Tetra­butyl­ammonium α-acetyl-γ-butyrolactonate containing a three-dimensional hydrogen-bonded network

The title compound, C₁₆H₃₆N⁺·C₆H₇O₃⁻, crystallizes with two independent anions and two independent cations in the asymmetric unit. Each anion adopts an s-trans conformation and forms O...H—C hydrogen bonds to the α-methyl­ene groups of four neighbouring tetra­butyl­ammonium cations, to create a three-dimensional hydrogen-bonded network.

S1. Comment

The anions of tetrabutylammonium salts of CH-acidic and NH-acidic compounds are initiators for the metal-free anionic polymerization of acrylates, methacrylates and acrylonitrile (Reetz et al., 1995a). Moreover, they are intermediates in phase-transfer catalyzed reactions (Dehmlow & Dehmlow, 1993). Structural information on these compounds shows that most are not real carbanions, as previously suggested (March, 1992), but that they form dimers or higher aggregates via O···H—C or N···H—C hydrogen bonds, originating from the interaction of the anions with the tetrabutylammonium cations (Reetz, Hütte, Herzog & Goddard, 1996). In all known cases, the major hydrogen-bonding interactions are with the α-methylene groups of the n-butyl chains of the tetrabutylammonium cations, which are relatively C—H acidic. Indeed, ab initio calculations on the parent tetramethylammonium cation indicate that the positive charge does not reside on the N atom but is delocalized on the four methyl groups (Reetz et al., 1999a). The actual structure adopted by the salts depends, however, on the number and location of the donor atoms (hydrogen-bond acceptors) in the anion. Anions with two donor atoms, such as malonates, tend to form centrosymmetric dimers, in which the enolate takes up a U-shaped conformation and the donor atoms are simultaneously bonded to adjacent α-methylene groups of two neighboring tetrabutylammonium cations (Reetz, Hütte & Goddard, 1993). The result is a cage-like structure. Cryoscopic investigations on tetrabutylammonium malonates in benzene show that these dimers are also maintained in solution (Reetz et al., 1999b). In contrast, carbazolide or dibenzoazapinide anions, containing only one donor result in the formation of infinite chains (Reetz, Hütte, Goddard & Minet, 1995), while the salts of 9-ethylflourenide and cyclopentadienide anions, where suitable donor atoms are absent, exhibit weak hydrogen bonding or none at all, hence the interaction is non-directional (Reetz et al., 1995b). If one side of the anion is sterically shielded, then the anion can bond to only one side of the cation to give chiral ion pairs. (Reetz, Hütte, Goddard & Robyr, 1996; Reetz et al., 1999a).

The title compound, (I), is an initiator for the polymerization of n-butyl acrylate. The exothermic polymerization reaction occurs, however, only after a significant induction time, indicative of a low basicity. Methyl methacrylate cannot be polymerized using (I). Presumably, it is too weak a Michael acceptor to undergo a reaction with the weak nucleophile. The α-acetyl-γ-butyrolactonate anion contains two donor atoms available for forming hydrogen bonds, but the anion can adopt two possible conformations, s-cis (U-shape) as well as s-trans. A structure determination was undertaken in order to establish the conformation of the α-acetyl-γ-butyrolactonate anion in the solid and determine how the anion interacts with the tetrabutylammonium cation, so as to understand better the properties of the salt. \sch

Compound (I) crystallizes with two independent cations and two independent anions in the asymmetric unit (Fig. 1). Apart from a significant difference in the C34—C35 and C40—C41 bond lengths, comparable distances and angles in the independent ions differ by less than three standard uncertainties, so average geometries will be discussed. (The difference remains even after correction for libration, and therefore may be statistical in nature or the result of unresolved disorder.) Bond distances in the anions are in accord with extensive delocalization of the negative charges from the carbanion centers (C35, C41) to the carbonyl oxygen atoms (O1, O2, O4 and O5). Thus, the C—C distances are shortened to 1.405 (9) Å (mean) and the C═O distances are lengthened to 1.240 (7) Å. The enolate adopts the s-trans conformation, and the anions are planar (mean r.m.s. deviation 0.035 Å). This geometry corresponds to the most stable conformation found for β-ketoesterenolates in solution, as demonstrated by ¹H-NMR spectroscopy (Cambillau & Guibe, 1982). This contrasts with most malonates, which adopt the s-cis conformation (U-shape) in the solid state and in solution. To our knowledge it is only in the hexamethylguanidinium salt of dimethyl-2-ethylmalonate that this is not the case (Reetz, Bingel & Harms, 1993).

