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

Journal logoIUCrDATA
ISSN: 2414-3146

4-(1H-Indol-3-yl)-2,6-bis­­(pyrazin-2-yl)pyridine

CROSSMARK_Color_square_no_text.svg

aInstitute of Molecular Science, Shanxi University, Taiyuan, Shanxi 030006, People's Republic of China
*Correspondence e-mail: cxyuan@sxu.edu.cn

Edited by W. T. A. Harrison, University of Aberdeen, Scotland (Received 27 February 2018; accepted 27 March 2018; online 29 March 2018)

In the title compound, C21H14N6, the pyridine ring and two pyrazine rings are nearly coplanar [dihedral angles = 2.03 (7) and 1.60 (7)°], while the dihedral angle between the indole ring system and the pyridine ring is 29.04 (6)°. In the crystal, mol­ecules are linked by N—H⋯N hydrogen bonds, which generate [[\overline{1}]10] chains. The packing is consolidated by C—H⋯N hydrogen bonds and aromatic ππ stacking, generating a three-dimensional network.

3D view (loading...)
[Scheme 3D1]
Chemical scheme
[Scheme 1]

Structure description

Pyridine/pyrazine ligands have attracted attention for the synthesis of transition-metal complexes with a variety of geometries (Sengupta et al. 2017[Sengupta, A., Rajput, A., Barman, S. K. & Mukherjee, R. (2017). Dalton Trans. 46, 11291-11305.]; Rajput & Mukherjee 2013[Rajput, A. & Mukherjee, R. (2013). Coord. Chem. Rev. 257, 350-368.]). Specifically, many terpyridine compounds, as convergent tridentate chelating N-donor ligands, have been synthesized and their coordination chemistries have been explored (Yin et al. 2015[Yin, Z., Zhang, G., Phoenix, T., Zheng, S. & Fettinger, J. C. (2015). RSC Adv. 5, 36156-36166.]; Constable 2007[Constable, E. C. (2007). Chem. Soc. Rev. 36, 246-253.]; Wild et al. 2011[Wild, A., Winter, A., Schlütter, F. & Schubert, U. S. (2011). Chem. Soc. Rev. 40, 1459-1511.]). However, there is less research about the dipyrazinyl­pyridine compounds, which are close analogues of the terpyridines (Dai et al. 2010[Dai, J. W., Li, Z. Y., Chen, Y. L., Cai, B., Wu, J. Z. & Yu, Y. Z. (2010). Anorg. Allg. Chem. 636, 2475-2480.]; Li et al. 2017[Li, L., Liu, E., Xiong, H., Chan, C., Manke, D. R., Golen, J. A. & Zhang, G. (2017). Polyhedron, 132, 64-69.]).

The mol­ecular structure of the title compound is illustrated in Fig. 1[link]. The pyridine ring and the N1 and N4 pyrazine rings are nearly coplanar [dihedral angles = 2.03 (7) and 1.60 (7)°, respectively], indicating significant electronic conjugation, but the indole ring system deviates significantly from the pyridine ring [dihedral angle = 29.04 (6)°].

[Figure 1]
Figure 1
View of the title compound, shown with 50% probability displacement ellipsoids.

The N1 and N4 atoms of the pyrazine rings adopt trans conformations to the N3 atom of the central pyridine moiety, which does not seem to be a good conformation for a tridentate ligand. However, the single bond between the pyrazine ring and pyridine ring is easy to rotate freely in solution, so some tridentate metal complexes can also be obtained under appropriate conditions, for example the reported cadmium complexes with dipyrazinyl­pyridine ligands (Xie et al. 2016[Xie, L., Lu, L. P. & Zhu, M. L. (2016). Chin. J. Struct. Chem. 35, 1606-1614.]; Dai et al. 2010[Dai, J. W., Li, Z. Y., Chen, Y. L., Cai, B., Wu, J. Z. & Yu, Y. Z. (2010). Anorg. Allg. Chem. 636, 2475-2480.]).

