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organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 69| Part 4| April 2013| Page o503
doi:10.1107/S1600536813005527

7-Hy­dr­oxy­methyl-2-pivaloyl­amino-1,8-naphthyridine

Hoong-Kun Fun,a,b*‡ Ching Kheng Quah,a§ Krishnendu Aich,c Sangita Dasc and Shyamaprosad Goswamic

aX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia, bDepartment of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, PO Box 2457, Riyadh 11451, Saudi Arabia, and cDepartment of Chemistry, Bengal Engineering and Science University, Shibpur, Howrah 711 103, India
*Correspondence e-mail: hkfun@usm.my

(Received 20 February 2013; accepted 26 February 2013; online 6 March 2013)

In the title compound, C14H17N3O2, the mean plane of the 1,8-naphthyridine ring system (r.m.s deviation = 0.020 Å) forms a dihedral angle of 23.4 (1)° with the acetamide moiety (r.m.s deviation = 0.001 Å). The mol­ecular structure is stabilized by an intra­molecular O—H⋯N hydrogen bond, which generates an S(5) ring motif. In the crystal, mol­ecules are linked into inversion dimers by pairs of N—H⋯O hydrogen bonds, generating 18-membered R22(18) ring motifs.

Related literature

For general background to and the medicinal properties of 1,8-naphthyridine derivatives see: Badawneh et al. (2001[Badawneh, M., Ferrarini, P. L., Calderone, V., Manera, C., Martinotti, E., Mori, C., Saccomanni, G. & Testai, L. (2001). Eur. J. Med. Chem. 36, 925-934.]); Litvinov (2004[Litvinov, V. P. (2004). Russ. Chem. Rev. 73, 637-669.]). For standard bond-length data, see: Allen et al. (1987[Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1-19.]). For hydrogen-bond motifs, see: Bernstein et al. (1995[Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555-1573.]).

[Scheme 1]

Experimental

Crystal data

  • C14H17N3O2

  • Mr = 259.31

  • Monoclinic, P 21 /c

  • a = 14.7026 (3) Å

  • b = 6.2586 (1) Å

  • c = 14.7035 (3) Å

  • β = 97.447 (2)°

  • V = 1341.57 (4) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.09 mm−1

  • T = 297 K

  • 0.51 × 0.46 × 0.08 mm
Data collection

  • Bruker SMART APEXII CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2009[Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.956, Tmax = 0.993

  • 20410 measured reflections

  • 3949 independent reflections

  • 2551 reflections with I > 2σ(I)

  • Rint = 0.042
Refinement

  • R[F2 > 2σ(F2)] = 0.074

  • wR(F2) = 0.148

  • S = 1.14

  • 3949 reflections

  • 183 parameters

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.21 e Å−3

  • Δρmin = −0.14 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A D⋯A D—H⋯A
N3—H1N3⋯O2i 0.83 (2) 2.09 (2) 2.900 (2) 168 (2)
O2—H1O2⋯N2 0.86 (3) 2.10 (3) 2.648 (2) 121 (2)
Symmetry code: (i) -x+2, -y+1, -z+1.

Data collection: APEX2 (Bruker, 2009[Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2009[Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536813005527/rz5047sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536813005527/rz5047Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536813005527/rz5047Isup3.cml

checkCIF report


Comment top

1,8-Naphthyridine system is of great interest due to their broad application in medicine as they are potentially useful as antihypertensives, antitumor agents, immunostimulants, and herbicide safeners (Badawneh et al., 2001; Litvinov, 2004). Herein, we report the crystal structure of 2-pivaloylamino-7-hydroxymethyl-[1,8]naphthyridine.

In the title molecule, Fig. 1, the mean plane of [1,8]naphthyridine ring system (N1/N2/C1-C8, r.m.s deviation = 0.020 Å) forms a dihedral angle of 23.4 (1)° with the acetamide moiety (O1/N3/C9/C10, r.m.s deviation = 0.001 Å). Bond lengths (Allen et al., 1987) and angles are within normal ranges. The molecular structure is stabilized by an intramolecular O2–H1O2···N2 (Table 1) hydrogen bond, which generates an S(5) ring motif (Bernstein et al., 1995).

