The role of weak interactions in self-assembly of supramolecular associations of benzothiazole derivatives and their coordination compounds

Article abstract of DOI:10.1016/j.ica.2017.10.012

New benzothiazole derivatives and their transition metal coordination compounds were synthesized and structurally characterized. The participation of weak interactions, as H-bonding, π-stacking, O → S, N → S and S lone pair···π on the stabilization of their supramolecular assemble was analyzed. The bis-benzothiazole (ebbtz) derivative was obtained from the reaction of benzothiazole-2-carboxaldehyde and ethylenediamine. When reacting this ligand with copper(II) chloride, an electrophilic addition of methanol, as a methoxy group, gave place to the amino ether derivative on the coordination compound [Cu(MeO-ebbtz)Cl]Cl·4H₂O. The supramolecular arrangement of this compound is stabilized by H-bonding, O → S, N → S, lp(S)···π and π-stacking interactions. Whereas, from the reaction in situ of benzothiazole-2-carboxaldehyde, ethylenediamine and copper(II) bromide, the polymeric [Cu₂(μ-Br)₃(ebtz)Br]_n compound was obtained. In this compound, the copper(II) atoms present two different geometries, tetrahedral and octahedral, where a 3D assembly is driven by lp(S)···π and π···π stacking. Two isostructural [M(H₂O)₂(CH₃OH)₄]·2(prbtz) (M = Co^II and Ni^II) compounds and a polymeric sodium complex were obtained with 3-(benzothiazol-2-ylthio)-1-propanesulfonate (prbtz). In the [Na₂(prbtz)₂(H₂O)₂μ-(H₂O)]_n polymer, the prbtz^? is bound to the metal ion in a bent conformation, presenting a supramolecular arrangement stabilized by H-bonding, N → S, T-shape and lp(S)···π interactions. On the other hand, in the [M(H₂O)₂(CH₃OH)₄]·2(prbtz) compounds, prbtz^? co-crystallized, presenting an extended conformation, mainly with lp(S)···π interactions. Additionally, theoretical calculations on the association between two ebbtz molecules, were performed. The results indicate that these molecules have a binding energy of 79.49 kJ/mol promoted by lp(S)···π and π···π stacking interactions, taking place at the frontier LUMO and HOMO molecular orbitals.

Full text of DOI:10.1016/j.ica.2017.10.012

Accepted Manuscript
The role of weak interactions in self-assembly of supramolecular associations
of benzothiazole derivatives and their coordination compounds
Alma Lilia García-Ortiz, Ricardo Domínguez-González, Margarita Romero-
Ávila, Blas Flores-Pérez, Luis Guillén, Miguel Castro, Norah Barba-Behrens
PII:
S0020-1693(17)31267-7
https://doi.org/10.1016/j.ica.2017.10.012
ICA 17939
DOI:
Reference:
To appear in:
Inorganica Chimica Acta
Received Date:
Revised Date:
Accepted Date:
9 August 2017
4 October 2017
11 October 2017
Please cite this article as: A.L. García-Ortiz, R. Domínguez-González, M. Romero-Ávila, B. Flores-Pérez, L.
Guillén, M. Castro, N. Barba-Behrens, The role of weak interactions in self-assembly of supramolecular associations
of benzothiazole derivatives and their coordination compounds, Inorganica Chimica Acta (2017), doi: https://
doi.org/10.1016/j.ica.2017.10.012
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers
we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and
review of the resulting proof before it is published in its final form. Please note that during the production process
errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

ꢀ
The role of weak interactions in self-assembly of supramolecular associations of
benzothiazole derivatives and their coordination compounds
a
a
b
Alma Lilia García-Ortiz , Ricardo Domínguez-González , Margarita Romero-Ávila , Blas Flores-
b
c
c
a
Pérez , Luis Guillén , Miguel Castro , Norah Barba-Behrens *
a
Departamento de Química Inorgánica, Facultad de Química, Universidad Nacional Autónoma de
México, Ciudad Universitaria, Coyoacán, Ciudad de México. 04510, México
b
Departamento de Química Orgánica, Facultad de Química, Universidad Nacional Autónoma de
México, C. U., Coyoacán, Ciudad de México. 04510, México
c
Departamento de Física y Química Teórica, Facultad de Química, Universidad Nacional
Autónoma de México, C. U., Coyoacán, Ciudad de México. 04510, México
Corresponding author
E-mail address: norah@unam.mx (N. Barba-Behrens)
Tel/fax: 52(55)5622-3810
ꢁꢀ
ꢀ

ꢀ
Abstract
New benzothiazole derivatives and their transition metal coordination compounds were
synthesized and structurally characterized. The participation of weak interactions, as H-bonding,
4-stacking, OꢀS, NꢀS and S lone pair^^^4, on the stabilization of their supramolecular assemble
was analyzed.
The bis-benzothiazole (ebbtz) derivative was obtained from the reaction of benzothiazole-2-
carboxaldehyde and ethylenediamine. When reacting this ligand with copper(II) chloride, an
electrophilic addition of methanol, as a methoxy group, gave place to the amino ether derivative
on the coordination compound [Cu(MeO-ebbtz)Cl]Cl^4H O. The supramolecular arrangement of
2
this compound is stabilized by H-bonding, OꢀS, NꢀS, lp(S)^^^4 and 4-stacking interactions.
Whereas, from the reaction in situ of benzothiazole-2-carboxaldehyde, ethylenediamine and
copper(II) bromide, the polymeric [Cu
2
(µ-Br)
3
(ebtz)Br] compound was obtained. In this
n
compound, the copper(II) atoms present two different geometries, tetrahedral and octahedral,
where a 3D assembly is driven by lp(S)^^^4 and 4^^^4 stacking.
II
II
Two isostructural [M(H
2
O)
2
(CH
3
OH) ]^2(prbtz) (M = Co and Ni ) compounds and a
4
polymeric sodium complex were obtained with 3-(benzothiazol-2-ylthio)-1-propanesulfonate
-
(
prbtz). In the [Na
2
(prbtz)
2
(H
2
O)
2
µ-(H
2
O)]
n
polymer, the prbtz is bound to the metal ion in a bent
conformation, presenting a supramolecular arrangement stabilized by H-bonding, NꢀS, T-shape
and lp(S)^^^4 interactions. On the other hand, in the [M(H
2
O)
2
(CH
3
OH) ]^2(prbtz) compounds,
4
-
prbtz co-crystallized, presenting an extended conformation, mainly with lp(S)^^^4 interactions.
Additionally, theoretical calculations on the association between two ebbtz molecules, were
performed. The results indicate that these molecules have a binding energy of 79.49 kJ/mol
promoted by lp(S)^^^4 and 4^^^4 stacking interactions, taking place at the frontier LUMO and
HOMO molecular orbitals.
Keywords: benzothiazole derivatives; transition metal compounds; lp(S)^^^4; 4^^^4 stacking, NꢀS
and OꢀS interactions; supramolecular arrangements
ꢂꢀ
ꢀ