In the crystal, the N4 and N5 atoms in one pyrazine moiety accept C3—H3⋯N4 and N6—H6A⋯N5 hydrogen bonds, as shown in Fig. 2[link] and Table 1[link]. The N—H⋯N hydrogen bonds generate [1[\overline{1}]0] chains, which are cross-linked by the C—H⋯N bonds. Moreover, ππ stacking inter­actions between the pyrazine and pyridine rings are also observed (Fig. 3[link]). The ring-centroid distances between the pyrazine ring and the adjacent pyridine and indole rings are 3.7925 (11) and 3.8044 (11) Å, respectively. The overall packing is shown in Fig. 4[link].

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N6—H6A⋯N5i 0.88 2.18 3.0190 (19) 160
C3—H3⋯N4ii 0.95 2.54 3.425 (2) 155
Symmetry codes: (i) x-1, y+1, z; (ii) [x, -y+{\script{1\over 2}}, z-{\script{1\over 2}}].
[Figure 2]
Figure 2
The hydrogen-bonding inter­actions (dashed lines) in the title compound.
[Figure 3]
Figure 3
The aromatic ππ inter­actions (dashed lines) in the title compound.
[Figure 4]
Figure 4
The packing of the title compound.

Synthesis and crystallization

0.1 mmol of Pt(DMSO)2Cl2 (DMSO = dimethyl sulfoxide) was added to a stirring solution of 2,6-bis­(2-pyrazin­yl)-4-(indol-1-yl)pyridine (0.1 mmol) in 15 ml of methanol. The solution was refluxed at 338 K for 5 h under a nitro­gen atmosphere, cooled slowly and filtered. The filtrate was kept at room temperature and after about two weeks colorless block-shaped crystals of the title compound were collected by filtration.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2[link]. One outlier with was removed from the final refinement. DISP instructions appropriate to the synchrotron wavelength were used in the refinement.

Table 2
Experimental details

Crystal data
Chemical formula C21H14N6
Mr 350.38
Crystal system, space group Monoclinic, P21/c
Temperature (K) 100
a, b, c (Å) 8.5560 (17), 8.9820 (18), 22.130 (4)
β (°) 98.28 (3)
V3) 1683.0 (6)
Z 4
Radiation type Synchrotron, λ = 0.710 Å
μ (mm−1) 0.09
Crystal size (mm) 0.20 × 0.20 × 0.15
 
Data collection
Diffractometer Mar555
Absorption correction Multi-scan (SCALEPACK; Otwinowski & Minor, 1997)
Tmin, Tmax 0.983, 0.987
No. of measured, independent and observed [I > 2σ(I)] reflections 5341, 2943, 2746
Rint 0.136
(sin θ/λ)max−1) 0.596
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.053, 0.161, 1.04
No. of reflections 2943
No. of parameters 244
H-atom treatment H-atom parameters constrained
Δρmax, Δρmin (e Å−3) 0.39, −0.23
Computer programs: mar555, HKL-2000 (Minor et al., 2000[Minor, W., Tomchick, D. & Otwinowski, Z. (2000). Structure, 8, R105-R110.]), SHELXL97 and SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]), SHELXL2014 (Sheldrick, 2015[Sheldrick, G. M. (2015). Acta Cryst. C71, 3-8.]) and publCIF (Westrip, 2010[Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.]).

Structural data


Computing details top

Data collection: mar555; cell refinement: HKL-2000 (Minor et al., 2000); data reduction: HKL-2000 (Minor et al., 2000); program(s) used to solve structure: SHELXL97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: publCIF (Westrip, 2010).

