9.2–20.5°
b = 6.3510 (5) Å	µ = 1.74 mm^−1
c = 20.790 (3) Å	T = 293 K
β = 109.94 (1)°	Needle, yellow
V = 2910.4 (6) Å^3	0.35 × 0.08 × 0.05 mm
Z = 8

Data collection

Enraf-Nonius CAD-4 diffractometer	2177 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.030
Graphite monochromator	θmax = 76.1°, θmin = 4.0°
non–profiled ω/2θ scans	h = −27→29
Absorption correction: ψ scan (North et al., 1968)	k = −7→0
Tmin = 0.862, Tmax = 0.914	l = −26→0
3121 measured reflections	3 standard reflections every 120 min
3029 independent reflections	intensity decay: 1%

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)] = 0.050	w = 1/[σ^2(Fo^2) + (0.068P)^2 + 1.6186P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.133	(Δ/σ)max = 0.001
S = 1.04	Δρmax = 0.30 e Å^−3
3029 reflections	Δρmin = −0.54 e Å^−3
194 parameters

Special details

Experimental. For absorption correction, No. of ψ-scan sets used was 7. Theta correction was applied. Averaged transmission function was used. No Fourier smoothing was applied.

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
C1	0.80232 (11)	0.0955 (4)	0.41134 (13)	0.0113 (5)
C2	0.80101 (12)	−0.0697 (4)	0.45456 (13)	0.0143 (5)
H2	0.7907	−0.205	0.4375	0.017*
C3	0.81539 (12)	−0.0284 (5)	0.52370 (13)	0.0163 (6)
H3	0.8147	−0.1374	0.5533	0.02*
C4	0.83095 (12)	0.1742 (5)	0.54948 (14)	0.0159 (6)
H4	0.8408	0.2001	0.596	0.019*
C5	0.83169 (13)	0.3364 (4)	0.50545 (13)	0.0166 (6)
H5	0.8423	0.4715	0.5225	0.02*
C6	0.81662 (12)	0.2985 (4)	0.43564 (13)	0.0146 (6)
H6	0.8162	0.4081	0.4058	0.018*
C8	0.83959 (12)	0.0909 (4)	0.31230 (13)	0.0133 (5)
C9	0.89479 (12)	−0.0350 (4)	0.35280 (13)	0.0139 (5)
C10	0.95158 (13)	0.0569 (5)	0.37410 (17)	0.0255 (7)
H10	0.9555	0.1967	0.363	0.031*
C11	1.00277 (14)	−0.0545 (6)	0.4116 (2)	0.0349 (8)
H11	1.0407	0.0097	0.4248	0.042*
C12	0.99742 (15)	−0.2620 (6)	0.42930 (17)	0.0291 (7)
H12	1.0316	−0.3369	0.4553	0.035*
C13	0.94138 (14)	−0.3563 (5)	0.40831 (16)	0.0240 (7)
H13	0.9376	−0.4953	0.4203	0.029*
C14	0.89038 (13)	−0.2453 (4)	0.36927 (14)	0.0182 (6)
H14	0.8528	−0.3121	0.3539	0.022*
C18	0.87425 (16)	0.3529 (5)	0.19192 (17)	0.0258 (7)
H18A	0.8814	0.4218	0.2356	0.031*
H18B	0.8375	0.4105	0.1591	0.031*
C19	0.92712 (15)	0.3885 (6)	0.16784 (18)	0.0322 (8)
H19A	0.962	0.3148	0.1973	0.048*
H19B	0.9359	0.5364	0.1689	0.048*
H19C	0.9172	0.337	0.1219	0.048*
N7	0.78693 (10)	0.0566 (4)	0.33775 (11)	0.0112 (4)
O15	0.75680 (9)	0.1622 (3)	0.18785 (9)	0.0155 (4)
O16	0.81073 (8)	−0.1950 (3)	0.20775 (9)	0.0133 (4)
O17	0.86789 (9)	0.1264 (3)	0.19876 (9)	0.0165 (4)
P1	0.81344 (3)	0.03661 (10)	0.21966 (3)	0.01098 (18)
H8	0.8495 (15)	0.236 (6)	0.3180 (17)	0.024 (9)*
H7A	0.7525 (17)	0.149 (6)	0.3118 (19)	0.038 (11)*
H7B	0.7712 (16)	−0.071 (6)	0.3273 (18)	0.031 (10)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0141 (12)	0.0102 (13)	0.0100 (12)	0.0004 (10)	0.0045 (9)	−0.0004 (10)
C2	0.0195 (13)	0.0091 (13)	0.0137 (12)	−0.0009 (10)	0.0050 (10)	0.0006 (10)
C3	0.0232 (14)	0.0131 (14)	0.0134 (12)	0.0000 (11)	0.0074 (11)	0.0024 (11)
C4	0.0169 (13)	0.0185 (14)	0.0108 (12)	−0.0016 (11)	0.0028 (10)	−0.0023 (11)
C5	0.0222 (14)	0.0125 (14)	0.0134 (13)	0.0000 (11)	0.0041 (11)	−0.0038 (10)
C6	0.0222 (14)	0.0091 (13)	0.0126 (12)	−0.0010 (10)	0.0058 (11)	−0.0001 (10)
C8	0.0185 (13)	0.0108 (13)	0.0120 (12)	−0.0010 (10)	0.0071 (10)	−0.0001 (10)
C9	0.0202 (13)	0.0126 (13)	0.0104 (11)	0.0020 (10)	0.0070 (10)	−0.0006 (10)
C10	0.0209 (15)	0.0163 (15)	0.0377 (18)	−0.0022 (12)	0.0081 (13)	0.0004 (13)
C11	0.0161 (15)	0.0319 (19)	0.049 (2)	−0.0011 (14)	0.0014 (14)	−0.0016 (17)
C12	0.0213 (15)	0.0317 (18)	0.0307 (16)	0.0108 (14)	0.0044 (13)	0.0046 (14)
C13	0.0294 (17)	0.0177 (15)	0.0254 (15)	0.0084 (12)	0.0099 (13)	0.0077 (12)
C14	0.0194 (14)	0.0118 (14)	0.0216 (14)	0.0001 (11)	0.0047 (11)	0.0036 (11)
C18	0.0429 (19)	0.0099 (15)	0.0310 (17)	−0.0087 (13)	0.0209 (15)	−0.0019 (12)
C19	0.0268 (17)	0.033 (2)	0.0346 (18)	−0.0081 (14)	0.0076 (14)	0.0116 (15)
N7	0.0175 (11)	0.0061 (11)	0.0105 (10)	−0.0003 (9)	0.0052 (8)	0.0002 (8)
O15	0.0210 (10)	0.0110 (10)	0.0136 (9)	0.0044 (7)	0.0048 (8)	0.0003 (7)
O16	0.0199 (10)	0.0038 (9)	0.0161 (9)	−0.0005 (7)	0.0058 (8)	−0.0016 (7)
O17	0.0256 (11)	0.0096 (9)	0.0172 (9)	−0.0027 (8)	0.0112 (8)	−0.0006 (7)
P1	0.0176 (3)	0.0053 (3)	0.0104 (3)	0.0007 (2)	0.0053 (2)	−0.0002 (2)

