The tetrazine derivative, as well as the water molecule, of C12H9N7·H2O are involved in a hydrogen-bond network accompanied by π-stacking.
Keywords: crystal structure, hydrogen bonding, graph sets, asymmetric tetrazines
Abstract
The packing of the title compound, C12H9N7·H2O, is dominated by hydrogen bonding and π-stacking. Layers parallel to [010] are established by hydrogen bonds involving all amine donor functions and one of the water donor functions, while the remaining water donor function enables the stacking of the layers along [10-1], which is accompanied by π-stacking. In the molecule, the plane of the central tetrazine ring forms angles of 5.33 (7) and 19.84 (8)° with the adjacent 3-amine-pyridine and pyridine rings, respectively.
Chemical context
Click chemistry is employed to label biological targets because of its highly selective reaction profile at ambient temperature in physiological media (Kolb et al., 2001 ▸). Several chemical reactions can be used for this purpose. Among the most popular are alkyne–azide [3 + 2]-pericyclic reactions, and ene–tetrazine Diels–Alder/retro-Diels–Alder (DA/rDA) reactions. If the biomolecule carries a clickable chemical unit, possibly installed by the introduction of unnatural amino acids, various label-bearing functionalities can be introduced efficiently (Hong et al., 2010 ▸; Tsai et al., 2015 ▸). Side-chain norbornenes have proven particularly successful as unnatural amino acids (Kaya et al., 2012 ▸). They undergo a DA/rDA reaction with tetrazines, resulting in the extrusion of nitrogen (Kaya et al., 2012 ▸; Vrabel et al., 2013 ▸). This reaction exhibits fast kinetics at ambient temperatures, making it particularly useful for biological labeling. To improve biological stability, more electron-deficient 2-pyridinyl-substituted tetrazines are employed as they display improved stability (Vrabel et al., 2013 ▸). In order to decorate tetrazines with functionalities, asymmetric bispyridyl tetrazine versions with a desired label are synthesized. For instance, an amine group can be introduced that reacts with activated esters. Herein, we describe the crystal structure of such an asymmetric tetrazine in its hydrate form, bearing pyridyl groups on each side, one of them exposing a free amine (Selvaraj & Fox, 2014 ▸).
Structural commentary
The asymmetric unit of the title compound, which is depicted in Fig. 1 ▸, comprises 6-[6-(pyridin-2-yl)-1,2,4,5-tetrazin-3-yl]pyridin-3-amin (1) and a water molecule. The three almost planar six-membered rings of 1 deviate significantly from coplanarity. The plane of the central tetrazine ring forms angles of 5.33 (7) and 19.84 (8)° with the adjacent 3-amine-pyridine and pyridine rings, respectively. In two related structures of inversion-symmetric tetrazines these angles are 26.41 (10)° (Liu et al., 2001 ▸) and 19.71 (5)° (Klein et al., 1998 ▸). The latter two terminal rings enclose an angle of 14.60 (8)° in the title compound. This observation deviates from two related structures in which the terminal pyridine rings are coplanar (Klein et al., 1998 ▸; Liu et al., 2001 ▸). The hydrogen atoms of the amine are almost parallel with the adjacent pyridine ring and form an angle of 120.7 (16)° with amine N1. The H—O—H angle of the water molecule is 102.0 (17)°.
Figure 1.
The molecular structure of the title compound, showing atom labels and anisotropic displacement ellipsoids (drawn at the 50% probability level) for non-H atoms.
Supramolecular features
Hydrogen bonding is the main feature of packing of the title compound. Both amine donor functions as well as both H atoms of the water molecule are involved in hydrogen bonds with the two pyridine ring N atoms and the water molecule acting as hydrogen-bond acceptors (Table 1 ▸). It shall be mentioned that the tetrazine N5 atom is acceptor in a bifurcated hydrogen bond with donor O1. However, the donor–H–acceptor angle O1—H14⋯N5 is rather acute at 124.9 (15)° and the donor–acceptor distance rather long at 3.1934 (18) Å. Hence this hydrogen bond is not depicted in Figs. 2 ▸ and 3 ▸, and it is not considered in the following discussion of the hydrogen-bond network.
