ISSN 1070ꢀ3284, Russian Journal of Coordination Chemistry, 2011, Vol. 37, No. 7, pp. 501–505. © Pleiades Publishing, Ltd., 2011.
New Complex of Zn(II) with 3,4,5ꢀTrimethoxybenzoate
and 2ꢀMethylimidazolyl:
Synthesis, Structure, and Luminescence Properties1
B. Hu, H. Chen, X. L. Wu*, T. Wang, M. Cheng, and H. L. Fei
Faculty of Material Science and Chemistry Engineering, Engineering Research Center of NanoꢀGeomaterials of Ministry
of Education, China University of Geosciences, Wuhan 430074, P.R. China
*eꢀmail: xlwu@cug.edu.cn
Received August 30, 2010
Abstract
acid, 2ꢀMIM is 2ꢀmethylimidazole, was synthesized and characterized by Powder Xꢀray diffraction, FT-IR
and photoluminescence spectrum. The complex crystallizes in the monoclinic crystal system (space group
2/ ) with the unit cell parameters: = 18.104(9), = 8.509(4), = 17.688(9) = 103.185(9) = 4,
1 = 0.0740 and wR2 = 0.1790. At room temperature the hotoluminescence spectrum of complex in the
—A new zinc(II) complex Zn(TMB)2(2ꢀMIM)(H2O)2 (I), where HTMB is 3,4,5ꢀtrimethoxybenzoic
C
R
c
a
b
c
Å,
β
°, Z
I
p
solid state exhibits maximum excitation at 314 nm and maximum emission at 337 nm.
DOI: 10.1134/S1070328411070062
1
INTRODUCTION
Synthesis of complex I. As a selected ligand, 3,4,5ꢀtriꢀ
methoxybenzoic acid (2.0 mmol, 0.425 g), 2ꢀmethylimꢀ
idazole (0.082 g, 1.0 mmol), and zinc nitrate (0.290 g,
1 mmol) were added to 15 ml of a ethanol–water
(1 : 2 (v/v)) solution with stirring at room temperature.
After 1 h, the pH value of the mixture was adjusted to
about 5.5 with a NaOH solution (6 mol/l), and then the
cloudy solution was continually stirred for 0.5 h. After the
insoluble solis were filtered off, the colorless filtrate was
kept at room temperature and colorless block single crysꢀ
tals of the title complex were harvested after 5 days.
With the center ions of zinc, more and more coorꢀ
dination compounds have attracted considerable
attention to researchers because of their absorbing
architectures and potential applications in magneꢀ
tism, nonlinear optics, molecular recognition, and
catalysis [1–8]. Zinc, whose coordination number
could be four [9–11], five [12], and six [13], shows varꢀ
ious coordination behaviors. In view of this, we have
obtained unexpectedly a novel septocoordination
compound Zn(TMB)2(2ꢀMIM)(H2O)2 (I) and parꢀ
ticularly concerned its unique crystal structure and
fluorescence properties.
For C24H30N2O12Zn
anal. calcd., %: C, 47.74;
Found, %: C, 47.13;
H, 5.00;
H, 4.88;
N, 4.64.
N, 4.36.
EXPERIMENTAL
IR (KBr; ν
, cm–1): 3474 (H2O), 1558 νas(COO–),
Materials and methods. All reagents and solvents
employed were commercially available and used as
received without further purification. Elemental analꢀ
yses were performed on a PerkinꢀElmer 240C autoꢀ
mated analyzer. Fourier transform infrared spectrosꢀ
copy (FTꢀIR) was recorded from KBr pellets in a range
of 4000–400 cm–1 on a Nicolet FTꢀIR 360 spectromꢀ
eter. Powder Xꢀray diffraction (XRD) measurements
were performed using an X’Pert PRO diffractometer
(Spectris Pte Ltd.) with monochromatized CuKα radiꢀ
1394 νs(COO–), 1542 (C=N), 1217 (C–N).
Xꢀray crystallography. Diffraction intensities for the
crystals were collected at 298 K on a Bruker SMART
1000 CCD diffractometer employing graphite monoꢀ
chromatized MoKα radiation (
λ = 0.71073 Å) in ω and
ϕ
scan modes. The structure was solved by direct
methods [14] and refined by fullꢀmatrix leastꢀsquares
method on F 2 using the SHELXSꢀ97 and SHELXLꢀ
97 programs, respectively [15, 16]. Nonꢀhydrogen
atoms were refined anisotropically. Hydrogen atoms
were placed in geometrically calculated positions. 2ꢀ
Methylimidazolyl was found to be symmetrically disꢀ
ordered, which could only be characterized by split
positions being equally occupied. The crystallographic
data and experimental refinement parameters of the
ation (λ = 1.5418 Å). Photoluminescence (PL) excitaꢀ
tion and emission spectra were recorded at room temꢀ
perature by Fꢀ4500 FL Spectrophotometer with a
spectral resolution of 1 nm.
1
The article is published in the original.
501
Hu
