82
B.G. Vats et al. / Polyhedron 75 (2014) 81–87
(CH2OC6H4OCH2). This is very different from the bridging bidentate
structure expected for a six atom CH2 bridging ligand [9]. By
replacing the CH2 groups with oxygen atoms, the complexing prop-
erties of these bi-functional ligands in the solid state are signifi-
cantly changed. The bi-functional dithio-glycolamide based
ligands (Scheme 1) show selective extraction for the palladium
ion [13a] from high level liquid waste and it has been proposed
that they bond through both the thio-ether and amido groups to
the metal centre [13b]. Since, these ligands have two amide groups,
they are expected to show extraction for actinide(VI) and (IV) ions
from nitric acid medium. However, as no systematic work on the
extraction and complex chemistry of these ligands with actinide
ions has so far been reported, we have studied and report herein
the synthesis, structural and theoretical studies of dithio-glycola-
mide with uranyl nitrate and extraction studies with U(VI), Pu(IV)
and Am(III) ions.
–SCH2CO–), 3.355 (m, 2H, CH, iPr), 3.962 (m, 2H, CH, iPr). IR
(cmꢀ1
: 1624 (C@O). Anal. Calc. for C18H36N2S2O2: C, 57.4; H,
9.6; N, 7.4. Found: C, 57.1; H, 9.4; N, 7.2%.
)
m
2.3. Synthesis of L2
This was prepared similarly to L1 by taking ethylene-1,2-dithiol
(5.5 g, 0.059 mol) and N,N-di-n-butyl carbamoyl methyl chloride
(24.2 g, 0.118 mol), giving L2 in 82% yield. 1H NMR (25 °C, CDCl3)
d: 0.916 (m, 12H, CH3, Bu), 1.312 (m, 8H, NCCCH2, Bu), 1.527 (m,
8H, NCCH2, Bu), 2.921 (s, 4H, –CH2S–), 3.271 (m, 8H, NCH2, Bu)
3.324 (s, 4H, –SCH2CO–). IR (cmꢀ1
)
m: 1637 (C@O). Anal. Calc. for
C22H44N2S2O2: C, 61.1; H, 10.2; N, 6.5. Found: C, 60.6; H, 9.8; N,
6.2%.
2.4. Synthesis of L3
This was prepared similarly to L1 by taking ethylene-1,2-dithiol
(5.5 g, 0.059 mol) and N,N-di-isobutyl carbamoyl methyl chloride
(24.2 g, 0.118 mol), giving L3 in 80% yield. 1H NMR (25 °C, CDCl3)
2. Experimental
2.1. General considerations
i
i
d: 0.834 (d, 12H, CH3, Bu), 0.874 (d, 12H, CH3, Bu), 1.875 (m, 2H,
i
i
CH, Bu), 1.976 (m, 2H, CH, Bu), 2.884 (s, 4H, –CH2S–), 3.078 (d,
All reagents and solvents were of analytical grade and used as
received. IR spectra were recorded as nujol mulls using a JASCO-
610 FITR spectrometer. 1H NMR spectra were recorded using a Bru-
ker AMX-300 spectrometer. The chemical shifts (d) are reported in
ppm and coupling constants (J) are reported in hertz. Electrospray
ionization mass spectrometric detection of positive ions in CH2Cl2
or CH3COCH3 was recorded using a MicrOTOF Q-II instrument. The
samples were introduced into the source with the syringe pump.
Nitrogen was employed as both the drying and spraying gas, with
a source temperature of 180 °C. The cone voltage was set to 45 V,
the voltage applied on the capillary was 1162 kV and the sample
i
i
4H, NCH2, Bu), 3.133 (d, 4H, NCH2, Bu), 3.317 (s, 4H, –SCH2CO–).
IR (cmꢀ1
)
m
: 1632 (C@O). Anal. Calc. for C22H44N2S2O2: C, 61.1; H,
10.2; N, 6.5. Found: C, 60.8; H, 9.7; N, 6.3%.
2.5. Synthesis of L4
This was prepared similarly to L1 by taking ethylene-1,2-dithiol
(3.4 g, 0.036 mol) and N,N-di-n-octyl carbamoyl methyl chloride
(23 g, 0.72 mol), giving L4 in 85% yield. 1H NMR (25 °C, CDCl3) d:
0.864 (br, 12H,CH3, C8H17), 1.257 (br, 40H, CH2, C8H17), 1.523 (m,
8H, NC–CH2, C8H17), 2.910 (s, 4H, –CH2S–), 3.233 (m, 8H, NCH2,
solution flow rate was 5
m/z of 100 to 1000.
l
L minꢀ1. Spectra were recorded from
C8H17), 3.296 (s, 4H, –SCH2CO–). IR (cmꢀ1
) m: 1633 (C@O).