Table 1. Hydrogen-bond geometry (Å, °).
| D—H⋯A | D—H | H⋯A | D⋯A | D—H⋯A |
|---|---|---|---|---|
| N1—H11⋯O1i | 0.93 (2) | 2.12 (2) | 3.024 (2) | 166.2 (16) |
| N1—H12⋯O1ii | 0.90 (2) | 2.13 (2) | 3.012 (2) | 165.3 (16) |
| O1—H14⋯N5iii | 0.87 (2) | 2.614 (19) | 3.1934 (18) | 124.9 (15) |
| O1—H14⋯N7iii | 0.87 (2) | 2.12 (2) | 2.9321 (18) | 153.9 (17) |
| O1—H13⋯N2iv | 0.88 (2) | 2.19 (2) | 2.9688 (18) | 147.4 (16) |
Symmetry codes: (i) 
; (ii) 
; (iii) 
; (iv) 
.
Figure 2.
The hydrogen-bond pattern in layers viewed along [100].
Figure 3.
π-Stacking and hydrogen bonds in the packing of the title compound.
Fig. 2 ▸ shows a part of the herringbone-pattern-like layer parallel to [010] of the title compound. In that figure, the four different hydrogen bonds are shown in different colours. The region with the blue water–pyridine-N hydrogen bonds contains no amine groups. By this hydrogen bond, the layer is linked to next layer on top of it. By the other three hydrogen bonds, the moieties of the title compound form a two-dimensional network. According to graph set theory (Bernstein et al., 1995 ▸; Etter et al., 1990 ▸), the descriptor 
(11) can be assigned on the ternary level (three different hydrogen bonds) for the 11-membered rings formed by four hydrogen bonds involving two amine groups and two water molecules (two brown, one green and one red bond). In order to outline the chains along [101] formed by two different hydrogen bonds, the graph-set descriptor 
(7) may be assigned on the binary level. The seven-membered unit is formed by one N—H⋯O (green) and one O—H⋯N hydrogen bond (red).
Fig. 3 ▸ shows the interaction of stacking and hydrogen bonds. Centrosymmetric dimeric units consisting of two water and two organic molecules are linked by four O—H⋯N hydrogen bonds. In terms of graph-set theory, the descriptor 
(22) can be assigned. Within these dimeric units, a tetrazine ring has an adjacent tetrazine ring – exactly parallel due to an center of inversion – with a distance of 3.5896 (9) Å between the ring centroids. Additionally, the pyridine rings have adjacent amino-pyridine rings. The dihedral angles are 14.60 (8)° with a distance of 3.7477 (9) Å between the centroids. Between the dimeric units, the tetrazine ring has an adjacent amino-pyridine ring which subtends a dihedral angle of 5.33 (7)°. The distance between the ring centroids amounts to 3.6360 (9) Å. Fig. 4 ▸ shows the packing of the unit cell and gives a further impression of the herringbone pattern and the stacking.
Figure 4.
The packing of the title compound viewed along [100].
Synthesis and crystallization
The title compound was synthesized according to a literature procedure (Selvaraj & Fox, 2014 ▸) and the analytical data matched that reported. Single crystals were obtained by recrystallization from hot acetone.
Refinement
Crystal data, data collection and structure refinement details are summarized in Table 2 ▸. C-bonded H atoms were positioned geometrically (C—H = 0.95 Å) and treated as riding on their parent atoms [U iso(H) = 1.2U eq(C)]. The coordinates of N- and O-bound hydrogen atoms were refined freely with U iso(H) = 1.2U eq(N or O).
