P. Pitchaimani et al. / Polyhedron 93 (2015) 8–16
9
spectra of the complexes were recorded on a JASCO, Japan (V-630)
double beam spectrophotometer with chloroform solvent. H NMR
J = 4.8 Hz, 6H), 4.18 (d, J = 4.2 Hz, 12H), 7.85 (s, 2H), 8.05 (s, 2H),
8.57 (d, J = 6.3 Hz, 2H), 9.24 (s, 2H). Yield 80%.
1
spectra were recorded at Madurai Kamaraj University, Madurai in a
6
Bruker, Switzerland NMR spectrometer (300 MHz, DMSO-d ).
Room temperature luminescence measurements were con-
ducted using a JASCO, Japan (FP 6200) spectroflurimeter with
2
.3.2. [Ce(Pip-Dtc)
Brown solid Anal. Calc. for C30
3
(Phen)] (2)
H
5 6
38CeN S : C, 44.97; H, 4.78; N,
8
.74; S, 24.01. Found: C, 44.90; H, 5.04; N, 8.51; S, 24.05%. FT-IR
1
0 nm slit width and at a scan speed of 500 nm/min. Solutions for
À1
(
KBr pellet, cm ):
mC–N, 1472s;
m
C–S, 975s;
m(Phen), 1628, 1509,
À3
the study were of 10 M or otherwise mentioned. Electrochemical
experiments were performed with an electrochemical workstation
CHI Instrument (643B, Austin, USA) under dry nitrogen.
Tetrabutylammonium perchlorate (0.1 M) was used as the support-
ing electrolyte. A three-electrode configuration was employed with
a platinum working electrode, a calomel electrode as a reference
electrode and a platinum wire as auxiliary electrode.
1
9
352, 852, 722. UV–Vis (nm, log
0%.
e): 232 (4.46); 264 (4.90). Yield
2.3.3. [Pr(Pip-Dtc)
3
(Phen)] (3)
Light mint green solid Anal. Calc. for C30
.78; N, 8.73; S, 23.99. Found: C, 45.00; H, 5.12; N, 8.78; S, 23.90%.
5 6
H38PrN S : C, 44.93; H,
4
À1
FT-IR (KBr pellet, cm ):
1
0
m
C–N, 1473s;
m
C–S, 977s;
m(Phen), 1623,
Single crystal X-ray diffraction data for the complexes were col-
lected at the University of Malaya, Kuala Lumpur, Malaysia on a
1
513, 1344, 848, 728. H NMR (d ppm): (Fig. S3) 0.46 (s, 12H),
.95 (s, 6H), 3.16 (d, J = 6 Hz, 12H), 7.73 (s, 2H), 7.99 (s, 2H), 8.51
): 232 (4.64); 264 (4.72).
Bruker APEX-II CCD area-detector with Mo
Ka radiation
(
s, 2H), 9.07 (s, 2H). UV–Vis (nm, log
e
(k = 0.71073 Å) by the w scan mode. All esds (except the esd in
Yield 95%.
the dihedral angle between two l.s. planes) are estimated using
the full covariance matrix. The cell esds are taken into account
individually in the estimation of esds in distances, angles and tor-
sion angles; correlations between esds in cell parameters are only
used when they are defined by crystal symmetry. An approximate
2
.3.4. [Nd(Pip-Dtc)
Pale purple solid Anal. Calc. for C30
3
(Phen)] (4)
5 6
H38NdN S : C, 44.74; H, 4.76;
N, 8.70; S, 23.89. Found: C, 44.60; H, 4.84; N, 8.68; S, 23.82%. FT-IR
À1
(
KBr pellet, cm ):
m
C–N, 1473s;
m
C–S, 997s;
m
(Phen), 1623, 1515,
(
isotropic) treatment of cell esds is used for estimating esds involv-
1
1
1
2
454, 1359, 983, 887, 728. H NMR (d ppm): (Fig. S4) 1.12 (s,
2H), 1.41(s, 6H), 3.83 (s, 12H), 7.79 (s, 2H), 8.02 (s, 2H), 8.51 (s,
H), 9.11 (s, 2H). UV–Vis (nm, log ): 232 (4.73); 264 (4.84).
ing l.s. planes. Crystal structure refinements were carried using
SHELXTL Ver. 6.12 W95/98/NT/2000/ME.
e
Yield 97%.
2.2. Synthesis of the ligand
2
.3.5. [Sm(Pip-Dtc)
Light yellow solid Anal. Calc. for C30
3
(Phen)] (5)
The ligand piperidine dithiocarbamate sodium salt (Pip-Dtc)
H
5 6
38SmN S : C, 44.41; H,
has been synthesized using reported method with slight modi-
fication [16]. In typical experiment sodium hydroxide
0.05 mol) was dissolved in 3 mL of water in an ice bath and
4
2
m
.72; N, 8.63; S, 23.71. Found: C, 44.23; H, 5.10; N, 8.60; S,
mC–N, 1473s; mC–S, 985s;
(Phen), 1623, 1517, 1423, 1359, 948, 885, 728. H NMR (d ppm):
À1
a
3.75%. FT-IR (KBr pellet, cm ):
1
(
3
0 mL of ethanol was added to it. The solution was stirred with
(
Fig. S5) 1.39 (d, J = 3 Hz, 12H), 1.53 (d, J = 3 Hz, 6H), 4.11 (s,12H),
the addition of piperidine (0.05 mol), followed by drop by drop
addition of carbon disulfide (0.05 mol) which yielded the precipi-
tate of the dithiocarbamate sodium salt. The yellow product was
collected by filtration, re-dissolved in minimum amount of metha-
nol and the pure white product was precipitated by adding
7
2
.77 (m, 2H), 8.02 (s, 2H), 8.51(d, J = 9 Hz, 2H), 9.09 (d, J = 6 Hz,
H), UV–Vis (nm, log ): 232 (4.83); 264 (4.98). Yield 98%.