The n-butyl chains in the tetrabutylammonium cations adopt the commonly observed all-trans conformation, although there are structures where exceptions to this rule exist (e.g. in cyclopentadienyltetrabutylammonium; Reetz et al., 1995b). The coordination about the N atoms is not ideally tetrahedral but flattened with significantly smaller C—N—C angles in the planes of the n-butyl groups. Thus, the two C—N—C angles [mean 105.1 (3)°] in the planes of the alkane chains (e.g. C1—N1—C5 and C9—N1—C13) are significantly smaller than the other four C—N—C angles around each N atom [mean 111.7 (2)°]. Angles along the alkane chain alternate, with the N—C—C angle at the α-carbon atom [mean, 116.0 (3)°] larger than the C—C—C angle at the β-carbon atom [109.2 (5)°], which in turn is smaller than the C—C—C angle at the γ-C atom [mean 112.4 (3)°].

Figure 2 shows the packing of the molecules viewed along the a axis of the triclinic cell. The arrangement of the anions and cations approximates to the tetragonal space group P4₂. In fact, the (0kl) reflections show approximate fourfold symmetry and (h00) reflections with h = 2n (n = 1, 2, 3,..) are systematically strong. The packing is characterized by alternating sheets of anions and cations. Although not required by symmetry, the two independent acetylbutyrolactonate anions are almost coplanar (r.m.s. deviation 0.119 Å). The mean planes of the anions lie between close-packed layers of the tetrabutylammonium cations, 3.057 Å from the N atoms. Of particular worthy of note is the arrangement of the anions with respect to the cations. Each carbonyl group of the anions forms a short intermolecular interaction with one α-C—H of tetrabutylammonium ion in the neighboring layer. Thus, O1 is 3.316 (3) Å from C5(1 + x, y − 1, z) and 3.331 (3) Å from C1(-x, −y, −1 − z) while O2 is 3.222 (3) Å from C25(x, y, z − 1) and 3.305 (3) Å from C29(1 − x, −y, 1 − z). Similarly, O4 is 3.256 (3) from C9(x, y − 1, 1 + z) and 3.415 (3) Å from C13(-x, −y, −z), while O5 is 3.286 (3) from C17(x,y,z − 1) and 3.311 (3) Å from C21(-x, −y, 1 − z) (Fig. 2). Extended Hückel MO calculations (Hoffmann, 1963) on the anion show that most of the negative charge is delocalized on the O atoms of these carbonyl groups.

In summary, the crystal structure reveals that the title compound adopts an s-trans conformation in the solid. As a result, the anions do not form discrete dimers with the cations, as in the case of malonates, but rather adopt a three-dimensional hydrogen-bonding network. Such an association in the liquid, inter alia, may explain the poor nucleophilicity of the anion towards methylmethacrylate and the long initiation times observed in the polymerization of n-butylacrylate.

S2. Experimental

The title compound was synthesized in 88% yield by deprotonation of α-acetyl-γ-butyrolactone by HONBu₄ at room temperature using toluene to remove the water azeotropically (Reetz et al., 1988; Raj et al., 1992; Reetz, Hütte & Goddard, 1993). The residue was dissolved in warm DMSO at 353 K and slowly cooled to room temperature to give acicular crystals. The solvent was removed and the crystals were washed in diethylether, and a suitable crystal was mounted in a glass capillary under argon.

S3. Refinement

The methyl groups, C33 and C39, were refined as rigid rotating groups. The relatively high R value of 0.0743 is possibly due to unresolved disorder associated with the atoms C34, C35, C41 and C42 (see Comment section).

Computing details

Data collection: CAD-4 EXPRESS (Enraf-Nonius, 1995); cell refinement: CAD-4 EXPRESS; data reduction: DATAP (Coppens et al., 1965); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976).