ꢀ
Introduction
Weak interactions have been studied for some time, where the most analyzed is the classical
hydrogen bonding (D-H^^^A), formed between polar species D-H and a lone pair carrier
A(electron rich atom). They are characterized for a weak to medium interaction energy (ca.10-40
kJ/mol), a substantial overlap of electron density of the heteroatoms, electron transfer between
the heteroatoms and with preferred bond lengths from 2.2 Å to 3.2Å (D^^^A), and angles from 90°
to 180° (D-H^^^A) [1–3].
Interactions between aromatic rings have also been widely studied since 1985 when Burley and
Petsko proved their importance in their pioneering work on DNA and proteins. It was stated that
there is a competition between stacking and T-shape arrangements on interacting aromatic rings,
with very low energy difference (0-50 kJ/mol) [4,5].
Recently, it has been an increasing interest on sulfur-containing molecules, where the sulfur
atom may behave as a Lewis base or Lewis acid, due to its capability to act as an electron donor
as consequence of the directionality of their lone pairs, or as an electron acceptor driven by a
hypervalent behavior towards a pseudo trigonal bipyramidal geometry.[6–8] The latter could be
defined as weak donor-acceptor interactions, Yꢀꢁꢂꢃꢄhere Y is a main group element, an electron
rich atom with lone-pair (lp) electrons in the n
orbital of a positive potential [9,10]. Both, the YꢀS interaction and the S ꢅ* orbital are oriented
in the same plane, different from the out of the plane interaction in the π direction, which is
o
direction, N or O, that interacts with a S ꢅ*
o
observed for a carbonyl group[11]. These type of intermolecular associations have been found for
molecules containing PꢀS, ClꢀS, SnꢀS and SiꢀS interactions [12,13].
The SꢀS interaction has been considered as a “weak contact”, taking into account that the
distance between them is not larger than 3.7Å (ꢆ Van der Walls radii) [7], while, for OꢀS and
NꢀS are 3.32 and 3.35 Å, respectively [11].
Hypervalent YꢀS interactions may control the molecular structure and the formation of
different patterns of association as shape, size and packing, in addition to the chemical reactivity
of organic molecules and coordination compounds [14–19]. Lone pair^^^4 short contacts (lp^^^4),
have been less studied. Nevertheless, computational studies have demonstrated that such
interactions, between a lp donor and an aromatic ring acceptor can be energetically favorable, the
ꢃꢀ
ꢀ

ꢀ
maximum distance, from the lp donor to the aromatic ring centroid being of 3.82 Å[20–22].
However, in the case of S^^^4 interactions, distances in the range of 3.5-4.9 Å [4]. An example of
this type of interaction is shown in the X-ray crystal structure of the lysozyme protein (PDB
6
LYZ), figure SI 1, where the distances lp(S)^^^4 to the centroids of five membered rings are in
the range of 3.9-4.4 Å. These weak interactions are relevant for some organic molecules,
stabilizing a thermo-dependent conformation and restricting its rotation [23].
All these contributions are also important for maintaining folded protein structures and their
thermal stability [8]. Many of these interactions have been found on proteins by X-ray diffraction
analysis from databases and computational studies [24–26].
On the other hand, in the biological activity of some sulfur containing molecules, the
conformation stabilized by intra and inter molecular interactions YꢀS, plays a crucial role, in
antiangiogenetic drugs [27,28] or in the treatment of inflammatory diseases, such as rheumatoid
arthritis [29]. The understanding of these interactions will contribute to elucidate their mechanism
of action [30] and into the development of new drugs [26,31], for example, the treatment of
Chagas´ disease [32–34].
In this context, we studied different benzothiazole derivatives and their transition metal
coordination compounds. The role of weak interactions, as YꢀS (Y = N, O), lp(S)^^^4, 4^^^4 H^^^4
(
T-shape) and hydrogen bonding, on the stabilization of 3D crystal assembling was analyzed.
2
. Experimental
2
.1 General
The sodium 3-(benzothiazol-2-ylthio)-1-propanesulfonate (Aldrich), metal salts (Baker) and
solvents (THF and acetone, Baker; anhydrous MeOH, Aldrich) were commercial and used
-1
without further purification. FT IR spectra in the range 4000-400 cm were collected in a Perkin
Elmer FT-IR Spectrum 400 spectrophotometer with a universal ATR sampling, accessory at 298
-1
K. Electronic spectra were measured over the range 40,000-5000 cm by the diffuse reflectance
method on a Cary-5000 Varian spectrophotometer at 298 K. Mass spectra (MS-ESI+) were
determined in a Thermo Trace GC Ultra (capilar colum DB5) mass spectrometer. Elemental (C,
ꢄꢀ
ꢀ

ꢀ
1
13
N, H, S) analyses were made on a Perkin Elmer 2400 analyzer. H-NMR and C-NMR spectra
were recorded on a Varian 400 MHz instrument using TMS as internal reference in CDCl
3
.
2
.2 X-ray crystallographic study
Diffraction data were collected on a Bruker Smart APEX II or on a Xcalibur, Atlas, Gemini
diffractometer with a CCD area detector and Mo K radiation source (U = 0.71073 Å). APEX2 or
a
CrysAlisPro software packages were used for data collection and data integration. The
compounds were collected at RT (130 K) and the structures were solved by Direct Methods using
2
SHELXT 2014/5 (Sheldrick, 2014) and refined by full-matrix least-squares on F with SHELXL-
2
016/6 (Sheldrick, 2016) [35] using the ShelXle GUI. Anisotropic displacement parameters were
used for all non-H atoms. Hydrogen atoms for the C-H bonds were placed in idealized positions
and refined using a riding model. The H atoms attached to O or N atoms were found in difference
Fourier map and their position were refined with Uiso parameter equal to 1.2 times the equivalent
parameter of the atom to which they are attached with distance restraints (DFIX). The disordered
groups and solvent were refined using geometry (SAME, SADI) and Uij restraints (SIMU, RIGU)
by SHELXL. Molecular graphics were preparing using Mercury, POV-RAY and PAINT.NET
programs. Crystallographic data are listed in Table 1 and Table 2.
Table 1.
Table 2.
ꢅꢀ
ꢀ

