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Synchrotron radiation was used to study the structure of the title compound, C20H19BrN2O3·C3H7NO, which was obtained as fine fragile needle-shaped crystals by recrystallization from dimethyl­formamide (DMF), one mol­ecule of which is incorporated per asymmetric unit into the crystal. The compound adopts a compact closed conformation with the orientation of the benzyl group such that the aryl ring is positioned over the piperazinedione ring, resulting in a Cspiro...Ctrans—C—CPh pseudo-torsion angle of −3.3 (3)°. The five-membered ring is present in an expected envelope conformation and the six-membered piperazinedione ring adopts a less puckered boat-like conformation. Reciprocal amide-to-amide hydrogen bonding between adjacent piperazinedione rings and C—H...O inter­actions involving DMF mol­ecules propagate in the crystal as a thick ribbon in the a-axis direction.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270110017579/eg3048sup1.cif
Contains datablocks global, II

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270110017579/eg3048IIsup2.hkl
Contains datablock II

CCDC reference: 782540

Comment top

In the course of studies on the properties of piperazinediones (Jagadish et al, 2003; Ntirampebura et al., 2008; Weatherhead-Kloster et al, 2005), we recently prepared the enantiomers of 5-hydroxy-2-aminoindan-2-carboxylic acid, a conformationally constrained tyrosine analog (Murigi et al., 2010). Resolution of this acid was achieved by a process that passed through dipeptides (R,S)-(I) (Scheme) and (S,S)-(I) (not shown). Separation of these diastereomers by silica gel column chromatography was difficult, and so separation was deferred until a later step in the synthesis. However, enough pure (R,S)-(I) was available to carry out a thermolysis to produce the title piperazinedione, (R,S)-(II).

Crystallization of (R,S)-(II) from dimethylformamide (DMF) yielded a mass of very fine, fragile, colorless needle crystals. Single-crystal diffraction analysis was carried out using synchrotron radiation (λ = 0.7749 Å) and yielded reasonable, measurable diffraction to a resolution of approximately 0.8 Å with an exposure time of 7 s per frame. The asymmetric unit of (R,S)-(II) is shown in Fig. 1 and one fully ordered molecule of DMF solvate per molecule of (R,S)-(II) has been incorporated into the structure. The title compound, for which molecular dimensions are generally unexceptional, has a compact, closed conformation, similar to that found in the related compound (R,S)-cyclo[phenylalanyl-(2-amino-4-bromo-7-methoxyindan-2-carboxylic acid)] as reported by Williams et al. (1999). The benzyl group adopts an orientation such that the aryl ring is positioned over the piperazinedione ring, resulting in a torsion angle defined by C2–C4–C14–C15 of -3.3 (3)°. As a consequence of this orientation, atom H122 (bonded to C12) points towards the centroid of the phenyl ring with an H···Cg distance of approximately 2.80 Å. However, the driving force behind this molecular conformation is more likely to be crystal-packing stability rather than the attractive effect of a single C—H···Cg interaction between an aryl ring and an unactivated H atom. The methoxy group is coplanar with the aryl ring to which it is bonded and a mean plane fitted through atoms Br1, O3 and C5 to C13 has an r.m.s. deviation of 0.082 Å. The ring defined by C2, C5, C6, C11 and C12 is present in an envelope conformation with C2 as the `flap atom' and a Cremer–Pople puckering parameter (CPPP) Q = 0.377 (3) Å (Cremer & Pople, 1975). Similarly, the central piperazinedione ring adopts a less puckered boat-like conformation with C2 and C4 as the `bowsprit atoms' and a CPPP of 0.201 (3) Å.

Hydrogen bonding dominates the crystal packing. Reciprocal amide-to-amide hydrogen bonding is commonly (but not exclusively, see e.g. Jagadish et al., 2008) found between adjacent piperazinedione rings in compounds of this type. In this structure adjacent molecules of (R,S)-(II) are connected via an R22(8) motif (Bernstein et al., 1995) composed of two N—H···O interactions to form an infinite tape parallel with the a axis (Fig. 2). Similarly, adjacent DMF molecules are connected via a C(3) motif formed by C21iii—H21iii···O4vi (atoms used as an example in Fig. 2) into a chain which propagates along the a axis. The O atom in DMF acts as a bifurcated acceptor, participating in a further motif which is shown in Fig. 2 by a combination of C14v—H14v···O4iii, C21v—H21v···O4iii and C14vii—H14vii···O4v and is probably most appropriately described as D23(5) since it does not propagate beyond H14v or H14vii. Overall the combination of all hydrogen-bonding interactions results in a one-dimensional ribbon with molecules of (R,S)-(II) forming the outermost parts and DMF forming the innermost part of the ribbon.

