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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890

Lysergol monohydrate

aBAM Federal Institute for Materials Research and Testing, Department Analytical Chemistry, Reference Materials, Richard-Willstätter-Strasse 11, D-12489 Berlin-Adlershof, Germany
*Correspondence e-mail: franziska.emmerling@bam.de

(Received 11 January 2012; accepted 20 January 2012; online 25 January 2012)

In the title compound [systematic name: (7-methyl-4,6,6a,7,8,9-hexa­hydro­indolo[4,3,2-fg]quinoline-9-yl)methanol monohydrate], C16H18N2O·H2O, the non-aromatic ring (ring C of the ergoline skeleton) directly fused to the aromatic rings is nearly planar, with a maximum deviation of 0.659 (3) Å, and shows an envelope conformation. In the crystal, hydrogen bonds between the lysergol and water mol­ecules contribute to the formation of layers parallel to (10[\overline{2}]).

Related literature

For the natural occurrence of lysergol, see: Amor-Prats & Harborne (1993[Amor-Prats, D. & Harborne, J. B. (1993). Biochem. Syst. Ecol. 21, 455-462.]); Uhlig et al. (2007[Uhlig, S., Vikoren, T., Ivanova, L. & Handeland, K. (2007). Rapid Commun. Mass Spectrom. 21, 1651-1660.]). For the crystal structures of other alkaloids produced by Clavicipitaceae see: Pakhomova et al. (1995[Pakhomova, S., Ondráucek, J., Huusák, M., Kratochvíl, B., Jegorov, A. & Stuchlík, J. (1995). Acta Cryst. C51, 308-311.]); Merkel et al. (2010[Merkel, S., Köppen, R., Koch, M., Emmerling, F. & Nehls, I. (2010). Acta Cryst. E66, o2275.]).

[Scheme 1]

Experimental

Crystal data
  • C16H18N2O·H2O

  • Mr = 272.34

  • Orthorhombic, P 21 21 21

  • a = 7.6234 (12) Å

  • b = 12.3803 (19) Å

  • c = 15.877 (2) Å

  • V = 1498.5 (4) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.08 mm−1

  • T = 296 K

  • 0.2 × 0.1 × 0.08 mm

Data collection
  • Bruker APEX CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2001[Bruker (2001). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.85, Tmax = 0.96

  • 12705 measured reflections

  • 1569 independent reflections

  • 747 reflections with I > 2σ(I)

  • Rint = 0.122

Refinement
  • R[F2 > 2σ(F2)] = 0.036

  • wR(F2) = 0.052

  • S = 0.79

  • 1569 reflections

  • 188 parameters

  • 2 restraints

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

  • Δρmax = 0.10 e Å−3

  • Δρmin = −0.10 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
O1—H1⋯O2i 0.82 2.03 2.845 (3) 176
N2—H2A⋯O2ii 0.86 2.17 2.896 (4) 142
O2—H17⋯N1iii 0.84 (3) 2.00 (3) 2.826 (3) 171 (3)
O2—H18⋯O1iv 0.84 (3) 1.96 (2) 2.777 (3) 167 (3)
Symmetry codes: (i) [-x+1, y+{\script{1\over 2}}, -z+{\script{3\over 2}}]; (ii) [x+{\script{1\over 2}}, -y+{\script{3\over 2}}, -z+1]; (iii) [-x+{\script{3\over 2}}, -y+2, z+{\script{1\over 2}}]; (iv) [-x+{\script{1\over 2}}, -y+2, z+{\script{1\over 2}}].

Data collection: SMART (Bruker, 2001[Bruker (2001). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2001[Bruker (2001). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]) and ORTEPIII (Burnett & Johnson, 1996[Burnett, M. N. & Johnson, C. K. (1996). ORTEPIII. Report ORNL-6895. Oak Ridge National Laboratory, Tennessee, USA.]); software used to prepare material for publication: SHELXTL.

Supporting information


Comment top

Lysergol is a clavine alkaloid produced by fungi of the family Clavicipitaceae. It naturally occurs in sclerotia and can be isolated from seeds of some species of the genus Ipomoea (Amor-Prats et al., 1993). Lysergol has an ergoline skeleton and is therefore structurally related to ergot alkaloids like ergometrinine (Merkel et al., 2010) or ergotamine (Pakhomova et al., 1995).

The molecule crytsallizes in the orthorhombic space group P212121. The molecular structure of the compound and the atom-labeling scheme are shown in Fig 1.

