Synthesis and crystal structure of 2-[(3-bromo-phenylimino)methyl]phenol

Article abstract of DOI:10.14233/ajchem.2013.13769

A new Schiff base 2-[(3-bromo-phenylimino)methyl]phenol, derived from condensation of salicylaldehyde with m-bromoaniline, has been prepared and characterized by single crystal X-raydiffraction. Schiff base is in the monoclinic system, space group P21 with a = 3.928(14) ?, b = 10.590(4)?, c = 13.212(5)?, b = 97.360(4)?, Mr = 276.13, V = 545.1(3)?3, Dc = 1.682 g/cm3, Z = 2, μ = 3.745 mm-1, F(000) = 276, R = 0.0326, wR = 0.0455. The schiff base is stabilized by intermolecular C-H...O and p...p interaction and further linked into a 2D layer structure.

Full text of DOI:10.14233/ajchem.2013.13769

Asian Journal of Chemistry; Vol. 25, No. 7 (2013), 3762-3764
http://dx.doi.org/10.14233/ajchem.2013.13769
Synthesis and Crystal Structure of 2-[(3-Bromo-phenylimino)methyl]phenol
YA-NING GUO
Department of Chemistry and Chemical Engineering, Baoji University of Arts and Sciences, Baoji, P.R. China
Corresponding author: Tel: +86 917 3566589; E-mail: ggyn1997@163.com
(Received: 20 March 2012;
Accepted: 11 January 2013)
AJC-12689
A new Schiff base 2-[(3-bromo-phenylimino)methyl]phenol, derived from condensation of salicylaldehyde with m-bromoaniline, has
been prepared and characterized by single crystal X-raydiffraction. Schiff base is in the monoclinic system, space group P21 with a =
3.928(14) Å, b = 10.590(4)Å, c = 13.212(5)Å, β = 97.360(4)º, Mr = 276.13, V = 545.1(3)Å3, Dc = 1.682 g/cm3, Z = 2, µ = 3.745 mm-1,
F(000) = 276, R = 0.0326, wR = 0.0455. The schiff base is stabilized by intermolecular C-H···O and π···π interaction and further linked into
a 2D layer structure.
Key Words: Salicylaldehyde, Schiff base, Synthesis, Crystal structure.
further linked into a 2D layer structure. These interactions play
a very important role in the formation, stability and crystalli-
zation of compound.
INTRODUCTION
Hydrogen bondings and π···π stacking interactions are
important research content in supramolecular chemistry and
crystal engineering1,2. They play an important role in self-
assembly3,4, molecular recognition5,6 and the stability of
inclusion complexes7-9 as an auxiliary stabilizing short contact.
Numerous experiments have been performed and several
reviews have been documented for C-H···O interactions10 and
π···π stacking interactions11,12. Some Schiff bases can form
C-H···O interactions and π···π stacking because they possess
hydroxyl groups and aromatic rings, which play an important
role for formation, stabilization and packing of the complex
crystal. On the other hand, Schiff bases in general have been
reported as organic chelating ligands in the synthesis of metal
complexes due to their hard donor-atom frameworks, stability
and easy modification13. Metal complexes with Schiff base
ligands have played an important role in the development of
coordination chemistry due to their preparative accessibility,
structural variety and many functional properties. Based on
the extensive application and flexibility of these intheractions
in supramolecular network building14 and the discovery of
application prospect of Schiff base in catalysis15, photoelectric
and LED16 and biological acitivities17,18. We report herein the
synthesis and characterization of a new Schiff base obtained
from salicylaldehyde and o-bromoaniline. The structure of
compound had been established accurately from the single
crystal X-ray diffraction study. The results showed that the
compound is stabilized by intermolecular O-H···N and intra-
molecular C-H···O hydrogen bonds and π···π interactions and
EXPERIMENTAL
Crystal structure was determined on a Bruker APEX II
CCD area diffractometer. Salicylaldehyde and m-bromoaniline
were purchased from J & K Chemical Ltd.All other chemicals
were commercial products and used without further purifi-
cation.
Synthesis of 2-[(3-bromo-phenylimino)methyl]phenol:
2-[(3-Bromo-phenylimino)methy] phenol has been synthesized
by dissolving 5 mmol of salicylaldehyde and an equimolar
quantity of m-bromoaniline in 50 mL of methanol. The reaction
mixture was heated to 50 ºC for 1 h and then cooled to room
temperature followed by concentrating the resulting mixture
to a yellow solid product. The yield was 1.20 g (87 %)
(Scheme-I). Yellow block single crystals suitable for single
crystal X-ray diffraction were grown in methanol by slow
evaporation.
Br
Br
CHO
Methnol
N
+
OH
NH
2
OH
1
Scheme-I
X-Ray crystal structure determination:A yellow block
crystal with dimensions of 0.54 mm × 0.58 mm × 0.09 mm