Table 2. Experimental details.
| Crystal data | |
| Chemical formula | C12H9N7·H2O |
| M r | 269.28 |
| Crystal system, space group | Monoclinic, P21/n |
| Temperature (K) | 100 |
| a, b, c (Å) | 7.5488 (4), 21.4944 (14), 7.8936 (5) |
| β (°) | 111.7170 (19) |
| V (Å3) | 1189.88 (13) |
| Z | 4 |
| Radiation type | Mo Kα |
| μ (mm−1) | 0.11 |
| Crystal size (mm) | 0.13 × 0.08 × 0.02 |
| Data collection | |
| Diffractometer | Bruker D8 Venture TXS |
| Absorption correction | Multi-scan (SADABS; Bruker, 2015 ▸) |
| T min, T max | 0.924, 0.958 |
| No. of measured, independent and observed [I > 2σ(I)] reflections | 20441, 2186, 1751 |
| R int | 0.046 |
| (sin θ/λ)max (Å−1) | 0.603 |
| Refinement | |
| R[F 2 > 2σ(F 2)], wR(F 2), S | 0.038, 0.101, 1.06 |
| No. of reflections | 2186 |
| No. of parameters | 193 |
| H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
| Δρmax, Δρmin (e Å−3) | 0.28, −0.18 |
Supplementary Material
Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S2056989016000608/zl4001sup1.cif
Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989016000608/zl4001Isup2.hkl
Supporting information file. DOI: 10.1107/S2056989016000608/zl4001Isup3.cml
CCDC reference: 1446773
Additional supporting information: crystallographic information; 3D view; checkCIF report
Acknowledgments
The authors thank the Department of Chemistry of LMU Munich for financial support.
supplementary crystallographic information
Crystal data
| C12H9N7·H2O | F(000) = 560 |
| Mr = 269.28 | Dx = 1.503 Mg m−3 |
| Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
| a = 7.5488 (4) Å | Cell parameters from 4888 reflections |
| b = 21.4944 (14) Å | θ = 2.9–25.3° |
| c = 7.8936 (5) Å | µ = 0.11 mm−1 |
| β = 111.7170 (19)° | T = 100 K |
| V = 1189.88 (13) Å3 | Platelet, red |
| Z = 4 | 0.13 × 0.08 × 0.02 mm |
Data collection
| Bruker D8 Venture TXS diffractometer | 2186 independent reflections |
| Radiation source: rotating anode (TXS) | 1751 reflections with I > 2σ(I) |
| Detector resolution: 10.4167 pixels mm-1 | Rint = 0.046 |
| mix of phi and ω scans | θmax = 25.4°, θmin = 2.9° |
| Absorption correction: multi-scan (SADABS; Bruker, 2015) | h = −9→9 |
| Tmin = 0.924, Tmax = 0.958 | k = −25→25 |
| 20441 measured reflections | l = −9→9 |
Refinement
| Refinement on F2 | 0 restraints |
| Least-squares matrix: full | Hydrogen site location: mixed |
| R[F2 > 2σ(F2)] = 0.038 | H atoms treated by a mixture of independent and constrained refinement |
| wR(F2) = 0.101 | w = 1/[σ2(Fo2) + (0.0506P)2 + 0.4194P] where P = (Fo2 + 2Fc2)/3 |