The absolute configuration could not be defined confidently based on the single-crystal diffraction data. It was however established based on liquid chromatography data that confirmed the epimeric purity of the obtained lysergol crystals. Each lysergol molecule forms four hydrogen bonds to four adjacent water molecules. As a consequence, each water molecule is involved in four hydrogen bonds to four lysergol molecules, resulting in a three dimentional framework structure.

Related literature top

For the natural occurrence of lysergol, see: Amor-Prats & Harborne (1993); Uhlig et al. (2007). For the crystal structures of other alkaloids produced by Clavicipitaceae see: Pakhomova et al. (1995); Merkel et al. (2010).

Experimental top

1.4 mg of epimeric pure lysergol (purity > 97%, HPLC-FLD), obtained from Sigma-Aldrich (Taufkirchen, Germany), were dissolved in a glass vial in 1.2 ml of a 84:16 (v:v) acetonitril:water solution. The vial was subsequently capped and stored in the dark at ambient temperature (approximately 23 °C) until crystal formation was complete (2 days). To avoid any epimerization of lysergol to isolysergol the epimeric purity of the resulted crystals was proofed by HPLC-FLD.

Refinement top

In the absence of significant anomalous dispersion effects, Friedel pairs were merged.

The N—H and O—H hydrogen atoms were located in difference maps and and fixed in their found positions (AFIX 3) with Uĩso~(H) = 1.2 of the parent atom U~eq~ or 1.5 U~eq~(C~methyl~, O).

Computing details top

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008) and ORTEPIII (Burnett & Johnson, 1996); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. : ORTEP representation of the title compound with atomic labeling shown with 30% probability displacement ellipsoids.
[Figure 2] Fig. 2. : View of the unit cell of the title compound along [100], showing the hydrogen bonds between the lysergol and adjacent water molecules. Hydrogen bonds are drawn as dashed green lines.
(7-methyl-4,6,6a,7,8,9-hexahydroindolo[4,3,2-fg]quinoline-9-yl)methanol monohydrate top
Crystal data top
C16H18N2O·H2OF(000) = 584
Mr = 272.34Dx = 1.207 Mg m3
Orthorhombic, P212121Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2abCell parameters from 46 reflections
a = 7.6234 (12) Åθ = 4–22°
b = 12.3803 (19) ŵ = 0.08 mm1
c = 15.877 (2) ÅT = 296 K
V = 1498.5 (4) Å3Needle, colourless
Z = 40.2 × 0.1 × 0.08 mm
Data collection top
Bruker APEX CCD area-detector
diffractometer
1569 independent reflections
Radiation source: fine-focus sealed tube747 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.122
ω/2θ scansθmax = 25.4°, θmin = 2.1°
Absorption correction: multi-scan
(SADABS; Bruker, 2001)
h = 98
Tmin = 0.85, Tmax = 0.96k = 1314
12705 measured reflectionsl = 1818
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)] = 0.036Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.052H atoms treated by a mixture of independent and constrained refinement
S = 0.79 w = 1/[σ2(Fo2) + (0.0045P)2]
where P = (Fo2 + 2Fc2)/3
1569 reflections(Δ/σ)max < 0.001
188 parametersΔρmax = 0.10 e Å3
2 restraintsΔρmin = 0.10 e Å3
Crystal data top
C16H18N2O·H2OV = 1498.5 (4) Å3
Mr = 272.34Z = 4
Orthorhombic, P212121Mo Kα radiation
a = 7.6234 (12) ŵ = 0.08 mm1
b = 12.3803 (19) ÅT = 296 K
c = 15.877 (2) Å0.2 × 0.1 × 0.08 mm
Data collection top
Bruker APEX CCD area-detector
diffractometer
1569 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2001)
747 reflections with I > 2σ(I)
Tmin = 0.85, Tmax = 0.96Rint = 0.122
12705 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0362 restraints
wR(F2) = 0.052H atoms treated by a mixture of independent and constrained refinement
S = 0.79Δρmax = 0.10 e Å3
1569 reflectionsΔρmin = 0.10 e Å3
188 parameters
Special details top

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.