2.6. Synthesis of L5
2.2. Synthesis of L1
This was prepared similarly to L1 by taking tolyl-3,4-dithiol
(3.04 g, 0.0195 mol) and N,N-diisobutyl carbamoyl methyl chloride
(8 g, 0.39 mol), giving L5 in 81% yield. 1H NMR (25 °C, CDCl3) d:
To a methanolic solution (10 mL) of ethylene-1,2-dithiol (5.5 g,
0.059 mol), methanolic solution (20 mL) of NaOH (4.7 g,
a
i
i
0.118 mol) was added slowly with stirring. The whole solution
was stirred for 30 min. To this solution a solution of N,N-di-isopro-
pyl carbamoyl methyl chloride (21 g, 0.118 mmol) in methanol
(20 mL) was added slowly. The whole solution was stirred for 3
hours and then treated with 200 mL of 5% HCl solution. The organic
layer formed was extracted with CHCl3, dried over Na2SO4 and fil-
tered. The solution on evaporation yielded a colorless crystalline
solid in 75% yield. 1H NMR (25 °C, CDCl3) d: 1.203 (d, 12H, CH3,
0.854 (m, 24H, CH3, Bu), 1.924 (m, 4H, CH, Bu), 2.271 (s, 3H, –
CH3, tolyl), 3.130 (m, 8H, NCH2, iBu), 3.732 (s, 2H, –SCH2CO–),
3.764 (s, 2H, –SCH2CO–), 6.965 (dd, 1H, tolyl), 7.266 (d, 1H, tolyl),
7.389 (d, 1H, tolyl). IR (cmꢀ1
) m: 1652 (C@O). Anal. Calc. for C27H46-
N2S2O2: C, 65.6; H, 9.3; N, 5.7. Found: C, 65.3; H, 9.1; N, 5.7%.
2.7. Synthesis of 1
i
iPr), 1.371 (d, 12H, CH3, Pr), 2.897 (s, 4H, –CH2S–), 3.335 (s, 4H,
To a solution of L1 (250 mg, 0.67 mmol) in CH2Cl2 (20 mL), solid
[UO2(NO3)2ꢁ6H2O] (335 mg, 0.66 mmol) was added and stirred for
few minutes until all the [UO2(NO3)2ꢁ6H2O] dissolved to give a
clear solution. This solution was filtered and layered with iso-oc-
tane. The solution on slow evaporation yielded a yellow crystalline
solid, which was filtered, washed with hexane and dried. Yield:
CH SH
2
CH SCH CONR
2
2
2
NaOH
2 R NCOCH Cl
2
2
+
CH SH
2
CH SCH CONR
2
2
2
i
1
2
i
3
4
[ R = C H ( L ) ; R = C H ( L ) ; R = C H ( L ) ; R= C H ( L ) ]
17
i
84%. 1H NMR (25 °C, CD3COCD3) d: 1.551 (d, 12H,CH3, Pr), 1.663
3
7
4
9
4
9
8
i
(d, 12H, CH3, Pr), 2.955 (s, 4H, –CH2S–), 3.824 (s, 4H, –SCH2CO–),
SH
SH
SCH CONR
2
2
i
i
4.034 (m,2H, NCH, Pr), 4.509 (m, 2H, NCH, Pr). IR (cmꢀ1
) m: 1578
NaOH
CH
+
2 R NCOCH Cl
2 2
(C@O), 923 (O@U@O). Anal. Calc. for C18H36N4S2O10U: C, 28.1; H,
4.7; N, 7.3. Found: C, 27.9; H, 4.4; N, 7.0%.
CH
3
3
SCH CONR
2
2
i
5
[ R = C H ( L ) ]
4
9
2.8. Synthesis of 2
[ UO (NO ) .L ]
3 2
2
[ UO (NO ) .6H O ] + L
3 2
2
2
This was prepared similarly to
1
by taking L2 (259 mg,
0.60 mmol) and [UO2(NO3)2ꢁ6H2O] (300 mg, 0.59 mmol), giving 2
in 85% yield. 1H NMR (25 °C, CDCl3) d: 0.803 (t, 6H, CH3, Bu),
1.072 (t, 6H, CH3, Bu), 1.272 (m, 4H, CH2, Bu), 1.547 (m, 4H, CH2,
1
2
3
5
[ L = L ( 1 ); L = L ( 2 ); L = L ( 3 ); L = L ( 4 ) ]
Scheme 1. Synthesis of the ligands and their uranyl complexes.