Related literature top

For related literature, see: Bernstein et al. (1995); Cremer & Pople (1975); Flack (1983); Jagadish et al. (2003, 2008); Murigi et al. (2010); Ntirampebura et al. (2008); Weatherhead-Kloster, Selby, Miller & Mash (2005); Williams et al. (1999).

Experimental top

The synthesis of (R,S)-(I) has previously been reported (Murigi et al., 2010). Neat (R,S)-(I) (105 mg, 0.19 mmol) was heated in a sealed, evacuated tube in an oil bath at 513 K for 20 min, which produced a yellow solid. After cooling to room temperature, the tube was opened, the residue was triturated with CH2Cl2 (3 ml) to dissolve the yellow impurities, and the remaining solid was collected by filtration, giving (R,S)-(II) (45 mg, 0.108 mmol, 58%) as a white solid. The diastereomeric purity of (R,S)-(II) was estimated to be 95% by NMR. Crystallization from hot DMF solution with slow cooling gave, after 2–3 d, a white crystalline mass with a diastereomeric purity >99% as determined by NMR. Characterization data for (R,S)-(II): [α]24D -7.80 (c 0.3, DMSO); m.p. 563 K; IR (KBr, cm-1) 3434, 3034, 2961,1672, 1447, 1276, 1044; 1H NMR (500 MHz, DMSO-d6) δ 2.10 (d, 1H, J = 17.0 Hz), 2.51 (d, 1H, J = 17.0 Hz), 2.90 (m, 2H), 3.14 (dd, 1H, J = 3.5 Hz, J = 13.4 Hz), 3.34 (d, 1H, J = 16.5 Hz), 3.75 (s, 3H), 4.26 (s, 1H), 6.65 (s, 1H), 7.20 (d, 2H, J = 6.6 Hz), 7.27 (s, 1H), 7.32 (m, 3H), 8.22 (s, 1H), 8.48 (s, 1H); 13C NMR (125 MHz, DMSO-d6) δ 38.3, 45.5, 46.3, 55.6, 56.2, 63.8, 108.1, 108.6, 126.7, 127.8, 128.1, 130.3, 133.7, 136.1, 141.1, 154.2, 166.0, 169.9; HRMS (ESI) calcd for C20H18BrN2O3 (M—H)- 413.0506, found 413.0499.

Refinement top

H atoms were all located in a difference map, but those attached to C atoms were repositioned geometrically. The H atoms were initially refined with soft restraints on the bond lengths and angles to regularize their geometry (C—H in the range 0.93–0.98, N—H in the range 0.86–0.89) and Uiso(H) (in the range 1.2–1.5Ueq of the parent atom), after which the positions were refined with riding constraints. The value of the absolute structure parameter is based on 1890 Friedel pairs (Flack, 1983).

Computing details top

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: CRYSTALS (Betteridge et al., 2003); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and Mercury (Macrae et al., 2008); software used to prepare material for publication: CRYSTALS (Betteridge et al., 2003).