Vol. 25, No. 7 (2013)
Synthesis and Crystal Structure of 2-[(3-Bromo-phenylimino)methyl]phenol 3763
was selected for measurement. Diffraction data of compound
were collected at 153(2) K on a Bruker APEX II CCD area
diffractometer equipped with a graphite-monochromatic MoKα
radiation (λ = 0.71073 Å). A total of 4683 reflections were
collected in the range of 2.5 ≤ θ ≤ 29.1º by using an ϕ-ω multi-
scan mode, of which 2605 were unique with Rint = 0.030 and
2033 were observed with I > 2σ(I). The structure was solved
by direct methods and refined on F2 by full-matrix least-squares
procedures using the SHELX-97 program package19. All non-
hydrogen atoms were refined anisotropically. The hydrogen
atoms attached to carbon atoms were fixed at their ideal
positions. The final R = 0.0326, wR = 0.0455(w = 1/[σ2(Fo2) +
(0.0013P)2 + -0.1P], where P = (Fo2 + 2Fc2)/3), S = 0.98, (∆/
σ)max = 0.001, (∆ρ)max = 0.74 and (∆ρ)min = -0.56 e/Å3. The
crystal data, experimental details, refinement results and details
of structure determinations are shown in Table-1. Selected bond
lengths and bond angles are listed in Table-2.
Fig. 1. Molecular structure of the compound displacement ellipsoids are
drawn at the 30 % probability level
whole molecule assignes to be E configuration with respect to
the azomethine -CH=N- bond on the basis of the crystal data
with the C(7)=N(1) distance is 1.285(4) Å. The whole mole-
cule is nearly coplanar with the dihedral angle of two phenyl
rings (ring A, C(1)-C(6) and ring B, C(8)-C(13)) of 6.24°,
which is interpreted by conjugation effect and the stabilization
of ring from intramolecular hydrogen bond.
In the crystal structure of the Schif base, there is a "soft"
intermolecular interaction C-H···O hydrogen bonds and π···π
stacking interaction in the lattice structure. Discrete mono-
meric molecules are held together by intermolecular hydrogen
bond C(7)-H(7)···O(1), atom C7 acted as hydrogenbond donor,
via H7, to O1 at the symmetry position (-x + 2, 1/2 + y, -z +
1), thus hydrogen bond C7 H7···O1 is formed. The C7-H7···O1
hydrogen bond existed with bond lengths being 2.773 Å and
bond angle being 109.8º. Combination of the hydrogen bonds
link the molecules to form a 1D zig-zag chain along c-axis
(Fig. 2).
TABLE-1
CRYSTALLOGRAPHIC DATA AND STRUCTURE
REFINEMENT FOR THE COMPOUND
Parameter
Compound
Empirical formula
Formula weight
Crystal size (mm)
Crystal system, space group
a, b, c (Å)
C13H10NOBr
276.13
0.54 × 0.28 × 0.09
monoclinic, P21
3.9280(14), 10.59(4), 13.212(5)
β = 97.360(4)
5451(3)
α, β, γ (º)
V (Å3)
Dc (g cm-3) Z
1.682, 2
3.745
µ (mm-1)
F(000)
276
Index ranges (H, k, l)
θ range (º)
-5 ≤ h ≤ 5, -14 ≤ k ≤ 13,-16 ≤ l ≤ 17
2.47-29.12
Reflections collected/unique
R, wR[I ≥ 2σ(I)]
R, wR [all data]
GOF on F2
4683-2605
0.0326, 0.0455
0.0435, 0.0472
0.978
(∆ρ)max, (∆ρ)min (e Å-3)
0.740, -0.561
Final weighting scheme: w = 1/[σ2(Fo2) + (0.0013P)2 - 0.1P], where P
= (Fo2 + 2Fc2)/3.
Fig. 2. A one-dimentional zig-zag chain of 1 along b-axis (C-H···O
hydrogen bond was showed as dashed lines, hydrogen atomes were
omitted for clarity. i-x + 2, 1/2 + y, -z + 1)
RESULTS AND DISCUSSION
The Schiff base was prepared in excellent yields (87 %)
in absolute methanol. The compound is yellow solids and stable
in air at room temperature and also soluble in common polar
organic solvents, such as DMSO, methanol and ethanol.
The compound is build up only by Schiff base molecules,
within which all bond lengths and bond angles of ligand are
in normal ranges. Its crystal structure with the atomic num-
bering scheme is presented in Fig. 1. The result shows that the
Another, the Schiff base skeletons are stacked into column
through π-π interaction. A π-π interaction dimer is formed
between the adjacent Schiff bases with an parallel manner, of
which the dihedral angles being 0.00º, the intercentroid
distances of two rings A and two rings B in two neighboring
molecules are 3.928 and 3.928 Å, respectively. The corresponding
TABLE- 2
THE SELECTED BOND LENGTHS (Å) AND ANGLES (º) FOR THE COMPOUND
Bonds
d
Bonds
d
Bonds
d
Br(1)-C(12)
N(1)-C(7)
C(1)-C(6)
1.908(3)
1.285(4)
1.414(4)
O(1)-C(1)
N(1)-C(8)
C(8)-C(9)
1.360(4)
1.422(4)
1.394(4)
O(1)-H(1O)
C(6)-C(7)
C(7)-H(7)
0.8355
1.380(4)
0.9500
Angle
Angle
Angle
ω
ω
ω
C(1)O(1)H(1O)
C(1)C(6)C(7)
107.7
122.1(3)
C(7)N(1)C(8)
N(1)C(7)C(6)
121.5(3)
122.6(3)
O(1)-C(1)-C(2)
C(11)C(12)Br(1)
118.6(3)
119.4(3)