Figures

	Fig. 1. Molecular structure showing the labelling of the non-H atoms. Atomic displacement ellipsoids shown at 50% probability level.
	Fig. 2. Packing of the ions in the unit cell viewed down a, showing the pseudo 42 axis of symmetry. O···H—C interactions are shown as dashed lines.

tetrabutylammonium-α-acetyl-γ-butyrolactonate

Crystal data

C16H36N^+·C6H7O3^−	F(000) = 824
Mr = 369.57	Dx = 1.080 Mg m^−3
Triclinic, P1	Melting point: 428 K
a = 12.309 (4) Å	Mo Kα radiation, λ = 0.71073 Å
b = 13.659 (3) Å	Cell parameters from 25 reflections
c = 13.611 (1) Å	θ = 12.7–20.1°
α = 89.92 (1)°	µ = 0.07 mm^−1
β = 94.10 (1)°	T = 100 K
γ = 95.01 (2)°	Needle, colorless
V = 2273.8 (9) Å^3	0.63 × 0.39 × 0.18 mm
Z = 4

Data collection

Enraf-Nonius CAD4 diffractometer	Rint = 0.038
Radiation source: fine-focus sealed tube	θmax = 27.4°, θmin = 1.5°
Graphite monochromator	h = −15→15
ω–2θ scans	k = −17→17
11019 measured reflections	l = 0→17
10330 independent reflections	3 standard reflections every 30 min
7010 reflections with I > 2σ(I)	intensity decay: 4.7%

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)] = 0.074	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.219	H-atom parameters constrained
S = 1.04	w = 1/[σ^2(Fo^2) + (0.098P)^2 + 2.206P] where P = (Fo^2 + 2Fc^2)/3
10330 reflections	(Δ/σ)max < 0.001
471 parameters	Δρmax = 0.53 e Å^−3
0 restraints	Δρmin = −0.35 e Å^−3

Special details

Experimental. The structure was solved by Direct Methods (Sheldrick, 1990) and refined by full-matrix least-squares, where the quantity minimized was [Σω(F_o²-F_c²)²] (Sheldrick, 1997). Non-H atoms were refined anisotropically, and H atoms were included in the refinement using a riding model. Atomic scattering factors were taken from International Tables (1992).

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 > 2sigma(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.

International Tables for Crystallography (1992). Vol. C. Dordrecht: Kluwer Academic.

Sheldrick, G. M. (1990). Acta Cryst. A46, 467–473.

Sheldrick, G. M. (1997). SHELXL97. University of Göttingen, Germany.