ꢀ
2.3 Synthesis of the compounds
2.3.1 Synthesis of benzothiazole-2-carboxaldehyde (btzca)
Benzothiazole-2-carboxaldehyde was synthesized using a previously reported procedure [36]
from benzothiazole by eliminating of the proton in the position 2 with n-BuLi, followed by a
neutralization. A solution of nBuLi in hexane (2mL, 2M) was slowly added to a solution of
benzothiazole (0.5023g, 3.7mmol) in dry THF (5mL) at -78 °C. Then a solution DMF in THF
(
18.5mmol, 1.4mL) was dropped into the mixture and finally neutralized. A yellow powder was
obtained. The product was purified by a chromatography column with an AcOEt-hexane solution
(
1:50). Needle crystals were obtained by re-crystallization with dichloromethane. After the
1
purification, this precursor was characterized by H-NMR (400 MHz, CDCl
3
): ꢇ 10.17 (s, 1H),
8
7
1
.25 (ddd J=9.5, 6.6, 5.2, 0.7 Hz, 1H), 8.00 (ddd, J=9.4, 6.3, 5.0, 0.7 Hz, 1H), 7.59 (dqd, J=7.9,
13
.2, 1.5 Hz, 2H), 7.57 (s, 1H) and 7.62 (s, 1H) Fig. SI 2. C-NMR (400 MHz, CDCl ): ꢇ = 185,
3
65, 153, 136, 122, 125, 127 and 128. Fig. SI 3 MS(ESI): m/z =163.
2.3.2 Ebbtz ligand
This ligand was obtained from benzothiazole-2-carboxaldehyde (1.1557g, 7.08mmol) and
ethylenediamine (3.54mmol) in methanol (40mL) at 20h reflux. The colorless needles crystals
were characterized by M.P. 184-185°C. Mol. Wt: 350.46g/mol. Anal. Calc. for C18 : C,
1.68; H, 4.02; N, 15.98; S, 18.29%. Found: C, 61.89; H, 3.39; N, 16.37; S, 17.81%. MS(ESI):
H
14
N S
4 2
6
+
-1
m/z = 350 [M +H ]. FT-IR (ATR, cm ) ν(C=N) aliphatic 1636; ν(C=N) ring 1498-1455; ν (C=C)
s
1
1
6
590, νas(C=C) 1316. H-NMR (400 MHz, CDCl
3
): ꢇ 8.65 (s, 1H), 4.09 (s, 2H), 8.11 (ddd, J= 9.3,
.4, 5.3, 0.6 Hz, 1H), 8.05 (ddd, J=9.4, 6.7, 5.5, 0.7 Hz, 1H), 7.52 (ttd J=8.2, 7.6, 7.2, 2.0 Hz, 2H).
13
Fig. SI 4 C-NMR (400 MHz, CDCl ): ꢇ = 60, 123, 127, 134, 153, 158 and 167. Fig. SI 5.
3
2
.3.3 [Cu(MeO-ebbtz)Cl]Cl^4H
2
O
An anhydrous methanol solution of CuCl
2
^6H O (17.1 mg, 0.1 mmol) was added to a 10mL
2
anhydrous methanol solution of ebbtz (0.0348 g, 0.1 mmol). The reaction mixture was heated
under reflux with constant stirring during 3 h. The obtained blue solution was let to stand at RT,
after 15 days, blue crystals were formed which were collected and analyzed by X-ray diffraction.
ꢆꢀ
ꢀ

ꢀ
-1
-1
FT-IR (ATR, cm ): *(C=N)alip. 1598, *(C=N)ring 1474, *(C-O) 1057. UV-Vis-NIR * (cm ): * =
1
14133.
2
.3.4 [Cu
2
(µ-Br)
3
(ebtz)Br]
n
A solution of CuBr
2
^6H O (223.35 mg, 1 mmol) in THF was added to a benzothiazole-2-
2
carboxaldehyde solution (81.5 mg, 0.5 mmol) in THF (10 mL), stirred for 30 minutes then
ethylenediamine (0.5 mmol) was added in order to obtain the Schiff base in situ. The obtained
green solution was left to stand at RT, after 30 days, green lamina crystals were formed. UV-Vis-
-1
NIR * (cm ): * =14500.
1
2
.3.5 [Cu(ebtz)Br]Br^H
2
O
The same procedure as for 2.3.4, was followed to obtain this compound, changing the solvent
for acetone. The obtained green solution was left to stand at RT, after 30 days, green prism
crystals were formed, but the X-ray crystal diffraction data were not good enough, but
-1
connectivity between the atoms was adequate for the molecular structure. UV-Vis- NIR * (cm ):
=13776.
*
1
2
.3.6 [Co(CH
An aqueous solution, 20 mL, of Naprbtz (312 mg, 1.02mmol) was mixed with Co(NO
611 mg, 2.10 mmol), and left under reflux for 24 h. After this time, the reaction was evaporated
and the precipitate was filtered, which corresponds to the Na[Co(prbtz) (NO )(H O)]^6H O
3 4 2 2
OH) (H O) ] ^ 2(prbtz)
3
)
2
^6H O
2
(
2
3
2
2
compound, which was washed with cool EtOH. Anal. Calcd. C, 28.84; H, 4.30; N, 4.73; S, 21.39.
Found C, 28.37; H, 4.05; N, 4.97; S, 22.60%.
The Na[Co(prbtz)
left to stand at RT. After one week pale pink crystals of the [Co(CH
compound, were obtained which were suitable for X-ray diffraction analysis.
2
(NO
3
)(H
2
O)]^6H
2
O compound (100 mg) was dissolved in methanol (5mL) and
3
OH) (H O) ]^2(prbtz)
4
2
2
2
.3.7 [Ni(CH
An aqueous solution, 20 mL of Naprbtz (308 mg, 1.0 mmol) was mixed with Ni(NO
588 mg, 2.02 mmol), and left under reflux for 24 h. After this time, the reaction was evaporated
3 4 2 2
OH) (H O) ] ^ 2(prbtz)
3
)
2
^6H O
2
(
and the precipitate was filtered, which corresponds to the Na[Ni(prbtz)
2
3
(NO )(H
2
O)]^6H O
2
ꢇꢀ
ꢀ

ꢀ
compound, which was washed with cool EtOH. Anal. Calcd. C, 28.38; H, 4.29; N, 4.92; S, 19.70.
Found C, 28.40; H, 4.06; N, 4.97; S 22.70%.
The Na[Ni(prbtz)
left to stand at RT. After one week, green crystals of the [Ni(CH
were obtained, which were suitable for X-ray diffraction analysis.
2
(NO
3
)(H
2
O)]^6H
2
O compound (100 mg) was dissolved in methanol (5mL) and
3
OH) (H O) ]^2(prbtz) compound
4
2
2
2 2 2 2 2 n
2.3.8 [Na (prbtz) (H O) µ-(H O)]
A saturated aqueous solution of this compound was prepared, then let to stand at RT. After one
week, colorless crystals were observed. Anal. Calcd. C, 38.57; H, 3.24; N, 4.49; S, 30.89%. Found
C, 38.95; H, 3.37; N, 3.95; S, 30.64%.
2.4 Computational Procedure.
First principles density functional theory (DFT) calculations were performed for the analysis of
the structural, electronic and energetic properties for DRX data of benzothiazole derivatives and
their molecular aggregates. All electron calculations were done at the B3LYP level of theory
[
37,38], jointly with 6-311+G(d, p) basis sets[39-41]. The quantum chemistry software Gaussian
9 was employed.[42] The total energy for a basic building block, two layers, of the systems was
0
determined as this level of theory. The results allow to analyze the basic binding interactions
responsible for the stability of the system. Natural bond order (NBO) population analysis were
done for the GSs. Charge distributions were estimated also through the B3LYP/6-311+G(d,p)
method. The frontier molecular orbitals, LUMO, HOMO and other orbitals involved in the
binding interactions of the system were determined.
3. Results and Discussion
Benzothiazole-2-carboxaldehyde (btzca)
The X-ray diffraction analysis of the benzothiazole-2-carboxaldehyde shows a planar
conformation of the molecule that is stabilized by the interaction OŴS (3.065 Å; ꢆrVdW = 3.32 Å),
which also promotes that the C1-C8 bond length to be shorter (1.472 Å) than the expected for a C-
ꢈꢀ
ꢀ

