Inorganic Chemistry
Article
lane (TMS) was used as an internal standard for recording NMR
spectra. CD spectra were collected on a JASCO J-815 spectropho-
tometer. UV−visible absorption spectra in solution (DMSO) and the
solid state were obtained on a Shimadzu UV-1800 instrument and a
Harrick Praying Mantis accessory on a Shimadzu UV-3600 instru-
ment, whereas emission spectra were recorded on Fluorolog Horiba
Jobin Yvon spectrophotometers. Powder X-ray diffraction (PXRD)
patterns were collected using a Rigaku MiniFlex-600W system with
Cu Kα radiation (λ = 1.54056 Å), in which the X-ray tube was
operated at a voltage of 40 kV, a current of 20 mA, and an angular
range 2θ = 5−50° with a scan rate of 2° min−1 and a step size of 0.02°.
Synthesis of the Ligands HL1−HL3 and Their Potassium
Salts KL1−KL3. The ligands, methyl 3-hydroxy-3-(2-thienyl)-2-
propenedithioate (HL1), methyl 3-hydroxy-3-(3-pyridyl)-2-propene-
dithioate (HL2), and methyl 3-hydroxy-3-(4-pyridyl)-2-propenedi-
thioate (HL3) and their potassium salts KL1−KL3 were prepared by
following the procedure previously reported (Scheme 2).17 In the
procedure used in the synthesis of complex 1 from KL2 (0.249 g, 1
mmol) and Zn(NO3)2·6H2O (0.148 g, 0.5 mmol). A yellow
precipitate was obtained in the reaction, and brown needle-shaped
crystals of 2 suitable for X-ray studies were obtained from DMF
solution of the compound within 2−3 weeks. Empirical formula:
1
[Zn(L2)2]n. Yield: 0.41 g, 85%. Mp: 207−212 °C. H NMR (500
MHz, DMSO-d6, ppm): δ 9.11 (s, 1H, −C5H4N), 8.33 (d, J = 4.0 Hz,
1H, −C5H4N), 8.29 (d, J = 7.5 Hz, 1H, −C5H4N), 7.54 (dd, J = 7.5,
4.0 Hz, 1H, −C5H4N), 7.04 (s, 1H, −CHC(S)−), 2.58 (s, 3H,
−SCH3). 13C{1H} NMR (125 MHz, DMSO-d6, ppm): δ 193.3 (
C−S), 181.9 (−CO), 152.1, 148.5, 135.3, 135.0, 123.8 (−C5H4N),
108.9 (CH−C(S)−), 16.9 (−SCH3). IR (KBr, cm−1): 1580
(νCO), 1468 (νCC), 1118 (νC−S). Anal. Calcd for C18H16N2O2S4Zn
(485.94): C, 44.49; H, 3.32; N, 5.76. Found: C, 44.25; H, 3.37; N,
5.53. UV−vis: DMSO, λmax (nm), ε (M−1 cm−1) 400 (8.49 × 104),
315 (1.94 × 104); Nujol, λmax (nm) 335, 400.
Poly[{3-(methylthio)-1-(pyridin-4-yl)-3-thioxoprop-1-en-1-
olato}{μ2-3-(methylthio)-1-(pyridin-4-yl)-3-thioxoprop-1-en-1-
olato-κ3S∧O:N}zinc(II)] (3). Complex 3 was prepared following the
procedure used in the synthesis of complex 1 from KL3 (0.249 g, 1
mmol) and Zn(NO3)2·6H2O (0.148 g, 0.5 mmol). A yellow
precipitate was obtained in the reaction, and brown needle-shaped
crystals of 3 suitable for X-ray studies were obtained from a DMF
solution of the compound within 2−3 weeks. Empirical formula:
Scheme 2. Synthesis of the Ligands HL1−HL3 and Their
Potassium Salts KL1−KL3
1
[Zn(L3)2]n. Yield: 0.43 g, 89%. Mp: 214−218 °C. H NMR (500
MHz, DMSO-d6, ppm): δ 8.73 (s, 2H, −C5H4N), 7.82 (s, 2H,
−C5H4N), 7.04 (s, 1H, −CHC(S)−), 2.58 (s, 3H, −SCH3).