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 > σ(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
O10.3895 (3)1.17847 (16)0.55746 (12)0.0635 (7)
H10.44651.23440.55380.095*
N10.9193 (3)0.95002 (18)0.53144 (15)0.0442 (7)
N20.8345 (5)0.6912 (2)0.21044 (17)0.0648 (9)
H2A0.83990.64520.16990.078*
C10.4962 (4)1.0956 (2)0.5939 (2)0.0562 (9)
H1A0.42661.03050.60000.067*
H1B0.53261.11820.64970.067*
C20.6602 (4)1.0695 (2)0.5413 (2)0.0477 (8)
H110.72701.13620.53260.057*
C30.7769 (4)0.9876 (2)0.5872 (2)0.0521 (10)
H3A0.82691.02100.63710.062*
H3B0.70670.92640.60510.062*
C40.8463 (4)0.8815 (2)0.46293 (19)0.0442 (8)
H40.80200.81510.48890.053*
C50.9912 (4)0.8488 (2)0.3992 (2)0.0571 (10)
H5A1.05180.91290.37950.068*
H5B1.07620.80250.42680.068*
C60.9116 (5)0.7897 (3)0.3247 (2)0.0488 (9)
C70.9690 (5)0.7142 (3)0.2684 (2)0.0627 (11)
H71.07990.68280.26840.075*
C80.6916 (6)0.7556 (3)0.2301 (2)0.0541 (10)
C90.7374 (4)0.8162 (3)0.30186 (19)0.0458 (9)
C100.6234 (5)0.8872 (3)0.34156 (19)0.0457 (9)
C110.6897 (4)0.9386 (3)0.42089 (19)0.0435 (9)
C120.6124 (4)1.0234 (2)0.4570 (2)0.0514 (9)
H120.52161.05660.42760.062*
C130.4597 (4)0.9014 (3)0.30490 (19)0.0596 (10)
H130.38070.95000.32840.072*
C140.4120 (5)0.8423 (3)0.2318 (2)0.0637 (10)
H140.30140.85300.20850.076*
C150.5253 (6)0.7691 (3)0.1937 (2)0.0678 (12)
H150.49220.73050.14600.081*
C161.0496 (4)0.8895 (2)0.58200 (19)0.0682 (11)
H16A0.99840.82310.60130.102*
H16B1.08440.93220.62960.102*
H16C1.15040.87390.54790.102*
O20.4063 (3)0.86910 (19)0.96241 (15)0.0648 (7)
H170.468 (4)0.918 (2)0.9836 (19)0.097*
H180.327 (3)0.847 (3)0.9945 (17)0.097*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0514 (16)0.0583 (16)0.0807 (18)0.0025 (14)0.0038 (13)0.0068 (13)
N10.0467 (19)0.0461 (17)0.0398 (17)0.0035 (15)0.0078 (16)0.0001 (15)
N20.090 (3)0.050 (2)0.055 (2)0.003 (2)0.005 (2)0.0091 (16)
C10.055 (3)0.055 (2)0.058 (2)0.004 (2)0.005 (2)0.0022 (19)
C20.053 (2)0.044 (2)0.046 (2)0.0011 (18)0.0011 (19)0.0009 (19)
C30.065 (3)0.047 (2)0.044 (2)0.003 (2)0.001 (2)0.0040 (18)
C40.047 (2)0.041 (2)0.045 (2)0.0003 (17)0.0002 (19)0.0014 (19)
C50.054 (3)0.059 (2)0.058 (2)0.0101 (19)0.001 (2)0.0029 (19)
C60.059 (3)0.048 (2)0.040 (2)0.005 (2)0.004 (2)0.0014 (18)
C70.070 (3)0.063 (3)0.055 (2)0.009 (2)0.001 (2)0.001 (2)
C80.065 (3)0.054 (3)0.043 (2)0.006 (2)0.001 (2)0.001 (2)
C90.048 (3)0.055 (3)0.034 (2)0.006 (2)0.005 (2)0.0015 (19)
C100.047 (3)0.053 (2)0.038 (2)0.006 (2)0.0012 (19)0.0022 (18)
C110.044 (2)0.044 (2)0.043 (2)0.0015 (18)0.0029 (18)0.0008 (18)
C120.053 (2)0.052 (2)0.049 (2)0.0046 (19)0.001 (2)0.0075 (18)
C130.056 (3)0.069 (3)0.053 (3)0.000 (2)0.007 (2)0.005 (2)
C140.055 (3)0.075 (3)0.061 (3)0.008 (3)0.013 (2)0.002 (2)
C150.087 (4)0.067 (3)0.049 (3)0.016 (3)0.001 (3)0.003 (2)
C160.074 (3)0.066 (3)0.065 (2)0.012 (2)0.025 (2)0.002 (2)
O20.071 (2)0.0660 (18)0.0570 (16)0.0169 (14)0.0090 (14)0.0127 (14)
Geometric parameters (Å, º) top
O1—C11.432 (3)C5—H5B0.9700
O1—H10.8200C6—C71.365 (4)
N1—C31.476 (3)C6—C91.415 (4)
N1—C161.481 (3)C7—H70.9300
N1—C41.487 (3)C8—C151.403 (4)