ꢀ
C single bond. Also intermolecular associations are observed, through two weak hydrogen bonds
C-H···O1 (2.528 and 2.563Å), as depicted in Fig. 1.
Fig. 1.
The planarity of the benzothiazole-2-carboxaldehyde molecules gives place to organized
horizontal layers and the only interaction that stabilizes the 3D structure is the π(C=O)^^^π(aryl)
staking between them, Fig 2.
Fig. 2.
The benzothiazole-2-carboxaldehyde (btzca) was used as a precursor to obtain the Schiff base
N,N´-bis(1,3-benzothyazole-2-ylmethylene)ethane-1,2-diamine ebbtz ligand.
N,N´-bis(1,3-benzothyazole-2-ylmethylene)ethane-1,2-diamine (ebbtz)
The ebbtz ligand was obtained by a classical condensation reaction, where one water molecule is
lost, generating azomethine groups (C=N). Its X-ray crystal structure showed that the
benzothiazole fragments are symmetrically bound to the ethylenediamine moiety in the ebbtz
ligand, the N2-C9-C10-N3 atoms present a small torsion angle of 28.32°, indicating that the
complete molecule is in an extended conformation, Fig 3.
Fig. 3.
This extended conformation presents three different NꢀS interactions: two intramolecular
N2ꢀS1 and N3ꢀS2 (3.039 Å, 2.97; ꢆrVdW = 3.85 Å), from the nitrogen atom of the azomethine
group to the sulfur from benzothiazole and an intermolecular N4ꢀS1 (3.225 Å), between
neighboring molecules, yielding a zig-zag arrangement, Fig 4. The complete 3D network is shown
in Fig. SI 6
ꢉꢀ
ꢀ

ꢀ
Fig. 4.
Several π^^^π, lp(S)^^^π and H^^^π intermolecular interactions stabilize the ebbtz crystal network.
Two π^^^π interactions are observed: face to face, between the benzene and thiazole aromatic
ring(S1) from neighboring molecules (3.747 Å) and the azomethine group C11=N3 with the
nearest thiazole ring (3.787 Å). The sulfur lone pair lp(S2)^^^π interacts with a benzene ring (3.594
Å), while lp(S1) does this with the azomethine C8=N2 (S1^^^π C8=N2; 3.507 Å). Both methylene
groups, present H^^^π interactions, C-H10A^^^πC11=N3 and C-H9B^^^πC8=N2 (2.923Å, 3.076Å)
(
(
Fig 5A). Finally, ebbtz blocks are interconnected by H^^^π, in a T-shape arrangement
C-H16^^^π, 3.295Å, C-H5^^^π, 3.6.39Å) (Fig5 B).
Fig. 5.
[
Cu(MeO-ebbtz)Cl]Cl^4H
2
O
In the synthesis reaction of this compound, the ebbtz ligand presented an aldol condensation by
the addition of a methoxy group from the methanol solvent. This reaction was catalyzed by
copper(II), where each carbon atom from the azomethine group formed a new ester group through
an electrophilic addition, Scheme 1
CH3
H R
R
R
H
R
R
R
R H
O
+
-
O
C
N
N
CH3
O
CH3
N
II
II
II
Cu
R
Cu
R
Cu
Scheme 1. Reaction mechanism of the aldolic condensation
The IR spectrum from the ebbtz ligand, shows characteristic bands from the azomethine group
-1
(
C=N) in the region 1636 cm . This band is shifted in the coordination compound to a lower
-1
frequency, 1600 cm , indicating its coordination through the N atom to the copper(II) center. The
-
1
*
(C=N) band of the thiazole ring is at 1500 cm in the free ligand, while in the coordination
-1
compounds this band is shifted to 1470 cm . Upon the addition of the methoxy groups in the
ꢁꢊꢀ
ꢀ

ꢀ
-1
[
Cu(MeO-ebbtz)Cl]Cl^4H
2
O compound, a new band at 1057 cm was assigned to the *(C-O),
from the methoxy group.
II
The X-ray crystal structure of this compound shows a Cu in a square pyramidal geometry
(
τ=0.03), where N1 is found in the apical position (length 2.270 Å) and the square base is
constituted by N4, N2, N3 (length ca. 2.04 Å) and Cl1 (length 2.255 Å), Fig 6.
Fig. 6.
A methoxy group is bound to the C atoms from each azomethine, through an aldol condensation
reaction, forming four new chiral centers, C8, C11, N3 and N2.
The [Cu(MeO-ebbtz)Cl]Cl^4H O compound shows different hydrogen bonding interactions,
2
promoted by water molecules and the chloride , O4W-H^^^O3W (2.246 Å), O3W-H^^^Cl2 (2.361
Å), O2W-H^^^Cl2 (2.374 Å), O2W-H^^^Cl2 (2.550 Å), O1W-H^^^O2W (2.017 Å), N3-H^^^O1W
(
2.037 Å), N2-H^^^Cl2 (2.384 Å), Fig. 7. These associations generate a 3D pleated sheet
arrangement, with water channels on the b axis.
Fig. 7.
Intermolecular π stacking, between adjacent heterocycle rings, contribute to the supramolecular
structure, Fig. 8. Two neighboring benzene rings are eclipsed with a distance of 3.719Å and an
angle of 95.12°. Additionally, two symmetric parallel contacts, lp(S2)^^^π (3.582Å) are present. A
water molecule gives place to O1WŴS2, 3.202Å. Simultaneously intramolecular contributions are
also of relevance. A T-shape interaction, C-H2^^^π from the 6-membered ring with the thiazole
ring is observed (3.234Å). Due to the orientation of the methoxy group it allows two OŴS
intramolecular interactions O2ŴꢀTQꢁTꢂ[RUÅꢁꢃ,"ꢁO1ŴꢀSQꢁTꢂ[XTÅꢁꢄꢆrVdW = 3.32 Å). In Fig. SI 7 is
shown the supramolecular arrangement.
Fig. 8.
ꢁꢁꢀ
ꢀ

ꢀ
[
2 3 n
Cu (µ-Br) (ebtz)Br]
The DRX analysis (Fig. 9) shows that the asymmetric unit of this polymeric compound contains
two copper(II) atoms and the N-[(1H-benzimidazol-2-yl)methyl]ethane-1,2-diamine (ebtz) ligand.
The Cu2 atom presents a regular tetrahedral geometry with four coordinated Br atoms, where Br1,
Br2 and Br3 participate as a bridge connecting both copper atoms. The observed angles are in the
range from 101° to 110°. On the other hand, the Cu1 atom shows a distorted octahedral geometry
with a mer isomery. Their meridional angles are in the range from 84° to 98° and the axial angles
are 161.75° and 169.42°.
Fig. 9.
In this compound, two polymeric chains of [Cu
2
(µ-Br)
3
(ebtz)Br] are associated by different
n
interactions. One of them is by intercalation of their aromatic rings through weak parallel
lp(S)^^^π(ring) (3.571Å), Fig. 10A, which are in the expected range (3.5-3.82 Å). Additionally, the
Br4 atom participates in a bifurcated hydrogen bonding, C-H^^^Br4, with two benzyl ring protons
(
3.049 and 2.750 Å). This two chains behave as a building block which are interconnected through
hydrogen bonding N-H3B^^^Br4 (2.75 Å) and C-H3^^^Br4 (3.150 Å), Fig. 10 B. This 3D
arrangement gives place to Br channels on the c axis, Fig. SI 8.
Fig. 10.
The X-ray diffraction data of the [Cu(ebtz)Br]Br^H O compound was not of the adequate quality
2
to analyze weak interactions. Nevertheless, the connectivity of the copper(II) and the coordinated
atoms shows a square base pyramidal geometry, where the square base is formed by a Br and 3
nitrogen atoms, with a water molecule in the apical position. Fig 11.
Fig. 11.
ꢁꢂꢀ
ꢀ