| S = 1.06 | (Δ/σ)max < 0.001 |
| 2186 reflections | Δρmax = 0.28 e Å−3 |
| 193 parameters | Δρmin = −0.18 e Å−3 |
Special details
| 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 (Å2)
| x | y | z | Uiso*/Ueq | ||
| C1 | −0.1210 (2) | 0.64392 (7) | −0.4086 (2) | 0.0188 (4) | |
| C2 | −0.1550 (2) | 0.58094 (8) | −0.4525 (2) | 0.0205 (4) | |
| H2 | −0.2516 | 0.5687 | −0.5642 | 0.025* | |
| C3 | −0.0470 (2) | 0.53676 (7) | −0.3322 (2) | 0.0191 (4) | |
| H3 | −0.0695 | 0.4938 | −0.3604 | 0.023* | |
| C4 | 0.0953 (2) | 0.55506 (7) | −0.1693 (2) | 0.0165 (3) | |
| C5 | 0.0242 (2) | 0.65788 (7) | −0.2380 (2) | 0.0209 (4) | |
| H5 | 0.0473 | 0.7004 | −0.2043 | 0.025* | |
| C6 | 0.2153 (2) | 0.50924 (7) | −0.0406 (2) | 0.0167 (3) | |
| C7 | 0.4210 (2) | 0.42767 (7) | 0.1870 (2) | 0.0166 (3) | |
| C8 | 0.5358 (2) | 0.38179 (7) | 0.3232 (2) | 0.0174 (3) | |
| C9 | 0.6399 (2) | 0.40029 (8) | 0.5007 (2) | 0.0214 (4) | |
| H9 | 0.6403 | 0.4426 | 0.5356 | 0.026* | |
| C10 | 0.7430 (2) | 0.35636 (8) | 0.6260 (2) | 0.0253 (4) | |
| H10 | 0.8166 | 0.3679 | 0.7480 | 0.030* | |
| C11 | 0.7368 (2) | 0.29540 (8) | 0.5699 (2) | 0.0256 (4) | |
| H11A | 0.8039 | 0.2639 | 0.6533 | 0.031* | |
| C12 | 0.6312 (2) | 0.28102 (8) | 0.3901 (2) | 0.0242 (4) | |
| H12A | 0.6301 | 0.2390 | 0.3523 | 0.029* | |
| N1 | −0.2190 (2) | 0.69044 (7) | −0.5185 (2) | 0.0253 (4) | |
| H11 | −0.180 (3) | 0.7312 (10) | −0.487 (2) | 0.030* | |
| H12 | −0.310 (3) | 0.6815 (9) | −0.628 (3) | 0.030* | |
| N2 | 0.12937 (18) | 0.61569 (6) | −0.12284 (18) | 0.0199 (3) | |
| N3 | 0.36169 (19) | 0.53003 (6) | 0.10630 (17) | 0.0198 (3) | |
| N4 | 0.46638 (19) | 0.48774 (6) | 0.22296 (18) | 0.0199 (3) | |
| N5 | 0.27906 (18) | 0.40634 (6) | 0.03676 (17) | 0.0193 (3) | |
| N6 | 0.17398 (18) | 0.44830 (6) | −0.07911 (17) | 0.0202 (3) | |
| N7 | 0.53069 (19) | 0.32257 (6) | 0.26624 (18) | 0.0210 (3) | |
| O1 | 0.52583 (18) | 0.31449 (6) | 0.89374 (16) | 0.0253 (3) | |
| H14 | 0.488 (3) | 0.3167 (9) | 0.985 (3) | 0.030* | |
| H13 | 0.612 (3) | 0.3439 (9) | 0.920 (3) | 0.030* |
Atomic displacement parameters (Å2)
| U11 | U22 | U33 | U12 | U13 | U23 | |
| C1 | 0.0160 (8) | 0.0223 (8) | 0.0203 (8) | −0.0006 (6) | 0.0094 (6) | 0.0027 (7) |
| C2 | 0.0157 (8) | 0.0278 (9) | 0.0170 (8) | −0.0026 (7) | 0.0048 (6) | −0.0036 (7) |
| C3 | 0.0194 (8) | 0.0192 (8) | 0.0207 (9) | −0.0017 (7) | 0.0096 (7) | −0.0030 (7) |
| C4 | 0.0166 (8) | 0.0176 (8) | 0.0179 (8) | −0.0026 (6) | 0.0094 (6) | −0.0019 (6) |
