26
S.-L. Ma et al. / Journal of Molecular Structure 703 (2004) 25–29
2.3. Synthesis of the complex
A solution (Scheme 3) of Cu(NO3)2·3H2O (0.024 g,
0.1 mmol) in 5 ml DMF was added dropwise to a solution of
the ligand H2L3 (0.054 g, 0.10 mmol) in 5 ml DMF. The
color of the reacting solution changed to dark brown
suddenly, and it was refluxed with stirring for 2 h.
The mother liquor was stored at room temperature for
several days, and some yellow crystals were obtained, yield
0.048 g, 80%, mp carbonization on 453 K. Anal. calcd for
C26H34Cl2CuN2O6 ðMr ¼ 604:99Þ (%): C 51.61, H 5.62, N
4.63; found (%): C 51.21, H 5.51, N 4.27. UV-Vis(CH2Cl2),
Scheme 1.
CHN Analyses were determined using an Elementar
Vario EL elemental analyzer. UV-Visible spectra were
measured using a GBC Cintra 10e UV-Visible spectropho-
tometer in CH2Cl2 solution. The IR spectra were recorded
on a Nicolet-AVATAR 360 FT-IR spectrometer using KBr
pellets in 400–4000 cm21 region.
l
max/nm (1/dm3 mol21 cm21): 316(6650), 407(7423). IR
(KBr): 1603(m), 1514(vs), 1456(s), 1439(s), 1414(m),
1344(s), 1313(m), 1252(s), 1143(s), 1106(s), 1084(s),
1047(m), 972(m), 869(m), 814(m), 718(m), 518(w) cm21
.
2.2. Synthesis of the ligand H2L3
2.4. X-ray crystallography
A crystal with dimensions 0.25 £ 0.20 £ 0.15 mm3 was
selected for X-ray diffraction experiment. The diffraction
measurements were performed on a SMART 1000 CCD
diffractometer at 293 K with graphite monochromatized
The crown ether 7,16-bis(5-chloro-2-hydroxybenzyl)-
1,4,10,13-tetraoxa-7,16-diazacyclooctadecane (H2L3) was
prepared according to the literatures [10,11] following the
scheme below (Scheme 2):
˚
An anhydrous toluene solution (45 ml) containing 4,13-
diaza-18-crown-6 (0.262 g, 1.00 mmol), paraformaldehyde
(0.074 g, 2.45 mmol), and 4-chloro-phenol (0.308 g,
2.40 mmol) was refluxed at 383 K for 24 h. The solvent
was evaporated by rotatory evaporation, and a small amount
of MeOH was added. The mixture was ultrasonicated for
20 min. The resulting solid was collected by filtration and
dried, yield 0.418 g, 77%, mp 390–391 K. Anal. calcd for
C26H36N2O6Cl2 ðMr ¼ 543Þ(%): C 57.46, H 6.63, N 5.15;
found (%): C 57.54, H 6.325, N 5.33. UV (CH2Cl2),
Mo Ka radiation (l ¼ 0:71073 A). The structure was solved
by direct methods and refined by full-matrix least-squares on
F2 using the SHELXS-97 and SHELXL-97 programs [16]. All
nonhydrogen atoms were refined anisotropically. A sum-
mary of the crystallographic data and details of the structure
refinements for the complex are listed in Table 1.
3. Results and discussion
l
max/nm (1/dm3 mol21 cm21): 287(4873). IR(KBr):
3.1. IR and UV-Visible spectra
1605(w), 1478(s), 1451(m), 1357(m), 1257(m), 1248(s),
1154(s), 1139(s), 1118(s), 1069(m), 993(m), 933(w),
821(m), 761(w), 669(w).
For the original free ligand, H2L3, the multiple bands at
1154–1117 cm21 assigned to y(C–N–C) and (C–O–C)
Scheme 2.
Scheme 3.