ꢀ
It is interesting that a sulfure lp^^^π(benzene ring) interaction is observed, as well as parallel head
to tail associations (Fig 12). The apical coordinated water molecules forms water channels under c
axis Fig. SI 9.
Fig. 12.
[
2 2 2 2 2 n
Na (prbtz) (H O) µ-(H O)]
In this coordination compound the asymmetric unit generates a dimer, shown in Fig.13, which is
part of a polymeric chain. The dimer is constituted by two sodium atoms in a distorted octahedral
geometry with six oxygen atoms, from three water molecules and three from the sulfonate groups.
The meridional angles are in the range from 75° to 116° and the axial angles are 160° and 166°.
The sodium atoms are interconnected through two O-S-O bridges from the sulfonate groups. One
water molecule bridges the sodium metal ions and is found in the cavity formed by an eight-
membered ring.
Fig. 13.
On the c axis of the extended polymer, NŴS interactions are found between neighboring ligand
molecules (3.296Å) Fig. 14A, as well as bifurcated hydrogen bonds, O4-H^^^O2 (1.916 Å) and O4-
H^^^O1 (1.996 Å). These chains interact by face to edge contacts C5-H5^^^π(ring) and
lp(S)^^^π(ring) 3.661Å, Fig. 14B, promoting the association of 3D building blocks, as shown in Fig
14C.
Fig. 14.
When the prbtz is coordinated to a sodium atom presents a bent configuration, with a torsion
angle of C1-S2-C8-C9 (77.31°). On the other hand, in the [Co(H O) (CH OH) ]^2(prbtz) and
Ni(H O) (CH OH) ]^2(prbtz) compounds, where prbtz is outside from the metal coordination
2
2
3
4
[
2
2
3
4
sphere is stabilized an extended conformation, with torsion angles of 173.01° and 173.29°
respectively, for the same atoms, Fig 15.
ꢁꢃꢀ
ꢀ

ꢀ
Fig. 15.
II
II
[
M(H
The full structure of these octahedral coordination compounds is generated by symmetry. The
coordination sphere of the metal atom is constituted by six oxygen atoms from two water
2
O)
2
(CH
3
OH)
4
]^2(prbtz); M= Co , Ni
2
+
molecules and four methanol molecules. The metal complex [M(H
2
O)
2
(CH
3
OH) ] is enclosed by
4
-
four prbtz anions, constituting the second coordination sphere through moderate hydrogen
bonding interactions, O4-H4A^^^O3, 1.941Å; O4-H4B^^^O2, 1.973Å; O5-H5A^^^O1, 1.916Å; O6-
H6A^^^O1, 1.921Å. Fig 16
Fig. 16.
-
Different stacking contacts are observed between three prbtz molecules, C8-H8A^^^π(benzene
ring) in a face to edge orientation (2.800Å); lp(S1)^^^π(heterocycle ring) (3.583Å) and
lp(S2)^^^π(heterocycle ring) (3.459Å). The spacefill representation shows the interaction of the S
lone pair, from the aliphatic chain, with the heterocyclic rings, Fig. 17.
Fig. 17.
The supramolecular structure stabilizes an intercalated anion-cation-anion giving place to a 3D
arrangement, Fig. SI 10
Theoretical calculations
In order to analyze the stability and the interactions of the benzothiazole compounds, all electron
calculations were realized for the bis-benzothiazole (ebbtz). For this study, a model of two layers
of ebbtz was selected. The theoretical results allowed the determination of the main binding
interactions responsible for the stability for this benzothiazole systems, π-stacking, S lone pair^^^π,
NŴS intermolecular interactions.
These interactions take place at the frontier molecular orbitals, as it is shown in Fig. 18. The
highest occupied molecular orbital (HOMO, -6.50ev) contains the non-covalent sulfur lone pair^^^π
ꢁꢄꢀ
ꢀ

ꢀ
interaction. At lower energy (-6.95ev), appears the π stacking between the six membered ring and
the thiazole ring. Moreover, a NŴS intermolecular interaction is displayed by the lowest occupied
molecular orbital (LUMO, -2.25ev). The intermolecular interactions, π-stacking, S lone pair^^^π,
NŴS add up to 81.22 kJ/mol, which is the stabilization energy between two layers of ebbtz. Note
that a large HOMO-LUMO separation (4.25ev) is consistent with the structural stability of the
system. The weak interactions observed in the crystal structure of ebbtz are in agreement with the
theoretical results.
Fig. 18.
5
. Conclusions
This study of weak interactions in the benzothiazole derivatives and their coordination
compounds, contributed to the understanding of the preferred conformations and associations of
these molecules on their supramolecular arrangements.
The bis-benzothiazole (ebbtz) and the sulfonate-benzothiazole (prbtz) stabilized an extended
conformation, with intra and intermolecular NꢀS interactions, when they were not coordinated.
Upon coordination to a metal ion, a bent conformation was preferred.
The supramolecular arrangements of these sulfur-containing compounds are governed by several
and cooperative weak interactions, where the behavior of the sulfur atom, as Lewis base or Lewis
acid, was relevant. All compounds presented H-bonding, 4^^^4 stacking (eclipsed, head-to-tail or
T-shape) and lp(S)^^^4 interactions with the aromatic benzothiazole rings.
Theoretical calculations indicated that 4^^^4 stacking and S lone pair^^^4 interactions occur at the
most external molecular orbitals, LUMO and HOMO. As well as the NꢀS interaction was found
at the HOMO-7 orbital.
Acknowledgments
Financial support from Conacyt, grant CB2012-178851 and DGAPA postdoctoral fellowship
and grant IN224516, is acknowledged.
ꢁꢅꢀ
ꢀ

