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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890

(E)-2-(4-Chloro­phen­­oxy)-N′-(pyridin-4-yl­methyl­­idene)acetohydrazide

aCollege of Materials Science and Engineering, Huaqiao University, Xiamen, Fujian 361021, People's Republic of China
*Correspondence e-mail: wws@hqu.edu.cn

(Received 16 October 2012; accepted 7 November 2012; online 8 December 2012)

In the title compound, C14H12ClN3O2, the acyl­hydrazone base [C(=O)—N—N=C] is essentially planar, with an r.m.s. deviation of 0.0095 Å, and makes a dihedral angle of 12.52 (10)°with the pyridine ring. In the crystal, molecules are linked via pairs of N—H⋯O hydrogen bonds, forming inversion dimers with an R22(8) graph-set motif. The dimers are linked via C—H⋯π interactions forming chains along [101].

Related literature

For chemical properties of hydrazides, see: Narayana et al. (2005[Narayana, B., Ashalatha, B. V., Vijayaraj, K. K., Fernandes, J. & Sarojini, B. K. (2005). Bioorg. Med. Chem. 13, 4638-4644.]); Liu et al. (2006[Liu, F., Stephen, A. G., Adainson, C. S., Gousset, K., Aman, M. J., Freed, E. O., Fisher, R. J. & Burke, T. R. Jr (2006). Org. Lett. 8, 5165-5168.]). For the synthesis and structure of eth­yl(4-chloro­phen­oxy)acetate, see: Dutkiewicz et al. (2009[Dutkiewicz, G., Chidan Kumar, C. S., Narayana, B., Yathirajan, H. S. & Kubicki, M. (2009). Acta Cryst. E65, o3189.]). For graph-set motifs, see: Etter et al. (1990[Etter, M. C., MacDonald, J. C. & Bernstein, J. (1990). Acta Cryst. B46, 256-262.]) and for classification of hydrogen bonds, see: Gilli & Gilli (2009[Gilli, G. & Gilli, P. (2009). The Nature of the Hydrogen Bond, p. 61. New York: Oxford University Press.]).

[Scheme 1]

Experimental

Crystal data
  • C14H12ClN3O2

  • Mr = 289.72

  • Monoclinic, P 21 /n

  • a = 13.059 (4) Å

  • b = 5.3567 (16) Å

  • c = 19.175 (6) Å

  • β = 104.586 (5)°

  • V = 1298.2 (7) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.30 mm−1

  • T = 173 K

  • 0.53 × 0.21 × 0.14 mm

Data collection
  • Bruker SMART APEX diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996[Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.]) Tmin = 0.927, Tmax = 0.959

  • 7114 measured reflections

  • 2796 independent reflections

  • 2437 reflections with I > 2σ(I)

  • Rint = 0.033

Refinement
  • R[F2 > 2σ(F2)] = 0.041

  • wR(F2) = 0.104

  • S = 1.05

  • 2796 reflections

  • 184 parameters

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

  • Δρmax = 0.27 e Å−3

  • Δρmin = −0.24 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

Cg2 is the centroid of the C3–C8 phenyl ring.

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H1A⋯O1i 0.885 (19) 1.96 (2) 2.8423 (19) 172.9 (18)
C2—H2ACg2ii 0.97 2.88 3.676 (2) 140
Symmetry codes: (i) -x, -y+3, -z; (ii) [-x+{\script{1\over 2}}, y+{\script{1\over 2}}, -z+{\script{1\over 2}}].

Data collection: SMART (Bruker, 1999[Bruker (1999). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 1999[Bruker (1999). SMART and SAINT. 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.]); software used to prepare material for publication: SHELXTL.

Supporting information


Comment top

Hydrazides usually serve as precursors in the synthesis of several heterocyclic systems (Narayana et al., 2005). Some substituted hydrazides are used as intermediates in many pharmaceutically important compounds (Liu et al., 2006). A new hydrazide, (E)-2-(4-chlorophenoxy)-N'-(pyridin-4-ylmethylene)acetohydrazide, C14H12Cl1O2N3, has been synthesized and its crystal structure is reported here (Fig. 1).

In the title molecule, the principal cohesion interactions are N—H···O hydrogen bonds of moderate strength (Gilli & Gilli, 2009) which link the molecules into a dimer with the graph-set motif (Etter et al., 1990) R22(8) (Tab. 1). Moreover, there are present C—H···π-electron ring interactions in the structure (Fig. 2). The acylhydrazone base is essentially planar with the r.m.s. deviation from planarity which equals to 0.0095 Å. The pyridine ring and the acylhydrazone base [C1(O1)—N1—N2C9] contain the angle 12.52 (10)°.

