Synthesis, characterization and crystal structures of N′-(5-bromo-2- hydroxybenzylidene)-2-fluorobenzohydrazide in unsolvated and monohydrate forms

Article abstract of DOI:10.1007/s10870-011-0146-z

A new hydrazone derivative, N′-(5-bromo-2-hydroxybenzylidene)-2- fluorobenzohydrazide (BFBH), has been prepared and crystallized from absolute methanol and 95% ethanol, respectively, yielding unsolvated and monohydrate forms of the compound, viz. BFBH (1)

Full text of DOI:10.1007/s10870-011-0146-z

J Chem Crystallogr (2011) 41:1599–1603
DOI 10.1007/s10870-011-0146-z
ORIGINAL PAPER
Synthesis, Characterization and Crystal Structures of
N0-(5-Bromo-2-hydroxybenzylidene)-2-fluorobenzohydrazide
in Unsolvated and Monohydrate Forms
•
•
•
Ling-Wei Xue Yong-Jun Han Gan-Qing Zhao
Yun-Xiao Feng
Received: 16 March 2011 / Accepted: 31 May 2011 / Published online: 10 June 2011
Ó Springer Science+Business Media, LLC 2011
Abstract A new hydrazone derivative, N0-(5-bromo-2-
hydroxybenzylidene)-2-fluorobenzohydrazide (BFBH), has
been prepared and crystallized from absolute methanol and
95% ethanol, respectively, yielding unsolvated and mono-
hydrate forms of the compound, viz. BFBH (1) and
BFBHꢀH2O (2). The two forms of the compound were
have been proved to have interesting biological activities such
as antibacterial, antifungal, and antitumor [1–5]. In recent
years, hydrazone derivatives have also been introduced to
coordination chemistry, since they have versatile O, N, or S
donor atoms [6–8]. Detailed study on the preparation and
structures of such compounds seems important to understand
their biological activities and coordination capabilities. In this
paper, a new hydrazone derivative, N0-(5-bromo-2-hydro-
xybenzylidene)-2-fluorobenzohydrazide (BFBH), has been
prepared and crystallized from absolute methanol and 95%
ethanol, respectively, yielding unsolvated and monohydrate
forms of the compound, viz. BFBH (1) and BFBHꢀH2O (2)
(Chart 1).
1
characterized by elemental analysis, IR spectra, HNMR
spectra, and X-ray single crystal structural determination.
The unsolvated form of the compound crystallizes in the
monoclinic space group P21/c with unit cell dimensions
˚
˚
˚
a = 6.879(1) A, b = 28.911(2) A, c = 8.724(1) A,
´
3
˚
b = 127.685(2)8, V = 1373.1(3) A , Z = 4, R1 = 0.0569,
and wR2 = 0.1352. The monohydrate forms of the com-
pound crystallizes in the monoclinic space group P21/
˚
c with unit cell dimensions a = 14.873(3) A, b = 7.265(1)
´
3
˚
˚
˚
A, c = 13.043(2) A, b = 96.281(2)8, V = 1400.9(4) A ,
Z = 4, R1 = 0.0402, and wR2 = 0.0890. The two struc-
tures are similar to each other, except for the presence of a
water molecule in (2).
Experimental
Materials and Methods
5-Bromosalicylaldehyde and 2-fluorobenzohydrazide with
AR grade were purchased from Fluka. Other reagents and
solvents were used without further purification. Elemental
(C, H and N) analyses were made on a Perkin-Elmer Model
240B automatic analyser. IR spectra were recorded on an
IR-408 Shimadzu 568 spectrophotometer. The 1HNMR
spectra were recorded on Bruker AVANCE 400 MHz
spectrometer with tetramethylsilane as the internal refer-
ence. X-ray diffraction was carried out on a Bruker
SMART 1000 CCD area diffractometer.