ꢀ
Supplementary data
CCDC data contains the supplementary crystallographic data for: 1562798 [Cu (µ-
2
Br)
3
(ebtz)Br]
Co(H O) (CH
Ni(H O) (CH
n
; 1562799 btzca; 1562800 ebbtz; 1562801 [Cu(MeO-ebbtz)Cl]Cl^4H
OH) ]^2(prbtz); 1562803 [Na (prbtz) (H O) µ-(H O)]
OH) ]^2(prbtz) and 1562805 [Cu(ebtz)Br]Br^H O. These data can be obtained free
2
O; 1562802
[
[
2
2
3
4
2
2
2
2
2
n
;
1562804
2
2
3
4
2
of charge via http://www.ccdc.cam.ac.uk/conts/retrieving.html, or from the Cambridge
Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax: (+44) 1223-336-
0
33; or e-mail: deposit@ccdc.cam.ac.uk.ꢀ
Supplementary Information
1
13
H and C NMR spectra of ebbtz and btzca compounds and 3D supramolecular arrangements of all the
obtained compounds are given in Fig. SI 1 to Fig. SI 10.
6. References
[
[
[
[
[
[
[
[
1] T. Steiner, Angew. Chem. Int. Ed. 41 (2002) 48–76.
2] G.N. Pairas, P.G. Tsoungas, ChemistrySelect. 1 (2016) 4520–4532.
3] J.-A. van den Berg, K.R. Seddon, Cryst. Growth Desing. 3 (2003) 643–661.
4] E.A. Meyer, R.K. Castellano, D. Franois, Angew. Chem. Int. Ed. 42 (2003) 1210–1250.
5] J.W. Steed, Supramolecular chemistry, LONDON, UK, 2005.
6] R.E. Rosenfield, R. Parthasarathy, J.D. Dunitz, J. Am. Chem. Soc. 99 (1977) 4860–4862.
7] T.N. Guru Row, R. Parthasarathy, J. Am. Chem. Soc. 103 (1981) 477–479.
8] M. Iwaoka, S. Takemoto, M. Okada, S. Tomoda, Bull. Chem. Soc. Jpn. 75 (2002) 1611–
1
625.
9] A.A. Milov, R.M. Minyaev, V.I. Minkin, J. Phys. Chem. A 2011,. 115 (2011) 12973–
2982.
[
1
[
[
[
10] V.D.P.N. Nziko, S. Scheiner, J. Phys. Chem. A 2014,. 118 (2014) 10849–10856.
11] M. Iwaoka, S. Takemoto, S. Tomoda, J. Am. Chem. Soc. 124 (2002) 10613–10620.
12] R. Colorado-Peralta, C. Guadarrama-Pérez, L.A. Martínez-Chavando, J.C. Gálvez-Ruiz,
ꢁꢆꢀ
ꢀ

ꢀ
A.M. Duarte-Hernández, G. V. Suárez-Moreno, A. Vásquez-Badillo, S.A. Sánchez-Ruiz, R.
Contreras, A. Flores-Parra, J. Organomet. Chem. 751 (2014) 579–590.
13] Z. García-Hernández, A. Flores-Parra, J.M. Grevy, Á. Ramos-Organillo, R. Contreras,
Polyhedron. 25 (2006) 1662–1672.
[
[
[
[
14] M. Iwaoka, N. Isozumi, Molecules. 17 (2012) 7266–7283.
15] M. Iwaoka, N. Isozumi, Biophysics, 2 (2006) 23–34.
16] A. Peña-Hueso, F. Téllez, R. Vieto-Peña, R.O. Esquivel, A. Esparza-Ruiz, I. Ramos-García,
R. Contreras, N. Barba-Behrens, A. Flores-Parra, J. Mol. Struct. 984 (2010) 409–415.
17] E.W. Reinheimer, M. Fourmigué, K.R. Dunbar, J. Chem. Crystallogr. 39 (2009) 723–729.
18] S. Biswas, G.P.A. Yap, K. Dey, Polyhedron. 28 (2009) 3094–3100.
19] A. Esparza-Ruiz, A. Peña-Hueso, J. Hernández-Díaz, A. Flores-Parra, R. Contreras, Cryst.
Growth Des. 7 (2007) 2031–2040.
[
[
[
[
[
[
20] T.J. Mooibroek, P. Gamez, J. Reedijk, CrystEngComm. 10 (2008) 1501.
21] M. Egli, S. Sarkhel, Acc. Chem. Res. 40 (2007) 197–205.
22] J. Novotný, S. Bazzi, R. Marek, J. Kozelka, Phys. Chem. Chem. Phys. 18 (2016) 19472–
1
9481.
23] Y. Nagao, H. Iimori, S. Goto, T. Hirata, S. Sano, H. Chuman, M. Shiro, Tetrahedron Lett.
3 (2002) 1709–1712.
[
4
[
[
24] M.K. Si, R. Lo, B. Ganguly, Chem. Phys. Lett. 631–632 (2015) 6–11.
25] M.R. Koebel, A. Cooper, G. Schmadeke, S. Jeon, M. Narayan, S. Sirimulla, J. Chem. Inf.
Model. 2016,. 56 (2016) 2298–2309.
[
[
[
[
26] Y. Nagao, T. Honjo, H. Iimori, S. Goto, S. Sano, M. Shiro, K. Yamaguchi, Y. Sei,
Tetrahedron Lett. 45 (2004) 8757–8761.
27] T. Honda, H. Tajima, Y. Kaneko, M. Ban, T. Inaba, Y. Takeno, K. Okamoto, H. Aono,
Bioorganic Med. Chem. Lett. 18 (2008) 2939–2943.
28] Y. Nagao, T. Hirata, S. Goto, S. Sano, A. Kakehi, K. Iizuka, M. Shiro, J. Am. Chem. Soc.
1
20 (1998) 3104–3110.
29] S. Lin, S.T. Wrobleski, J. Hynes, S. Pitt, R. Zhang, Y. Fan, A.M. Doweyko, K.F. Kish, J.S.
Sack, M.F. Malley, S.E. Kiefer, J.A. Newitt, M. McKinnon, J. Trzaskos, J.C. Barrish, J.H.
Dodd, G.L. Schieven, K. Leftheris, Bioorganic Med. Chem. Lett. 20 (2010) 5864–5868.
30] K. Hayashi, S. Ogawa, S. Sano, M. Shiro, K. Yamaguchi, Y. Sei, Y. Nagao, Chem. Pharm.
[
ꢁꢇꢀ
ꢀ

ꢀ
Bull. (Tokyo). 56 (2008) 802–6.
[
[
31] M. Feng, B. Tang, S.H. Liang, X. Jiang, Curr. Top. Med. Chem. 16 (2016) 1200–1216.
32] L.M. Espinoza-Fonseca, J.G. Trujillo-Ferrara, Biochem. Biophys. Res. Commun. 328
(
2005) 922–928.
33] R. Chávez-Calvillo, M. Costas, J. Hernández-Trujillo, Phys. Chem. Chem. Phys. 12 (2010)
067–2074.
34] N. Hassan, M.P. Gárate, T. Sandoval, L. Espinoza, Á. Piñeiro, J.M. Ruso, Langmuir. 26
2010) 16681–16689.
[
[
2
(
[
[
35] G.M. Sheldrick, Acta Crystallogr. Sect. A Found. Crystallogr. 64 (2007) 112–122.
36] B. Jianming, R. Beresis, R. Berger, S. L. Colletti, S. Miao, W. Parson, K. M. Rupprecht, J.
N. Johanson, F. Kayser, E. W. Kovacs. WO Patent 2004058763 (A1), July 15, (2004).
37] A.D. Becke, J. Chern. Phys. 98 (1993) 5648–5652.
[
[
[
[
[
38] C. Lee, W. Yang, R.G. Parr, Phys. Rev. B. 37 (1988) 785–789.
39] A.D. McLean, G.S. Chandler, J. Chem. Phys. 72 (1980) 5639–5648.
40] A.J.H. Wachters, J. Chem. Phys. 52 (1970) 1033–1036.
41] T. Clark, J. Chandrasekhar, G.W. Spitznagel, P.V.R. Schleyer, J. Comput. Chem. 4 (1983)
2
94–301.
[
42] Gaussian 09, Revision D.01, M. J. Frisch, G. W. Trucks, H. B. Schlegel, G. E. Scuseria, M. A.
Robb, J. R. Cheeseman, G. Scalmani, V. Barone, B. Mennucci, G. A. Petersson, H. Nakatsuji, M.
Caricato, X. Li, H. P. Hratchian, A. F. Izmaylov, J. Bloino, G. Zheng, J. L. Sonnenberg, M. Hada,
M. Ehara, K. Toyota, R. Fukuda, J. Hasegawa, M. Ishida, T. Nakajima, Y. Honda, O. Kitao, H.
Nakai, T. Vreven, J. A. Montgomery, Jr., J. E. Peralta, F. Ogliaro, M. Bearpark, J. J. Heyd, E.
Brothers, K. N. Kudin, V. N. Staroverov, T. Keith, R. Kobayashi, J. Normand, K. Raghavachari, A.
Rendell, J. C. Burant, S. S. Iyengar, J. Tomasi, M. Cossi, N. Rega, J. M. Millam, M. Klene, J. E.
Knox, J. B. Cross, V. Bakken, C. Adamo, J. Jaramillo, R. Gomperts, R. E. Stratmann, O. Yazyev,
A. J. Austin, R. Cammi, C. Pomelli, J. W. Ochterski, R. L. Martin, K. Morokuma, V. G.
Zakrzewski, G. A. Voth, P. Salvador, J. J. Dannenberg, S. Dapprich, A. D. Daniels, O. Farkas, J. B.
Foresman, J. V. Ortiz, J. Cioslowski, and D. J. Fox, Gaussian, Inc., Wallingford CT, 2013.
ꢁꢈꢀ
ꢀ