4-(1H-Indol-3-yl)-2,6-bis(pyrazin-2-yl)pyridine top
Crystal data top
C21H14N6F(000) = 728
Mr = 350.38Dx = 1.383 Mg m3
Monoclinic, P21/cSynchrotron radiation, λ = 0.710 Å
a = 8.5560 (17) ÅCell parameters from 8169 reflections
b = 8.9820 (18) Åθ = 2.4–29.5°
c = 22.130 (4) ŵ = 0.09 mm1
β = 98.28 (3)°T = 100 K
V = 1683.0 (6) Å3Block, colorless
Z = 40.20 × 0.20 × 0.15 mm
Data collection top
Mar555
diffractometer
2746 reflections with I > 2σ(I)
Radiation source: synchrotron, 3W1A at BSRFRint = 0.136
oscillation mode scansθmax = 25.1°, θmin = 2.5°
Absorption correction: multi-scan
(SCALEPACK; Otwinowski & Minor, 1997)
h = 010
Tmin = 0.983, Tmax = 0.987k = 1010
5341 measured reflectionsl = 2626
2943 independent reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.053H-atom parameters constrained
wR(F2) = 0.161 w = 1/[σ2(Fo2) + (0.0852P)2 + 0.3936P]
where P = (Fo2 + 2Fc2)/3
S = 1.04(Δ/σ)max = 0.001
2943 reflectionsΔρmax = 0.39 e Å3
244 parametersΔρmin = 0.23 e Å3
0 restraints
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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
C11.03422 (15)0.27853 (16)0.37871 (6)0.0206 (3)
C21.15461 (16)0.20143 (18)0.35555 (6)0.0238 (4)
H21.22020.13670.38200.029*
C31.08481 (17)0.3086 (2)0.26267 (7)0.0300 (4)
H31.09920.32260.22130.036*
C40.96495 (18)0.38505 (19)0.28541 (7)0.0291 (4)
H40.89960.44990.25890.035*
C51.29758 (16)0.05260 (17)0.66620 (7)0.0246 (4)
H51.29170.06630.70840.029*
C61.41440 (16)0.12564 (17)0.64057 (7)0.0243 (4)
H61.48690.18720.66580.029*
C71.20761 (15)0.05372 (16)0.57419 (6)0.0187 (3)
C81.32527 (15)0.02103 (17)0.54830 (6)0.0225 (4)
H81.33230.00680.50620.027*
C91.09203 (15)0.15450 (16)0.53679 (6)0.0184 (3)
C101.00918 (15)0.26218 (16)0.44353 (6)0.0192 (3)
C110.89131 (15)0.34194 (16)0.46693 (6)0.0195 (3)
H110.82460.40750.44130.023*
C120.97715 (15)0.22973 (16)0.56388 (6)0.0202 (3)
H120.97060.21640.60600.024*
C130.87170 (15)0.32504 (16)0.52825 (6)0.0193 (3)
C140.74714 (15)0.40481 (16)0.55418 (6)0.0195 (3)
C150.68268 (14)0.53939 (16)0.53282 (6)0.0194 (3)
H150.71160.59260.49900.023*
C160.66742 (14)0.36347 (17)0.60505 (6)0.0191 (3)
C170.67148 (16)0.23950 (17)0.64456 (6)0.0234 (4)
H170.74420.16080.64160.028*
C180.56950 (17)0.23335 (18)0.68735 (7)0.0264 (4)
H180.57370.15050.71420.032*
C190.45876 (16)0.34818 (19)0.69195 (6)0.0265 (4)
H190.38850.34070.72140.032*
C200.45158 (16)0.47124 (18)0.65405 (6)0.0244 (4)
H200.37710.54840.65690.029*
C210.55699 (15)0.47885 (16)0.61143 (6)0.0203 (3)
N10.93776 (14)0.37132 (15)0.34299 (6)0.0252 (3)
N21.18128 (14)0.21474 (17)0.29804 (6)0.0288 (4)
N31.10821 (12)0.16745 (14)0.47763 (5)0.0191 (3)
N41.19234 (13)0.03709 (14)0.63322 (5)0.0218 (3)
N51.42847 (14)0.11231 (15)0.58137 (6)0.0251 (3)