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
O1	0.49742 (15)	−0.36096 (15)	−0.36924 (14)	0.0339 (5)
O2	0.50227 (15)	−0.13762 (15)	−0.13849 (13)	0.0322 (4)
O3	0.51419 (18)	−0.03879 (15)	−0.26826 (15)	0.0390 (5)
O4	−0.01567 (16)	−0.37392 (16)	0.35216 (16)	0.0395 (5)
O5	0.00909 (15)	−0.14199 (13)	0.13132 (15)	0.0315 (4)
O6	0.02016 (18)	−0.27096 (16)	0.03429 (16)	0.0417 (5)
N1	−0.25003 (15)	0.48491 (13)	−0.47121 (13)	0.0148 (4)
N2	0.24988 (15)	0.01817 (14)	0.96618 (13)	0.0168 (4)
C1	−0.31881 (18)	0.39637 (16)	−0.43582 (16)	0.0167 (4)
H1A	−0.3655	0.3690	−0.4913	0.020*
H1B	−0.3659	0.4184	−0.3877	0.020*
C2	−0.25583 (19)	0.31531 (17)	−0.39008 (17)	0.0200 (5)
H2A	−0.2023	0.3427	−0.3395	0.024*
H2B	−0.2172	0.2850	−0.4400	0.024*
C3	−0.3343 (2)	0.23811 (17)	−0.34490 (18)	0.0225 (5)
H3A	−0.3697	0.2682	−0.2926	0.027*
H3B	−0.3906	0.2143	−0.3948	0.027*
C4	−0.2761 (2)	0.15211 (18)	−0.3035 (2)	0.0284 (6)
H4A	−0.3278	0.1058	−0.2750	0.043*
H4B	−0.2205	0.1753	−0.2539	0.043*
H4C	−0.2431	0.1208	−0.3555	0.043*
C5	−0.33182 (18)	0.55141 (16)	−0.51783 (16)	0.0172 (4)
H5A	−0.3723	0.5163	−0.5726	0.021*
H5B	−0.3837	0.5634	−0.4697	0.021*
C6	−0.28552 (19)	0.64984 (17)	−0.55504 (18)	0.0210 (5)
H6A	−0.2297	0.6404	−0.6000	0.025*
H6B	−0.2525	0.6901	−0.5003	0.025*
C7	−0.3783 (2)	0.70060 (18)	−0.60775 (18)	0.0237 (5)
H7A	−0.4062	0.6624	−0.6656	0.028*
H7B	−0.4373	0.7024	−0.5644	0.028*
C8	−0.3430 (2)	0.80474 (19)	−0.6390 (2)	0.0304 (6)
H8A	−0.4038	0.8328	−0.6731	0.046*
H8B	−0.2845	0.8035	−0.6819	0.046*
H8C	−0.3184	0.8438	−0.5818	0.046*
C9	−0.16980 (18)	0.45642 (17)	−0.54346 (16)	0.0172 (4)
H9A	−0.1247	0.5151	−0.5600	0.021*
H9B	−0.1220	0.4119	−0.5106	0.021*
C10	−0.21943 (19)	0.40820 (18)	−0.63835 (16)	0.0213 (5)
H10A	−0.2588	0.4549	−0.6774	0.026*
H10B	−0.2706	0.3529	−0.6237	0.026*
C11	−0.1280 (2)	0.37318 (19)	−0.69558 (18)	0.0249 (5)
H11A	−0.0723	0.4272	−0.7018	0.030*
H11B	−0.0947	0.3212	−0.6590	0.030*
C12	−0.1690 (2)	0.3352 (2)	−0.79786 (19)	0.0334 (6)
H12A	−0.1090	0.3136	−0.8310	0.050*
H12B	−0.2004	0.3869	−0.8349	0.050*
H12C	−0.2235	0.2811	−0.7921	0.050*
C13	−0.17959 (18)	0.53591 (16)	−0.38701 (16)	0.0172 (4)
H13A	−0.1249	0.4927	−0.3638	0.021*
H13B	−0.1413	0.5945	−0.4125	0.021*
C14	−0.2395 (2)	0.56520 (18)	−0.29993 (17)	0.0217 (5)
H14A	−0.2687	0.5068	−0.2668	0.026*
H14B	−0.3000	0.6024	−0.3225	0.026*
C15	−0.1610 (2)	0.62760 (19)	−0.22839 (18)	0.0254 (5)
H15A	−0.0988	0.5911	−0.2089	0.030*