N2—C81.385 (4)C8—C91.408 (4)
N2—C71.407 (4)C9—C101.388 (4)
N2—H2A0.8600C10—C131.388 (4)
C1—C21.538 (3)C10—C111.499 (4)
C1—H1A0.9700C11—C121.333 (3)
C1—H1B0.9700C12—H120.9300
C2—C121.500 (4)C13—C141.420 (4)
C2—C31.534 (4)C13—H130.9300
C2—H110.9800C14—C151.390 (4)
C3—H3A0.9700C14—H140.9300
C3—H3B0.9700C15—H150.9300
C4—C111.540 (4)C16—H16A0.9600
C4—C51.552 (4)C16—H16B0.9600
C4—H40.9800C16—H16C0.9600
C5—C61.517 (4)O2—H170.838 (10)
C5—H5A0.9700O2—H180.837 (10)
C1—O1—H1109.5C7—C6—C9107.0 (3)
C3—N1—C16109.1 (2)C7—C6—C5135.4 (4)
C3—N1—C4110.1 (2)C9—C6—C5117.6 (3)
C16—N1—C4111.0 (2)C6—C7—N2109.4 (3)
C8—N2—C7108.0 (3)C6—C7—H7125.3
C8—N2—H2A126.0N2—C7—H7125.3
C7—N2—H2A126.0N2—C8—C15133.3 (4)
O1—C1—C2113.1 (3)N2—C8—C9107.1 (3)
O1—C1—H1A109.0C15—C8—C9119.6 (4)
C2—C1—H1A109.0C10—C9—C8123.3 (4)
O1—C1—H1B109.0C10—C9—C6128.2 (3)
C2—C1—H1B109.0C8—C9—C6108.4 (3)
H1A—C1—H1B107.8C9—C10—C13116.9 (3)
C12—C2—C3108.3 (2)C9—C10—C11116.1 (3)
C12—C2—C1111.5 (3)C13—C10—C11127.0 (3)
C3—C2—C1110.6 (3)C12—C11—C10123.1 (3)
C12—C2—H11108.8C12—C11—C4121.2 (3)
C3—C2—H11108.8C10—C11—C4115.5 (3)
C1—C2—H11108.8C11—C12—C2125.1 (3)
N1—C3—C2110.4 (3)C11—C12—H12117.4
N1—C3—H3A109.6C2—C12—H12117.4
C2—C3—H3A109.6C10—C13—C14120.5 (3)
N1—C3—H3B109.6C10—C13—H13119.7
C2—C3—H3B109.6C14—C13—H13119.7
H3A—C3—H3B108.1C15—C14—C13122.2 (4)
N1—C4—C11110.2 (2)C15—C14—H14118.9
N1—C4—C5111.1 (2)C13—C14—H14118.9
C11—C4—C5112.9 (3)C14—C15—C8117.4 (4)
N1—C4—H4107.5C14—C15—H15121.3
C11—C4—H4107.5C8—C15—H15121.3
C5—C4—H4107.5N1—C16—H16A109.5
C6—C5—C4110.5 (3)N1—C16—H16B109.5
C6—C5—H5A109.6H16A—C16—H16B109.5
C4—C5—H5A109.6N1—C16—H16C109.5
C6—C5—H5B109.6H16A—C16—H16C109.5
C4—C5—H5B109.6H16B—C16—H16C109.5
H5A—C5—H5B108.1H17—O2—H18114 (3)
O1—C1—C2—C1264.4 (3)C7—C6—C9—C80.4 (4)
O1—C1—C2—C3175.0 (2)C5—C6—C9—C8177.9 (3)
C16—N1—C3—C2168.4 (2)C8—C9—C10—C133.2 (5)
C4—N1—C3—C269.5 (3)C6—C9—C10—C13178.2 (3)
C12—C2—C3—N148.7 (3)C8—C9—C10—C11175.5 (3)
C1—C2—C3—N1171.3 (2)C6—C9—C10—C113.1 (5)
C3—N1—C4—C1149.4 (3)C9—C10—C11—C12166.3 (3)
C16—N1—C4—C11170.4 (2)C13—C10—C11—C1215.2 (5)
C3—N1—C4—C5175.3 (2)C9—C10—C11—C418.4 (4)
C16—N1—C4—C563.8 (3)C13—C10—C11—C4160.1 (3)
N1—C4—C5—C6173.7 (2)N1—C4—C11—C1214.6 (4)
C11—C4—C5—C649.3 (3)C5—C4—C11—C12139.5 (3)
C4—C5—C6—C7152.8 (4)N1—C4—C11—C10170.0 (2)
C4—C5—C6—C929.4 (4)C5—C4—C11—C1045.1 (4)
C9—C6—C7—N20.5 (4)C10—C11—C12—C2172.3 (3)
C5—C6—C7—N2178.5 (3)C4—C11—C12—C22.7 (5)
C8—N2—C7—C61.3 (4)C3—C2—C12—C1114.0 (4)
C7—N2—C8—C15178.3 (4)C1—C2—C12—C11136.0 (3)
C7—N2—C8—C91.5 (4)C9—C10—C13—C142.0 (5)
N2—C8—C9—C10177.6 (3)C11—C10—C13—C14176.5 (3)
C15—C8—C9—C102.5 (5)C10—C13—C14—C150.3 (5)
N2—C8—C9—C61.2 (4)C13—C14—C15—C80.4 (5)
C15—C8—C9—C6178.6 (3)N2—C8—C15—C14179.6 (3)
C7—C6—C9—C10178.4 (3)C9—C8—C15—C140.6 (5)
C5—C6—C9—C103.3 (5)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H1···O2i0.822.032.845 (3)176
N2—H2A···O2ii0.862.172.896 (4)142
O2—H17···N1iii0.84 (3)2.00 (3)2.826 (3)171 (3)
O2—H18···O1iv0.84 (3)1.96 (2)2.777 (3)167 (3)
Symmetry codes: (i) x+1, y+1/2, z+3/2; (ii) x+1/2, y+3/2, z+1; (iii) x+3/2, y+2, z+1/2; (iv) x+1/2, y+2, z+1/2.