Geometric parameters (Å, º)

C1—C6	1.384 (4)	C11—C12	1.386 (5)
C1—C2	1.388 (4)	C11—H11	0.93
C1—N7	1.468 (3)	C12—C13	1.373 (5)
C2—C3	1.385 (4)	C12—H12	0.93
C2—H2	0.93	C13—C14	1.387 (4)
C3—C4	1.394 (4)	C13—H13	0.93
C3—H3	0.93	C14—H14	0.93
C4—C5	1.382 (4)	C18—O17	1.458 (3)
C4—H4	0.93	C18—C19	1.504 (5)
C5—C6	1.392 (4)	C18—H18A	0.97
C5—H5	0.93	C18—H18B	0.97
C6—H6	0.93	C19—H19A	0.96
C8—C9	1.510 (4)	C19—H19B	0.96
C8—N7	1.516 (3)	C19—H19C	0.96
C8—P1	1.844 (3)	N7—H7A	0.99 (4)
C8—H8	0.95 (4)	N7—H7B	0.88 (4)
C9—C10	1.381 (4)	O15—P1	1.4959 (19)
C9—C14	1.391 (4)	O16—P1	1.4895 (19)
C10—C11	1.382 (4)	O17—P1	1.588 (2)
C10—H10	0.93
C6—C1—C2	121.6 (2)	C13—C12—H12	120.2
C6—C1—N7	118.7 (2)	C11—C12—H12	120.2
C2—C1—N7	119.7 (2)	C12—C13—C14	120.3 (3)
C3—C2—C1	118.5 (3)	C12—C13—H13	119.8
C3—C2—H2	120.7	C14—C13—H13	119.8
C1—C2—H2	120.7	C13—C14—C9	120.7 (3)
C2—C3—C4	120.8 (3)	C13—C14—H14	119.7
C2—C3—H3	119.6	C9—C14—H14	119.7
C4—C3—H3	119.6	O17—C18—C19	107.7 (3)
C5—C4—C3	119.6 (2)	O17—C18—H18A	110.2
C5—C4—H4	120.2	C19—C18—H18A	110.2
C3—C4—H4	120.2	O17—C18—H18B	110.2
C4—C5—C6	120.4 (3)	C19—C18—H18B	110.2
C4—C5—H5	119.8	H18A—C18—H18B	108.5
C6—C5—H5	119.8	C18—C19—H19A	109.5
C1—C6—C5	119.0 (2)	C18—C19—H19B	109.5
C1—C6—H6	120.5	H19A—C19—H19B	109.5
C5—C6—H6	120.5	C18—C19—H19C	109.5
C9—C8—N7	112.0 (2)	H19A—C19—H19C	109.5
C9—C8—P1	113.58 (18)	H19B—C19—H19C	109.5
N7—C8—P1	108.50 (17)	C1—N7—C8	113.6 (2)
C9—C8—H8	109 (2)	C1—N7—H7A	109 (2)
N7—C8—H8	107 (2)	C8—N7—H7A	109 (2)
P1—C8—H8	107 (2)	C1—N7—H7B	110 (2)
C10—C9—C14	118.1 (3)	C8—N7—H7B	111 (2)
C10—C9—C8	120.3 (3)	H7A—N7—H7B	102 (3)
C14—C9—C8	121.6 (2)	C18—O17—P1	119.97 (19)
C9—C10—C11	121.4 (3)	O16—P1—O15	118.16 (11)
C9—C10—H10	119.3	O16—P1—O17	107.58 (11)
C11—C10—H10	119.3	O15—P1—O17	111.28 (11)
C10—C11—C12	119.8 (3)	O16—P1—C8	109.78 (12)
C10—C11—H11	120.1	O15—P1—C8	106.92 (12)
C12—C11—H11	120.1	O17—P1—C8	101.92 (11)
C13—C12—C11	119.6 (3)
C6—C1—C2—C3	−1.0 (4)	C12—C13—C14—C9	−2.3 (5)
N7—C1—C2—C3	−179.6 (2)	C10—C9—C14—C13	2.5 (4)
C1—C2—C3—C4	−0.1 (4)	C8—C9—C14—C13	−178.0 (3)
C2—C3—C4—C5	0.4 (4)	C6—C1—N7—C8	66.3 (3)
C3—C4—C5—C6	0.4 (4)	C2—C1—N7—C8	−115.0 (3)
C2—C1—C6—C5	1.8 (4)	C9—C8—N7—C1	53.9 (3)
N7—C1—C6—C5	−179.5 (2)	P1—C8—N7—C1	−179.93 (18)
C4—C5—C6—C1	−1.5 (4)	C19—C18—O17—P1	−176.7 (2)
N7—C8—C9—C10	−135.5 (3)	C18—O17—P1—O16	167.8 (2)
P1—C8—C9—C10	101.1 (3)	C18—O17—P1—O15	36.9 (2)
N7—C8—C9—C14	45.1 (3)	C18—O17—P1—C8	−76.7 (2)
P1—C8—C9—C14	−78.3 (3)	C9—C8—P1—O16	47.2 (2)
C14—C9—C10—C11	−0.9 (5)	N7—C8—P1—O16	−78.03 (19)
C8—C9—C10—C11	179.6 (3)	C9—C8—P1—O15	176.53 (19)
C9—C10—C11—C12	−1.0 (6)	N7—C8—P1—O15	51.3 (2)
C10—C11—C12—C13	1.2 (6)	C9—C8—P1—O17	−66.6 (2)
C11—C12—C13—C14	0.3 (5)	N7—C8—P1—O17	168.15 (16)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N7—H7A···O16^i	0.99 (4)	1.71 (4)	2.674 (3)	161 (3)
N7—H7B···O15^ii	0.88 (4)	1.81 (4)	2.690 (3)	175 (4)