N60.57157 (13)0.58462 (14)0.56739 (5)0.0211 (3)
H6A0.51760.66820.56240.025*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0160 (6)0.0159 (7)0.0264 (7)0.0035 (6)0.0083 (5)0.0009 (6)
C20.0202 (7)0.0233 (8)0.0256 (7)0.0010 (6)0.0049 (5)0.0004 (6)
C30.0279 (7)0.0348 (10)0.0245 (7)0.0040 (7)0.0059 (6)0.0019 (7)
C40.0278 (7)0.0289 (9)0.0275 (7)0.0004 (7)0.0068 (6)0.0066 (7)
C50.0237 (7)0.0203 (8)0.0264 (7)0.0027 (6)0.0077 (5)0.0028 (6)
C60.0213 (7)0.0170 (8)0.0309 (7)0.0048 (6)0.0092 (5)0.0007 (6)
C70.0166 (6)0.0125 (7)0.0243 (7)0.0010 (6)0.0056 (5)0.0011 (6)
C80.0196 (7)0.0189 (8)0.0265 (7)0.0039 (6)0.0055 (5)0.0006 (6)
C90.0160 (6)0.0119 (7)0.0246 (7)0.0011 (6)0.0058 (5)0.0003 (6)
C100.0152 (6)0.0135 (7)0.0259 (7)0.0015 (5)0.0077 (5)0.0003 (6)
C110.0151 (6)0.0141 (7)0.0262 (7)0.0005 (6)0.0071 (5)0.0015 (6)
C120.0183 (6)0.0160 (7)0.0238 (7)0.0003 (6)0.0058 (5)0.0007 (6)
C130.0145 (6)0.0130 (7)0.0276 (7)0.0011 (6)0.0068 (5)0.0014 (6)
C140.0157 (6)0.0160 (8)0.0236 (7)0.0011 (6)0.0086 (5)0.0024 (6)
C150.0152 (6)0.0160 (7)0.0238 (7)0.0006 (5)0.0084 (5)0.0011 (6)
C160.0147 (6)0.0163 (7)0.0233 (7)0.0008 (5)0.0077 (5)0.0037 (6)
C170.0214 (7)0.0174 (8)0.0287 (7)0.0025 (6)0.0055 (5)0.0010 (6)
C180.0264 (7)0.0223 (8)0.0280 (7)0.0031 (6)0.0048 (6)0.0041 (6)
C190.0195 (7)0.0320 (9)0.0263 (7)0.0019 (6)0.0025 (5)0.0027 (7)
C200.0176 (7)0.0252 (8)0.0273 (7)0.0031 (6)0.0073 (5)0.0044 (7)
C210.0158 (6)0.0173 (7)0.0239 (7)0.0014 (6)0.0099 (5)0.0028 (6)
N10.0234 (6)0.0234 (7)0.0262 (6)0.0021 (5)0.0054 (4)0.0045 (6)
N20.0246 (6)0.0338 (8)0.0262 (6)0.0005 (6)0.0025 (5)0.0012 (6)
N30.0157 (5)0.0137 (6)0.0253 (6)0.0007 (5)0.0057 (4)0.0007 (5)
N40.0192 (6)0.0176 (7)0.0258 (6)0.0023 (5)0.0066 (4)0.0017 (5)
N50.0207 (6)0.0203 (7)0.0312 (7)0.0073 (5)0.0064 (5)0.0005 (6)
N60.0173 (6)0.0154 (6)0.0273 (6)0.0038 (5)0.0080 (4)0.0008 (5)
Geometric parameters (Å, º) top
C1—N11.3463 (18)C10—C111.396 (2)
C1—C21.398 (2)C11—C131.399 (2)
C1—C101.488 (2)C11—H110.9500
C2—N21.330 (2)C12—C131.4014 (19)
C2—H20.9500C12—H120.9500
C3—N21.348 (2)C13—C141.468 (2)
C3—C41.388 (2)C14—C151.383 (2)
C3—H30.9500C14—C161.446 (2)
C4—N11.334 (2)C15—N61.3650 (19)
C4—H40.9500C15—H150.9500
C5—N41.3429 (18)C16—C171.413 (2)
C5—C61.384 (2)C16—C211.423 (2)
C5—H50.9500C17—C181.378 (2)
C6—N51.338 (2)C17—H170.9500
C6—H60.9500C18—C191.414 (2)
C7—N41.3399 (19)C18—H180.9500
C7—C81.399 (2)C19—C201.384 (2)
C7—C91.4989 (18)C19—H190.9500
C8—N51.3422 (18)C20—C211.397 (2)
C8—H80.9500C20—H200.9500
C9—N31.3412 (19)C21—N61.380 (2)
C9—C121.397 (2)N6—H6A0.8800
C10—N31.3518 (18)
N1—C1—C2120.87 (13)C11—C13—C12117.03 (13)
N1—C1—C10117.77 (13)C11—C13—C14121.42 (12)
C2—C1—C10121.36 (12)C12—C13—C14121.55 (13)
N2—C2—C1122.89 (13)C15—C14—C16106.31 (12)