Related literature top

For chemical properties of hydrazides, see: Narayana et al. (2005); Liu et al. (2006). For the synthesis and structure of ethyl(4-chlorophenoxy)acetate, see: Dutkiewicz et al. (2009). For graph-set motifs, see: Etter et al. (1990) and for classification of hydrogen bonds, see: Gilli & Gilli (2009).

Experimental top

The synthesis of the title structure proceeded in three steps.

First, concentrated H2SO4 (98 weight %, 1.4 ml) was added slowly while stirring to a mixture of 4-chlorophenoxyacetic acid (11.2 g, 0.06 mol) in ethanol (99.7 volume %, 120 ml). The mixture was left to reflux for 6 h at 359 K. Then 34.2 ml of 98.5 weight % of tris(2-hydroxyethyl)amine (trolamine) were added dropwise into the mixture while stirring in order to neutralize the mixture. Then the ethanol in the mixture was removed by reduced pressure distillation (335 K, about 0.003 MPa). What has left was poured into 100 ml of water heated to 321 K. The white precipitate (12.21 g) of ethyl(4-chlorophenoxy)acetate was filtered and washed.

Second step consisted in the synthesis of 2-(4-chlorophenoxy)acetohydrazide. It was carried out according to the method applied by Dutkiewicz et al. (2009). A mixture of ethyl(4-chlorophenoxy)acetate (8.56 g, 0.04 mol) and 50 ml of hydrazine hydrate (85 weight %) was refluxed over water bath for 5 h at 365 K. The precipitate was filtered off and recrystallized from ethanol (99.7 volume %) yielding plate-like colourless crystals of 2-(4-chlorophenoxy)acetohydrazide.

Finally, the title compound was synthesized by adding 4-pyridinecarboxaldehyde (5 ml) slowly to a mixture of 2-(4-chlorophenoxy) acetohydrazide in ethanol (99.7 volume %, 20 ml) and water (15 ml) while stirring. Then the mixture was refluxed for 3.5 h at room temperature. Prismatic colourless crystals with the size about that of the used sample formed in 24 h.

Refinement top

All the hydrogen atoms were identified in the difference electron density map, nevertheless the aryl and methylene H atoms were situated into idealized positions and constrained to ride on their parent atoms with C—H = 0.93 and 0.97 Å for aryl and methylene H atoms, respectively, with Uiso(Haryl/methylene) = 1.2Ueq(Caryl/methylene). The positional parameters of the secondary amine H atom were refined freely while its isotropic displacement parameter was constrained as 1.2 multiple of the equivalent isotropic parameter of its carrier atom.

