2
28
M.A. Affan et al. / Inorganica Chimica Acta 366 (2011) 227–232
CHN analyses were recorded with a Flash EA 1112 series CHN ele-
mental analyzer. Molar conductance values were measured with
DMF solvent using a Jenway 4510 conductivity meter. Single crystal
X-ray analyses were carried out using a Bruker 300 MHz CCD
diffractometer.
methyltin(IV) trichloride (0.24 g 1.0 mmol) was added drop-wise,
and resulted in a yellow solution. The yellow solution was refluxed
for 4 h (Scheme 2) and cooled to room temperature. The yellow
microcrystals were obtained from slow evaporation of the solution
at room temperature. The microcrystals were filtered, washed with
a small amount of cold methanol and dried in vacuo over silica gel.
Yield: 0.48 g, 84%: Mp.: 202–204 °C: Molar conductance (DMF)
2.2. Synthesis of N(4)-cyclohexylthiosemicarbazide
À1
2
À1
X
cm mol : 11.3.
UV–Vis (DMF) kmax/nm: 295, 334, 385, 417: FT-IR (KBr, cm
max: 3360 (s, NH), 2933, 2852 (s, cyclohexyl), 1596 (m, C@N–
N@C), 1028 (w, N–N), 1308, 816 (m, C–S), 649 (w, pyridine in
À1
Cyclohexylisothiocyanate (1.41 g, 10 mmol) in 4 mL of ether
)
was added drop-wise into 4 mL of ether solution of hydrazine hy-
drate (2 g, 40 mmol). The mixture was stirred vigorously for 5 h.
Then, 5 mL petroleum ether was added into the resulting solution
and stirred for another 1 h and white precipitate was formed. The
white precipitate was filtered, washed with a small amount of cool
m
1
3
plane), 578 (w,Sn–C), 484 (w, Sn–N). H NMR (CDCl ) d: 8.83 (d,
1H, pyridine ring C31–H), 8.01 (t, 1H, pyridine ring C33–H), 7.96
(d, 1H, , pyridine ring C34–H), 7.66 (d, 2H, 1H of N1–H, 1H of
CyC1–H), 7.51–7.25 (m, 6H, 1H of pyridine ring C32–H, 5H of phe-
diethyl ether and dried in vacuo over silica gel. Yield: 2.12 g, 62%:
À1
Mp.: 146–148 °C: FT-IR (KBr disk, cm
)
m
max: 3334 (s, NH
2
), 3297
nyl ring), 2.15–1.73 (m, Cy-H), 1.08 (s, 3H, Sn–CH
SSnCl : C, 47.19; H, 4.55; N, 11. Found: C, 46.92; H, 4.37;
N, 10.74%.
3
). Anal. Calc. for
(
s, NH), 2929, 2853 (s, cyclohexyl), 1349, 849 (w, C@S).
C H
20 23
N
4
2
2
.3. Synthesis of 2-benzoylpyridine-N(4)-cyclohexylthiosemicarbazone
The other complexes (3–4) were synthesized using a similar
procedure to organotin(IV) complex (2) using appropriate organo-
tin(IV) chloride(s).
[HBPCT (1)]
The N(4)-cyclohexylthiosemicarbazide (0.51 g, 3 mmol) was
dissolved in 10 mL of dry methanol before mixing it with 10 mL
of dry methanolic solution of 2-benzoylpyridine (0.54 g, 3 mmol).
The resulting mixture was refluxed for 4 h (Scheme 1) and cooled
to room temperature. White microcrystals were formed and fil-
tered off. The microcrystals were washed several times with small
amounts of cold methanol and subsequently with cold hexane. The
microcrystals were recrystallised from methanol and dried in va-
2.5. Synthesis of [PhSnCl
2
(BPCT)] (3)
Yield: 0.473 g, 81.27%: Mp.: 297–299 °C: Molar conductance
À1
2
À1
(DMF)
X
cm mol : 15.18: UV–Vis (DMF) kmax/nm: 289, 312,
À1
367, 422; FT-IR (KBr, cm
cyclohexyl), 1595 (m, C@N–N@C), 1063 (w, N–N), 1305, 817 (m,
) mmax: 3378 (s, NH), 2924, 2846 (s,
C–S), 653 (w, pyridine in plane), 579 (w, Sn–C), 484 (w, Sn–N).
1
cuo over silica gel. Yield: 0.94 g, 89%: Mp.: 174–176 °C: UV–Vis
3
H NMR (CDCl ) d: 8.82 (d, 1H, pyridine ring C31–H), 8.41 (t, 1H,
À1
(
DMF) kmax/nm: 280, 300, 347: FT-IR (KBr, cm
)
mmax: 3335 (s,
pyridine ring C33–H), 8.28 (d, 1H pyridine ring C34–H), 7.95 (d,
2H, 1H of N1–H, 1H of CyC1–H), 7.58–7.25 (m, 11H, 1H of pyridine
ring C32-H, 10H of phenyl ring), 2.20–1.70 (m, Cy-H). Anal. Calc. for
NH), 2938, 2845 (s, cyclohexyl), 1583 (w, C@N), 984 (m, N–N),
345, 863 (w, C@S), 608 (m, pyridine in plane). 1H NMR (CDCl
d: 10.80 (s, 1H, N4–H), 8.81 (d, 1H, pyridine ring C31–H), 7.76 (t,
H, pyridine ring C33–H), 7.62 (d, 2H, 1H of N1–H, 1H of CyC1–
1
3
)
25 26 4 2
C H N SSnCl : C, 49.70; H, 4.33; N, 9.27. Found: C, 49.23; H, 4.12;
1
N, 9.08%.
2.6. Synthesis of [Ph
Yield: 0.52.g, 76%: Mp.: 192–195 °C: Molar conductance (DMF)
H), 7.53 (d, 1H, , pyridine ring C34–H), 7.48 (t, 1H, pyridine ring
C32–H), 7.29–7.25 (m, 5H, phenyl ring), 2.11–1.71 (m, Cy-H). Anal.
2
SnCl(BPCT)] (4)
Calc. for C19
22 4
H N S: C, 67.42; H, 6.55; N, 16.55. Found: C, 67.11; H,
5
.61; N, 16.07%.
À1
2
À1
À1
X
cm mol : 8.15: UV–Vis (DMF) kmax/nm: 295, 306, 368, 417:
2.4. Synthesis of [MeSnCl
2
(BPCT)] (2)
FT-IR (KBr, cm
)
mmax: 3379 (s, NH), 2929, 2851 (s, cyclohexyl),
1
592 (m, C@N–N@C), 1020 (w, N–N), 1302, 811 (m, C–S), 636 (w,
1
The [HBPCT, (1)] ligand (0.34 g, 1.0 mmol) was dissolved in
3
pyridine in plane), 588 (w, Sn–C), 457 (w, Sn–N). H NMR (CDCl )
1
0 mL of absolute methanol under a nitrogen atmosphere in a
d: 8.82 (d, 1H, pyridine ring C31–H), 8.60 (t, 1H, pyridine ring
Schlenk round bottom flask. Then, 10 mL methanolic solution of
C33–H), 8.55 (d, 1H, pyridine ring C34–H), 7.70 (d, 2H, 1H of
Scheme 1. Synthesis of 2-benzoylpyridine-N(4)-cyclohexyl thiosemicarbazone [HBPCT, (1)] ligand.