56
S. Jin et al. / Journal of Molecular Structure 1016 (2012) 55–63
Br
compound [(L). (Hfum)0.5] (2). Yield: 24 mg, 83.58% (Based on L).
S
N
O
m. p. 232–233 °C. Elemental analysis performed on crystals ex-
posed to the atmosphere: Calcd for C9H7BrN2O2S (287.14): C,
37.61; H, 2.44; N, 9.75; S, 11.14. Found: C, 37.56; H, 2.39; N,
NO2
NH
2
HO
p-nitrobenzoic acid
9.72; S, 11.08. Infrared spectrum (KBr disc, cmꢁ1): 3560s(
m
(OH)),
s(NH)), 3092 m, 2996 m, 2498 m, 1904 m,
(C@O)), 1622 m, 1542 m, 1488s, 1436s, 1296s( (CAO)),
6-bromobenzo[d]thiazol-2-amine
3412s(
1701s(
m
m
as(NH)), 3213s(m
O
m
OH
O
HO
O
1186 m, 1132 m, 1105 m, 1054 m, 1012 m, 936 m, 859 m, 808 m,
738 m, 680 m, 620 m.
OH
HO
OH
HO
O
OH
L-tartaric acid
Scheme 1. Hydrogen bond building blocks discussed in this paper.
O
OH
O
fumaric acid
terephthalic acid
2.2.3. (6-Bromobenzo[d]thiazol-2-amine): (L-tartaric acid): 2H2O
[(HL+). (Htartꢁ) 2H2O] (3)
To an ethanol solution (8 mL) of 6-bromobenzo[d]thiazol-2-
amine (22.9 mg, 0.1 mmol) was added -tartaric acid (15 mg,
L
0.1 mmol). The solution was stirred for 3 min, then the solution
was filtered into a test tube. The solution was left standing at room
temperature for 2 h, light yellow crystals were isolated. The crys-
tals were dried in air to give the title compound [(HL1+).
(Htartꢁ)ꢀ ꢀ ꢀ2H2O] (3). Yield: 32 mg, 77.07% (Based on L). m. p.
188–189 °C. Elemental analysis performed on crystals exposed to
the atmosphere: Calcd for C11H15BrN2O8S (415.22): C, 31.79; H,
3.61; N, 6.74; S, 7.70. Found: C, 31.72; H, 3.58; N, 6.69; S, 7.66.
(6-bromobenzo[d]thiazol-2-amine): (fumaric acid)0.5 (2) [(L).
(H2fum)0.5
,
L
H2fum = fumaric acid], (6-bromobenzo[d]thiazol-2-
amine):
(
-tartaric acid): 2H2O (3) [(HL1+). (Htartꢁ)ꢀ ꢀ ꢀ2H2O,
Htartꢁ = hydrogen tartarate], and (6-bromobenzo[d]thiazol-2-
amine)2: (terephthalic acid) (4) [(L)2 (H2tpa), H2tpa = terephthalic
acid], respectively (Scheme 2).
Infrared spectrum (KBr disc, cmꢁ1): 3645s(
3332s( s(NH)), 3078 m, 1730s( (C@O)), 1631 m, 1598s(mas
(COOꢁ)), 1550 m, 1484 m, 1426 m, 1382s( s(COOꢁ)), 1358 m,
1302s( (CAO)), 1196 m, 1122 m, 1054 m, 940 m, 853 m, 803 m,
732 m, 676 m, 616 m.
m(OH)), 3462s(mas(NH)),
2. Experimental section
m
m
2.1. Materials and physical measurements
m
m
The chemicals and solvents used in this work are of analytical
grade and available commercially and were used without further
purification. The FT-IR spectra were recorded from KBr pellets in
range 4000–400 cmꢁ1 on a Mattson Alpha-Centauri spectrometer.
Microanalytical (C, H, N, S) data were obtained with a Perkin–
Elmer Model 2400II elemental analyzer. Melting points of new
compounds were recorded on an XT-4 thermal apparatus without
correction.