Computing details top

Data collection: SMART (Bruker, 1999); cell refinement: SAINT (Bruker, 1999); data reduction: SAINT (Bruker, 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The title molecule with the displacement ellipsoids at the 40% probability level.
[Figure 2] Fig. 2. The hydrogen bonds in the title compound. Hydrogen bonds are shown as dashed lines. O1A is a symmetry equivalent to O1 transformed by x, -y + 3, -z. Cg2ii is a centroid of the phenyl ring C3\C4\C5\C6\C7\C8; symmetry code (ii): -x + 1/2, y + 1/2, -z + 1/2.
(E)-2-(4-Chlorophenoxy)-N'-(pyridin-4-ylmethylidene)acetohydrazide top
Crystal data top
C14H12ClN3O2F(000) = 600
Mr = 289.72Dx = 1.482 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 3317 reflections
a = 13.059 (4) Åθ = 2.2–27.9°
b = 5.3567 (16) ŵ = 0.30 mm1
c = 19.175 (6) ÅT = 173 K
β = 104.586 (5)°Prism, colourless
V = 1298.2 (7) Å30.53 × 0.21 × 0.14 mm
Z = 4
Data collection top
Bruker SMART APEX
diffractometer
2796 independent reflections
Radiation source: fine-focus sealed tube2437 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.033
ω scansθmax = 27.0°, θmin = 1.7°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 1616
Tmin = 0.927, Tmax = 0.959k = 66
7114 measured reflectionsl = 2415
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)] = 0.041Hydrogen site location: difference Fourier map
wR(F2) = 0.104H atoms treated by a mixture of independent and constrained refinement
S = 1.05 w = 1/[σ2(Fo2) + (0.037P)2 + 0.573P]
where P = (Fo2 + 2Fc2)/3
2796 reflections(Δ/σ)max < 0.001
184 parametersΔρmax = 0.27 e Å3
0 restraintsΔρmin = 0.24 e Å3
45 constraints
Crystal data top
C14H12ClN3O2V = 1298.2 (7) Å3
Mr = 289.72Z = 4
Monoclinic, P21/nMo Kα radiation
a = 13.059 (4) ŵ = 0.30 mm1
b = 5.3567 (16) ÅT = 173 K
c = 19.175 (6) Å0.53 × 0.21 × 0.14 mm
β = 104.586 (5)°
Data collection top
Bruker SMART APEX
diffractometer
2796 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
2437 reflections with I > 2σ(I)
Tmin = 0.927, Tmax = 0.959Rint = 0.033
7114 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0410 restraints
wR(F2) = 0.104H atoms treated by a mixture of independent and constrained refinement
S = 1.05Δρmax = 0.27 e Å3
2796 reflectionsΔρmin = 0.24 e Å3
184 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
C10.07691 (12)1.4108 (3)0.10391 (8)0.0216 (3)
C20.12993 (12)1.3618 (3)0.18254 (8)0.0244 (3)
H2A0.09591.46060.21270.029*
H2B0.12241.18700.19340.029*
C30.29987 (12)1.2712 (3)0.16797 (8)0.0210 (3)
C40.40322 (12)1.3495 (3)0.17631 (8)0.0242 (3)
H4A0.42601.49790.20040.029*
C50.47256 (13)1.2089 (3)0.14905 (9)0.0269 (4)
H5A0.54201.26160.15450.032*
C60.43774 (13)0.9893 (3)0.11357 (9)0.0267 (4)
C70.33550 (13)0.9090 (3)0.10505 (8)0.0262 (4)
H7A0.31300.76070.08080.031*
C80.26625 (12)1.0497 (3)0.13270 (8)0.0230 (3)
H8A0.19710.99530.12760.028*
C90.12003 (12)0.9586 (3)0.06945 (8)0.0236 (3)
H9A0.14550.99870.02100.028*
C100.28617 (13)0.4072 (3)0.08435 (9)0.0287 (4)
H10A0.33330.30230.05320.034*
C110.24060 (12)0.5978 (3)0.05463 (9)0.0262 (4)
H11A0.25730.62040.00500.031*
C120.16955 (12)0.7556 (3)0.09964 (8)0.0231 (3)
C130.14931 (14)0.7123 (4)0.17301 (9)0.0326 (4)
H13A0.10270.81430.20540.039*
C140.19892 (15)0.5172 (4)0.19725 (10)0.0368 (4)
H14A0.18400.49030.24670.044*
Cl10.52572 (4)0.80977 (9)0.08079 (3)0.04032 (16)
N10.00592 (10)1.2696 (3)0.07166 (7)0.0233 (3)
H1A0.0369 (15)1.304 (4)0.0261 (10)0.028*
N20.04318 (10)1.0820 (3)0.10753 (7)0.0232 (3)
N30.26732 (11)0.3633 (3)0.15439 (8)0.0308 (3)
O10.10839 (9)1.5774 (2)0.07075 (6)0.0277 (3)