3764 Guo
Asian J. Chem.
perpendicular distances of them are 3.4685 Å and 3.3984 Å,
respectively.All the intercentroid and interplanar distances are
comparable to the reported contact calculated20. Combination
of these aromatic π-π stacking interactions generates a column
along b-axis.
Combination of the C(7)-H(7)···O(1) and the aromatic
π···π stacking interactions linked 1 to generate a 2D network
structure (Fig. 3). These interactions also mutually strengthen
and solidify the molecule.
ACKNOWLEDGEMENTS
The work was supported by the Special Scientific
Research Project of the Phytochemistry Key Laboratory of
Shaanxi Province (grant No.2010JS069) and the Key Project
Foundation of Baoji University of Arts and Sciences (grant
No. ZK11018).
REFERENCES
1. J.C. MacDonald and G.M. Whitesides, Chem. Rev., 94, 2383 (1994).
2. J. Bernstein, R.E. Davis and L. Shimoni, Angew Chem. Int. Ed Engl.,
34, 1555 (1995).
3. C. Janiak, J. Chem. Soc. Dalton Trans., 3885 (2000).
4. J.A.R.P. Sarma and G.R. Desiraju, Acc. Chem. Res., 19, 222 (1986).
5. I. Chao and J.C. Chen, Angew. Chem., 108, 200 (1996).
6. G. Müller, M. Lutz and S. Harder, Acta Crystallogr., B52, 1014 (1996).
7. D. Braga, F. Grepioni and J.J. Byrne, J. Chem. Soc. Chem.Commun.,
125 (1995).
8. B.R. Kaafarani, A.A. Pinkerton and D.C. Neckers, Tetrahedron Lett.,
42, 8137 (2001).
9. T. Steiner and W. Saenger, J. Chem. Soc. Chem. Commun., 2087 (1995).
10. T. Steiner and G.R. Desiraju, J. Chem. Soc. Chem. Commun., 891
(1998).
11. X.B. Wang, Z.T. Zhang and Q.Y. Wang, Struct. Chem., 16, 461 (2005).
12. Y.N. Guo, Chin. J. Inorg. Chem., 27, 1875 (2011).
13. M. Santanu, K.R. Ashok and P. Guillaume, Transition Met. Chem., 34,
719 (2009).
14. J.L. Atwood, J.E. Davies and D.D. MacNicol, In eds.: F. Vogtle, In
Comprehensive Supramolecular Chemistry, Pergamon, Oxford, Vol.
6, p. 1 (1996).
Fig. 3. 2D packing diagram of the title compound, the π···π stacking
interactions and C-H···O hydrogen bonds were showed as dashed
lines. (Forclarity, some H atoms have been omitted. Symmetry code:
(#): x-1, y, z; (i): -x + 2, 1/2 + y, -z + 1. Cg is the center of ring A or
ring B)
15. S.A. Schuetz, C.M. Silvernail and C.D. Incarvito, Inorg. Chem., 43,
6203 (2004).
Conclusion
16. S. Akine, T. Taniguchi and T. Nabeshima, Angew. Chem. Int. Ed., 41,
4670 (2002).
17. Y.N. Guo, Russ. J. Coord. Chem., 38, 122 (2012).
18. R. Natarajan, P. Krishnan and B. Thanasekaran, J. Mol. Struct., 1000,
135 (2011).
19. G.M. Sheldrick, SHELX-97. Program Package for Crystal Structure
Solution and Refinement; University of Gottingen: Germany (1997).
20. R. Kiralj, B. Kojic-Prodic and I. Piantanida, Acta Crystallogr., B55,
55 (1999).
A new Schiff base prepared by the condensation of salicy-
laldehyde with m-bromoaniline. The structure had been
established accurately from the single crystal X-ray diffraction
study. The results showed that the compound is stabilized by
intermolecular O-H···N and intramolecular C-H···O hydrogen
bonds and π···π interactions and further linked into a 2D layer
structure. These interactions play a very important role in the
formation, stability and crystallization of compound.