N2—C2—H2118.6C15—C14—C13124.70 (13)
C1—C2—H2118.6C16—C14—C13129.00 (13)
N2—C3—C4121.44 (14)N6—C15—C14110.13 (13)
N2—C3—H3119.3N6—C15—H15124.9
C4—C3—H3119.3C14—C15—H15124.9
N1—C4—C3122.71 (14)C17—C16—C21118.03 (13)
N1—C4—H4118.6C17—C16—C14135.37 (14)
C3—C4—H4118.6C21—C16—C14106.53 (12)
N4—C5—C6121.94 (13)C18—C17—C16119.68 (15)
N4—C5—H5119.0C18—C17—H17120.2
C6—C5—H5119.0C16—C17—H17120.2
N5—C6—C5122.08 (13)C17—C18—C19121.15 (15)
N5—C6—H6119.0C17—C18—H18119.4
C5—C6—H6119.0C19—C18—H18119.4
N4—C7—C8121.51 (12)C20—C19—C18120.72 (14)
N4—C7—C9117.16 (12)C20—C19—H19119.6
C8—C7—C9121.33 (13)C18—C19—H19119.6
N5—C8—C7121.69 (13)C19—C20—C21118.14 (14)
N5—C8—H8119.2C19—C20—H20120.9
C7—C8—H8119.2C21—C20—H20120.9
N3—C9—C12123.70 (12)N6—C21—C20130.04 (14)
N3—C9—C7116.02 (12)N6—C21—C16107.61 (12)
C12—C9—C7120.28 (12)C20—C21—C16122.26 (14)
N3—C10—C11122.97 (13)C4—N1—C1116.21 (13)
N3—C10—C1115.76 (12)C2—N2—C3115.88 (13)
C11—C10—C1121.26 (12)C9—N3—C10117.06 (12)
C10—C11—C13119.86 (12)C7—N4—C5116.42 (12)
C10—C11—H11120.1C6—N5—C8116.34 (13)
C13—C11—H11120.1C15—N6—C21109.40 (12)
C9—C12—C13119.33 (13)C15—N6—H6A125.3
C9—C12—H12120.3C21—N6—H6A125.3
C13—C12—H12120.3
N1—C1—C2—N20.2 (2)C15—C14—C16—C210.06 (14)
C10—C1—C2—N2179.25 (13)C13—C14—C16—C21179.99 (12)
N2—C3—C4—N10.1 (2)C21—C16—C17—C180.3 (2)
N4—C5—C6—N50.6 (2)C14—C16—C17—C18176.23 (15)
N4—C7—C8—N50.2 (2)C16—C17—C18—C190.9 (2)
C9—C7—C8—N5179.50 (12)C17—C18—C19—C201.0 (2)
N4—C7—C9—N3178.98 (12)C18—C19—C20—C210.2 (2)
C8—C7—C9—N30.3 (2)C19—C20—C21—N6177.50 (13)
N4—C7—C9—C121.70 (19)C19—C20—C21—C161.5 (2)
C8—C7—C9—C12179.00 (13)C17—C16—C21—N6178.34 (11)
N1—C1—C10—N3179.73 (12)C14—C16—C21—N60.88 (14)
C2—C1—C10—N30.8 (2)C17—C16—C21—C201.56 (19)
N1—C1—C10—C111.0 (2)C14—C16—C21—C20175.90 (12)
C2—C1—C10—C11178.47 (13)C3—C4—N1—C10.3 (2)
N3—C10—C11—C130.2 (2)C2—C1—N1—C40.4 (2)
C1—C10—C11—C13179.44 (12)C10—C1—N1—C4179.03 (13)
N3—C9—C12—C130.2 (2)C1—C2—N2—C30.2 (2)
C7—C9—C12—C13179.10 (12)C4—C3—N2—C20.4 (2)
C10—C11—C13—C121.8 (2)C12—C9—N3—C101.8 (2)
C10—C11—C13—C14178.80 (12)C7—C9—N3—C10177.52 (11)
C9—C12—C13—C111.6 (2)C11—C10—N3—C91.6 (2)
C9—C12—C13—C14178.97 (12)C1—C10—N3—C9177.70 (11)
C11—C13—C14—C1527.0 (2)C8—C7—N4—C51.2 (2)
C12—C13—C14—C15152.40 (13)C9—C7—N4—C5179.48 (12)
C11—C13—C14—C16152.92 (14)C6—C5—N4—C70.8 (2)
C12—C13—C14—C1627.7 (2)C5—C6—N5—C81.6 (2)
C16—C14—C15—N61.00 (14)C7—C8—N5—C61.2 (2)
C13—C14—C15—N6179.07 (12)C14—C15—N6—C211.60 (15)
C15—C14—C16—C17176.75 (14)C20—C21—N6—C15174.92 (13)
C13—C14—C16—C173.2 (3)C16—C21—N6—C151.52 (15)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N6—H6A···N5i0.882.183.0190 (19)160
C3—H3···N4ii0.952.543.425 (2)155
Symmetry codes: (i) x1, y+1, z; (ii) x, y+1/2, z1/2.
 