H15B	−0.1340	0.6868	−0.2616	0.030*
C16	−0.2147 (3)	0.6558 (2)	−0.1375 (2)	0.0384 (7)
H16A	−0.1629	0.6955	−0.0951	0.058*
H16B	−0.2394	0.5975	−0.1033	0.058*
H16C	−0.2759	0.6924	−0.1564	0.058*
C17	0.17103 (19)	0.03625 (17)	1.04401 (16)	0.0188 (5)
H17A	0.1231	0.0847	1.0189	0.023*
H17B	0.1259	−0.0244	1.0536	0.023*
C18	0.2233 (2)	0.07132 (18)	1.14320 (17)	0.0221 (5)
H18A	0.2692	0.1318	1.1353	0.027*
H18B	0.2689	0.0224	1.1712	0.027*
C19	0.1341 (2)	0.08878 (19)	1.21214 (18)	0.0267 (5)
H19A	0.0918	0.1407	1.1857	0.032*
H19B	0.0850	0.0295	1.2153	0.032*
C20	0.1814 (3)	0.1171 (2)	1.3154 (2)	0.0356 (6)
H20A	0.1231	0.1276	1.3563	0.053*
H20B	0.2291	0.1763	1.3126	0.053*
H20C	0.2219	0.0652	1.3424	0.053*
C21	0.17774 (19)	−0.01864 (17)	0.87630 (16)	0.0193 (5)
H21A	0.1280	0.0307	0.8582	0.023*
H21B	0.1338	−0.0774	0.8946	0.023*
C22	0.2368 (2)	−0.04243 (18)	0.78587 (17)	0.0229 (5)
H22A	0.2794	0.0159	0.7647	0.027*
H22B	0.2863	−0.0926	0.8018	0.027*
C23	0.1527 (2)	−0.0789 (2)	0.70363 (19)	0.0319 (6)
H23A	0.1095	−0.1362	0.7262	0.038*
H23B	0.1037	−0.0282	0.6884	0.038*
C24	0.2052 (3)	−0.1054 (3)	0.6108 (2)	0.0457 (8)
H24A	0.1493	−0.1278	0.5611	0.069*
H24B	0.2526	−0.1566	0.6251	0.069*
H24C	0.2470	−0.0485	0.5874	0.069*
C25	0.32915 (18)	−0.05611 (17)	1.00083 (16)	0.0184 (5)
H25A	0.3801	−0.0622	0.9504	0.022*
H25B	0.3710	−0.0302	1.0596	0.022*
C26	0.2786 (2)	−0.15765 (17)	1.02362 (18)	0.0224 (5)
H26A	0.2413	−0.1875	0.9644	0.027*
H26B	0.2254	−0.1533	1.0724	0.027*
C27	0.3686 (2)	−0.22050 (18)	1.06299 (19)	0.0260 (5)
H27A	0.4243	−0.2198	1.0159	0.031*
H27B	0.4026	−0.1918	1.1240	0.031*
C28	0.3263 (3)	−0.3265 (2)	1.0816 (2)	0.0351 (6)
H28A	0.3857	−0.3625	1.1068	0.053*
H28B	0.2947	−0.3560	1.0210	0.053*
H28C	0.2717	−0.3278	1.1287	0.053*
C29	0.32066 (18)	0.11107 (17)	0.94416 (17)	0.0185 (5)
H29A	0.3660	0.1303	1.0034	0.022*
H29B	0.3691	0.0957	0.8943	0.022*
C30	0.26102 (19)	0.19837 (17)	0.90925 (17)	0.0199 (5)
H30A	0.2105	0.2142	0.9572	0.024*
H30B	0.2194	0.1826	0.8472	0.024*
C31	0.3441 (2)	0.28674 (18)	0.89582 (19)	0.0243 (5)
H31A	0.3852	0.3020	0.9582	0.029*
H31B	0.3953	0.2696	0.8490	0.029*
C32	0.2901 (2)	0.37753 (19)	0.8593 (2)	0.0317 (6)
H32A	0.3451	0.4311	0.8531	0.048*
H32B	0.2395	0.3950	0.9054	0.048*
H32C	0.2517	0.3637	0.7963	0.048*
C33	0.4833 (2)	−0.3546 (2)	−0.1960 (2)	0.0363 (6)
H33A	0.4077	−0.3755	−0.1892	0.054*
H33B	0.5091	−0.3086	−0.1444	0.054*
H33C	0.5254	−0.4106	−0.1914	0.054*
C34	0.49556 (19)	−0.3053 (2)	−0.29612 (19)	0.0272 (6)