Figures top
[Figure 1] Fig. 1. The asymmetric unit of (R,S)-(II) with displacement ellipsoids at the 50% probability level.
[Figure 2] Fig. 2. Part of the crystal packing in (R,S)-(II), projected along the c axis. [Symmetry codes: (iii) x + 1/2, -y + 1/2, -z + 1; (iv) x - 1/2, -y + 1/2, -z + 1; (v) x + 1/2, -y + 1/2, -z + 1.]
(2R,5'S)-5'-benzyl-5-bromo-6-methoxyspiro[indane-2,2'- piperazine]-3',6'-dione dimethylformamide solvate top
Crystal data top
C20H19BrN2O3·C3H7NOF(000) = 1008
Mr = 488.38Dx = 1.480 Mg m3
Orthorhombic, P212121Synchrotron radiation, λ = 0.7749 Å
Hall symbol: P 2ac 2abCell parameters from 1876 reflections
a = 6.0741 (7) Åθ = 3–25°
b = 13.8336 (16) ŵ = 1.91 mm1
c = 26.076 (3) ÅT = 100 K
V = 2191.1 (4) Å3Needle, colourless
Z = 41.00 × 0.01 × 0.01 mm
Data collection top
Bruker SMART APEXII CCD
diffractometer
3882 reflections with I > 2σ(I)
Silicon 111 monochromatorRint = 0.057
0.3 degree ω scansθmax = 29.0°, θmin = 3.0°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 77
Tmin = 0.25, Tmax = 0.98k = 1717
31454 measured reflectionsl = 3232
4493 independent reflections
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.034Only H-atom displacement parameters refined
wR(F2) = 0.073 Method = Modified Sheldrick w = 1/[σ2(F2) + ( 0.03P)2 + 2.95P],
where P = (max(Fo2,0) + 2Fc2)/3
S = 1.00(Δ/σ)max = 0.001
4479 reflectionsΔρmax = 0.60 e Å3
281 parametersΔρmin = 0.67 e Å3
0 restraintsAbsolute structure: Flack (1983), 1890 Friedel-pairs
Primary atom site location: structure-invariant direct methodsAbsolute structure parameter: 0.015 (7)
Crystal data top
C20H19BrN2O3·C3H7NOV = 2191.1 (4) Å3
Mr = 488.38Z = 4
Orthorhombic, P212121Synchrotron radiation, λ = 0.7749 Å
a = 6.0741 (7) ŵ = 1.91 mm1
b = 13.8336 (16) ÅT = 100 K
c = 26.076 (3) Å1.00 × 0.01 × 0.01 mm
Data collection top
Bruker SMART APEXII CCD
diffractometer
4493 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
3882 reflections with I > 2σ(I)
Tmin = 0.25, Tmax = 0.98Rint = 0.057
31454 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.034Only H-atom displacement parameters refined
wR(F2) = 0.073Δρmax = 0.60 e Å3
S = 1.00Δρmin = 0.67 e Å3
4479 reflectionsAbsolute structure: Flack (1983), 1890 Friedel-pairs
281 parametersAbsolute structure parameter: 0.015 (7)
0 restraints
Special details top