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

(II) monoethyl {α-[4-(phenyldiazenyl)anilino]benzyl}phosphonate

Crystal data

C21H22N3O3P	F(000) = 1664
Mr = 395.39	Dx = 1.28 Mg m^−3
Monoclinic, C2/c	Cu Kα radiation, λ = 1.5418 Å
Hall symbol: -C 2yc	Cell parameters from 25 reflections
a = 35.20 (2) Å	θ = 12.0–17.1°
b = 6.419 (4) Å	µ = 1.41 mm^−1
c = 22.86 (1) Å	T = 293 K
β = 127.42 (4)°	Prism, orange
V = 4102 (4) Å^3	0.15 × 0.12 × 0.1 mm
Z = 8

Data collection

Enraf-Nonius CAD-4 diffractometer	2567 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.040
Graphite monochromator	θmax = 76.2°, θmin = 11.3°
non–profiled ω/2θ scans	h = 0→44
Absorption correction: ψ scan (North et al., 1968)	k = −8→0
Tmin = 0.788, Tmax = 0.862	l = −28→22
4545 measured reflections	3 standard reflections every 130 reflections
4261 independent reflections	intensity decay: none

Refinement

Refinement on F^2	1 restraint
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F^2 > 2σ(F^2)] = 0.061	w = 1/[σ^2(Fo^2) + (0.062P)^2 + 2.9216P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.161	(Δ/σ)max < 0.001
S = 1.01	Δρmax = 0.37 e Å^−3
4261 reflections	Δρmin = −0.27 e Å^−3
255 parameters

Special details

Experimental. For absorption correction, No. of ψ-scan sets used was 7. Theta correction was applied. Averaged transmission function was used. No Fourier smoothing was applied.