In the crystal, Fig. 2, molecules are linked into inversion dimers by pairs of intermolecular N3–H1N3···O2 (Table 1) hydrogen bonds, generating eighteen-membered R22(18) ring motifs (Bernstein et al., 1995).

Related literature top

For general background to and the medicinal properties of 1,8-naphthyridine derivatives see: Badawneh et al. (2001); Litvinov (2004). For standard bond-length data, see: Allen et al. (1987). For hydrogen-bond motifs, see: Bernstein et al. (1995).

Experimental top

To a stirred solution of 7-pivaloylamino-[1,8]naphthyridine-2-carbaldehyde (514 mg, 2 mmol) in dry THF was added NaBH4 (40 mg, 1mmol) at 0°C and the resulting mixture was stirred for half an hour at room temperature under nitrogen atmosphere. After evaporation of the solvent, water was added to it and then the reaction mixture was extracted with dichloromethane thrice. The organic layer was dried over anhydrous sodium sulphate and then evaporated under reduced pressure. The crude solid was purified through column chromatography (silica gel, 60-120 mesh) using ethyl acetate as eluent to afford a pure brown crystalline solid. Yield: 87%. M.p. 135-137 °C

Refinement top

Atoms H1N3 and H1O2 were located in a difference Fourier map and refined freely [N–H = 0.83 (2) Å and O–H 0.86 (3) Å]. The remaining H atoms were positioned geometrically and refined using a riding model with C–H = 0.93-0.97 Å and Uiso(H) = 1.2 or 1.5 Ueq(C). A rotating-group model was applied for the methyl groups.