13C{1H} NMR (125 MHz, DMSO-d6, ppm): δ 195.7 (C−S), 181.2
(−CO), 150.5, 146.9, 121.0 (−C5H4N), 108.7 (CH−C(S)−),
16.9 (−SCH3). IR (KBr, cm−1): 1571 (νCO), 1503 (νCC), 1064
(νC−S). Anal. Calcd for C18H16N2O2S4Zn (485.94): C, 44.49; H, 3.32;
N, 5.76. Found: C, 44.32; H, 3.43; N, 5.61. UV−vis: DMSO, λmax
(nm), ε (M−1 cm−1) 415 (8.46 × 104), 315 (2.02 × 104); Nujol, λmax
(nm) 335, 400.
Poly[bis{μ2-3-(methylthio)-1-(thiophen-2-yl)-3-thioxoprop-1-en-
1-olato-κ3S∧O:S}cadmium(II)] (4). A solution of Cd(NO3)2·4H2O
(0.154 g, 0.5 mmol) in 10 mL of methanol/water (80/20) was added
dropwise to a 10 mL methanolic solution of the potassium salt of the
ligand KL1 (0.254 g, 1 mmol) at room temperature with stirring. The
reaction mixture was further stirred for 2 h. The yellow solid thus
formed was filtered, washed with methanol, and dried in air. Pale
yellow needle-shaped crystals of 4 suitable for X-ray studies were
obtained from a DMF solution of the compound within 2−3 weeks.
Empirical formula: [Cd(L1)2]n. Yield: 0.40 g, 73%. Mp: 172−175 °C.
1H NMR (400 MHz, DMSO-d6, ppm): δ 7.79 (d, J = 4.8 Hz, 1H,
−C4H3S), 7.76 (d, J = 3.2 Hz, 1H, −C4H3S), 7.79 (t, 1H, −C4H3S),
6.87 (s, 1H, −CHC(S)−), 2.47 (s, 3H, −SCH3). 13C{1H} NMR
(100 MHz, DMSO-d6, ppm): δ 187.8 (C−S), 178.1 (−CO),
148.0, 132.5, 129.0, 128.3 (−C4H3S), 109.1 (CH−C(S)−), 17.14
(−SCH3). IR (KBr, cm−1): 1547 (νCO), 1515 (νCC), 1065 (νC−S).
Anal. Calcd for C16H14O2S6Cd (543.03): C, 35.39; H, 2.60. Found:
C, 35.18; H, 2.70. UV−vis: DMSO, λmax (nm), ε (M−1 cm−1) 410
(8.54 × 104), 315 (2.39 × 104); Nujol, λmax (nm) 325, 400.
Poly[bis{μ2-3-(methylthio)-1-(pyridin-3-yl)-3-thioxoprop-1-en-1-
olato-κ3S∧O:N}cadmium(II)] (5). Complex 5 was prepared following
the procedure used in the synthesis of complex 4 from KL2 (0.249 g,
1 mmol) and Cd(NO3)2·4H2O (0.154 g, 0.5 mmol). A yellow
precipitate was obtained in the reaction, and brown rectangular-
shaped crystals of 5 suitable for X-ray studies were obtained from a
DMF solution of the compound within 2−3 weeks. Empirical
formula: [Cd(L2)2]n. Yield: 0.42 g, 79%. Mp: 195−198 °C. 1H NMR
(500 MHz, DMSO-d6, ppm): δ 9.01 (s, 1H, −C6H4N), 8.67 (d, J =
6.0 Hz, 1H, −C5H4N), 8.16 (d, J = 8.5 Hz, 1H, −C5H4N), 7.46−7.44
(m, 1H, −C5H4N), 6.87 (s, 1H, −CHC(S)−), 2.53 (s, 3H,
−SCH3). 13C{1H} NMR (125 MHz DMSO-d6, ppm): δ 191.4 (C−
S), 183.0 (−CO), 151.5, 148.5, 136.3, 134.9, 123.5 (−C5H4N),
109.7 (CH−C(S)−), 17.3 (−SCH3). IR (KBr, cm−1): 1596
(νCO), 1515 (νCC), 1065 (νC−S). Anal. Calcd for C18H16N2O2S4Cd
(532.97): C, 40.56; H, 3.03; N, 5.26. Found: C, 40.48; H, 2.85; N,
general procedure, an acetyl derivative (10.0 mmol) was added
dropwise to a solution of NaH (0.6 g, 25 mmol) in a DMF/hexane
mixture (4/1; 20 mL) with constant stirring under an N2 atmosphere.