Experimental. The needle crystal significantly exceeds the radiation spot size at sample in one dimension. We recognize that this is not an ideal experimental setup. The fragility of the crystals used precluded cutting into a smaller length. However, the crystal was mounted such that the long dimension was orthogonal to the beam, and a multiply redundant data set was measured. We do not believe that this has adversely affected the quality of the data measured.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Br10.24708 (6)0.93502 (2)0.732893 (11)0.0232
O10.1620 (4)0.60362 (16)0.50036 (8)0.0216
O20.8810 (4)0.74044 (17)0.59505 (9)0.0232
O30.1772 (4)0.73383 (16)0.76569 (9)0.0268
N10.3119 (4)0.68900 (19)0.56549 (9)0.0169
N20.7268 (5)0.65885 (16)0.52939 (8)0.0171
C10.7160 (5)0.7066 (2)0.57385 (11)0.0178
C20.4920 (5)0.7198 (2)0.59872 (11)0.0161
C30.3270 (5)0.6328 (2)0.52393 (11)0.0167
C40.5522 (5)0.6048 (2)0.50483 (11)0.0156
C50.4530 (5)0.8269 (2)0.61443 (12)0.0187
C60.2870 (5)0.8158 (2)0.65724 (10)0.0180
C70.1310 (5)0.8810 (2)0.67449 (11)0.0185
C80.0191 (6)0.8511 (2)0.71144 (11)0.0207
C90.0145 (5)0.7565 (2)0.73092 (12)0.0201
C100.1474 (5)0.6925 (2)0.71467 (11)0.0219
C110.2958 (5)0.7226 (2)0.67739 (11)0.0178
C120.4738 (5)0.6653 (2)0.65075 (11)0.0188
C130.1984 (6)0.6345 (3)0.77997 (13)0.0328
C140.5921 (5)0.4945 (2)0.50874 (12)0.0203
C150.6082 (5)0.4583 (2)0.56369 (13)0.0216
C160.8021 (5)0.4697 (2)0.59115 (12)0.0244
C170.8163 (5)0.4370 (3)0.64143 (13)0.0287
C180.6388 (7)0.3910 (3)0.66458 (14)0.0332
C190.4463 (6)0.3785 (3)0.63695 (14)0.0301
C200.4300 (6)0.4124 (2)0.58712 (13)0.0238
O40.9677 (5)0.3410 (2)0.47242 (11)0.0433
N31.2704 (6)0.33877 (19)0.42177 (10)0.0281
C211.1428 (6)0.3063 (3)0.45948 (14)0.0300
C221.4787 (6)0.2930 (3)0.40944 (15)0.0367
C231.2052 (8)0.4224 (3)0.39215 (15)0.0495
H410.55440.62090.46870.0171*
H510.58710.85430.62730.0216*
H520.39750.86620.58630.0216*
H710.12540.94290.66150.0221*
H1010.15410.63030.72890.0265*
H1210.60970.67280.66940.0215*
H1220.43360.59840.64620.0227*
H1310.32140.63150.80330.0481*
H1320.06660.61290.79680.0478*
H1330.22600.59330.75090.0477*
H1410.72750.47700.49180.0238*
H1420.47170.46330.49140.0240*
H1610.92350.49910.57630.0280*
H1710.94710.44290.65930.0343*
H1810.65090.37040.69870.0391*
H1910.32650.34780.65130.0361*
H2010.30400.40420.56790.0272*
H2111.19410.25060.47800.0346*
H2211.47430.27060.37480.0537*
H2231.59360.33960.41290.0534*
H2221.49840.24000.43310.0538*
H2311.20000.40790.35630.0731*
H2331.30810.47400.39810.0730*
H2321.05910.44260.40230.0726*
H110.18330.70620.57360.0197*
H210.85390.64730.51850.0197*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.02134 (14)0.02512 (14)0.02310 (13)0.00248 (19)0.00516 (18)0.00406 (13)
O10.0155 (10)0.0251 (12)0.0241 (12)0.0015 (9)0.0001 (9)0.0054 (10)
O20.0126 (12)0.0312 (13)0.0259 (12)0.0015 (10)0.0003 (9)0.0069 (10)
O30.0269 (12)0.0277 (12)0.0257 (11)0.0018 (9)0.0120 (10)0.0039 (10)
N10.0085 (13)0.0243 (13)0.0181 (12)0.0008 (10)0.0003 (9)0.0028 (10)
N20.0112 (13)0.0209 (12)0.0191 (11)0.0014 (12)0.0015 (11)0.0030 (9)
C10.0160 (19)0.0205 (14)0.0170 (13)0.0005 (13)0.0020 (12)0.0008 (11)
C20.0128 (15)0.0217 (16)0.0137 (14)0.0017 (13)0.0018 (12)0.0008 (12)
C30.0199 (15)0.0164 (15)0.0139 (14)0.0017 (12)0.0013 (12)0.0011 (12)
C40.0104 (15)0.0225 (16)0.0137 (14)0.0006 (12)0.0019 (11)0.0028 (12)
C50.0129 (15)0.0215 (17)0.0217 (16)0.0021 (13)0.0007 (12)0.0027 (13)
C60.017 (2)0.0221 (14)0.0146 (13)0.0020 (13)0.0007 (12)0.0033 (11)
C70.0210 (17)0.0191 (16)0.0154 (14)0.0018 (13)0.0007 (12)0.0023 (12)
C80.0236 (17)0.0247 (17)0.0137 (14)0.0008 (14)0.0015 (13)0.0042 (12)
C90.0205 (15)0.0283 (16)0.0116 (13)0.0031 (13)0.0014 (14)0.0007 (14)
C100.0230 (17)0.0216 (16)0.0212 (16)0.0036 (14)0.0016 (13)0.0018 (13)
C110.0163 (19)0.0229 (15)0.0142 (13)0.0002 (12)0.0023 (11)0.0019 (11)
C120.0146 (15)0.0226 (16)0.0192 (15)0.0044 (13)0.0002 (12)0.0000 (13)