Computing details top

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound showing 30% probability displacement ellipsoids for non-H atoms. The intramolecular hydrogen bond is shown as a dashed line.
[Figure 2] Fig. 2. The crystal structure of the title compound, viewed along the b axis. H atoms not involved in hydrogen bonds (dashed lines) have been omitted for clarity.
7-Hydroxymethyl-2-pivaloylamino-1,8-naphthyridine top
Crystal data top
C14H17N3O2F(000) = 552
Mr = 259.31Dx = 1.284 Mg m−3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 4518 reflections
a = 14.7026 (3) Åθ = 2.8–30.1°
b = 6.2586 (1) ŵ = 0.09 mm−1
c = 14.7035 (3) ÅT = 297 K
β = 97.447 (2)°Plate, brown
V = 1341.57 (4) Å30.51 × 0.46 × 0.08 mm
Z = 4
Data collection top
Bruker SMART APEXII CCD area-detector
diffractometer		3949 independent reflections
Radiation source: fine-focus sealed tube2551 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.042
ϕ and ω scansθmax = 30.2°, θmin = 2.8°
Absorption correction: multi-scan
(SADABS; Bruker, 2009)		h = −20→20
Tmin = 0.956, Tmax = 0.993k = −8→8
20410 measured reflectionsl = −20→19
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.074Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.148H atoms treated by a mixture of independent and constrained refinement
S = 1.14 w = 1/[σ2(Fo2) + (0.0366P)2 + 0.506P]
where P = (Fo2 + 2Fc2)/3
3949 reflections(Δ/σ)max = 0.001
183 parametersΔρmax = 0.21 e Å−3
0 restraintsΔρmin = −0.14 e Å−3
Crystal data top
C14H17N3O2V = 1341.57 (4) Å3
Mr = 259.31Z = 4
Monoclinic, P21/cMo Kα radiation
a = 14.7026 (3) ŵ = 0.09 mm−1
b = 6.2586 (1) ÅT = 297 K
c = 14.7035 (3) Å0.51 × 0.46 × 0.08 mm
β = 97.447 (2)°
Data collection top
Bruker SMART APEXII CCD area-detector
diffractometer		3949 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2009)		2551 reflections with I > 2σ(I)
Tmin = 0.956, Tmax = 0.993Rint = 0.042
20410 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0740 restraints
wR(F2) = 0.148H atoms treated by a mixture of independent and constrained refinement
S = 1.14Δρmax = 0.21 e Å−3
3949 reflectionsΔρmin = −0.14 e Å−3
183 parameters
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. 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.70708 (11)−0.0049 (3)0.72243 (11)0.0731 (5)
O21.20193 (11)0.4754 (2)0.50680 (10)0.0564 (4)
N10.93270 (10)0.1958 (2)0.60449 (9)0.0398 (4)
N21.08422 (10)0.2310 (2)0.58087 (9)0.0403 (4)
C11.01722 (12)0.1059 (3)0.60905 (10)0.0369 (4)
C21.16763 (13)0.1520 (3)0.58648 (11)0.0424 (4)
C31.19173 (15)−0.0552 (3)0.61930 (12)0.0509 (5)
H3A1.2519−0.10320.62260.061*
C41.12550 (14)−0.1827 (3)0.64593 (12)0.0495 (5)
H4A1.1396−0.32060.66680.059*
C51.03554 (13)−0.1052 (3)0.64177 (11)0.0410 (4)
C60.96182 (14)−0.2230 (3)0.66823 (11)0.0468 (5)
H6A0.9707−0.36390.68760.056*
C70.87830 (14)−0.1325 (3)0.66566 (12)0.0475 (5)
H7A0.8296−0.20730.68500.057*
C80.86672 (13)0.0803 (3)0.63253 (11)0.0406 (4)
N30.78116 (12)0.1817 (3)0.62256 (12)0.0490 (4)
C90.70570 (14)0.1334 (3)0.66391 (14)0.0505 (5)
C100.61984 (14)0.2648 (3)0.63154 (15)0.0578 (6)
C110.59481 (17)0.2364 (5)0.52733 (18)0.0814 (8)
H11A0.58920.08690.51300.122*
H11B0.64200.29790.49620.122*
H11C0.53760.30660.50770.122*
C120.54109 (18)0.1846 (5)0.6811 (2)0.0986 (10)
H12A0.52860.03760.66560.148*
H12B0.48720.26870.66270.148*
H12C0.55800.19730.74620.148*
C130.63721 (16)0.5019 (4)0.65370 (17)0.0688 (6)
H13A0.65400.51900.71860.103*
H13B0.58240.58220.63440.103*
H13C0.68600.55300.62200.103*
C141.23927 (14)0.2947 (3)0.55470 (14)0.0536 (5)
H14A1.28100.34120.60750.064*
H14B1.27450.21360.51520.064*
H1N30.7793 (14)0.288 (4)0.5889 (14)0.057 (6)*
H1O21.1439 (18)0.474 (4)0.5097 (18)0.087 (9)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0823 (11)0.0626 (10)0.0797 (11)−0.0054 (9)0.0311 (9)0.0198 (9)
O20.0555 (9)0.0436 (8)0.0725 (10)0.0026 (7)0.0170 (8)0.0102 (7)