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
C1	1.03927 (17)	−0.6327 (10)	0.5948 (3)	0.0909 (17)
H1	1.0551	−0.7149	0.5822	0.109*
C2	1.05593 (16)	−0.4404 (10)	0.6230 (3)	0.0830 (14)
H2	1.0834	−0.3917	0.6303	0.1*
C3	1.03258 (14)	−0.3162 (8)	0.6410 (2)	0.0710 (12)
H3	1.0442	−0.1839	0.6605	0.085*
C4	0.99178 (13)	−0.3891 (7)	0.6299 (2)	0.0609 (10)
C5	0.97516 (14)	−0.5864 (8)	0.6025 (2)	0.0736 (12)
H5	0.9482	−0.6378	0.5961	0.088*
C6	0.99931 (17)	−0.7068 (9)	0.5847 (3)	0.0932 (16)
H6	0.9882	−0.8398	0.5655	0.112*
C9	0.91489 (12)	−0.1690 (6)	0.66445 (19)	0.0526 (9)
C10	0.93272 (11)	0.0289 (6)	0.69356 (18)	0.0521 (9)
H10	0.9593	0.0783	0.6982	0.063*
C11	0.91148 (11)	0.1521 (6)	0.71554 (18)	0.0495 (8)
H11	0.9241	0.2829	0.7356	0.059*
C12	0.87117 (11)	0.0821 (6)	0.70796 (17)	0.0439 (7)
C13	0.85282 (12)	−0.1142 (6)	0.6773 (2)	0.0526 (9)
H13	0.8256	−0.162	0.6709	0.063*
C14	0.87472 (13)	−0.2374 (6)	0.6566 (2)	0.0587 (10)
H14	0.8624	−0.3688	0.6369	0.07*
C16	0.80493 (10)	0.1676 (5)	0.71476 (16)	0.0403 (7)
H16	0.8036	0.0192	0.7235	0.048*
C17	0.76291 (11)	0.2130 (5)	0.63449 (17)	0.0435 (7)
C18	0.72560 (13)	0.0745 (7)	0.59510 (19)	0.0591 (10)
H18	0.7263	−0.0485	0.6172	0.071*
C19	0.68692 (15)	0.1160 (9)	0.5226 (2)	0.0819 (14)
H19	0.6619	0.0212	0.4964	0.098*
C20	0.68577 (17)	0.2970 (10)	0.4898 (2)	0.0860 (15)
H20	0.6598	0.3257	0.4413	0.103*
C21	0.72249 (19)	0.4340 (9)	0.5280 (3)	0.0867 (15)
H21	0.7216	0.5564	0.5054	0.104*
C22	0.76163 (14)	0.3941 (7)	0.6006 (2)	0.0644 (10)
H22	0.7867	0.4888	0.6262	0.077*
N7	0.97032 (11)	−0.2445 (6)	0.65045 (18)	0.0670 (9)
N8	0.93515 (11)	−0.3141 (6)	0.64231 (17)	0.0625 (8)
N15	0.85138 (10)	0.2075 (5)	0.73245 (17)	0.0508 (7)
O23	0.84383 (8)	0.2448 (4)	0.85682 (13)	0.0583 (7)
O26	0.81216 (8)	0.5398 (4)	0.77415 (15)	0.0524 (6)
O27	0.75314 (8)	0.2851 (3)	0.76222 (13)	0.0469 (6)
P1	0.80029 (3)	0.31183 (13)	0.77791 (5)	0.0401 (2)
C24	0.84645 (19)	0.0511 (9)	0.8891 (3)	0.108 (2)
H24A	0.8184	0.0364	0.8874	0.13*
H24B	0.8458	−0.0604	0.8598	0.13*
C25	0.8871 (2)	0.0279 (14)	0.9617 (4)	0.143 (4)
H25A	0.8866	−0.1062	0.9798	0.159*
H25B	0.8877	0.135	0.9916	0.159*
H25C	0.9152	0.039	0.9639	0.159*