| C5 | 0.0205 (8) | 0.0184 (8) | 0.0228 (9) | −0.0020 (7) | 0.0070 (7) | −0.0006 (7) |
| C6 | 0.0170 (8) | 0.0189 (8) | 0.0177 (8) | −0.0032 (6) | 0.0104 (6) | −0.0033 (6) |
| C7 | 0.0170 (8) | 0.0185 (8) | 0.0174 (8) | −0.0016 (6) | 0.0102 (6) | −0.0032 (6) |
| C8 | 0.0164 (8) | 0.0184 (8) | 0.0192 (8) | −0.0013 (6) | 0.0087 (6) | −0.0011 (6) |
| C9 | 0.0226 (9) | 0.0200 (8) | 0.0213 (9) | −0.0024 (7) | 0.0079 (7) | −0.0039 (7) |
| C10 | 0.0230 (9) | 0.0313 (10) | 0.0186 (8) | −0.0008 (7) | 0.0044 (7) | −0.0002 (7) |
| C11 | 0.0202 (9) | 0.0258 (9) | 0.0275 (9) | 0.0022 (7) | 0.0051 (7) | 0.0056 (7) |
| C12 | 0.0230 (9) | 0.0177 (9) | 0.0296 (10) | 0.0027 (7) | 0.0072 (7) | 0.0007 (7) |
| N1 | 0.0241 (8) | 0.0223 (8) | 0.0224 (8) | −0.0018 (6) | 0.0004 (6) | 0.0027 (6) |
| N2 | 0.0202 (7) | 0.0179 (7) | 0.0201 (7) | −0.0020 (6) | 0.0059 (6) | −0.0002 (6) |
| N3 | 0.0211 (7) | 0.0179 (7) | 0.0192 (7) | −0.0005 (6) | 0.0060 (6) | −0.0008 (6) |
| N4 | 0.0221 (7) | 0.0167 (7) | 0.0195 (7) | −0.0005 (6) | 0.0063 (6) | −0.0010 (6) |
| N5 | 0.0202 (7) | 0.0175 (7) | 0.0191 (7) | 0.0004 (5) | 0.0060 (6) | −0.0007 (5) |
| N6 | 0.0212 (7) | 0.0177 (7) | 0.0208 (7) | −0.0015 (6) | 0.0068 (6) | −0.0020 (6) |
| N7 | 0.0215 (7) | 0.0179 (7) | 0.0226 (7) | −0.0005 (6) | 0.0071 (6) | −0.0021 (6) |
| O1 | 0.0287 (7) | 0.0252 (7) | 0.0220 (6) | −0.0055 (5) | 0.0093 (5) | −0.0040 (5) |
Geometric parameters (Å, º)
| C1—N1 | 1.351 (2) | C8—N7 | 1.346 (2) |
| C1—C2 | 1.397 (2) | C8—C9 | 1.387 (2) |
| C1—C5 | 1.419 (2) | C9—C10 | 1.380 (2) |
| C2—C3 | 1.376 (2) | C9—H9 | 0.9500 |
| C2—H2 | 0.9500 | C10—C11 | 1.378 (2) |
| C3—C4 | 1.393 (2) | C10—H10 | 0.9500 |
| C3—H3 | 0.9500 | C11—C12 | 1.382 (2) |
| C4—N2 | 1.352 (2) | C11—H11A | 0.9500 |
| C4—C6 | 1.464 (2) | C12—N7 | 1.334 (2) |
| C5—N2 | 1.321 (2) | C12—H12A | 0.9500 |
| C5—H5 | 0.9500 | N1—H11 | 0.93 (2) |
| C6—N3 | 1.348 (2) | N1—H12 | 0.90 (2) |
| C6—N6 | 1.355 (2) | N3—N4 | 1.3268 (18) |
| C7—N4 | 1.339 (2) | N5—N6 | 1.3201 (18) |
| C7—N5 | 1.351 (2) | O1—H14 | 0.87 (2) |
| C7—C8 | 1.480 (2) | O1—H13 | 0.88 (2) |
| N1—C1—C2 | 123.47 (15) | C9—C8—C7 | 120.23 (14) |
| N1—C1—C5 | 120.00 (15) | C10—C9—C8 | 119.07 (15) |
| C2—C1—C5 | 116.53 (14) | C10—C9—H9 | 120.5 |
| C3—C2—C1 | 119.33 (14) | C8—C9—H9 | 120.5 |
| C3—C2—H2 | 120.3 | C11—C10—C9 | 118.52 (15) |
| C1—C2—H2 | 120.3 | C11—C10—H10 | 120.7 |
| C2—C3—C4 | 119.98 (15) | C9—C10—H10 | 120.7 |
| C2—C3—H3 | 120.0 | C10—C11—C12 | 118.72 (16) |
| C4—C3—H3 | 120.0 | C10—C11—H11A | 120.6 |
| N2—C4—C3 | 121.78 (14) | C12—C11—H11A | 120.6 |
