440
J. Sirirak et al. / Journal of Molecular Structure 1036 (2013) 439–446
Table 1
2.2. X-ray crystallography
Crystallographic data and structure refinement for 1–4.
Crystal data processing parameters for the structures of 1–4 are
1
2
3
4
given in Table 1. X-ray quality crystals of 1–4 were grown by slow
evaporation of a diisopropyl solution of HqsalX. Crystals were
mounted on a glass fibre using perfluoropolyether oil and cooled
rapidly to 150 or 100 K in a stream of cold nitrogen. In the case
of 1 the structure was determined at 293 K. All diffraction data
were collected on a Bruker APEXII area detector with graphite
Formula
Molecular
weight
C
16H11FN2O C16H11ClN2O C16H11BrN2O C16H11IN2O
266.27
282.72
327.18
374.17
(g molꢁ1
)
Crystal system
Space group
a (Å)
b (Å)
c (Å)
Monoclinic
P21/c
10.0551(5)
9.2429(4)
14.1107(7)
90
104.421(2)
90
293(2)
Monoclinic
P21/c
Monoclinic
P21/n
Monoclinic
P21/c
13.4764(14)
3.7721(4)
25.991(2)
90
16.4841(3)
4.68910(10)
17.1739(3)
90
17.014(4)
4.6068(10)
17.418(4)
90
monochromated Mo Ka (k = 0.71073 Å) [24]. After data collection,
in each case an empirical absorption correction (SADABS) was ap-
plied [25], and the structures were then solved by direct methods
and refined on all F2 data using the SHELX suite of programs [26].
In all cases non-hydrogen atoms were refined with anisotropic
thermal parameters; hydrogen atoms were included in calculated
positions and refined with isotropic thermal parameters which
were ca. 1.2 times the carbon atoms. The exception were the hy-
droxyl hydrogens which were located by low-theta difference Fou-
rier and then refined with isotropic thermal parameters 1.5 times
those of the oxygen atoms to which they are attached. All pictures
were generated using the POV-Ray interface in X-SEED [27,28].
a
(°)
b (°)
(°)
104.802(7)
90
99.7460(10)
90
99.835(4)
90
c
T (K)
100(2)
100(2)
1308.31(4)
4
150(2)
1345.1(5)
4
Cell volume (Å3)
Z
1270.10(10) 1277.4(2)
4
0.099
4
Absorption
coefficient
0.295
3.138
2.377
(mmꢁ1
)
Reflections
collected
Independent
reflections,
Rint
Max. and min.
transmission
Restraints/
parameters
Final R indices
16663
6562
13316
11812
3413, 0.027 2267, 0.055
3033, 0.026
3083,
0.055
2.3. Synthesis of 5-fluoro-N-(8-quinolyl)salicylaldimine HqsalF
0.9882 and
0.9795
0/182
0.9740 and
0.8963
0.5726 and
0.4064
0.7800 and
0.5168
0/181
0/181
0/182
5-Fluorosalicylaldehyde (0.701 g, 5 mmol) was dissolved in
diisopropyl ether (20 ml) giving a pale yellow solution. 8-Amino-
quinoline (0.721 g, 5 mmol) was added and the solution stirred
for 4 h giving an orange solution. Slow evaporation of the solution
to ca. 5 ml gave orange crystals which were isolated by filtration,
0.0492,
0.1476
0.0391,
0.1416
0.0246,
0.0767
0.0447,
0.1194
[I > 2r(I)]: R1,
wR2
1.22 g (92%).
m mOH), 3036, 2970 (mCH), 1613
max(KBr)/cmꢁ1 3435 (
(m
C=N). 1H NMR (CDCl3, 295 K; d; ppm) 13.67 (OH), 8.99 (dd, 1Ha,
types of aromatic rings, a hydroxyl group as well as the halogens
and may be expected to also engage in hydrogen bonding, CAHꢀ ꢀ ꢀ
and interactions in addition to any halogen bonds. In examin-
JHH 1.8, 4.2), 8.91 (s, 1Hg), 8.20 (dd, 1Hc, JHH 1.8, 8.4), 7.75 (dd,
p
1Hd JHH 1.5, 8.1), 7.45–7.61 (m, 3Hb,e,f), 7.13 (m, 2Hh,j), 7.02 (dd,
p–p
1Hi, JHH 4.2, 8.7). kmax(CH2Cl2)/nm
(e, ) 360
dm3 molꢁ1cmꢁ1
ing this series, we hope to develop a better understanding of the
interplay between the various types of interactions and which
dominate or cooperate with each other in such structures. Thus,
in this work we report the crystal structures of all four compounds,
explore the different structural motifs present and determine what
affect the different halogens have on the extended structures in
this apparently simple series.
(48,000). m/z (ESI) 266 [M]+. Calcd. for (found%) C16H11FN2O: C,
72.16 (72.33); H, 4.16 (4.36); N, 10.53% (10.81).
2.4. Synthesis of 5-chloro-N-(8-quinolyl)salicylaldimine HqsalCl
HqsalCl was prepared in an analogous manner to HqsalF, orange/
red microcrystals, 78%.
CH), 1624 (
C=N). 1H NMR (CDCl3, 295 K; d; ppm) 13.96 (OH),
8.98 (s, 1Hg), 8.91 (s, 1Ha), 8.19 (dd, 1Hc, JHH 8.1), 7.74 (s, 1Hh),
m mOH), 3042, 2994
max(KBr)/cmꢁ1 3436 (
(m
m
2. Experimental
7.60 (m, 4Hb,d,e,f), 7.04 (s, 1Hi), 7.01 (s, 1Hj). kmax(CH2Cl2)/nm (e,
dm3 molꢁ1cmꢁ1) 359 (65,500). m/z (ESI) 282 [M]+. Calcd. for
(found%) C16H11ClN2O: C, 67.96 (68.22); H, 3.92 (3.87); N, 9.91%
(10.04).
2.1. General remarks
All reactions were conducted in air using reagent grade sol-
vents. All other chemicals were purchased from Sigma–Aldrich
Chemical Company and used as received. Infrared spectra (as KBr
discs) were recorded on a Perkin–Elmer Spectrum One infrared
spectrophotometer in the range 400–4000 cmꢁ1. Electronic spectra
were recorded in CH2Cl2 on a Shimadzu 1800 UV–Visible spec-
trometer. Elemental analyses were carried out on a Eurovector
EA3000 analyser. ESI–MS were carried out on a Bruker Daltonics
7.0T Apex 4 FTICR Mass Spectrometer.
2.5. Synthesis of 5-bromo-N-(8-quinolyl)salicylaldimine HqsalBr
HqsalBr was prepared in an analogous manner to HqsalF, red
microcrystals, 88%.
m mOH), 3049, 2968 (mCH),
max(KBr)/cmꢁ1 3369 (
1617 (
m
C=N). 1H NMR (CDCl3, 295 K; d; ppm) 14.01 (OH), 8.99 (d,
1Ha, JHH 4.2), 8.91 (s, 1Hg), 8.21 (d, 1Hc, JHH 8.4), 7.75 (d, 1Hd JHH
8.1), 7.45–7.59 (m, 5Hb,e,f,h,j), 6.97 (d, 1Hi, JHH 8.7). kmax(CH2Cl2)/
Scheme 1. Synthesis of HqsalX.