H15	0.8628 (14)	0.328 (6)	0.746 (2)	0.069 (13)*
H26	0.7866 (18)	0.630 (8)	0.758 (3)	0.109 (17)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.070 (3)	0.129 (5)	0.079 (3)	0.030 (3)	0.048 (3)	−0.015 (3)
C2	0.057 (2)	0.123 (4)	0.080 (3)	0.016 (3)	0.047 (2)	0.006 (3)
C3	0.053 (2)	0.087 (3)	0.075 (3)	0.003 (2)	0.040 (2)	−0.006 (3)
C4	0.0480 (19)	0.083 (3)	0.051 (2)	0.016 (2)	0.0292 (17)	−0.003 (2)
C5	0.052 (2)	0.088 (3)	0.076 (3)	0.003 (2)	0.036 (2)	−0.018 (3)
C6	0.073 (3)	0.094 (4)	0.097 (4)	0.012 (3)	0.043 (3)	−0.031 (3)
C9	0.0471 (18)	0.064 (2)	0.0492 (19)	0.0131 (18)	0.0308 (16)	0.0010 (18)
C10	0.0308 (16)	0.077 (3)	0.0488 (19)	0.0066 (17)	0.0241 (15)	0.0032 (19)
C11	0.0378 (16)	0.061 (2)	0.0478 (18)	0.0012 (16)	0.0252 (15)	0.0000 (17)
C12	0.0361 (15)	0.054 (2)	0.0440 (17)	0.0056 (15)	0.0259 (14)	0.0030 (16)
C13	0.0469 (18)	0.053 (2)	0.069 (2)	0.0011 (16)	0.0412 (18)	−0.0035 (18)
C14	0.058 (2)	0.057 (2)	0.068 (2)	0.0007 (18)	0.042 (2)	−0.0069 (19)
C16	0.0349 (14)	0.0428 (17)	0.0486 (17)	0.0021 (13)	0.0281 (14)	0.0013 (15)
C17	0.0420 (16)	0.0499 (19)	0.0478 (18)	0.0014 (15)	0.0321 (15)	−0.0001 (16)
C18	0.055 (2)	0.077 (3)	0.047 (2)	−0.012 (2)	0.0324 (18)	−0.005 (2)
C19	0.055 (2)	0.127 (4)	0.043 (2)	−0.009 (3)	0.0193 (19)	−0.009 (3)
C20	0.067 (3)	0.136 (5)	0.045 (2)	0.021 (3)	0.029 (2)	0.015 (3)
C21	0.098 (4)	0.100 (4)	0.072 (3)	0.035 (3)	0.057 (3)	0.041 (3)
C22	0.065 (2)	0.066 (3)	0.066 (3)	0.007 (2)	0.041 (2)	0.014 (2)
N7	0.0522 (17)	0.088 (3)	0.064 (2)	0.0052 (17)	0.0371 (16)	−0.0031 (18)
N8	0.0539 (17)	0.072 (2)	0.0646 (19)	0.0071 (17)	0.0377 (16)	−0.0023 (18)
N15	0.0388 (14)	0.0503 (18)	0.0690 (19)	−0.0048 (14)	0.0358 (14)	−0.0122 (16)
O23	0.0481 (13)	0.0672 (17)	0.0464 (14)	0.0019 (12)	0.0218 (11)	0.0046 (12)
O26	0.0427 (13)	0.0403 (13)	0.0837 (18)	−0.0034 (11)	0.0434 (13)	−0.0052 (12)
O27	0.0449 (11)	0.0417 (13)	0.0683 (15)	−0.0052 (10)	0.0418 (12)	−0.0073 (11)
P1	0.0362 (4)	0.0404 (4)	0.0474 (4)	0.0009 (4)	0.0273 (3)	−0.0018 (4)
C24	0.088 (4)	0.108 (4)	0.083 (4)	−0.003 (3)	0.029 (3)	0.041 (3)
C25	0.082 (4)	0.135 (9)	0.120 (5)	−0.017 (5)	0.020 (4)	0.102 (6)