Keywords Synthesis ꢀ Crystal structure ꢀ X-ray
diffraction ꢀ Hydrazone ꢀ Solvent effect
Introduction
Hydrazone derivatives are readily prepared by the reaction of
aldehydes with hydrazine compounds, with quantitive yields
and highpurity. In the last few decades, hydrazone derivatives
Preparation of BFBH (1)
L.-W. Xue (&) ꢀ Y.-J. Han ꢀ G.-Q. Zhao ꢀ Y.-X. Feng
College of Chemistry and Chemical Engineering, Pingdingshan
University, Pingdingshan 467000, Henan, People’s Republic
of China
The compound was prepared by the condensation reaction
of equimolar quantities of 5-bromosalicylaldehyde (0.20 g,
1 mmol) with 2-fluorobenzohydrazide (0.15 g, 1 mmol) in
e-mail: pdsuchemistry@163.com
123

1600
J Chem Crystallogr (2011) 41:1599–1603
placed at the calculated positions. Idealized H atoms were
refined with isotropic displacement parameters set to 1.2
(1.5 for O) times the equivalent isotropic U values of the
parent carbon and oxygen atoms. The F atom in (1) is
disordered over two sites with occupancies of 0.629(3) and
0.371(3). The crystallographic data for the compounds are
listed in Table 1. Selected bond lengths and angles are in
listed in Table 2. Hydrogen bonding interactions are
summarized in Table 3.
H
N
Br
H
N
N
Br
N
O
F
OH
(2)
O
F
H2O
OH
(1)
Chart 1 The unsolvated and monohydrate forms of BFBH
absolute methanol (30 ml). The mixture was stirred at
ambient temperature for 1 h to give a colorless solution.
After keeping the solution in air for a week to slow
evaporate, colorless block-like single crystals were formed.
The crystals were isolated by filtration, and were washed
three times with methanol, and dried in air. Yield 0.18 g
(53%). Analysis calculated for C14H10BrFN2O2: C, 49.9;
H, 3.0; N, 8.3%; found: C, 49.7; H, 3.0; N, 8.2%. IR data
(KBr, cm-1): 3237 (m), 1642 (s), 1605 (s), 1540 (s), 1509
(s), 1472 (s), 1383 (w), 1345 (s), 1313 (m), 1265 (s), 1188
(m), 1122 (w), 1018 (m), 917 (m), 837 (m), 810 (m), 693
(w), 621 (m), 556 (w), 473 (w). 1H NMR (CDCl3): d (ppm)
6.82 (d, 1H), 7.40–7.43 (m, 3H), 7.79 (s, 1H), 8.01 (m, 2H),
8.76 (s, 1H), 10.08 (b, 1H).
Results and Discussion
We have first prepared and crystallized the block-liked
monohydrate form of the compound in 95% ethanol.
Considering the presence of a lattice water molecule in the
compound, the absolute methanol was used to repeat the
Table 1 Crystal and structure refinement data for (1) and (2)
Compound:
(1)
(2)
CCDC
817500
817501
Molecular formula
Molecular weight
Crystal system
Space group
C
14H10BrFN2O2
C14H12BrFN2O3
355.2
337.2
Preparation of BFBHꢀH2O (2)
Monoclinic
P21/c
Monoclinic
P21/c
The monohydrate form of BFBH was prepared by the same
method as that for (1), with 95% ethanol as solvent instead
of absolute methanol. Colorless needle-like single crystals
of the compound were formed after evaporating the solvent
for a week. Yiled 0.21 g (59%). Analysis calculated for
C14H12BrFN2O3: C, 47.3; H, 3.4; N, 7.9%; found: C, 47.5;
H, 3.5; N, 7.8%. IR data (KBr, cm-1): 3450 (w), 3229 (m),
1642 (s), 1605 (s), 1540 (s), 1509 (s), 1471 (s), 1382 (w),
1345 (s), 1312 (m), 1265 (s), 1183 (m), 1121 (w), 1018
(m), 917 (m), 837 (m), 811 (m), 693 (w), 623 (m), 556
´
˚
a/A
6.879(1)
28.911(2)
8.724(1)
127.685(2)
1373.1(3)
4
14.873(3)
7.265(1)
13.043(2)
96.281(2)
1400.9(4)
4
´
˚
b/A
´
˚
c/A
b/°
´
3
˚
V/A
Z
Dcalc (g cm-3
)
1.631
1.684
Crystal dimensions
(mm)
0.23 9 0.21 9 0.20 0.27 9 0.23 9 0.22
l (mm-1
Radiation k
min/Tmax
)
3.007
2.957
1
(w), 475 (w). H NMR (CDCl3): d (ppm) 6.82 (d, 1H),
7.40–7.43 (m, 3H), 7.79 (s, 1H), 8.01 (m, 2H), 8.76 (s, 1H),
´
´
˚
˚
Mo Ka (0.71073 A) Mo Ka (0.71073 A)
T
0.5447/0.5846
10752
0.5023/0.5623
8686
10.08 (b, 1H).