N10.0502 (9)0.0312 (8)0.0379 (7)0.0001 (7)0.0052 (6)0.0041 (6)
N20.0505 (9)0.0323 (8)0.0381 (7)0.0023 (7)0.0061 (6)0.0028 (6)
C10.0543 (11)0.0285 (9)0.0277 (8)0.0023 (8)0.0041 (7)−0.0003 (7)
C20.0531 (11)0.0408 (10)0.0333 (8)0.0059 (9)0.0058 (8)−0.0014 (7)
C30.0610 (13)0.0464 (12)0.0453 (10)0.0178 (10)0.0074 (9)0.0020 (9)
C40.0760 (14)0.0356 (10)0.0373 (9)0.0169 (10)0.0082 (9)0.0056 (8)
C50.0648 (12)0.0305 (9)0.0276 (8)0.0050 (8)0.0060 (8)−0.0004 (7)
C60.0770 (14)0.0275 (9)0.0354 (9)0.0005 (9)0.0058 (9)0.0041 (7)
C70.0673 (13)0.0343 (10)0.0415 (10)−0.0090 (9)0.0087 (9)0.0036 (8)
C80.0524 (11)0.0351 (9)0.0339 (8)−0.0032 (8)0.0035 (8)−0.0002 (7)
N30.0524 (10)0.0409 (9)0.0547 (10)−0.0029 (8)0.0105 (8)0.0112 (8)
C90.0579 (12)0.0413 (11)0.0538 (11)−0.0123 (9)0.0132 (9)−0.0048 (9)
C100.0519 (12)0.0484 (12)0.0749 (14)−0.0070 (10)0.0151 (11)−0.0055 (11)
C110.0617 (15)0.0837 (19)0.0930 (18)0.0035 (13)−0.0122 (13)−0.0208 (15)
C120.0694 (17)0.084 (2)0.152 (3)−0.0073 (15)0.0491 (18)0.009 (2)
C130.0699 (15)0.0540 (14)0.0838 (16)−0.0001 (12)0.0141 (12)−0.0100 (12)
C140.0532 (12)0.0512 (12)0.0571 (12)0.0051 (10)0.0094 (9)0.0030 (10)
Geometric parameters (Å, º) top
O1—C91.219 (2)C8—N31.399 (2)
O2—C141.406 (2)N3—C91.366 (2)
O2—H1O20.86 (3)N3—H1N30.83 (2)
N1—C81.318 (2)C9—C101.530 (3)
N1—C11.358 (2)C10—C121.531 (3)
N2—C21.315 (2)C10—C131.534 (3)
N2—C11.364 (2)C10—C111.539 (3)
C1—C51.420 (2)C11—H11A0.9600
C2—C31.412 (3)C11—H11B0.9600
C2—C141.501 (3)C11—H11C0.9600
C3—C41.356 (3)C12—H12A0.9600
C3—H3A0.9300C12—H12B0.9600
C4—C51.403 (3)C12—H12C0.9600
C4—H4A0.9300C13—H13A0.9600
C5—C61.407 (3)C13—H13B0.9600
C6—C71.348 (3)C13—H13C0.9600
C6—H6A0.9300C14—H14A0.9700
C7—C81.421 (3)C14—H14B0.9700
C7—H7A0.9300
C14—O2—H1O2106.9 (18)N3—C9—C10115.32 (18)
C8—N1—C1117.60 (15)C9—C10—C12108.7 (2)
C2—N2—C1117.98 (15)C9—C10—C13110.25 (18)
N1—C1—N2116.06 (15)C12—C10—C13109.4 (2)
N1—C1—C5122.31 (17)C9—C10—C11109.20 (18)
N2—C1—C5121.63 (16)C12—C10—C11109.8 (2)
N2—C2—C3123.87 (18)C13—C10—C11109.6 (2)
N2—C2—C14116.29 (16)C10—C11—H11A109.5
C3—C2—C14119.83 (17)C10—C11—H11B109.5
C4—C3—C2118.79 (18)H11A—C11—H11B109.5
C4—C3—H3A120.6C10—C11—H11C109.5
C2—C3—H3A120.6H11A—C11—H11C109.5
C3—C4—C5119.48 (17)H11B—C11—H11C109.5
C3—C4—H4A120.3C10—C12—H12A109.5
C5—C4—H4A120.3C10—C12—H12B109.5
C4—C5—C6124.22 (17)H12A—C12—H12B109.5
C4—C5—C1118.24 (17)C10—C12—H12C109.5
C6—C5—C1117.54 (17)H12A—C12—H12C109.5
C7—C6—C5120.21 (17)H12B—C12—H12C109.5
C7—C6—H6A119.9C10—C13—H13A109.5
C5—C6—H6A119.9C10—C13—H13B109.5
C6—C7—C8118.16 (18)H13A—C13—H13B109.5
C6—C7—H7A120.9C10—C13—H13C109.5
C8—C7—H7A120.9H13A—C13—H13C109.5
N1—C8—N3113.99 (16)H13B—C13—H13C109.5
N1—C8—C7124.12 (18)O2—C14—C2112.97 (16)
N3—C8—C7121.81 (18)O2—C14—H14A109.0
C9—N3—C8128.60 (18)C2—C14—H14A109.0
C9—N3—H1N3118.5 (15)O2—C14—H14B109.0
C8—N3—H1N3112.8 (15)C2—C14—H14B109.0
O1—C9—N3122.1 (2)H14A—C14—H14B107.8
O1—C9—C10122.61 (19)
C8—N1—C1—N2−178.99 (14)C5—C6—C7—C82.3 (3)
C8—N1—C1—C50.6 (2)C1—N1—C8—N3−177.86 (14)
C2—N2—C1—N1178.24 (14)C1—N1—C8—C7−1.0 (2)
C2—N2—C1—C5−1.3 (2)C6—C7—C8—N1−0.4 (3)
C1—N2—C2—C30.5 (2)C6—C7—C8—N3176.20 (16)
C1—N2—C2—C14179.94 (15)N1—C8—N3—C9−162.20 (18)
N2—C2—C3—C40.7 (3)C7—C8—N3—C920.9 (3)
C14—C2—C3—C4−178.71 (17)C8—N3—C9—O15.0 (3)
C2—C3—C4—C5−1.1 (3)C8—N3—C9—C10−174.93 (18)
C3—C4—C5—C6−179.53 (17)O1—C9—C10—C12−2.5 (3)
C3—C4—C5—C10.3 (2)N3—C9—C10—C12177.52 (19)
N1—C1—C5—C4−178.57 (15)O1—C9—C10—C13117.4 (2)
N2—C1—C5—C40.9 (2)N3—C9—C10—C13−62.6 (2)
N1—C1—C5—C61.3 (2)O1—C9—C10—C11−122.2 (2)
N2—C1—C5—C6−179.22 (15)N3—C9—C10—C1157.8 (2)
C4—C5—C6—C7177.13 (17)N2—C2—C14—O2−12.0 (2)
C1—C5—C6—C7−2.7 (2)C3—C2—C14—O2167.53 (16)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N3—H1N3···O2i0.83 (2)2.09 (2)2.900 (2)168 (2)
O2—H1O2···N20.86 (3)2.10 (3)2.648 (2)121 (2)
Symmetry code: (i) −x+2, −y+1, −z+1.