2.2.4. (6-Bromobenzo[d]thiazol-2-amine)2: (terephthalic acid) [(L)2
(H2tpa)] (4)
To a methanol solution (8 mL) of 6-bromobenzo[d]thiazol-2-
amine (22.9 mg, 0.1 mmol) was added terephthalic acid (17 mg,
0.1 mmol) in 10 mL methanol. The solution was stirred for half
an hour, then the solution was filtered into a test tube. The solution
was left standing at room temperature for 27 days, light yellow
block crystals were isolated after slow evaporation of the methanol
solution to ca. 5 mL in air. The crystals were dried in air to give the
title compound [(L)2 (H2tpa)] (4). Yield: 27 mg, 86.49% (Based on
L). m. p. 265–266 °C. Elemental analysis performed on crystals ex-
posed to the atmosphere: Calcd for C22H16Br2N4O4S2 (624.33): C,
42.28; H, 2.56; N, 8.97; S, 10.25; Found: C, 42.24; H, 2.52; N,
2.2. Preparation of the supramolecular compounds 1–4
2.2.1. (6-Bromobenzo[d]thiazol-2-amine): (p-nitrobenzoic acid) [(L)
(Hnba)] (1)
To an ethanol solution (8 mL) of 6-bromobenzo[d]thiazol-2-
amine (22.9 mg, 0.1 mmol) was added p-nitrobenzoic acid
(16.6 mg, 0.1 mmol). The solution was stirred for a few minutes,
then the solution was filtered into a test tube. The solution was left
standing at room temperature for 16 days, light yellow crystals were
isolated after slow evaporation of the ethanol solution to ca. 1 mL in
air. The crystals were collected and dried in air to give the title com-
pound [(L). (Hnba)] (1). Yield: 29 mg, 73.19% (based on L). m. p. 221–
222 °C. Anal. Calcd for C14H10BrN3O4S (396.22): C, 42.40; H, 2.52; N,
10.60; S, 8.07. Found: C, 42.35; H, 2.47; N, 10.54; S, 8.03. Infrared
8.89; S, 10.19. Infrared spectrum (KBr disc, cmꢁ1): 3584s(
3348s( as(NH)), 3242s( s(NH)), 3085 m, 2496 m, 1906 m, 1712s
m(OH)),
m
m
(C@O), 1629 m, 1542 m, 1492 m, 1416 m, 1342 m, 1286s(CAO),
1240 m, 1192 m, 1108 m, 1056 m, 1002 m, 944 m, 878 m, 813 m,
786 m, 722 m, 668 m, 629 m.
spectrum (KBr disc, cmꢁ1): 3616s(
3215s( s(NH)), 3087 m, 2984s, 2508 m, 1896 m, 1668s(
1620 m, 1536s( as(NO2)), 1486 m, 1442 m, 1400 m, 1320s(
NO2)), 1292s( (CAO)), 1246 m, 1202 m, 1162 m, 1094 m, 1006 m,
m
(OH)), 3385s(
m
m
as(NH)),
(C@O)),
as(-
m
2.3. X-ray crystallography and data collection
m
m
m
Suitable crystals were mounted on a glass fiber on a Bruker
SMART 1000 CCD diffractometer operating at 50 kV and 40 mA
952w, 861w, 811 m, 767w, 714 m, 656w, 618w.
using Mo Ka radiation (0.71073 Å). Data collection and reduction
2.2.2. (6-Bromobenzo[d]thiazol-2-amine): (fumaric acid)0.5 [(L).
(H2fum)0.5] (2)
were performed using the SMART and SAINT software [20]. The
structures were solved by direct methods, and the non-hydrogen
atoms were subjected to anisotropic refinement by full-matrix
least squares on F2 using SHELXTL package [21].
Hydrogen atom positions for all of the structures were located
in a difference map and refined independently. Further details of
the structural analysis are summarized in Table 1. Selected bond
lengths and angles for the compounds 1–4 are listed in Table 2,
the relevant hydrogen bond parameters are provided in Table 3.
To an ethanol solution (8 mL) of 6-bromobenzo[d]thiazol-2-
amine (22.9 mg, 0.1 mmol) was added fumaric acid (12 mg,
0.1 mmol) in 5 mL methanol. The solution was stirred for a few
minutes, then the solution was filtered into a test tube. The solu-
tion was left standing at room temperature for 25 days, light yel-
low crystals were isolated after slow evaporation of the solution
to ca. 3 mL in air. The crystals were dried in air to give the title