Reflections measured
X-ray Diffraction
Range/indices (h, k, l)
-8, 8; -36, 36;
-11, 11
-18, 18; -8, 9;
-16, 14
h limit (°)
Unique reflections
1.41–27.00
2.76–27.00
Data were collected from selected crystals mounted on
glass fibres. The data for the two compounds were pro-
cessed with SAINT [9] and corrected for absorption using
SADABS [10]. The structures were solved by direct
method using the program SHELXS-97, and were refined
by full-matrix least-squares technique on F2 using aniso-
tropic displacement parameters [11]. The amino and water
H atoms in both compounds were located from difference
Fourier maps and refined isotropically, with N–H, O–H,
and HꢀꢀꢀH distances restrained to 0.90(1), 0.85(1), and
2933
[Rint = 0.0665]
3038
[Rint = 0.0409]
Observed reflections
(I [ 2r(I))
Parameters
1358
1934
195
200
Restraints
2
4
Goodness of fit on F2
R1, wR2 [I C 2r(I)]a
R1, wR2 (all data)a
a
1.019
1.027
0.0569, 0.1352
0.1340, 0.1693
0.0402, 0.0890
0.0822, 0.1048
R1 = R||Fo| - |Fc||/R|Fo|, wR2 = [Rw(F2o - F2c)2/Rw(Fo2)2]1/2
˚
1.37(2) A, respectively. The remaining H atoms were
123

J Chem Crystallogr (2011) 41:1599–1603
1601
´
˚
Table 2 Selected bond lengths (A) and angles (°) for (1) and (2)
(1)
(2)
Bond lengths
C1–C7
1.447(6)
1.340(5)
1.275(5)
1.381(5)
1.350(5)
1.229(5)
1.485(6)
1.314(5)
1.453(5)
1.359(4)
1.278(4)
1.378(4)
1.349(4)
1.227(4)
1.498(5)
1.327(4)
C2–O1
C7–N1
N1–N2
N2–C8
C8–O2
Fig. 1 Perspective view of (1) with 30% probability thermal
ellipsoids. Hydrogen bond is drawn as a dashed line. Only the major
component of the disordered F atom is shown
C8–C9
C10–F1
Bond angles
C1–C2–O1
C2–C1–C7
C1–C7–N1
C7–N1–N2
N1–N2–C8
N2–C8–O2
N2–C8–C9
O2–C8–C9
122.5(4)
122.6(4)
120.1(4)
117.2(4)
119.3(4)
121.4(4)
116.0(4)
122.6(4)
122.7(3)
122.5(3)
120.9(3)
117.8(3)
118.6(3)
122.5(3)
117.8(3)
119.6(3)
Table 3 Hydrogen geometries for (1) and (2)
Fig. 2 Perspective view of (2) with 30% probability thermal
ellipsoids. Hydrogen bonds are drawn as dashed lines
˚
D–HꢀꢀꢀA
d(D–H)
˚
(A)
d(HꢀꢀꢀA)
d(DꢀꢀꢀA) (A) Angle(D–
˚
(A)
HꢀꢀꢀA) (°)
the monoclinic space group P21/c. The major difference
between the complexes is in the components of the mole-
cules: compound (1), synthesized and crystallized in
absolute methanol, has no water molecule in the structure,
while compound (2), synthesized and crystallized in 95%
ethanol, has solvent water molecules in the crystal. The
water molecule in (2) is linked to the hydrazone compound
via N–HꢀꢀꢀO and O–HꢀꢀꢀO hydrogen bonds.