| N2—C4—C6 | 116.96 (13) | N7—C12—C11 | 123.96 (15) |
| C3—C4—C6 | 121.26 (14) | N7—C12—H12A | 118.0 |
| N2—C5—C1 | 124.37 (15) | C11—C12—H12A | 118.0 |
| N2—C5—H5 | 117.8 | C1—N1—H11 | 118.9 (11) |
| C1—C5—H5 | 117.8 | C1—N1—H12 | 119.8 (12) |
| N3—C6—N6 | 124.14 (14) | H11—N1—H12 | 120.7 (16) |
| N3—C6—C4 | 118.29 (14) | C5—N2—C4 | 117.99 (14) |
| N6—C6—C4 | 117.56 (14) | N4—N3—C6 | 117.25 (13) |
| N4—C7—N5 | 124.82 (14) | N3—N4—C7 | 118.28 (13) |
| N4—C7—C8 | 116.98 (14) | N6—N5—C7 | 117.03 (13) |
| N5—C7—C8 | 118.21 (13) | N5—N6—C6 | 118.40 (13) |
| N7—C8—C9 | 122.97 (15) | C12—N7—C8 | 116.74 (14) |
| N7—C8—C7 | 116.79 (14) | H14—O1—H13 | 102.0 (17) |
| N1—C1—C2—C3 | 179.62 (15) | C9—C10—C11—C12 | 1.4 (2) |
| C5—C1—C2—C3 | −0.8 (2) | C10—C11—C12—N7 | −1.3 (3) |
| C1—C2—C3—C4 | −0.4 (2) | C1—C5—N2—C4 | −0.8 (2) |
| C2—C3—C4—N2 | 1.2 (2) | C3—C4—N2—C5 | −0.6 (2) |
| C2—C3—C4—C6 | −178.61 (14) | C6—C4—N2—C5 | 179.24 (13) |
| N1—C1—C5—N2 | −178.91 (15) | N6—C6—N3—N4 | −2.6 (2) |
| C2—C1—C5—N2 | 1.5 (2) | C4—C6—N3—N4 | 178.76 (12) |
| N2—C4—C6—N3 | −5.9 (2) | C6—N3—N4—C7 | 0.4 (2) |
| C3—C4—C6—N3 | 173.94 (13) | N5—C7—N4—N3 | 2.2 (2) |
| N2—C4—C6—N6 | 175.42 (13) | C8—C7—N4—N3 | −177.71 (13) |
| C3—C4—C6—N6 | −4.8 (2) | N4—C7—N5—N6 | −2.5 (2) |
| N4—C7—C8—N7 | −160.90 (13) | C8—C7—N5—N6 | 177.39 (13) |
| N5—C7—C8—N7 | 19.2 (2) | C7—N5—N6—C6 | 0.2 (2) |
| N4—C7—C8—C9 | 20.0 (2) | N3—C6—N6—N5 | 2.3 (2) |
| N5—C7—C8—C9 | −159.94 (14) | C4—C6—N6—N5 | −179.07 (13) |
| N7—C8—C9—C10 | −0.2 (2) | C11—C12—N7—C8 | 0.4 (2) |
| C7—C8—C9—C10 | 178.84 (14) | C9—C8—N7—C12 | 0.4 (2) |
| C8—C9—C10—C11 | −0.7 (2) | C7—C8—N7—C12 | −178.73 (13) |
Hydrogen-bond geometry (Å, º)
| D—H···A | D—H | H···A | D···A | D—H···A |
| N1—H11···O1i | 0.93 (2) | 2.12 (2) | 3.024 (2) | 166.2 (16) |
| N1—H12···O1ii | 0.90 (2) | 2.13 (2) | 3.012 (2) | 165.3 (16) |
| O1—H14···N5iii | 0.87 (2) | 2.614 (19) | 3.1934 (18) | 124.9 (15) |
| O1—H14···N7iii | 0.87 (2) | 2.12 (2) | 2.9321 (18) | 153.9 (17) |
| O1—H13···N2iv | 0.88 (2) | 2.19 (2) | 2.9688 (18) | 147.4 (16) |
Symmetry codes: (i) −x+1/2, y+1/2, −z+1/2; (ii) −x, −y+1, −z; (iii) x, y, z+1; (iv) −x+1, −y+1, −z+1.
References
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S2056989016000608/zl4001sup1.cif
Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989016000608/zl4001Isup2.hkl
Supporting information file. DOI: 10.1107/S2056989016000608/zl4001Isup3.cml
CCDC reference: 1446773
Additional supporting information: crystallographic information; 3D view; checkCIF report