O20.23832 (8)1.4241 (2)0.19755 (6)0.0237 (3)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0174 (7)0.0246 (9)0.0239 (7)0.0029 (6)0.0071 (6)0.0003 (6)
C20.0182 (7)0.0337 (9)0.0218 (7)0.0036 (7)0.0060 (6)0.0021 (7)
C30.0208 (8)0.0261 (8)0.0147 (7)0.0005 (6)0.0022 (6)0.0038 (6)
C40.0219 (8)0.0257 (9)0.0233 (7)0.0037 (6)0.0028 (6)0.0009 (6)
C50.0187 (8)0.0312 (9)0.0307 (8)0.0020 (7)0.0063 (6)0.0073 (7)
C60.0253 (8)0.0289 (9)0.0274 (8)0.0077 (7)0.0095 (6)0.0069 (7)
C70.0281 (8)0.0244 (9)0.0237 (8)0.0006 (7)0.0023 (6)0.0009 (6)
C80.0187 (7)0.0258 (9)0.0224 (7)0.0021 (6)0.0015 (6)0.0040 (6)
C90.0200 (7)0.0278 (9)0.0228 (7)0.0012 (6)0.0048 (6)0.0006 (6)
C100.0232 (8)0.0305 (10)0.0335 (9)0.0046 (7)0.0093 (7)0.0074 (7)
C110.0225 (8)0.0317 (10)0.0251 (8)0.0006 (7)0.0076 (6)0.0033 (7)
C120.0175 (7)0.0260 (9)0.0266 (8)0.0004 (6)0.0072 (6)0.0007 (6)
C130.0308 (9)0.0391 (11)0.0260 (8)0.0120 (8)0.0036 (7)0.0024 (7)
C140.0384 (10)0.0454 (12)0.0269 (9)0.0093 (9)0.0087 (7)0.0041 (8)
Cl10.0365 (3)0.0378 (3)0.0524 (3)0.0111 (2)0.0219 (2)0.0032 (2)
N10.0197 (7)0.0277 (8)0.0214 (7)0.0029 (6)0.0032 (5)0.0041 (6)
N20.0184 (6)0.0262 (7)0.0261 (7)0.0011 (5)0.0074 (5)0.0019 (5)
N30.0269 (7)0.0316 (8)0.0358 (8)0.0040 (6)0.0115 (6)0.0008 (6)
O10.0238 (6)0.0315 (7)0.0260 (6)0.0056 (5)0.0029 (5)0.0043 (5)
O20.0176 (5)0.0304 (6)0.0227 (5)0.0028 (5)0.0042 (4)0.0048 (5)
Geometric parameters (Å, º) top
C1—O11.2251 (19)C8—H8A0.9300
C1—N11.337 (2)C9—N21.268 (2)
C1—C21.515 (2)C9—C121.458 (2)
C2—O21.4117 (18)C9—H9A0.9300
C2—H2A0.9700C10—N31.324 (2)
C2—H2B0.9700C10—C111.376 (2)
C3—O21.3667 (19)C10—H10A0.9300
C3—C81.382 (2)C11—C121.385 (2)
C3—C41.384 (2)C11—H11A0.9300
C4—C51.378 (2)C12—C131.384 (2)
C4—H4A0.9300C13—C141.371 (3)
C5—C61.378 (3)C13—H13A0.9300
C5—H5A0.9300C14—N31.335 (2)
C6—C71.373 (2)C14—H14A0.9300
C6—Cl11.7331 (17)N1—N21.3740 (19)
C7—C81.381 (2)N1—H1A0.885 (19)
C7—H7A0.9300
O1—C1—N1120.66 (14)C3—C8—H8A120.1
O1—C1—C2120.91 (14)N2—C9—C12121.74 (14)
N1—C1—C2118.43 (14)N2—C9—H9A119.1
O2—C2—C1110.20 (12)C12—C9—H9A119.1
O2—C2—H2A109.6N3—C10—C11124.23 (16)
C1—C2—H2A109.6N3—C10—H10A117.9
O2—C2—H2B109.6C11—C10—H10A117.9
C1—C2—H2B109.6C10—C11—C12119.14 (15)
H2A—C2—H2B108.1C10—C11—H11A120.4
O2—C3—C8124.76 (14)C12—C11—H11A120.4
O2—C3—C4115.40 (14)C13—C12—C11117.25 (16)
C8—C3—C4119.83 (15)C13—C12—C9122.58 (15)
C5—C4—C3120.37 (16)C11—C12—C9120.17 (14)
C5—C4—H4A119.8C14—C13—C12119.13 (16)
C3—C4—H4A119.8C14—C13—H13A120.4
C6—C5—C4119.18 (15)C12—C13—H13A120.4
C6—C5—H5A120.4N3—C14—C13124.18 (16)
C4—C5—H5A120.4N3—C14—H14A117.9
C7—C6—C5121.09 (15)C13—C14—H14A117.9
C7—C6—Cl1119.78 (14)C1—N1—N2121.96 (14)
C5—C6—Cl1119.11 (13)C1—N1—H1A117.0 (12)
C6—C7—C8119.65 (16)N2—N1—H1A121.1 (12)
C6—C7—H7A120.2C9—N2—N1114.93 (14)
C8—C7—H7A120.2C10—N3—C14116.08 (15)
C7—C8—C3119.88 (15)C3—O2—C2115.99 (12)
C7—C8—H8A120.1
O1—C1—C2—O230.5 (2)N2—C9—C12—C1311.5 (3)
N1—C1—C2—O2150.25 (14)N2—C9—C12—C11169.00 (16)
O2—C3—C4—C5179.56 (13)C11—C12—C13—C140.6 (3)
C8—C3—C4—C50.6 (2)C9—C12—C13—C14179.92 (17)
C3—C4—C5—C60.2 (2)C12—C13—C14—N30.4 (3)
C4—C5—C6—C70.0 (2)O1—C1—N1—N2179.81 (14)
C4—C5—C6—Cl1178.81 (12)C2—C1—N1—N20.5 (2)
C5—C6—C7—C80.3 (2)C12—C9—N2—N1179.18 (14)
Cl1—C6—C7—C8178.51 (12)C1—N1—N2—C9177.82 (15)
C6—C7—C8—C30.7 (2)C11—C10—N3—C140.3 (3)
O2—C3—C8—C7179.75 (14)C13—C14—N3—C100.3 (3)
C4—C3—C8—C70.9 (2)C8—C3—O2—C28.0 (2)
N3—C10—C11—C120.5 (3)C4—C3—O2—C2173.13 (13)
C10—C11—C12—C130.6 (2)C1—C2—O2—C369.79 (17)
C10—C11—C12—C9179.86 (15)
Hydrogen-bond geometry (Å, º) top
Cg2 is the centroid of the C3–C8 phenyl ring.
D—H···AD—HH···AD···AD—H···A
N1—H1A···O1i0.885 (19)1.96 (2)2.8423 (19)172.9 (18)
C2—H2A···Cg2ii0.972.883.676 (2)140
Symmetry codes: (i) x, y+3, z; (ii) x+1/2, y+1/2, z+1/2.

