A. Hori et al.
FULL PAPER
mental data were corrected for trace background values of the sam-
ple holder and Kapton sheet, and for the sample’s diamagnetic con-
tribution calculated from Pascal constants.
changed to bluish brown. The XRD patterns of the powder
dramatically changed (Figure 7, c). The peaks from 5a dis-
appeared and new weak and complicated peaks were ob-
served, which were also different to 6a (Figure 7, d). The
ferromagnetic interaction of 5a also decreased with the
color change. Generally, the vapochromism is mainly in-
Preparation and Physical Properties
[CuCl2(2a)2] (4a): 2-Propanol solutions of CuCl2·2H2O (43 mg,
0.25 mmol) and 2a (58 mg, 0.25 mmol) were combined at room
duced due to two reasons: (i) a coordination exchange reac- temperature to give brown microcystals; yield 76%; m.p. 201–
tion between the metal and the solvents[15–18] and (ii) a
change in the crystal packing due to inclusion of sol-
vents.[19–25] In this case, we suggest that a dynamic dispro-
portionation reaction of 5a (CuCl2/3a = 1:1) occurred and
produced a new aggregation state composed of the mono-
nuclear complex 6a (CuCl2/3a = 1:2) and the solvated metal
ion in the solid. The orange–yellow powder 5a is stable in
a dry atmosphere after isolation from the solvent.
202 °C. IR (KBr disk): ν = 1689, 1545, 1501, 1478, 1456, 1443,
˜
1397, 1339, 1302, 1254, 795, 760, 694, 642 cm–1. Elemental analysis:
Calcd for C22H18Cl2CuN6O2S2 (%): C 44.26, H 3.04, N 14.08;
found C 44.32, H 3.16, N 13.96. Crystallization was performed in a
CH2Cl2/MeOH mixture to give dark blue plate crystals 4a·CH2Cl2
suitable for X-ray crystallography.
[CuCl2(3a)]n (5a): 2-Propanol solutions (5 mL) of CuCl2·2H2O
(86 mg, 0.50 mmol) and 3a (58 mg, 0.25 mmol) were combined at
room temperature to give an orange–yellow powder of 5a and a
dark blue powder of 6a as a mixture. This reaction is sensitive to
external conditions. The purity of 5a was examined each time by
elemental analysis and the highest purity precipitates were used for
further physical measurements; m.p. Ͼ 270 °C (dec). IR (KBr
Conclusions
We have precisely characterized mono- and polynuclear
coordination complexes with the thiazolo-1,2,4-triazine de-
rivatives 2a and 3a. In the complexation reaction, the meta-
stable 1D-network 5a was obtained due to its lower solubil-
ity and kinetic stability, compared to the mononuclear com-
plex 6a. The orange product 5a irreversibly transformed to
the blue product 6a. This color change is also observed in
the powder samples; XRD studies show that the dynamic
transformation between the complexes occurs in the solid
state. The unexpected kinetic product was obtained and
characterized because of the stabilization through π-π
stacking between phenyl and triazine moieties. Both of the
coordination sites with Cu2+ ions were proved to be the
N imino donor through a single coordination bond. These
results are important because several cases of multiple do-
nor species in biological systems are assumed to be poly-
dentate with predominantly S donors. These results also
indicate that complicated coordination systems can be de-
signed using multiple donor ligands. Controlling the coordi-
nation behavior by external conditions will be further inves-
tigated.
disk): ν = 1667, 1545, 1478, 1418, 1310, 1254, 1111, 806, 694 cm–1.
˜
Elemental analysis: Calcd for C11H9Cl2CuN3OS (%): C 36.12, H
2.48, N 11.49; found C 36.68, H 2.70, N 11.47. A higher concentra-
tion and a large amount of the starting materials unexpectedly pro-
duced a few orange–yellow block crystals. These crystals also disap-
peared in solution, and the blue crystals grew.