Geometric parameters (Å, º)

C1—C2	1.350 (7)	C16—P1	1.804 (3)
C1—C6	1.365 (7)	C16—H16	0.98
C1—H1	0.93	C17—C18	1.374 (5)
C2—C3	1.375 (6)	C17—C22	1.382 (5)
C2—H2	0.93	C18—C19	1.389 (5)
C3—C4	1.380 (5)	C18—H18	0.93
C3—H3	0.93	C19—C20	1.370 (7)
C4—C5	1.376 (6)	C19—H19	0.93
C4—N7	1.444 (5)	C20—C21	1.355 (7)
C5—C6	1.381 (6)	C20—H20	0.93
C5—H5	0.93	C21—C22	1.393 (6)
C6—H6	0.93	C21—H21	0.93
C9—C14	1.384 (5)	C22—H22	0.93
C9—C10	1.394 (5)	N7—N8	1.219 (4)
C9—N8	1.439 (4)	N15—H15	0.84 (4)
C10—C11	1.376 (5)	O23—C24	1.420 (5)
C10—H10	0.93	O23—P1	1.558 (3)
C11—C12	1.395 (4)	O26—P1	1.539 (3)
C11—H11	0.93	O26—H26	0.93 (5)
C12—N15	1.386 (4)	O27—P1	1.479 (2)
C12—C13	1.394 (5)	C24—C25	1.393 (6)
C13—C14	1.375 (5)	C24—H24A	0.97
C13—H13	0.93	C24—H24B	0.97
C14—H14	0.93	C25—H25A	0.96
C16—N15	1.449 (4)	C25—H25B	0.96
C16—C17	1.530 (4)	C25—H25C	0.96
C2—C1—C6	120.2 (4)	C18—C17—C16	120.3 (3)
C2—C1—H1	119.9	C22—C17—C16	120.7 (3)
C6—C1—H1	119.9	C17—C18—C19	120.7 (4)
C1—C2—C3	120.5 (5)	C17—C18—H18	119.6
C1—C2—H2	119.7	C19—C18—H18	119.6
C3—C2—H2	119.7	C20—C19—C18	119.8 (4)
C2—C3—C4	119.5 (5)	C20—C19—H19	120.1
C2—C3—H3	120.2	C18—C19—H19	120.1
C4—C3—H3	120.2	C21—C20—C19	119.9 (4)
C5—C4—C3	120.2 (4)	C21—C20—H20	120.1
C5—C4—N7	125.3 (4)	C19—C20—H20	120.1
C3—C4—N7	114.5 (4)	C20—C21—C22	121.0 (5)
C4—C5—C6	118.8 (4)	C20—C21—H21	119.5
C4—C5—H5	120.6	C22—C21—H21	119.5
C6—C5—H5	120.6	C17—C22—C21	119.6 (4)
C1—C6—C5	120.7 (5)	C17—C22—H22	120.2
C1—C6—H6	119.6	C21—C22—H22	120.2
C5—C6—H6	119.6	N8—N7—C4	113.5 (4)
C14—C9—C10	118.7 (3)	N7—N8—C9	112.5 (4)
C14—C9—N8	115.7 (4)	C12—N15—C16	122.9 (3)
C10—C9—N8	125.6 (3)	C12—N15—H15	117 (3)
C11—C10—C9	120.7 (3)	C16—N15—H15	118 (3)
C11—C10—H10	119.6	C24—O23—P1	123.4 (3)
C9—C10—H10	119.6	P1—O26—H26	112 (3)
C10—C11—C12	120.5 (3)	O27—P1—O26	113.53 (13)
C10—C11—H11	119.8	O27—P1—O23	114.70 (15)
C12—C11—H11	119.8	O26—P1—O23	102.59 (15)
N15—C12—C13	122.3 (3)	O27—P1—C16	112.35 (14)
N15—C12—C11	119.1 (3)	O26—P1—C16	106.49 (15)