Experimental details

Crystal data
Chemical formulaC14H12ClN3O2
Mr289.72
Crystal system, space groupMonoclinic, P21/n
Temperature (K)173
a, b, c (Å)13.059 (4), 5.3567 (16), 19.175 (6)
β (°) 104.586 (5)
V3)1298.2 (7)
Z4
Radiation typeMo Kα
µ (mm1)0.30
Crystal size (mm)0.53 × 0.21 × 0.14
Data collection
DiffractometerBruker SMART APEX
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.927, 0.959
No. of measured, independent and
observed [I > 2σ(I)] reflections
7114, 2796, 2437
Rint0.033
(sin θ/λ)max1)0.638
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.041, 0.104, 1.05
No. of reflections2796
No. of parameters184
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.27, 0.24

Computer programs: SMART (Bruker, 1999), SAINT (Bruker, 1999), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top
Cg2 is the centroid of the C3–C8 phenyl ring.
D—H···AD—HH···AD···AD—H···A
N1—H1A···O1i0.885 (19)1.96 (2)2.8423 (19)172.9 (18)
C2—H2A···Cg2ii0.972.883.676 (2)140.0
Symmetry codes: (i) x, y+3, z; (ii) x+1/2, y+1/2, z+1/2.
 

Acknowledgements

We are grateful for financial support from the National Science Foundation of Fujian Province of China (No. 2010 J01288) and the Fundamental Research Funds for the Central Universities (No. JB-JC1003). We also thank Dr Zhan-bin Wei (Department of Chemistry, Xiamen University) for the data collection.

References

First citationBruker (1999). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.
First citationDutkiewicz, G., Chidan Kumar, C. S., Narayana, B., Yathirajan, H. S. & Kubicki, M. (2009). Acta Cryst. E65, o3189.  Web of Science CSD CrossRef IUCr Journals
First citationEtter, M. C., MacDonald, J. C. & Bernstein, J. (1990). Acta Cryst. B46, 256–262.  CrossRef CAS Web of Science IUCr Journals
First citationGilli, G. & Gilli, P. (2009). The Nature of the Hydrogen Bond, p. 61. New York: Oxford University Press.
First citationLiu, F., Stephen, A. G., Adainson, C. S., Gousset, K., Aman, M. J., Freed, E. O., Fisher, R. J. & Burke, T. R. Jr (2006). Org. Lett. 8, 5165–5168.  Web of Science CrossRef PubMed CAS
First citationNarayana, B., Ashalatha, B. V., Vijayaraj, K. K., Fernandes, J. & Sarojini, B. K. (2005). Bioorg. Med. Chem. 13, 4638–4644.  Web of Science CrossRef PubMed CAS
First citationSheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals

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