C35	0.5024 (2)	−0.2038 (2)	−0.30395 (18)	0.0271 (5)
C36	0.5125 (3)	−0.1528 (2)	−0.4010 (2)	0.0379 (7)
H36A	0.4511	−0.1734	−0.4472	0.046*
H36B	0.5799	−0.1657	−0.4295	0.046*
C37	0.5124 (3)	−0.0453 (2)	−0.3735 (2)	0.0426 (8)
H37A	0.5762	−0.0081	−0.3969	0.051*
H37B	0.4475	−0.0187	−0.4034	0.051*
C38	0.5050 (2)	−0.1330 (2)	−0.22900 (19)	0.0270 (5)
C39	−0.0225 (3)	−0.1984 (2)	0.3430 (3)	0.0440 (8)
H39A	−0.0553	−0.2061	0.4047	0.066*
H39B	−0.0676	−0.1621	0.2984	0.066*
H39C	0.0486	−0.1635	0.3534	0.066*
C40	−0.0114 (2)	−0.2987 (2)	0.2994 (2)	0.0334 (6)
C41	0.0055 (2)	−0.3066 (2)	0.1976 (2)	0.0322 (6)
C42	0.0169 (3)	−0.4028 (2)	0.1493 (2)	0.0391 (7)
H42A	−0.0444	−0.4500	0.1609	0.047*
H42B	0.0843	−0.4297	0.1730	0.047*
C43	0.0182 (3)	−0.3765 (2)	0.0408 (2)	0.0436 (7)
H43A	0.0824	−0.3989	0.0135	0.052*
H43B	−0.0463	−0.4072	0.0044	0.052*
C44	0.0098 (2)	−0.2309 (2)	0.1287 (2)	0.0320 (6)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0274 (10)	0.0429 (11)	0.0313 (10)	0.0031 (8)	0.0021 (8)	−0.0140 (9)
O2	0.0291 (10)	0.0496 (12)	0.0174 (9)	−0.0022 (8)	0.0051 (7)	−0.0094 (8)
O3	0.0497 (13)	0.0371 (11)	0.0295 (10)	−0.0041 (9)	0.0071 (9)	−0.0045 (8)
O4	0.0261 (10)	0.0461 (12)	0.0460 (12)	−0.0011 (9)	0.0054 (9)	0.0263 (10)
O5	0.0263 (10)	0.0233 (9)	0.0446 (11)	0.0008 (7)	0.0010 (8)	0.0146 (8)
O6	0.0473 (13)	0.0397 (12)	0.0367 (12)	−0.0003 (10)	−0.0003 (10)	0.0095 (9)
N1	0.0165 (9)	0.0158 (9)	0.0118 (8)	0.0007 (7)	0.0011 (7)	0.0021 (7)
N2	0.0183 (9)	0.0172 (9)	0.0149 (9)	0.0001 (7)	0.0021 (7)	0.0017 (7)
C1	0.0189 (11)	0.0166 (10)	0.0144 (10)	−0.0011 (8)	0.0027 (8)	0.0042 (8)
C2	0.0213 (11)	0.0193 (11)	0.0194 (11)	0.0005 (9)	0.0021 (9)	0.0071 (9)
C3	0.0240 (12)	0.0215 (12)	0.0206 (11)	−0.0037 (9)	−0.0017 (9)	0.0070 (9)
C4	0.0323 (14)	0.0215 (12)	0.0301 (13)	−0.0032 (10)	0.0010 (11)	0.0103 (10)
C5	0.0187 (11)	0.0181 (11)	0.0148 (10)	0.0023 (8)	0.0011 (8)	0.0038 (8)
C6	0.0226 (12)	0.0199 (11)	0.0210 (11)	0.0027 (9)	0.0049 (9)	0.0061 (9)
C7	0.0260 (12)	0.0220 (12)	0.0241 (12)	0.0057 (9)	0.0042 (10)	0.0102 (9)
C8	0.0358 (15)	0.0254 (13)	0.0317 (14)	0.0077 (11)	0.0096 (11)	0.0148 (11)
C9	0.0177 (11)	0.0200 (11)	0.0143 (10)	0.0008 (8)	0.0035 (8)	0.0028 (8)
C10	0.0212 (11)	0.0276 (12)	0.0149 (11)	0.0008 (9)	0.0024 (9)	−0.0011 (9)
C11	0.0261 (13)	0.0295 (13)	0.0191 (11)	−0.0009 (10)	0.0065 (9)	−0.0032 (10)
C12	0.0384 (16)	0.0397 (16)	0.0228 (13)	0.0009 (12)	0.0094 (11)	−0.0089 (11)