Experimental details

Crystal data
Chemical formulaC14H17N3O2
Mr259.31
Crystal system, space groupMonoclinic, P21/c
Temperature (K)297
a, b, c (Å)14.7026 (3), 6.2586 (1), 14.7035 (3)
β (°) 97.447 (2)
V (Å3)1341.57 (4)
Z4
Radiation typeMo Kα
µ (mm−1)0.09
Crystal size (mm)0.51 × 0.46 × 0.08
Data collection
DiffractometerBruker SMART APEXII CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2009)
Tmin, Tmax0.956, 0.993
No. of measured, independent and
observed [I > 2σ(I)] reflections		20410, 3949, 2551
Rint0.042
(sin θ/λ)max (Å−1)0.708
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.074, 0.148, 1.14
No. of reflections3949
No. of parameters183
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å−3)0.21, −0.14

Computer programs: APEX2 (Bruker, 2009), SAINT (Bruker, 2009), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N3—H1N3···O2i0.83 (2)2.09 (2)2.900 (2)168 (2)
O2—H1O2···N20.86 (3)2.10 (3)2.648 (2)121 (2)
Symmetry code: (i) −x+2, −y+1, −z+1.
 

Footnotes

‡Thomson Reuters ResearcherID: A-3561-2009.

§Thomson Reuters ResearcherID: A-5525-2009.

Acknowledgements

The authors thank Universiti Sains Malaysia (USM) for the RUC grant (Structure Determination of 50 kDa Outer Membrane Proteins From S.typhi By X-ray Protein Crystallography, No. 1001/PSKBP/8630013) and APEX DE2012 grant (No.1002/PFIZIK/910323). The authors also thank the CSIR and DST, Government of India, for financial support.

References

First citationAllen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19.  CrossRef Web of Science Google Scholar
 First citationBadawneh, M., Ferrarini, P. L., Calderone, V., Manera, C., Martinotti, E., Mori, C., Saccomanni, G. & Testai, L. (2001). Eur. J. Med. Chem. 36, 925–934.  Web of Science CrossRef PubMed CAS Google Scholar
 First citationBernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555-1573.  CrossRef CAS Web of Science Google Scholar
 First citationBruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
 First citationLitvinov, V. P. (2004). Russ. Chem. Rev. 73, 637–669.  CrossRef CAS Google Scholar
 First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
 First citationSpek, A. L. (2009). Acta Cryst. D65, 148–155.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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ISSN: 2056-9890
Volume 69| Part 4| April 2013| Page o503
doi:10.1107/S1600536813005527
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