e
2.3.6. [Gd(Pip-Dtc)
3
(Phen)] (6)
White solid Anal. Calc. for C30
5 6
H38GdN S : C, 44.03; H, 4.68; N,
6 2
required volume of diethyl ether. Anal. Calc. for C H10NS Na: C,
8
.56; S, 23.51. Found: C, 44.24; H, 5.23; N, 8.60; S, 23.15%. FT-IR
3
7
1
2
9.32; H, 5.50; N, 7.64; S, 34.99. Found: C, 40.50; H, 5.20; N,
À1
(
KBr pellet, cm ):
m
C–N, 1474s;
m
C–S, 988s;
m
(Phen), 1622, 1517,
À1
.62; S, 34.90%. FT-IR (KBr pellet, cm ):
002s, 967s. H NMR (d ppm): (Fig. S1) 1.36 (m, 4H), 1.51 (m,
mC–N, 1467s; mC–S,
1
424, 1350, 883, 722. UV–Vis (nm, log
e
): 232 (5.23); 264 (6.78).
1
Yield 85%.
H), 4.25 (t, J = 5.4 Hz, 4H). UV–Vis (nm, log e): 232 (4.00); 264
(
4.35). Yield 85%.
2.3.7. [Tb(Pip-Dtc)
3
(Phen)] (7)
White solid Anal. Calc. for C30
H
5 6
38TbN S : C, 43.94; H, 4.67; N,
2
.3. Preparation of Ln(III) complexes
8.54; S, 23.46. Found: C, 44.24; H, 5.23; N, 8.60; S, 23.15%. FT-IR
À1
(
KBr pellet, cm ):
m
C–N, 1475s;
m
C–S, 989s;
m
(Phen), 1625, 1513,
): 232 (5.63);
The general method adopted for the preparation of the Ln(III)
complexes (1–9) is shown in Scheme 1. A solution of Pip-Dtc
1.5 mmol) and Phen (0.5 mmol) in 10 mL methanol was added
to a solution of corresponding hydrated lanthanide chloride
0.5 mmol) in 5 mL methanol. The mixture was stirred for few min-
1425, 1351, 1229, 1111, 883, 722. UV–Vis (nm, log
264 (6.88). Yield 87%.
e
(
2
3
.3.8. [Dy(Pip-Dtc) (Phen)] (8)
(
Light yellow solid Anal. Calc. for C30
5 6
H38DyN S : C, 44.75; H,
utes during which the solid complex gets precipitated. Then the
solid was isolated through vacuum filtration, washed with metha-
nol and recrystalized from hot acetonitrile. The analytical and
spectral characterizations of the complexes are:
4
2
m
.65; N, 8.50; S, 23.36. Found: C, 44.25; H, 4.63; N, 8.54; S,
À1
3.35%. FT-IR (KBr pellet, cm ):
mC–N, 1475s; mC–S, 990s;
(Phen), 1623, 1512, 1426, 1351, 1229, 1112, 884, 723. UV–Vis
(
nm, log ): 232 (5.73); 264 (6.67). Yield 92%.
e
3
2.3.1. [La(Pip-Dtc) (Phen)] (1)
2.3.9. [Er(Pip-Dtc)
3
(Phen)] (9)
White solid Anal. Calc. for C30
H38LaN
5 6
S : C, 45.04; H, 4.79; N,
Pale pink solid Anal. Calc. for C30H38ErN S : C, 43.50; H, 4.62; N,
5 6
8
.75; S, 24.05. Found: C, 44.93; H, 5.00; N, 8.63; S, 23.90%. FT-IR
8.46; S, 23.23. Found: C, 44.01; H, 4.53; N, 8.34; S, 23.34%. FT-IR
À1
À1
(
KBr pellet, cm ):
m
C–N, 1480s;
m
C–S, 1008s;
m
(Phen), 1621,
(KBr pellet, cm ):
mC–N, 1475s;
m
C–S, 990s;
m(Phen), 1623, 1512,
1
587, 1513, 850, 728. UV–Vis (nm, log
e
): 232 (2.46); 264 (3.21).
1426, 1351, 1229, 1112, 884, 723. UV–Vis (nm, log
264 (6.67). Yield 96%.
e): 232 (5.73);
1
H-NMR (d ppm): (Fig. S2) 1.42 (d, J = 6 Hz, 12H), 1.56 (d,