C13	0.0178 (11)	0.0177 (11)	0.0153 (10)	−0.0010 (8)	−0.0009 (8)	0.0002 (8)
C14	0.0237 (12)	0.0248 (12)	0.0166 (11)	0.0021 (9)	0.0012 (9)	−0.0018 (9)
C15	0.0269 (13)	0.0276 (13)	0.0211 (12)	0.0014 (10)	−0.0022 (10)	−0.0028 (10)
C16	0.0420 (17)	0.0469 (18)	0.0257 (14)	0.0007 (14)	0.0008 (12)	−0.0150 (12)
C17	0.0196 (11)	0.0205 (11)	0.0172 (11)	0.0027 (9)	0.0063 (8)	0.0026 (9)
C18	0.0248 (12)	0.0243 (12)	0.0179 (11)	0.0036 (9)	0.0046 (9)	0.0021 (9)
C19	0.0296 (13)	0.0278 (13)	0.0235 (12)	0.0000 (10)	0.0100 (10)	−0.0011 (10)
C20	0.0479 (17)	0.0395 (16)	0.0216 (13)	0.0106 (13)	0.0096 (12)	−0.0014 (11)
C21	0.0190 (11)	0.0202 (11)	0.0179 (11)	−0.0004 (9)	−0.0024 (8)	0.0017 (9)
C22	0.0259 (12)	0.0247 (12)	0.0178 (11)	0.0016 (10)	0.0004 (9)	−0.0001 (9)
C23	0.0336 (15)	0.0379 (15)	0.0235 (13)	0.0040 (12)	−0.0031 (11)	−0.0066 (11)
C24	0.056 (2)	0.055 (2)	0.0250 (14)	−0.0052 (16)	0.0041 (13)	−0.0113 (14)
C25	0.0176 (11)	0.0220 (11)	0.0161 (10)	0.0039 (9)	0.0021 (8)	0.0039 (8)
C26	0.0230 (12)	0.0225 (12)	0.0216 (12)	0.0024 (9)	0.0012 (9)	0.0052 (9)
C27	0.0285 (13)	0.0251 (13)	0.0254 (13)	0.0064 (10)	0.0049 (10)	0.0090 (10)
C28	0.0434 (17)	0.0250 (14)	0.0363 (15)	0.0023 (12)	0.0006 (12)	0.0105 (11)
C29	0.0184 (11)	0.0198 (11)	0.0166 (10)	−0.0029 (8)	0.0023 (8)	0.0027 (8)
C30	0.0219 (12)	0.0199 (11)	0.0178 (11)	−0.0004 (9)	0.0042 (9)	0.0027 (9)
C31	0.0237 (12)	0.0215 (12)	0.0263 (12)	−0.0029 (9)	−0.0010 (10)	0.0048 (10)
C32	0.0341 (15)	0.0221 (13)	0.0386 (15)	−0.0021 (11)	0.0060 (12)	0.0092 (11)
C33	0.0340 (15)	0.0413 (16)	0.0330 (15)	0.0013 (12)	0.0015 (12)	0.0016 (12)
C34	0.0140 (11)	0.0415 (15)	0.0256 (13)	0.0006 (10)	−0.0008 (9)	−0.0060 (11)
C35	0.0218 (12)	0.0398 (15)	0.0193 (12)	−0.0007 (10)	0.0033 (9)	−0.0058 (10)
C36	0.0451 (17)	0.0490 (18)	0.0186 (13)	−0.0035 (14)	0.0040 (12)	−0.0017 (12)
C37	0.0520 (19)	0.0457 (18)	0.0275 (15)	−0.0104 (15)	0.0019 (13)	0.0019 (13)
C38	0.0185 (12)	0.0380 (15)	0.0237 (12)	−0.0030 (10)	0.0027 (9)	−0.0058 (11)
C39	0.0328 (16)	0.0485 (19)	0.0506 (19)	0.0006 (14)	0.0063 (14)	0.0005 (15)
C40	0.0159 (12)	0.0350 (15)	0.0480 (17)	−0.0005 (10)	−0.0028 (11)	0.0043 (13)
C41	0.0259 (13)	0.0300 (14)	0.0399 (16)	0.0007 (11)	−0.0007 (11)	0.0099 (12)
C42	0.0379 (16)	0.0348 (16)	0.0439 (17)	0.0007 (12)	0.0014 (13)	0.0080 (13)
C43	0.0470 (19)	0.0380 (17)	0.0452 (18)	0.0023 (14)	−0.0004 (14)	0.0049 (14)
C44	0.0191 (12)	0.0295 (14)	0.0456 (17)	−0.0002 (10)	−0.0066 (11)	0.0099 (12)