(1)
O1–H1ꢀꢀꢀN1
N2–H2ꢀꢀꢀO2i
N2–H2ꢀꢀꢀF10
C7–H7ꢀꢀꢀO2i
(2)
0.82
1.92
2.624(5)
2.861(5)
2.856(8)
3.187(5)
144
0.90(1)
0.90(1)
0.93
2.01(2)
2.35(4)
2.47
157(4)
115(3)
134
O3–H3AꢀꢀꢀO2 0.847(10) 1.860(11) 2.703(4)
174(4)
110(3)
157(4)
145
N2–H2ꢀꢀꢀF1
N2–H2ꢀꢀꢀO3i
O1–H1ꢀꢀꢀN1
0.896(10)
0.896(10) 1.987(19) 2.832(4)
0.82 1.93 2.646(4)
2.36(4)
2.796(4)
In both compounds, the hydrazone molecules display
trans configuration about the C=N double bonds. The bond
lengths are within normal ranges [12–14], and are com-
parable to each other. The C7=N1 bond lengths in both
Symmetry code: (i) -1/2 ? x, 3/2 - y, -1/2 ? z
˚
compounds are 1.28(1) A, confirming them as double
˚
bonds. The C8–N2 bond lengths of 1.35(1) A and the N1–
˚
N2 bond lengths of 1.38(1) A in the compounds are rela-
preparation. Fortunately, needle-like single crystals of the
unsolvated form of the compound were obtained. Both the
monohydrate and the unsolvated forms of the compound
were crystallizing in air-stable colorless crystals. The ele-
mental analyses are in agreement with the formulae pro-
posed by the X-ray determination. The crystals of (1) and
(2) are soluble in methanol, ethanol, acetonitrile, and
chloroform, and insoluble in water.
tively short, suggesting some degree of delocalization in
each of the acetohydrazide systems. The dihedral angles
between the two benzene rings in the compounds are
14.9(2)8 in (1) and 48.8(2)8 in (2). It can be seen that
molecule of (2) is much more distorted than (1), which
might be caused by the intermolecular hydrogen bonds
formed among the hydrazone molecules with the water
molecules in (2).
Crystal Structure Description
In the crystal structure of (1), the hydrazone molecules
are linked through intermolecular N–HꢀꢀꢀO and C–HꢀꢀꢀO
hydrogen bonds, forming chains along the c axis (Fig. 3).
The molecular structures of (1) and (2) are depicted in
Figs. 1 and 2, respectively. Both compounds crystallize in
123

1602
J Chem Crystallogr (2011) 41:1599–1603
Fig. 4 Molecular packing of (2), viewed along the b axis. Hydrogen
bonds are drawn as dashed lines
In the crystal structure of (2), the hydrazone molecules
are linked by the water molecules through intermolecular
N–HꢀꢀꢀO and O–HꢀꢀꢀO hydrogen bonds, forming chains
along the c axis (Fig. 4). In addition, there are pꢀꢀꢀp
stacking interactions (Table 4), O–Hꢀꢀꢀp, and C–Fꢀꢀꢀp
interactions among the adjacent benzene rings in both
compounds [15].