Acknowledgements

The authors thank Zeng-Qiang Gao for assistance with the data collection of the title compound.

Funding information

Funding for this research was provided by: National Natural Science Foundation of China (grant No. 21471092).

References

First citationConstable, E. C. (2007). Chem. Soc. Rev. 36, 246–253.  Web of Science CrossRef PubMed CAS Google Scholar
First citationDai, J. W., Li, Z. Y., Chen, Y. L., Cai, B., Wu, J. Z. & Yu, Y. Z. (2010). Anorg. Allg. Chem. 636, 2475–2480.  CrossRef CAS Google Scholar
First citationLi, L., Liu, E., Xiong, H., Chan, C., Manke, D. R., Golen, J. A. & Zhang, G. (2017). Polyhedron, 132, 64–69.  CrossRef CAS Google Scholar
First citationMinor, W., Tomchick, D. & Otwinowski, Z. (2000). Structure, 8, R105–R110.  Web of Science CrossRef PubMed CAS Google Scholar
First citationRajput, A. & Mukherjee, R. (2013). Coord. Chem. Rev. 257, 350–368.  CrossRef CAS Google Scholar
First citationSengupta, A., Rajput, A., Barman, S. K. & Mukherjee, R. (2017). Dalton Trans. 46, 11291–11305.  CrossRef CAS Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSheldrick, G. M. (2015). Acta Cryst. C71, 3–8.  Web of Science CrossRef IUCr Journals Google Scholar
First citationWestrip, S. P. (2010). J. Appl. Cryst. 43, 920–925.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationWild, A., Winter, A., Schlütter, F. & Schubert, U. S. (2011). Chem. Soc. Rev. 40, 1459–1511.  Web of Science CrossRef CAS PubMed Google Scholar
First citationXie, L., Lu, L. P. & Zhu, M. L. (2016). Chin. J. Struct. Chem. 35, 1606–1614.  CAS Google Scholar
First citationYin, Z., Zhang, G., Phoenix, T., Zheng, S. & Fettinger, J. C. (2015). RSC Adv. 5, 36156–36166.  CrossRef 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 logoIUCrDATA
ISSN: 2414-3146
Follow IUCr Journals
Sign up for e-alerts
Follow IUCr on Twitter
Follow us on facebook
Sign up for RSS feeds