[CuCl2(3a)2] (6a): Complex 6a was obtained as dark blue block
crystals in the same reaction of 5a; yield 93%; m.p. 243–244 °C. IR
(KBr disk): ν = 1668, 1551, 1495, 1481, 1460, 1418, 1310, 1267,
˜
1113, 806, 766, 696, 532 cm–1. C22H18Cl2CuN6O2S2 (596.55): calcd.
C 44.26, H 3.04, N 14.08; found C 44.21, H 3.02, N 13.97.
[CuCl2(3b)2] (6b): This was obtained as blue prismatic crystals
using the same procedure as 6a with 3b; yield 76%; m.p. 198–
200 °C. IR (KBr disk, cm–1): ν = 1666, 1578, 1514, 1468, 1427,
˜
1319, 1227, 1132, 453 cm–1. C14H18Cl2CuN6O2S2 (500.55): calcd.
C 33.57, H 3.62, N 16.78; found C 33.78, H 3.58, N 16.77.
[CuCl2(3c)2] (6c): This was obtained as green block crystals using
the same procedure as 6a with 3c; yield 80%; m.p. 162–163 °C. IR
(KBr disk, cm–1): ν = 1661, 1576, 1487, 1439, 1425, 1418, 1242,
˜
745, 698 cm–1. C24H22Cl2CuN6O2S2 (624.58): calcd. C 46.12, H
3.55, N 13.45; found C 46.50, H 3.61, N 13.40.
X-ray Crystallography: Single crystal X-ray structures were deter-
mined with a Bruker SMART APEX CCD diffractometer with
graphite monochrometer Mo-Kα (λ = 0.71073 Å) generated at
50 kV and 35 mA. All crystals were coated by paraton-N and were
measured at 100 K. For all compounds, cell refinement and re-
duction were performed by using Bruker SAINT program, the
structure solution was by using SHELXS97, the refinement was by
SHELXL97.[49] All non-hydrogen atoms were refined anisotropi-
cally unless otherwise stated. H atoms attached to C atoms were
constrained at idealized positions and refined riding on their carrier
atoms, with aromatic, methylene, and methyl C–H distances of
0.95, 0.98, and 0.99 Å, respectively, and with Uiso(H) = 1.2
Ueq(C). The crystal data are summarized in Table 2. Powder XRD
studies were curried out at room temp. using an M03XHF22 dif-
fractometer (Mac Science) with Cu-Kα radiation (λ = 1.5418 Å).
Experimental Section
General: All chemicals were of reagent grade and used without fur-
ther purification. Ligands, 2 and 3, were prepared as previously
reported.[16] 1H NMR spectra were recorded with a Bruker
DRX600 spectrometer. The infrared spectra were recorded with a
Shimadzu IR 8400s using a KBr disk. The melting points were
determined with a Yanako MP-500D melting point apparatus. The
elemental analysis of C, H, and N was performed with a Perkin–
Elmer PE2400 analyzer. The DFT calculation using B3LYP/6-
31G** (C, H, N, O, S, and Cl) and LANL2DZ (Cu) was performed
using Spartan Ј06 for Linux[48] on a home-made dual-core-CPU
Linux machine. The magnetic susceptibility measurements were
performed using
MPMS-XL. DC (direct current) data were collected in the range
a
Quantum Design SQUID magnetometer
CCDC-787916 (for 4a·CH2Cl2), -787917 (for 5a), -787918 (for 6a),
-787919 (for 6b), and -787920 (for 6c) contain the supplementary
from 2.0 to 300 K with an applied field of 10 kOe. The measure- crystallographic data for this paper. These data can be obtained
ments were performed on polycrystalline samples that were
wrapped in a Kapton sheet and fixed in a glass holder. The experi-
free of charge from The Cambridge Crystallographic Data Centre
via www.ccdc.cam.ac.uk/data_request/cif.
3064
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Eur. J. Inorg. Chem. 2011, 3059–3066