Supplementary Material
CCDC-817500 and 817501 contain the supplementary
crystallographic data for this paper. These data can be
obtained free of charge at http://www.ccdccam.ac.uk/
Fig. 3 Molecular packing of (1), viewed along the a axis. Hydrogen
bonds are drawn as dashed lines
Table 4 Parameters between the planes for (1) and (2)
Cg
Distance
between ring
˚
centroids (A)
Dihedral
angle (8)
Perpendicular
distance of Cg(I)
˚
on Cg(J) (A)
Beta
angle (8)
Gamma
angle (8)
Perpendicular
distance of
Cg(J) on Cg(I) (A)
˚
(1)
Cg(1)–Cg(2)a
4.099
3.816
3.816
4.099
5.47
5.47
5.47
5.47
3.546
3.499
3.480
3.493
31.53
24.24
23.51
30.10
30.10
23.51
24.24
31.53
3.493
3.480
3.499
3.546
Cg(1)–Cg(2)b
Cg(2)–Cg(1)c
Cg(2)–Cg(1)d
(2)
Cg(3)–Cg(3)e
Cg(4)–Cg(4)f
4.360
3.775
0.02
0.02
3.529
3.333
35.96
28.02
35.96
28.02
3.529
3.333
Cg(1) and Cg(2) are the centroids of C1–C2–C3–C4–C5–C6 and C9–C10–C11–C12–C13–C14 in (1), respectively. Cg(3) and Cg(4) are the
centroids of C1–C2–C3–C4–C5–C6 and C9–C10–C11–C12–C13–C14 in (2), respectively. Symmetry codes: (a) -1/2 ? x, 1/2 - y, -1/2 ? z;
(b) -1/2 ? x, 1/2 - y, 1/2 ? z; (c) 1/2 ? x, 1/2 - y, -1/2 ? z; (d) 1/2 ? x, 1/2 - y, 1/2 ? z; (e) -x, 2 - y, -z; (f) 1 - x, 1 - y, -z
123

J Chem Crystallogr (2011) 41:1599–1603
1603
5. Adibi H, Khodaei MM, Pakravan P, Abiri R (2010) Pharm Chem
J 44:219–227
6. Liu F, Zhang WP, He SY (2010) Russ J Coord Chem 36:105–112
7. Wang J-X, Li X-Z, Zhu L-N, Wang J-Y, Qu H (2010) J Chem
Crystallogr 40:726–730
const/retrieving.html or from the Cambridge Crystallo-
graphic Data Centre (CCDC), 12 Union Road, Cambridge
CB2 1EZ, UK; fax: ?44(0)1223-336033 or e-mail: deposit
@ccdc.cam.ac.uk.
8. Naskar S, Naskar S, Butcher RJ, Chattopadhyay SK (2010) Inorg
Chim Acta 363:3641–3646
9. Bruker, SMART and SAINT. Area Detector Control and Inte-
gration Software, Bruker Analytical X-ray Instruments Inc.,
Madison, WI, USA, 1997
Acknowledgments This research was supported by the National
Sciences Foundation of China (No. 20676057 and 20877036) and
Top-class foundation of Pingdingshan University (No. 2008010).
10. Sheldrick GM (1996) SADABS. Program for empirical absorp-
¨
tion correction of area detector. University of Gottingen,
¨
References
Gottingen
11. Sheldrick GM (1997) SHELXL-97. Program for the refinement of
1. Adibi H, Khodaei MM, Pakravan P, Abiri R (2010) Pharm Chem
J 44:219–227
2. Ajani OO, Obafemi CA, Nwinyi OC, Akinpelu DA (2010) Bio-
org Med Chem 18:214–221
3. Rasras AJM, Al-Tel TH, Al-Aboudi AF, Al-Qawasmeh RA
(2010) Eur J Med Chem 45:2307–2313
¨
¨
crystal structures. University of Gottingen, Gottingen
12. Allen FH, Kennard O, Watson DG, Brammer L, Orpen AG,
Taylor R (1987) J Chem Soc Perkin Trans 2:S1–S19
13. Yang D-S (2007) J Chem Crystallogr 37:343–348
14. Li W-H (2009) J Chem Crystallogr 39:449–452
15. Spek AL (2009) Acta Crystallogr D65:148–155
4. Ozkay Y, Tunali Y, Karaca H, Isikdag I (2010) Eur J Med Chem
45:3293–3298
123