Geometric parameters (Å, º)

O1—C34	1.256 (3)	C13—C14	1.512 (3)
O2—C38	1.236 (3)	C14—C15	1.527 (3)
O3—C38	1.391 (3)	C15—C16	1.509 (4)
O3—C37	1.434 (3)	C17—C18	1.513 (3)
O4—C40	1.253 (3)	C18—C19	1.529 (3)
O5—C44	1.216 (3)	C19—C20	1.519 (4)
O6—C44	1.416 (4)	C21—C22	1.523 (3)
O6—C43	1.442 (4)	C22—C23	1.523 (3)
N1—C1	1.513 (3)	C23—C24	1.518 (4)
N1—C9	1.517 (3)	C25—C26	1.511 (3)
N1—C13	1.518 (3)	C26—C27	1.527 (3)
N1—C5	1.519 (3)	C27—C28	1.523 (4)
N2—C29	1.517 (3)	C29—C30	1.513 (3)
N2—C21	1.519 (3)	C30—C31	1.532 (3)
N2—C25	1.520 (3)	C31—C32	1.524 (3)
N2—C17	1.522 (3)	C33—C34	1.531 (4)
C1—C2	1.514 (3)	C34—C35	1.387 (4)
C2—C3	1.526 (3)	C35—C38	1.403 (4)
C3—C4	1.516 (3)	C35—C36	1.500 (4)
C5—C6	1.515 (3)	C36—C37	1.516 (4)
C6—C7	1.523 (3)	C39—C40	1.513 (4)
C7—C8	1.520 (3)	C40—C41	1.422 (4)
C9—C10	1.515 (3)	C41—C44	1.394 (4)
C10—C11	1.524 (3)	C41—C42	1.492 (4)
C11—C12	1.522 (3)	C42—C43	1.520 (4)
C38—O3—C37	109.3 (2)	C23—C22—C21	109.1 (2)
C44—O6—C43	109.6 (2)	C24—C23—C22	112.4 (2)
C1—N1—C9	111.89 (17)	C26—C25—N2	116.03 (19)
C1—N1—C13	111.54 (16)	C25—C26—C27	109.0 (2)
C9—N1—C13	104.95 (16)	C28—C27—C26	112.8 (2)
C1—N1—C5	104.95 (16)	C30—C29—N2	116.36 (19)
C9—N1—C5	112.00 (16)	C29—C30—C31	109.41 (19)
C13—N1—C5	111.69 (17)	C32—C31—C30	112.5 (2)
C29—N2—C21	111.73 (17)	O1—C34—C35	122.6 (3)
C29—N2—C25	105.51 (17)	O1—C34—C33	116.9 (3)
C21—N2—C25	111.68 (17)	C35—C34—C33	120.4 (2)
C29—N2—C17	111.50 (17)	C34—C35—C38	128.8 (2)
C21—N2—C17	105.07 (17)	C34—C35—C36	122.0 (2)
C25—N2—C17	111.50 (17)	C38—C35—C36	109.2 (2)
N1—C1—C2	115.65 (18)	C35—C36—C37	102.8 (2)
C1—C2—C3	109.90 (19)	O3—C37—C36	107.9 (2)
C4—C3—C2	111.9 (2)	O2—C38—O3	115.8 (2)
C6—C5—N1	116.57 (18)	O2—C38—C35	133.7 (3)
C5—C6—C7	108.45 (19)	O3—C38—C35	110.5 (2)
C8—C7—C6	112.8 (2)	O4—C40—C41	120.0 (3)
C10—C9—N1	116.05 (18)	O4—C40—C39	120.8 (3)
C9—C10—C11	108.82 (19)	C41—C40—C39	119.2 (3)
C12—C11—C10	112.3 (2)	C44—C41—C40	127.1 (3)
C14—C13—N1	115.86 (18)	C44—C41—C42	110.5 (3)
C13—C14—C15	109.6 (2)	C40—C41—C42	122.3 (3)
C16—C15—C14	112.3 (2)	C41—C42—C43	103.1 (2)
C18—C17—N2	115.65 (19)	O6—C43—C42	107.2 (3)
C17—C18—C19	109.5 (2)	O5—C44—C41	135.8 (3)
C20—C19—C18	111.9 (2)	O5—C44—O6	115.0 (2)
N2—C21—C22	116.08 (19)	C41—C44—O6	109.2 (2)