C130.034 (3)0.0369 (19)0.0270 (18)0.0000 (16)0.0122 (14)0.0094 (14)
C140.0181 (16)0.0212 (17)0.0217 (16)0.0027 (13)0.0004 (12)0.0052 (13)
C150.0197 (16)0.0178 (17)0.0272 (17)0.0029 (12)0.0026 (13)0.0025 (13)
C160.0163 (19)0.0280 (17)0.0289 (17)0.0066 (12)0.0028 (12)0.0007 (13)
C170.0213 (17)0.0373 (18)0.0276 (17)0.0072 (16)0.0015 (12)0.0012 (16)
C180.039 (2)0.034 (2)0.0265 (19)0.0134 (18)0.0071 (16)0.0064 (15)
C190.027 (2)0.029 (2)0.034 (2)0.0003 (16)0.0119 (15)0.0006 (16)
C200.0235 (17)0.0169 (17)0.0310 (18)0.0008 (13)0.0037 (14)0.0041 (13)
O40.0365 (17)0.0364 (16)0.0569 (18)0.0035 (13)0.0137 (14)0.0042 (14)
N30.0296 (17)0.0286 (14)0.0260 (13)0.0011 (16)0.0018 (15)0.0011 (11)
C210.030 (2)0.0251 (18)0.035 (2)0.0017 (16)0.0007 (16)0.0043 (15)
C220.033 (2)0.039 (2)0.038 (2)0.0008 (18)0.0050 (17)0.0043 (18)
C230.053 (3)0.050 (3)0.045 (2)0.008 (2)0.0070 (19)0.0210 (19)
Geometric parameters (Å, º) top
Br1—C81.891 (3)C12—H1220.965
O1—C31.243 (4)C13—H1310.964
O2—C11.237 (4)C13—H1320.961
O3—C91.377 (4)C13—H1330.963
O3—C131.430 (4)C14—C151.521 (4)
N1—C21.459 (4)C14—H1410.965
N1—C31.337 (4)C14—H1420.962
N1—H110.843C15—C161.387 (4)
N2—C11.336 (4)C15—C201.396 (5)
N2—C41.447 (4)C16—C171.389 (5)
N2—H210.838C16—H1610.927
C1—C21.518 (4)C17—C181.390 (5)
C2—C51.555 (4)C17—H1710.925
C2—C121.556 (4)C18—C191.384 (5)
C3—C41.507 (4)C18—H1810.937
C4—C141.548 (4)C19—C201.385 (5)
C4—H410.967C19—H1910.922
C5—C61.512 (4)C20—H2010.921
C5—H510.959O4—C211.215 (4)
C5—H520.974N3—C211.330 (5)
C6—C71.384 (4)N3—C221.451 (5)
C6—C111.393 (4)N3—C231.447 (4)
C7—C81.390 (4)C21—H2110.961
C7—H710.920C22—H2210.956
C8—C91.404 (4)C22—H2230.954
C9—C101.390 (4)C22—H2220.965
C10—C111.390 (4)C23—H2310.957
C10—H1010.938C23—H2330.961
C11—C121.510 (4)C23—H2320.967
C12—H1210.964
C9—O3—C13117.1 (2)C2—C12—H122112.0
C2—N1—C3126.8 (3)C11—C12—H122112.3
C2—N1—H11117.6H121—C12—H122112.5
C3—N1—H11115.5O3—C13—H131105.9
C1—N2—C4127.1 (3)O3—C13—H132110.0
C1—N2—H21115.6H131—C13—H132110.1
C4—N2—H21115.3O3—C13—H133112.2
N2—C1—O2122.4 (3)H131—C13—H133109.7
N2—C1—C2118.3 (3)H132—C13—H133108.8
O2—C1—C2119.3 (3)C4—C14—C15113.3 (3)
C1—C2—N1112.5 (2)C4—C14—H141110.4
C1—C2—C5111.3 (3)C15—C14—H141107.2
N1—C2—C5108.7 (2)C4—C14—H142107.0
C1—C2—C12112.2 (2)C15—C14—H142110.1
N1—C2—C12108.8 (2)H141—C14—H142108.7
C5—C2—C12102.8 (2)C14—C15—C16120.2 (3)
N1—C3—O1122.3 (3)C14—C15—C20120.8 (3)
N1—C3—C4118.7 (3)C16—C15—C20118.9 (3)
O1—C3—C4119.0 (3)C15—C16—C17120.2 (3)
C3—C4—N2112.7 (2)C15—C16—H161120.6
C3—C4—C14112.0 (3)C17—C16—H161119.2
N2—C4—C14111.5 (3)C16—C17—C18120.7 (3)
C3—C4—H41105.9C16—C17—H171120.1
N2—C4—H41107.5C18—C17—H171119.2
C14—C4—H41106.8C17—C18—C19119.1 (3)
C2—C5—C6101.5 (2)C17—C18—H181119.4
C2—C5—H51109.9C19—C18—H181121.5
C6—C5—H51110.4C18—C19—C20120.5 (3)
C2—C5—H52112.8C18—C19—H191120.8
C6—C5—H52112.5C20—C19—H191118.8
H51—C5—H52109.6C15—C20—C19120.6 (3)
C5—C6—C7129.1 (3)C15—C20—H201117.6
C5—C6—C11110.3 (3)C19—C20—H201121.8
C7—C6—C11120.5 (3)C21—N3—C22121.6 (3)
C6—C7—C8118.7 (3)C21—N3—C23120.4 (3)
C6—C7—H71120.8C22—N3—C23118.0 (3)
C8—C7—H71120.5N3—C21—O4125.6 (4)
Br1—C8—C7120.2 (2)N3—C21—H211117.0
Br1—C8—C9118.7 (2)O4—C21—H211117.4
C7—C8—C9121.0 (3)N3—C22—H221109.1
C8—C9—O3115.9 (3)N3—C22—H223108.8
C8—C9—C10119.8 (3)H221—C22—H223109.2
O3—C9—C10124.3 (3)N3—C22—H222107.4
C9—C10—C11118.8 (3)H221—C22—H222111.1
C9—C10—H101119.7H223—C22—H222111.2
C11—C10—H101121.6N3—C23—H231111.2
C6—C11—C10121.1 (3)N3—C23—H233109.2
C6—C11—C12109.9 (3)H231—C23—H233109.7
C10—C11—C12129.0 (3)N3—C23—H232109.6
C2—C12—C11101.4 (2)H231—C23—H232107.3
C2—C12—H121109.1H233—C23—H232109.8
C11—C12—H121109.0
C2—C4—C14—C153.3 (3)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H11···O2i0.841.982.820 (5)177
N2—H21···O1ii0.842.022.854 (5)171
C14—H141···O40.962.433.257 (5)143
C21—H211···O4iii0.962.463.346 (5)154
Symmetry codes: (i) x1, y, z; (ii) x+1, y, z; (iii) x+1/2, y+1/2, z+1.