ꢀ
Table 1.
Crystal data and structure refinement for benzothiazole derivatives and their coordination compounds
Data
btzca
NOS
ebbtz
[Cu(MeO-ebbtz)Cl]Cl^4H
Cl Cu
2
O
[Cu (µ-Br)
2
3
(ebtz)Br]
n
[Cu(ebtz)Br]Br^H
2
O
Chemical formula
C
8
H
5
18
C H
14
N
S
4 2
C
20
H
30
N
4
O
6
S
2
2
C
10
H11 Br
4
Cu
2
N
3
S
C
20
H28 Br
4
Cu N O S
2 6 3 2
-1
F. W (g mol )
T (K)
163.19
350.45
293(2)
621.04
293(2)
651.98
293(2)
911.31
150(2)
293(2)
Crystal system
Orthorhombic
Monoclinic
Triclinic
Monoclinic
Monoclinic
Space group
Pnma
1
P2 /c
PSŬ
1
P2 /c
1
P2 /c
a (Å)
13.484(3)
16.361(3)
7.7787(16)
7.2963(15)
7.6036(7)
b (Å)
c (Å)
6.5285(13)
8.5603(17)
90
4.6924(9)
22.304(5)
90
13.178(3)
13.669(3)
100.00(3)
7.5256(15)
31.550(6)
90
7.7508(9)
26.014(3)
90
ꢀ
(º)
!
"
(º)
(º)
90
90
106.16(3)
90
93.28(3)
93.45(3)
91.58(3)
90
97.865(3)
90
3
V (Å )
Z
753.6(3)
4
1644.7(6)
4
1374.1(5)
2
1731.72(6)
1518.7(3)
2
4
3
D
calc (mg/m )
1.438
1.415
1.501
2.501
1.993
Absorption Coefficient
0.361
0.330
1.182
11.797
6.833
-1
(
mm )
F(000)
336
728
642
1224
888
Crystal size (mm)
Data collected/unique
0.5422 x 0.5169 x 0.4118
31585 / 1012
0.4807 x 0.1176 x 0.0215
6996 / 3352
0.3282 x 0.0894 x 0.0462
10348 / 5611
0.150x0.051x0.034
3164 / 1910
0.129x 0.108x 0.037
47714 / 27495
Restrains/parameters
Goodness of fit (S)
0 / 67
1.125
0 / 217
1.047
60 / 378
1.020
82/195
1.042
0/179
1.029
R1, wR2[I>2r(I)]
0.0318, 0.0924
0.0361, 0.0967
0.246 and -0.193
0.0476, 0.1069
0.0768, 0.1228
0.257 and -0.318
0.0484, 0.0993
0.0866, 0.1185
0.438 and -0.285
0.0650, 0.0978
0.1224, 0.1147
0.798 and -0.679
0.0936, 0.2256
0.1622, 0.2699
5.225 and -4.704
R1, wR2(all data)
Largest difference peak
-3
and hole (e. Å )
1
2
2
2
2
2
2
2
2
Fo − Fc
2
R int =
B Fo
− Fo
B Fo
, R =
B Fo − Fc B Fo , wR 2 = B w
[
(
) B w(
Fo
)
]
1
ꢂꢊꢀ
ꢀ

ꢀ
Table 2
Crystal data and structure refinement for benzothiazole derivatives and their coordination compounds
Data
[Na (prbtz)
2
2
(H
O)
2 2
µ-H
2
O]
n
[Ni(H O)
2
2
(CH
3
OH)
4
]^2(prbtz)
2 2 3 4
[Co(H O) (CH OH) ]^2(prbtz)
Chemical formula
C
20
H
26
N
2
Na
2
O
9
S
6
C
23.47
H
40
N
2
Ni O12.53
S
6
23.87 2 12.13 6
C H40 Co N O S
-1
F. W (g mol )
T (K)
676.77
130 (2)
801.76
130 (2)
800.39
130(2)
Crystal system
Space group
a (Å)
Monoclinic
C2/c
Triclinic
Ŭ
PS
Triclinic
Ŭ
PS
43.516(9)
6.8892(14)
6.8627(14)
b (Å)
c (Å)
5.5768(11)
11.301(2)
90.0
7.5577(15)
16.709(3)
93.71(3)
7.5786(15)
16.857(3)
94.30(3)
ꢀ
!
(º)
(º)
90.96(3)
93.13(3)
93.08(3)
"
(º)
90.0
100.14(3)
852.7(3)
100.11(3)
858.7(3)
3
V (Å )
Z
2742.2(10)
4
1
1
3
D
calc (mg/cm )
1.639
1.562
1.548
Absorption Coefficient
0.584
0.997
0.924
-1
(
mm )
F(000)
1400
419
417
Crystal size (mm)
0.6027 x 0.4200 x 0.0462
10670/2683
0.4004 x 0.1877 x 0.1784
5820/3358
0.2809 x 0.1492 x 0.1204
6426/3384
Data collected/unique
Restrains/parameters
Goodness of fit (S)
R1, wR2[I>2r(I)]
5 / 186
1.092
R1 = 0.0356, wR2 = 0.0868
132 / 271
1.027
R1 = 0.0340, wR2 = 0.0727
21/ 238
1.051
R1 = 0.0281, wR2 = 0.0614
R1, wR2(all data)
R1 = 0.0397, wR2 = 0.0894
0.567 and -0.378
R1 = 0.0442, wR2 = 0.0786
0.330 and -0.360
R1 = 0.0373, wR2 = 0.0649
0.270 and -0.294
Largest difference peak
-3
and hole (e. Å )
1
2
2
2
2
2
2
2
2
2
R int =
B Fo
− Fo
B Fo
, R =
B Fo − Fc
F , wR 2
=
[B w
(Fo
− Fc
) B w( o
F
)
]
1
B
o
ꢂꢁꢀ
ꢀ