After the mixture was stirred for 1 h in an ice bath, a solution of
dimethyltrithiocarbonate (TTC)21 (1.38 g, 10 mmol) was added
slowly and the reaction mixture was further stirred for 10 h at room
temperature. Excess NaH was neutralized by adding 0.1 M HCl (50
mL), and the product was extracted with dichloromethane (3 × 50
mL). The dichloromethane solution was collected, washed with water
and brine solution, and dried over anhydrous Na2SO4. The crude
product was further purified by silica gel (100−200 mesh)
chromatography using hexane as the eluent, resulting in HL1−HL3
as yellow solids (characterization data and NMR and FTIR spectra are
potassium salts of the ligands KL1−KL3 were obtained by refluxing
solutions of HL1−HL3 (1.0 mmol) with solid K2CO3 (0.21 g, 1.5
mmol) in acetone (10 mL) for 4−5 h with constant stirring. The
solution was cooled and filtered, and the filtrate was dried using a
rotary evaporator to yield KL1−KL3 as orange solid products.
Synthesis and Characterization of Complexes 1−5. [Bis{3-
(methylthio)-1-(thiophen-2-yl)-3-thioxoprop-1-en-1-olato-S∧O}-
zinc(II)] (1). A solution of Zn(NO3)2·6H2O (0.148 g, 0.5 mmol) in 10
mL of methanol/water (80/20) was added dropwise to a 10 mL
methanolic solution of the potassium salt of the ligand KL1 (0.254 g,
1 mmol) at room temperature with stirring. The reaction mixture was
further stirred for 2 h. The yellow solid thus formed was filtered,
washed with methanol, and dried in air. Pale yellow needle-shaped
crystals of product were obtained from a DMF solution of the
compound within 2−3 weeks. Empirical formula: [Zn(L1)2]. Yield:
0.45 g, 91%. Mp: 216−220 °C. 1H NMR (500 MHz, DMSO-d6,
ppm): δ 7.95 (d, J = 3.5 Hz, 1H, −C4H3S), 7.91 (d, J = 5.0 Hz, 1H,
−C4H3S), 7.20 (t, 1H, −C4H3S), 6.99 (s, 1H, −CHC(S)−), 2.55
(s, 3H, −SCH3). 13C{1H} NMR (125 MHz, DMSO-d6, ppm): δ
189.3 (C−S), 172.6 (−CO), 153.3, 146.9, 116.2, 112.8
(−C4H3S), 107.6 (CH−C(S)−), 16.6 (−SCH3). IR (KBr, cm−1):
1572 (νCO), 1524 (νCC), 1101 (νC−S). Anal. Calcd for
C16H14O2S6Zn (496.0): C, 38.74; H, 2.84. Found: C, 38.61; H,
3.05. UV−vis: DMSO, λmax (nm), ε (M−1 cm−1) 410 (8.19 × 104),
315 (2.18 × 104); Nujol, λmax (nm) 325, 430.
Poly[bis{μ2-3-(methylthio)-1-(pyridin-3-yl)-3-thioxoprop-1-en-1-
olato-κ3S∧O:N}zinc(II)] (2). Complex 2 was prepared following the
C
Inorg. Chem. XXXX, XXX, XXX−XXX