Experimental details

Crystal data
Chemical formulaC20H19BrN2O3·C3H7NO
Mr488.38
Crystal system, space groupOrthorhombic, P212121
Temperature (K)100
a, b, c (Å)6.0741 (7), 13.8336 (16), 26.076 (3)
V3)2191.1 (4)
Z4
Radiation typeSynchrotron, λ = 0.7749 Å
µ (mm1)1.91
Crystal size (mm)1.00 × 0.01 × 0.01
Data collection
DiffractometerBruker SMART APEXII CCD
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.25, 0.98
No. of measured, independent and
observed [I > 2σ(I)] reflections
31454, 4493, 3882
Rint0.057
(sin θ/λ)max1)0.626
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.034, 0.073, 1.00
No. of reflections4479
No. of parameters281
H-atom treatmentOnly H-atom displacement parameters refined
Δρmax, Δρmin (e Å3)0.60, 0.67
Absolute structureFlack (1983), 1890 Friedel-pairs
Absolute structure parameter0.015 (7)

Computer programs: APEX2 (Bruker, 2007), SAINT (Bruker, 2007), SIR92 (Altomare et al., 1993), CRYSTALS (Betteridge et al., 2003), ORTEP-3 for Windows (Farrugia, 1997) and Mercury (Macrae et al., 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H11···O2i0.841.982.820 (5)177
N2—H21···O1ii0.842.022.854 (5)171
C14—H141···O40.962.433.257 (5)143
C21—H211···O4iii0.962.463.346 (5)154
Symmetry codes: (i) x1, y, z; (ii) x+1, y, z; (iii) x+1/2, y+1/2, z+1.
 

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