ꢀ
Figure Captions
Fig. 1. ORTEP representation of btzca, with thermal ellipsoids at 30% of probability (left)
and hydrogen bonds and preferred conformation OꢀS are showed (right).
Fig. 2. Structure stabilized by 4-staking interactions in btzca.
Fig 3. ORTEP representation of ebbtz with thermal ellipsoids at 30% of probability and
angle between the planes of benzothiazole moieties.
Fig 4. Zig-zag arrangement through NꢀS inter and intramolecular interactions.
Fig 5. Interactions found in the ebbtz crystal A) 4 stacking, B) T-shape.
Fig 6. ORTEP representation of [Cu(MeO-ebbtz)Cl]Cl^4H O compound with thermal
2
ellipsoids at 30% of probability.
Fig 7. Association of H O molecules by hydrogen bonding.
2
Fig 8. Supramolecular structure of [Cu(MeO-ebbtz)Cl]Cl^4H O, stabilized by lp(S)^^^π
2
interactions.
Fig. 9. ORTEP representation (30% thermal ellipsoid probability) of octahedral and
tetrahedral geometries for copper(II) atoms in the [Cu (µ-Br) (ebtz)Br] compound.
2
3
n
Fig. 10. Interactions in [Cu
2
(µ-Br)
3
(ebtz)Br]
n
polymer. A) π-staking and lp(S)^^^π
interactions. B) Hydrogen bonding that interconnect the building blocks.
Fig. 11. ORTEP representation for the [Cu(ebtz)Br]Br^H O compound, 30% probability.
2
Fig. 12. Weak interactions, π-staking and lp(S)^^^π, in [Cu(enbt)Br]Br^H O
2
ꢂꢂꢀ
ꢀ

ꢀ
Fig. 13 Dimeric unit of [Na
2
(prbtz)
2
(H
2
O)
2
µ-(H
2
O)]
n
, showing the bridging H O molecule
2
in the eight membered ring (thermal ellipsoid 30% probability).
Fig. 14 Weak interactions on the c axis of [Na
2
(prbtz)
2
(H
2
O)
2
µ-H
2
O] A) NꢀS
n
interactions; B) face to edge contacts; C) 3D building blocks association
Fig. 15. In the [Na
2
(prbtz)
2
(H
2
O)
2
µ-(H
2
O)] , compound, prbtz is coordinated to a sodium
n
II
II
atom with a bent conformation (A), while for [M(H
2
O)
2
(CH
3
OH) ]^2(prbtz) (M= Co , Ni )
4
compounds, prbtz is not coordinated, adopting a planar conformation (B).
ꢀ
2
+
II
II
Fig. 16. Second coordination sphere of [M(H
2
O)
2
(CH
3
OH) ] (M= Co , Ni )
4
ꢀ
-
Fig. 17. Stacking contacts between neighboring prbtz molecules, S1 and S2 lp^^^π(ring)
ꢀ
Fig.18. Frontier molecular orbitals for a two layer model of the ebbtz compound.
ꢀ
ꢂꢃꢀ
ꢀ

ꢀ
ꢀ
:
:
.Vꢁ`QCVꢁQꢂꢁ1V:@ꢁꢃJꢄV`:HꢄꢃQJꢅꢁꢃJꢁꢅVCꢂR
'1(RGVJ<Qꢏ.1:<QCVꢀ ꢑV`10:ꢏ10V(ꢀ :Jꢑꢀ ꢏ.V1`ꢀ
HQQ`ꢑ1J:ꢏ1QJꢀ HQI]Q%Jꢑ(ꢀ ꢗV`Vꢀ (7Jꢏ.V(1<Vꢑꢀ
:Jꢑꢀꢏ.V1`ꢀꢗV:@ꢀ1JꢏV`:Hꢏ1QJ(ꢀ:J:C7<Vꢑ8ꢀ6ꢀCQJVꢀ
]:1`\\\ꢘ5ꢀ ꢘ\\\ꢘꢀ (ꢏ:@1J$5ꢀ -o65ꢀ ꢎo65ꢀ ꢙ\\\ꢘꢀ :Jꢑꢀ
.7ꢑ`Q$VJꢀ GQJꢑ1J$ꢀ (ꢏ:G1C1<Vꢑꢀ ꢑ1ꢚꢚV`VJꢏꢀ
ꢀ
ꢅꢅVIGC7ꢁ
Qꢂꢁ
Qꢂꢁ
ꢅ%]`:IQCVH%C:`ꢁ
GVJ<Qꢄ.ꢃ:<QCVꢁ
ꢅꢅQHꢃ:ꢄꢃQJꢅꢁ
ꢁ
ꢁ
ꢁ
ꢁ
ꢆV`ꢃ0:ꢄꢃ0Vꢅꢁ :Jꢆꢁ ꢄ.Vꢃ`ꢁ HQQ`ꢆꢃJ:ꢄꢃQJꢁ
HQI]Q%Jꢆꢅꢁ
(
%]`:IQCVH%C:`ꢀ :``:J$VIVJꢏ(8ꢀ ꢛ.VQ`Vꢏ1H:Cꢀ
H:CH%C:ꢏ1QJ(ꢀ (.QꢗVꢑꢀ ꢏ.:ꢏꢀ ꢏ.Vꢀ 6ꢀ CQJVꢀ ]:1`\\\ꢘꢀ
Jꢑꢀ ꢘ\\\ꢘꢀ 1JꢏV`:Hꢏ1QJ(ꢀ ꢏ:@Vꢀ ]C:HVꢀ :ꢏꢀ ꢏ.Vꢀ
ꢁ
:
ꢋCI:ꢀ ꢌ1C1:ꢀ ꢍ:`H3:Rꢎ`ꢏ1<5ꢀ ꢐ1H:`ꢑQꢀ
ꢚ`QJꢏ1V`ꢀ ꢌꢜꢔꢎꢀ :Jꢑꢀ ꢙꢎꢔꢎꢀ IQCVH%C:`ꢀ
Q`G1ꢏ:C(8ꢀ
ꢒQI3J$%V<RꢍQJ<ꢓCV<5ꢀ
ꢔ:`$:`1ꢏ:ꢀ
ꢐQIV`QRꢕ01C:5ꢀ'C:(ꢀ)CQ`V(R*X`V<5ꢀꢌ%1(ꢀ
ꢍ%1CCXJ5ꢀꢔ1$%VCꢀ,:(ꢏ`Q5ꢀ-Q`:.ꢀ':`G:R
8ꢀꢀ
'
V.`VJ(ꢖꢀ
ꢀ
ꢁ
ꢀ
ꢀ
ꢀ
1
2
3
4
5
- Benzothiazole derivatives and coordination compounds
- Synthesis of benzothiazole Schiff bases
- Supramolecular arrangements
- Weak interactions: sulfur (lp)^^^4, 4^^^4 stacking, NꢀS, OꢀS and hydrogen bonding.
Theoretical calculations
-
ꢂꢄꢀ
ꢀ

ꢀ
ꢂꢅꢀ
ꢀ

ꢀ
ꢂꢆꢀ
ꢀ

ꢀ
ꢂꢇꢀ
ꢀ

ꢀ
ꢂꢈꢀ
ꢀ

ꢀ
ꢂꢉꢀ
ꢀ

ꢀ
ꢃꢊꢀ
ꢀ