C13—C12—C11	118.6 (3)	O23—P1—C16	106.32 (15)
C14—C13—C12	120.5 (3)	C25—C24—O23	114.1 (5)
C14—C13—H13	119.8	C25—C24—H24A	108.7
C12—C13—H13	119.8	O23—C24—H24A	108.7
C13—C14—C9	121.0 (4)	C25—C24—H24B	108.7
C13—C14—H14	119.5	O23—C24—H24B	108.7
C9—C14—H14	119.5	H24A—C24—H24B	107.6
N15—C16—C17	113.9 (3)	C24—C25—H25A	109.5
N15—C16—P1	108.8 (2)	C24—C25—H25B	109.5
C17—C16—P1	111.7 (2)	H25A—C25—H25B	109.5
N15—C16—H16	107.4	C24—C25—H25C	109.5
C17—C16—H16	107.4	H25A—C25—H25C	109.5
P1—C16—H16	107.4	H25B—C25—H25C	109.5
C18—C17—C22	119.0 (3)
C6—C1—C2—C3	−0.8 (8)	C18—C19—C20—C21	0.4 (7)
C1—C2—C3—C4	−0.1 (7)	C19—C20—C21—C22	−0.1 (7)
C2—C3—C4—C5	1.4 (6)	C18—C17—C22—C21	0.8 (5)
C2—C3—C4—N7	−179.7 (4)	C16—C17—C22—C21	−178.6 (3)
C3—C4—C5—C6	−1.7 (7)	C20—C21—C22—C17	−0.5 (7)
N7—C4—C5—C6	179.5 (4)	C5—C4—N7—N8	1.0 (6)
C2—C1—C6—C5	0.5 (8)	C3—C4—N7—N8	−177.9 (3)
C4—C5—C6—C1	0.7 (7)	C4—N7—N8—C9	178.9 (3)
C14—C9—C10—C11	1.4 (5)	C14—C9—N8—N7	179.8 (3)
N8—C9—C10—C11	−177.5 (3)	C10—C9—N8—N7	−1.2 (5)
C9—C10—C11—C12	−1.0 (5)	C13—C12—N15—C16	−13.4 (5)
C10—C11—C12—N15	178.3 (3)	C11—C12—N15—C16	168.0 (3)
C10—C11—C12—C13	−0.4 (5)	C17—C16—N15—C12	−72.0 (4)
N15—C12—C13—C14	−177.2 (3)	P1—C16—N15—C12	162.7 (3)
C11—C12—C13—C14	1.4 (5)	C24—O23—P1—O27	49.1 (4)
C12—C13—C14—C9	−1.0 (6)	C24—O23—P1—O26	172.7 (4)
C10—C9—C14—C13	−0.4 (6)	C24—O23—P1—C16	−75.7 (4)
N8—C9—C14—C13	178.6 (3)	N15—C16—P1—O27	178.2 (2)
N15—C16—C17—C18	135.2 (3)	C17—C16—P1—O27	51.6 (3)
P1—C16—C17—C18	−101.1 (3)	N15—C16—P1—O26	53.3 (3)
N15—C16—C17—C22	−45.4 (4)	C17—C16—P1—O26	−73.3 (2)
P1—C16—C17—C22	78.4 (3)	N15—C16—P1—O23	−55.6 (3)
C22—C17—C18—C19	−0.6 (5)	C17—C16—P1—O23	177.8 (2)
C16—C17—C18—C19	178.9 (3)	P1—O23—C24—C25	−176.1 (5)
C17—C18—C19—C20	0.0 (6)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O26—H26···O27^i	0.93 (5)	1.54 (5)	2.476 (3)	175 (5)
N15—H15···O26	0.84 (4)	2.61 (5)	2.99 (4)	109 (6)

Symmetry code: (i) −x+3/2, y+1/2, −z+3/2.