Experimental details

Crystal data
Chemical formulaC16H18N2O·H2O
Mr272.34
Crystal system, space groupOrthorhombic, P212121
Temperature (K)296
a, b, c (Å)7.6234 (12), 12.3803 (19), 15.877 (2)
V3)1498.5 (4)
Z4
Radiation typeMo Kα
µ (mm1)0.08
Crystal size (mm)0.2 × 0.1 × 0.08
Data collection
DiffractometerBruker APEX CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2001)
Tmin, Tmax0.85, 0.96
No. of measured, independent and
observed [I > 2σ(I)] reflections
12705, 1569, 747
Rint0.122
(sin θ/λ)max1)0.602
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.036, 0.052, 0.79
No. of reflections1569
No. of parameters188
No. of restraints2
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.10, 0.10

Computer programs: SMART (Bruker, 2001), SAINT (Bruker, 2001), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008) and ORTEPIII (Burnett & Johnson, 1996), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H1···O2i0.822.032.845 (3)176
N2—H2A···O2ii0.862.172.896 (4)142
O2—H17···N1iii0.84 (3)2.00 (3)2.826 (3)171 (3)
O2—H18···O1iv0.84 (3)1.96 (2)2.777 (3)167 (3)
Symmetry codes: (i) x+1, y+1/2, z+3/2; (ii) x+1/2, y+3/2, z+1; (iii) x+3/2, y+2, z+1/2; (iv) x+1/2, y+2, z+1/2.
 

References

First citationAmor-Prats, D. & Harborne, J. B. (1993). Biochem. Syst. Ecol. 21, 455–462.  CAS Google Scholar
First citationBruker (2001). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationBurnett, M. N. & Johnson, C. K. (1996). ORTEPIII. Report ORNL-6895. Oak Ridge National Laboratory, Tennessee, USA.  Google Scholar
First citationMerkel, S., Köppen, R., Koch, M., Emmerling, F. & Nehls, I. (2010). Acta Cryst. E66, o2275.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationPakhomova, S., Ondráucek, J., Huusák, M., Kratochvíl, B., Jegorov, A. & Stuchlík, J. (1995). Acta Cryst. C51, 308–311.  CSD CrossRef CAS Web of Science IUCr Journals Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationUhlig, S., Vikoren, T., Ivanova, L. & Handeland, K. (2007). Rapid Commun. Mass Spectrom. 21, 1651–1660.  Web of Science CrossRef PubMed CAS Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds