N-(Diisopropylthiophosphoryl)-N′-(R)-thioureas: Synthesis, characterization, crystal structures and competitive bulk liquid membrane transport of some metal ions

Article abstract of DOI:10.1039/c2dt11862a

Ten N-thiophosphorylated thioureas of the common formula RC(S)NHP(S)(OiPr)₂ [R = iPrNH (1), EtNH (2), Et₂N (3), 2,5-Me₂C₆H₃NH (4), 4-Me₂NC ₆H₄NH (5), 2-MeO(O)CC₆H₄NH (6), 2-PyNH (7), 2-PyCH₂NH (8), 3-PyCH₂NH (9), cyclo-C ₂H₂N₃NH (10)] have been synthesized and characterized by IR, NMR spectroscopy and elemental analysis. Molecular structures of 1 and 4-8 were elucidated by X-ray diffraction revealing linear, bi- or trifurcated intramolecular hydrogen bonds. Additionally, their crystal structures are stabillized by two intermolecular hydrogen bonds, which in turn lead to a centrosymmetric dimer formation. The hydrogen bonded dimers of 5-8 are packed to polymeric chains through the π...π stacking interactions between aryl or pyridyl rings. Competitive transport experiments involving metal ions from an aqueous source phase through a chloroform membrane into an aqueous receiving phase have been carried out using 2-6 and 8-10 as the ionophore present in the organic phase. The source phase contained equimolar concentrations of Co^II, Ni^II, Cu^II, Zn ^II, Ag^I, Cd^II and Pb^II with the source and receiving phases being buffered at pH = 5.5 and 1.0, respectively. The obtained data were compared with the transport and extraction properties of 1 and 7, which were described recently. The Royal Society of Chemistry 2012.

Full text of DOI:10.1039/c2dt11862a

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PAPER
N-(Diisopropylthiophosphoryl)-N′-(R)-thioureas: synthesis, characterization,
crystal structures and competitive bulk liquid membrane transport of some
metal ions†
Maria G. Babashkina,*a Damir A. Safin,a Michael Bolteb and Yann Garciaa
Received 2nd October 2011, Accepted 1st December 2011
DOI: 10.1039/c2dt11862a
Ten N-thiophosphorylated thioureas of the common formula RC(S)NHP(S)(OiPr)2 [R = iPrNH (1), EtNH
(2), Et2N (3), 2,5-Me2C6H3NH (4), 4-Me2NC6H4NH (5), 2-MeO(O)CC6H4NH (6), 2-PyNH (7), 2-
PyCH2NH (8), 3-PyCH2NH (9), cyclo-C2H2N3NH (10)] have been synthesized and characterized by IR,
NMR spectroscopy and elemental analysis. Molecular structures of 1 and 4–8 were elucidated by X-ray
diffraction revealing linear, bi- or trifurcated intramolecular hydrogen bonds. Additionally, their crystal
structures are stabillized by two intermolecular hydrogen bonds, which in turn lead to a centrosymmetric
dimer formation. The hydrogen bonded dimers of 5–8 are packed to polymeric chains through the π⋯π
stacking interactions between aryl or pyridyl rings. Competitive transport experiments involving metal
ions from an aqueous source phase through a chloroform membrane into an aqueous receiving phase have
been carried out using 2–6 and 8–10 as the ionophore present in the organic phase. The source phase
contained equimolar concentrations of CoII, NiII, CuII, ZnII, AgI, CdII and PbII with the source and
receiving phases being buffered at pH = 5.5 and 1.0, respectively. The obtained data were compared with
the transport and extraction properties of 1 and 7, which were described recently.
range of functional groups at the nitrogen atoms, makes these
molecules very attractive.
We have extensively studied the synthesis, membrane trans-
Introduction
Crystal engineering1 is a main objective for the creation and
design of new materials with desirable structures and properties.
Understanding of intermolecular interactions and packing in
crystals is one of the main goals for the fine tuning of a number
of useful properties. Noncovalent interactions are considered as
the most effective tool for the creation of molecular aggregates
and assemblies.1,2 Among these interactions hydrogen bonds
and π⋯π stacking are the most frequently used and legally take
front rank due to their ability for rational design.3 The single
crystal growth issue, which is mostly influenced by fortune than
skills, can however be overcome by combination of donor and
acceptor functions in a molecule providing an effective way for
the formation of intra- and intermolecular interactions. In this
frame, the (thio)urea group is frequently used as a crystallizing
building block since it contains both hydrogen donors through
the NH groups and acceptor centres through the CvO or CvS
groups.4 The possibility to modify (thio)urea at will, with a wide
port, extraction, separation and complexation properties of N-
(thio)phosphorylated thioureas RR′NC(X)NHP(Y)(OiPr)2 (X,
Y = O, S) (NTTU).5 The easiest synthetic way of NTTU is the
reaction of primary or secondary amines with the corresponding
(thio)phosphorylated isocyanates (iPrO)2P(Y)NCX (X, Y = O,
S).5a The main advantageous of this synthetic route is the ability
to work with molecules having one or more amine groups as a
starting amine. Depending on the nature of the donor CvX and
PvY atoms, as well as on the presence of the NH fragment at
the (thio)carbonyl group, a number of hydrogen bonded struc-
tures were observed in crystals of NTTU.5a The influence of the
R and R′ substituents is also crucial for the formation of assem-
blies in crystals. Thus, investigation of NTTU is an outstanding
and evergrowing branch of crystal engineering.
Herein, we report ten N-thiophosphorylated thioureas, contain-
ing various substituents at the thiocarbonyl group (Chart 1) with
their IR and NMR data. The crystal structures and packing of 1
and 4–8 were elucidated by X-ray diffraction. The thioureas 3
and 7 were recently synthesized by two of us.6 However, in the
present work we describe the crystal structure of 7. Furthermore,
the IR and NMR data of 3 were previously analyzed but not cor-
rectly interpreted.6b
aInstitute of Condensed Matter and Nanosciences, MOST – Inorganic
Chemistry, Université Catholique de Louvain, Place L. Pasteur 1, 1348
Louvain-la-Neuve, Belgium. E-mail: maria.babashkina@ksu.ru; Fax:
+32(0) 1047 2330; Tel: +32(0) 1047 2831
bInstitut für Anorganische Chemie J.-W.-Goethe-Universität, Frankfurt/
Main, Germany
In this contribution we also studied the competitive bulk
liquid membrane transport of some metal ions using 2–6 and
8–10. We used the three phase arrangement, which involves two
†CCDC reference numbers 805546 (1), 818224 (4), 818225 (5), 818226
(6), 818227 (7) and 818223 (8). For crystallographic data in CIF or other
electronic format see DOI: 10.1039/c2dt11862a
This journal is © The Royal Society of Chemistry 2012
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5, 7, 9 and 10 contain two characteristic bands for the RNH and
PNH groups at 3051–3382 cm−1, whereas there is one broad
band in the spectra of 6 and 8 at 3151–3167 cm−1, that might be
caused by the overlapping of two bands due to the influence of
hydrogen bonds. It is noteworthy, that there are no bands for the
PNH group in the IR spectrum of 3·Et2NH which is obviously
due to the presence of the deprotonated form of 3. The IR spec-
trum of the thiourea 6 also contains an intense band at
1707 cm−1, corresponding to the CvO group.
The 31P{1H} NMR signal of 1, 2, 4–6 and 8–10 in CDCl3
appears as a singlet at 52.6–53.9 ppm. The signals are in the
area characteristic for the neutral NTTU (X = Y = S).5a The 31P
{1H} NMR spectra of 3·Et2NH and 7 contain a singlet signal at
57.5–58.5 ppm. These signals are considerably low-field shifted,
confirming the deprotonated form of the phosphorus containing
1
compounds.5a The H NMR spectra of 1–10 in CDCl3 reveal a
single set of signals for the iPrO protons: a doublet or two doub-
lets for the CH3 protons at 1.24–1.42 ppm and a doublet of
septets for the CHO protons in the area 4.71–5.00 ppm. The
spectrum of 1 contains signals for the iPrN group: a doublet for
the CH3 protons at 1.26 ppm and a doublet of septets for the
CHN protons at 4.47 ppm. The signals for the Et groups in 2
and in the thiourea fragment of 3·Et2NH were found as a triplet
for the CH3 protons at 1.15–1.23 ppm and as a doublet of quar-
tets or a broad singlet for the the CH2 protons at about
3.62 ppm. Furthermore, the spectrum of 3·Et2NH contains a
Chart 1
+
number of signals for the Et groups of the Et2NH2 cation: a
triplet for the CH3 protons at 1.23 ppm and a quartet for the CH2
protons at 2.88 ppm. The signals for the Me protons in the
spectra of 4–6 are shown as singlets at 2.28–2.34, 2.96 and
3.92 ppm, respectively. The CH2 protons in the spectra of 8 and
9 were found as a doublet at 4.85–4.91 ppm. The aryl and
pyridyl protons in the spectra of 4–10 are shown as a number of
signals at 6.71–8.93 ppm. Besides, the spectra of the thioureas 1,
2, 4–6 and 8–10 contain the signals for the PNH proton at
6.62–7.22 ppm. The same signal in the spectrum of 7 is con-
siderably low-field shifted and shown at δ = 13.31 ppm, indicat-
ing a strong intramolecular hydrogen bonding between the
nitrogen atom of the pyridine function and the hydrogen atom of
the phosphorylamide fragment. The signals for the RNH proton
are observed at 7.64–11.03 ppm. It is noteworthy that the signals
for the alkylNH proton of 1 and 2 are considerably high-field
shifted compared to the arylNH or PyNH proton of 4–10. More-
over, the signal for the arylNH proton of 6 is extremely low-field
shifted due to a strong intramolecular hydrogen bonding
between the oxygen atom of the carbonyl function and the
hydrogen atom of the arylNH fragment. The signal for the NH2
buffered aqueous phases (source and receiving phases) separated
by an immiscible organic phase (chloroform) incorporating the
ionophore.5c,d The advantage of this procedure is a measurement
(by difference) of metal ions present in the organic phase. The
source phase contained equimolar concentrations of CoII, NiII,
CuII, ZnII, AgI, CdII and PbII. The obtained data were compared
with the transport properties of 1 and 7, which were described
recently.5c,d
Results and discussion
The N-thiophosphorylated thioureas 1–10 were synthesized by
reacting the corresponding amine with the isothiocyanate
(iPrO)2P(S)NCS. It is noteworthy, that according to the IR,
NMR spectroscopy and elemental analysis (see below and
Experimental section) the reaction of diethylamine with
(iPrO)2P(S)NCS leads to the corresponding diethylammonium
salt 3·Et2NH. The compounds 1 and 4–8 are colorless crystalline
solids, whereas 2, 3·Et2NH, 9 and 10 are yellow viscous oils.
All compounds are soluble in dichloromethane, chloroform,
acetone, acetonitrile and insoluble in n-hexane and water.
+
protons of the Et2NH2 cation in the spectrum of 3·Et2NH is
observed as a broad singlet at δ = 8.91 ppm.
The IR spectra of 1, 2 and 4–10 contain a band at
632–647 cm−1 for the PvS group. This band is shifted to low
frequencies in the spectrum of 3·Et2NH (at 617 cm−1) and
testifies of the presence of the anionic form of the thiopho-
sphorylated thiourea 3. In the IR spectra of 1, 2 and 4–10 there
is a band at 1528–1545 cm−1, corresponding to the SvC–N
fragment, whereas the spectrum of 3·Et2NH contains a band at
1504 cm−1, which is the evidence of the conjugated SCN frag-
ment.7 In addition, there is a broad intense band arising from the
POC group at 955–978 cm−1. Besides, the IR spectra of 1, 2, 4,
Thus, according to NMR spectroscopy data, the thiourea
3·Et2NH is deprotonated due to the presence of the Et2NH
amine, while the thiourea 7 is completely in a zwitterionic form
in CDCl3 (Chart 2). A similar zwitterion formation was observed
in the NMR spectra of N-(thio)phosphorylated thiosemicarba-
zides NH2N(Me)C(S)NHP(X)(OiPr)2 (X = O, S) and thiourea 2-
PyNHC(S)NHP(O)(OiPr)2.8
Crystals of 1 and 4–8 were obtained by slow evaporation of
the solvent from a CH2Cl2–n-hexane solution. The molecular
structures are shown in Fig. 1–6, whereas the crystal and
3224 | Dalton Trans., 2012, 41, 3223–3232
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Chart 2
Fig. 4 View on the hydrogen bonded dimer of 6. Thermal ellipsoids
are drawn at the 30% probability level. Hydrogen atoms not involved in
H-bonding were omitted for clarity.
Fig. 1 View on the hydrogen bonded dimer of 1. Thermal ellipsoids
are drawn at the 30% probability level. Hydrogen atoms not involved in
H-bonding were omitted for clarity.
Fig. 5 View on the hydrogen bonded dimer of 7. Thermal ellipsoids
are drawn at the 30% probability level. Hydrogen atoms not involved in
H-bonding were omitted for clarity.
Fig. 2 View on the hydrogen bonded dimer of 4. Thermal ellipsoids
are drawn at the 30% probability level. Hydrogen atoms not involved in
H-bonding were omitted for clarity.
Fig. 6 View on the hydrogen bonded dimer of 8. Thermal ellipsoids
are drawn at the 30% probability level. Hydrogen atoms not involved in
H-bonding were omitted for clarity.
structure refinement data are given in the Experimental section.
The thiourea 5 contains two independent molecules in the unit
cell.
Compounds 1 and 4–8 crystallize in the space groups P1, P21/
c, P21/n or Pbca. The parameters of the CvS, C–N, P–N and
PvS bonds are in the typical range for N-thiophosphorylated
thiourea derivatives (Table 1).5a The SvC–N–P backbone in 1,
4–6 and 8 has an E conformation (Fig. 1–4 and 6), while the
same fragment has a Z conformation in the structure of 7
(Fig. 5). The crystal structures of 1 (Fig. 1) and 4 (Fig. 2) are
stabilized by bifurcated intramolecular hydrogen bonds of the
type RN–H⋯O–P, which are formed between the hydrogen atom
Fig. 3 View on the hydrogen bonded dimer of one of the independent
molecule of 5. Thermal ellipsoids are drawn at the 30% probability
level. Hydrogen atoms not involved in H-bonding were omitted for
clarity.
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Table 1 Selected bond lengths (Å), and bond angles (°) for 1 and 4–8
5
1
4
Molecule A
Molecule B
6
7
8
CvS
PvS
P–N
C–N(P)
C–N(C)
SvC–N(C)
SvC–N(P)
N–C(S)–N
N–PvS
CvN–P
1.6757(8)
1.9122(3)
1.6685(7)
1.3792(11)
1.3298(11)
123.30(7)
119.74(6)
116.95(8)
111.48(3)
129.44(6)
1.662(4)
1.9039(12)
1.664(3)
1.369(4)
1.336(4)
122.3(3)
121.7(3)
116.0(3)
111.71(11)
130.2(2)
1.675(4)
1.9162(15)
1.675(3)
1.370(5)
1.335(5)
122.8(3)
120.7(3)
116.5(3)
116.45(14)
128.7(3)
1.673(4)
1.9178(16)
1.672(3)
1.372(5)
1.331(5)
123.6(3)
120.2(3)
116.2(3)
116.54(14)
127.3(3)
1.6700(14)
1.9076(5)
1.6750(12)
1.3717(17)
1.3492(17)
125.90(11)
119.29(10)
114.77(12)
111.38(4)
1.6734(19)
1.9076(8)
1.6729(17)
1.344(2)
1.6831(19)
1.9194(7)
1.6717(16)
1.393(2)
1.356(2)
1.326(2)
120.14(15)
123.36(14)
116.50(17)
116.88(7)
127.25(14)
123.43(15)
119.30(14)
117.27(16)
111.49(6)
129.79(13)
130.05(10)
Table 2 Selected hydrogen bond lengths (Å) and angles (°) for 1 and 4–8
D–H⋯A
d(D–H)
d(H⋯A)
d(D⋯A)
∠(DHA)
1a
4b
N(1)–H(1)⋯S(2)#1
N(2)–H(2)⋯O(1)
N(2)–H(2)⋯O(2)
N(1)–H(1)⋯S(2)#1
N(2)–H(2)⋯O(1)
N(2)–H(2)⋯O(2)
N(2)–H(2)⋯O(2′)
N(1)–H(1)⋯S(2)#1
N(2)–H(2)⋯S(1)
N(1A)–H(1A)⋯S(2A)#1
N(2A)–H(2A)⋯S(1A)
N(1)–H(1)⋯S(2)#1
N(2)–H(2)⋯O(1)
N(2)–H(2)⋯O(2)
N(2)–H(2)⋯O(3)
N(2)–H(2)⋯S(2)#1
N(1)–H(1)⋯N(3)
N(1)–H(1)⋯S(2)#1
N(2)–H(2)⋯O(1)
N(2)–H(2)⋯O(2)
N(2)–H(2)⋯N(3)
0.831(15)
0.790(16)
0.790(16)
0.875(10)
0.88(3)
0.879(10)
0.879(10)
0.906(10)
0.903(10)
0.907(10)
0.905(10)
0.848(18)
0.870(18)
0.870(19)
0.870(19)
0.79(2)
2.504(15)
2.370(16)
2.518(16)
2.459(14)
2.34(3)
2.35(4)
2.41(3)
2.460(11)
2.58(2)
2.467(14)
2.53(3)
2.599(19)
2.811(17)
2.253(19)
1.999(19)
2.61(2)
1.94(2)
2.60
3.3262(8)
2.9582(11)
3.0526(11)
3.310(3)
2.960(4)
2.898(6)
3.109(6)
3.365(3)
3.361(4)
3.362(3)
170.5(13)
132.0(14)
126.2(14)
164(3)
127(3)
120(3)
137(4)
179(5)
145(3)
169(4)
146(4)
169.1(16)
99
137.8(16)
132.8(16)
163(2)
143(2)
162
126
125
5c
6d
3.322(4)
3.4351(12)
3.0689(16)
2.9557(15)
2.6674(17)
3.3714(18)
2.615(2)
3.4417(17)
3.030(2)
3.074(2)
7e
8f
0.80(2)
0.88
0.88
0.88
2.43
2.48
2.28
0.88
2.677(2)
107
a Symmetry transformations used to generate equivalent atoms: #1 −x + 2, −y + 2, −z + 2. b Symmetry transformations used to generate equivalent
atoms: #1 −x + 2, −y + 1, −z + 2. c Symmetry transformations used to generate equivalent atoms: #1 −x + 1, − y, − z; #2 −x, − y + 1, − z.
d Symmetry transformations used to generate equivalent atoms: #1 −x, −y + 1, −z. e Symmetry transformations used to generate equivalent atoms:
#1 −x + 1, −y + 1, −z + 1. f Symmetry transformations used to generate equivalent atoms: #1 −x, −y, −z + 1.
of the RNH fragment and two oxygen atoms of the P(OiPr)2
group (Table 2). The crystal structures of 5 (Fig. 3) and 7
(Fig. 5) contain a linear intramolecular hydrogen bond of the
type RN–H⋯SvP (5) or PN–H⋯N(pyridine) (7), respectively
(Table 2). In the former structure the H-bond is formed between
the hydrogen atom of the RNH fragment and the sulfur atom of
the PvS group, while in the latter structure the H-bond is
formed between the hydrogen atom of the phosphorylamide
group and the nitrogen atom of the pyridine ring. It is worthy to
note, that the distance H(1)⋯N(3) in the structure of 7 is con-
siderably shortened (Table 2), indicating a strong intramolecular
hydrogen bonding formation. The crystal structures of 6 (Fig. 4)
and 8 (Fig. 6) are stabillized by trifurcated intramolecular hydro-
gen bonds (Table 2). Two of the three H-bonds are of the type
RN–H⋯O–P, similar to those observed for 1 and 4, while the
third H-bond is formed between the same hydrogen atom of the
RNH group and the carbonyl oxygen atom in 6 or the nitrogen
atom of the pyridine ring in 8. Furthermore, the crystal structures
of the thioureas 1, 4–6 and 8 are additionally stabilized by inter-
molecular hydrogen bonds of the type PN–H⋯S#1vC#1
(Fig. 1–4 and 6, Table 2), which are formed between the S atoms
of the CvS groups and the H atoms of the PNH fragment of
two molecules. The similar intermolecular hydrogen bonds were
observed in the structure of 7. However, these bonds are formed
between the S atoms of the CvS groups and the H atoms of the
RNH fragment of two molecules (Fig. 5, Table 2). As a result of
intermolecular interactions, centrosymmetric dimers are formed
in the crystal structures of 1 and 4–8. Additionally, the centro-
symmetric dimers of 5–8 form π⋯π stacking interactions
between the aryl (5 and 6) or pyridine (7 and 8) rings
(Fig. 7–10, Table 3). These interactions produce polymeric
chains in the crystal structures.
Recently, we have studied the competitive transport properties
of 1 and 7.5c,d In this work we present the transport properties of
3226 | Dalton Trans., 2012, 41, 3223–3232
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Fig. 10 View on the π⋯π stacking interactions between the hydrogen
bonded dimers of 8. Hydrogen atoms except NH were omitted for
clarity.
Fig. 7 View on the π⋯π stacking interactions between the hydrogen
bonded dimers of 5. Hydrogen atoms except NH were omitted for
clarity.
Table 3 Selected π⋯π interactions for 5–8
Cg(I)
Cg(J)
Cg–Cg (Å)
Dihedral angle (°)
β (°)
5a
Cg(1)
Cg(2)
Cg(1)
Cg(1)
Cg(1)
Cg(1)
Cg(1)
Cg(1)#1
Cg(2)#2
Cg(1)#1
Cg(1)#1
Cg(1)#2
Cg(1)#1
Cg(1)#2
4.087(2)
4.140(3)
3.7095(12)
3.8611(12)
3.8612(12)
3.9362(13)
3.9850(13)
0
0
0
2
2
0
0
25.06
24.37
18.25
31.06
28.91
26.47
26.79
6b
7c
8d
Fig. 8 View on the π⋯π stacking interactions between the hydrogen
bonded dimers of 6. Hydrogen atoms except NH were omitted for
clarity.
a Symmetry codes: #1 −x + 1, −y + 1, −z + 1; #2 −x + 2, −y, −z +
1. Cg(1): C(8)–C(9)–C(10)–C(11)–C(12)–C(13), Cg(2): C(8A)–C(9A)–
C(10A)–C(11A)–C(12A)–C(13A). b Symmetry codes: #1 −x + 1, −y +
1, −z + 1. Cg(1): C(8)–C(9)–C(10)–C(11)–C(12)–C(13). c Symmetry
codes: #1 −x + 1/2, y − 1/2, z; #2 −x + 1/2, y + 1/2, z. Cg(1): N(3)–
C(8)–C(9)–C(10)–C(11)–C(12). d Symmetry codes: #1 −x, −y, −z;
#2 −x + 1, −y, −z. Cg(1): N(3)–C(9)–C(10)–C(11)–C(12)–C(13).
and 13%, respectively). This is, obviously, due to the presence
of the less sterically demanding ethyl group. The thiourea 3 also
shows no transport properties. Furthermore, only a very small
amount of the AgI (3%) and CuII (1.6%) ions were found in the
membrane phase, which became pale yellow and muddy during
the first few hours of the experiment. It was established that
compound 3 decomposes rather rapidly under the experimental
conditions. It is well known, that NTTUs, containing strong σ-
donor substituents at the thiocarbonyl group, are significantly
decomposed in solution.5a In general, the extraction properties of
the thioureas RNHC(S)NHP(S)(OiPr)2 (R = H, Et, iPr, tBu)
towards AgI and CuII from the source phase to the membrane
phase decrease with increasing of the bulkiness of the substi-
tuent.5c,d Moreover, the compound H2NC(S)NHP(S)(OiPr)2
transports both AgI and CuII to a receiving phase in approxi-
mately equal amounts, and does not show transport selectivity of
the two cations. It is necessary to note, that the degree of trans-
port of both cations is rather low and is of the order of 2%.5c,d
Compounds 4–6 contain the substituted benzene functions at
the CvS fragment. The thioureas 4 and 5 show no transport
properties and extract both AgI and CuII ions with the values of
32–37 and 29–40%, respectively (Table 4). In general, the trans-
port and extraction properties of 4 and 5 are very similar to those
of the previously described thioureas RNHC(S)NHP(S)(OiPr)2
(R = Ph, α-naphthyl).5c,d Contrariwise, the thiourea 6 displays
the best transport properties for AgI for all the ligands studied
(Table 4). Furthermore, it also transports CuII but in a 15.5 times
smaller amount. However, a very high amount of CuII was found
in the membrane phase (92%). The sums AgTr% + AgTM% and
CuTr% + CuTM% are 98% and 94%, respectively. Thus,
Fig. 9 View on the π⋯π stacking interactions between the hydrogen
bonded dimers of 7. Hydrogen atoms except NH were omitted for
clarity.
2–6 and 8–10. The ligands shown in Chart 1 can be divided into
three groups. The first group displays thiophosphorylated thiour-
eas 1–3, containing the alkyl substituents at the thiocarbonyl
group. In the second group the compounds 4–6, containing the
substituted benzene rings, have been combined. The third group
comprises of thioureas 7–10 with nitrogen-containing hetero-
cycles at the thiocarbonyl group. This division is very useful to
discuss the results of the membrane transport investigations sum-
marized in Table 4, since the number and type of the substituent
at the thiocarbonyl group of an ionophore strongly determines its
binding efficiency and selectivity.5c,d
Recently, it was established that using the thiourea 1 as an
ionophore leads to no cations in the receiving phase.5c,d
However, this ligand shows moderate extraction properties of
AgI from a water phase into an organic phase during the trans-
port experiment. CuII cations are also extracted into the organic
phase, but in a 1.77 times smaller amount. The thiourea 2, con-
taining the EtNH group instead of the iPrNH fragment in 1,
shows similar extraction properties as 1. However, it extracts
both AgI and CuII in the membrane phase more efficiently (by 9
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Table 4 The average flux rate (J) values for the competitive metal ion transport studies involving 1–10. The experimental conditions were as
follows: pH of the source phase = 5.5, pH of receiving phase = 1.0 and concentration of ligand = 0.002 mol dm−3
Metal ion transport, J/(mol 24 h) × 106
Ligand number
1a
2
3
4
5
6
7a
8
9
10
CoII, NiII, ZnII, CdII, PbII
CuII
—
—
—
—
69
—
39
69
39
—
1.77
—
—
—
—
78
—
52
78
52
—
1.50
—
—
—
—
3
—
1.6
3
—
—
—
—
32
—
29
32
29
—
1.10
—
—
—
—
37
—
40
37
40
—
0.93
—
2
31
31
67
2
92
98
94
15.5
0.73
—
—
—
—
85
—
70
85
70
—
1.21
—
—
—
—
78
—
64
78
64
—
1.22
—
6
4
4
72
6
67
76
73
0.67
1.07
—
59
8
AgI
AgTr%b
8
AgTM%c
84
59
38
92
97
0.14
2.21
CuTr%b
CuTM%c
AgTr% + AgTM%
CuTr% + CuTM%
ηr(AgI/CuII)d
ηM(AgI/CuII)e
1.6
—
1.88
a The data from [5c,d]. b AgTr% and CuTr% = percentage of AgI and CuII transported into the receiving phase. c AgTM% and CuTM% = percentage of
AgI and CuII transported into the membrane phase. d ηr(AgI/CuII) = AgTr%/CuTr%. e ηM(AgI/CuII) = AgTM%/CuTM%.
compound 6 almost completely retrieves both AgI and CuII from
the source phase. These transport and extraction properties of the
ligand 6 are, obviously, explained by the presence of two coordi-
nation functions: C(S)NHP(S) and MeO(O)C.
the form of the long-chain acid is to inhibit any bleeding of par-
tially hydrophilic species (such as the protonated or deprotonated
ionophore and/or its corresponding charged metal complex)
from the organic membrane phase into either of the aqueous
phases.11–13 It was observed, that the thioureas 1, 2 and 4–10
alone are not effective carriers for the studied metal cations.
Even the MTM% values are less than 0.5% for about 3 days
during the separate experiments for each metal cations. Further-
more, no cations were observed in the receiving phase. This is
obviously due to the considerable solubilities of the complexed
forms of neutral 1, 2 and 4–10 in the aqueous source phase.
Thus, the thioureas 1, 2 and 4–10 and palmitic acid show the
cooperative action of the two components as a carrier.
On the other hand, the obtained transport properties of the
thioureas 1–10 might be also explained by the differences in the
complexes formed with the studied metal cations. For the CoII,
NiII, ZnII, CdII and PbII cations the formation of complexes of
the [ML2] composition was exclusively observed.5,8 Further-
more, the dithio-containing NTTU (X, Y = S) ligands are coor-
dinated towards the same metal cations through the sulfur atoms
of the CvS and PvS groups. However, it was established, that
the NTTU compounds, containing the pyridine function at the
thiocarbonyl group, are additionally coordinated through the pyr-
idine nitrogen atom.8b Contrariwise, the AgI and CuII cations
form polynuclear complexes with the NTTU (X, Y = S) ligands
of the 1 : 1 metal to ligand ratio (Chart 3).5c,d,14 Moreover, the
The compounds 7–10 are grouped together because these thio-
phosphorylated thioureas are ligands that have nitrogen-contain-
ing heterocycles at the thiocarbonyl group. The compounds 7
and 8 show no transport properties and extract AgI and CuII simi-
larly (Table 4). However, incorporation of the methylene frag-
ment between the pyridyl and thiocarbonyl groups leads to a
slightly decrease of the extraction of AgI and CuII. This is due to
the lability (a relatively easier rotation along the HN–C(S) bond)
of the 2-PyCH2NH fragment compared to 2-PyNH. The thiourea
9 extracts both the AgI and CuII cations at the same degree as 7
and 8 but also shows some transport properties towards the same
cations (Table 4). This might be explained by the formation of
less stable coordination compounds of 9 and AgI and/or CuII due
to the 3-Py fragment instead of 2-Py. The thiourea 10 displays
the best transport properties for CuII for all the ligands investi-
gated (Table 4). It also transports AgI but in a about 7.4 times
smaller amount. This is due to the presence of the triazole ring,
which shows a great affinity towards CuII,9 in the structure of 10.
Furthermore, a high amount of AgI was found in the membrane
phase (84%). The sums AgTr% + AgTM% and CuTr% + CuTM%
are 92% and 97%, respectively. Thus, compound 10 almost com-
pletely retrieves both AgI and CuII from the source phase similar
to the thiourea 6.
Throughout the transport experiments, we have incorporated 4
× 10−3 mol dm−3 palmitic acid in the membrane phase. It was
established, that at this concentration and under the experimental
conditions employed, no metal ion transport was observed when
only palmitic acid was present in the membrane phase. Palmitic
acid is widely used in transport experiments involving a variety
of ligands as ionophores.5c,d,10,11 A major role of palmitic acid is
to aid the transpost process by providing a lipophilic counter ion
in the organic phase on proton loss to the aqueous source phase,
giving rise to charge neutralisation of the metal cation being
transported through ion pairing or adduct formation. In this
manner the uptake of lipophobic nitrate anions into the organic
phase is avoided. An additional benefit of adding lipophilicity in
Chart 3
3228 | Dalton Trans., 2012, 41, 3223–3232
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formation of such polymeric compounds might lead to the for-
mation of the cyclic crown ether-like structures of a different
size (Chart 3). Cavities of these cycles might be also suitable for
the coordination of additional metals through the sulfur atoms of
the thiocarbonyl groups. Furthermore, the donor oxygen and
sulfur atoms of the SvP(OiPr)2 fragments together with donor
functions of the substituent at the thiocarbonyl group might also
possesses coordination properties towards metals.14d
efficient for the transport of AgI and CuII, respectively. Further-
more, the same two ligands almost completely retrieve both AgI
and CuII from the source phase.
Experimental
General procedures
As can be seen for Table 4, the sum AgTM% + CuTM% for 1, 2
and 6–10 exceeds 100%. This indicates that these thioureas must
be simultaneously coordinating to both AgI and CuII ions which
gives strong evidence for the formation of oligomeric heteronuc-
lear species in the membrane phase. This explains that no CoII,
NiII, ZnII, CdII and PbII cations were extracted even into the
organic phase during the transport conditions. However, moder-
ate amounts of the NiII cations were observed in the membrane
phase when the thioureas 4 (NiTM% 3.8) and 5 (NiTM% 4.6) were
used as ionophores. This might be explained by the fact that the
sum AgTM% + CuTM% for 4 and 5 is 61 and 77%, respectively,
and hence not all amount of these thioureas is coordinated
towards AgI and CuII. Furthermore, the affinity of 4 and 5 to
extract NiII cations among the rest metals might be explained by
the formation of a 1,3-N,S-coordinated complex form in
CHCl3,5e which might be more suitable for extraction upon the
experimental conditions used for transport experiments. For the
CoII, ZnII, CdII and PbII cations the formation of complexes with
an exclusive 1,5-S,S′-coordination mode of ligands was
observed.5,8 Furthermore, the differences for the obtained trans-
port and extraction properties of 1, 2 and 4–10 towards the
studied metal cations might be explained by significantly differ-
ent stability constants of the formed complexes as well as the
used experimental time (24 h) is not enough for the transport of
the CoII, NiII, ZnII, CdII and PbII cations. However, increasing of
the experimental time leads to the decomposition of 1, 2 and
4–10 in solution as it was observed for the thiourea 3 (see
above).
Infrared spectra (Nujol) were recorded with a Thermo Nicolet
380 FT-IR spectrometer in the range 400–3600 cm−1. NMR
spectra in CDCl3 were obtained on a Bruker Avance 300 MHz
spectrometer at 25 °C. 1H and 31P{1H} NMR spectra were
recorded at 299.948, and 121.420 MHz, respectively. Chemical
shifts are reported with reference to SiMe4 (1H) and 85% H3PO4
(31P{1H}). Elemental analyses were performed on a Thermo-
quest Flash EA 1112 Analyzer from CE Instruments.
Synthesis of 1–10
A solution of isopropylamine, ethylamine, diethylamine, 2,5-
dimethylaniline, 4-(dimethylamino)aniline, methyl 2-amino-
benzoate, 2-aminopyridine, 2-(aminomethyl)pyridine, 3-(amino-
methyl)pyridine or 4-amino-4H-1,2,4-triazole (5 mmol; 0.296,
0.225, 0.366, 0.606, 0.681, 0.756, 0.471, 0.541, 0.541 or
0.420 g) in anhydrous CH2Cl2 (15 mL) was treated under vigor-
ous stirring with a solution of (iPrO)2P(S)NCS (6 mmol,
1.436 g) in the same solvent (15 mL). The mixture was stirred
for 1 h. The solvent was removed in a vacuum, and the product
was purified by recrystallisation from a 1 : 5 (v/v) mixture of
CH2Cl2 and n-hexane.
1. Yield: 1.402 g (94%). IR ν (cm−1): 640 (PvS), 964
1
(POC), 1543 (SvC–N), 3090, 3382 (NH). H NMR: δ = 1.26
(d, 3JH,H = 6.6 Hz, 6H, CH3, iPrN), 1.33 (d, 3JH,H = 6.2 Hz, 6H,
3
CH3, iPrO), 1.35 (d, JH,H = 6.2 Hz, 6H, CH3, iPrO), 4.47 (d.
3
sept, JHNCH = 8.0 Hz, 3JH,H = 6.5 Hz, 1H, NCH), 4.79 (d. sept,
3
3JPOCH = 10.6 Hz, JH,H = 6.2 Hz, 2H, OCH), 6.86 (br. s, 1H,
PNH), 7.64 (br. s, 1H, alkylNH) ppm. 31P{1H} NMR: δ =
52.8 ppm. Calc. for C10H23N2O2PS2 (298.40): C, 40.25; H,
7.77; N, 9.39. Found: C, 40.28; H, 7.74; N, 9.44%.
Conclusions
In summary, we have synthesized a wide range of N-thiophos-
phorylated thioureas 1–10 by the addition of thiophosphoryli-
sothiocyanate to the corresponding amine.
According to IR and NMR spectroscopy data, 3·Et2NH is
deprotonated due to the presence of the Et2NH amine, while the
thiourea 7 is completely in a zwitterionic form.
Single crystal X-ray diffraction studies showed that an E
arrangement of the CvS and P–N bonds in the SvC–N–P
backbones was found for the thioureas 1, 4–6 and 8. The
thiourea 7 was observed as a Z conformational isomer. In the
crystal, the thioureas 1 and 4–8 form linear, bi- or trifurcated
hydrogen bonds. Furthermore, their crystal structures are stabil-
ized by two intermolecular hydrogen bonds, which in turn lead
to a centrosymmetric dimer formation. Additionally, the hydro-
gen bonded dimers of 5–8 are packed to polymeric chains
through the π⋯π stacking interactions between aryl or pyridyl
rings.
2. Yield: 1.137 g (80%). IR ν (cm−1): 639 (PvS), 957
1
(POC), 1545 (SvC–N), 3103, 3374 (NH). H NMR: δ = 1.23
3
3
(t, JH,H = 7.3 Hz, 3H, CH3, Et), 1.31 (d, JH,H = 6.0 Hz, 6H,
3
CH3, iPr), 1.33 (d, JH,H = 6.0 Hz, 6H, CH3, iPr), 3.63 (d. q,
3JHCNH = 9.0 Hz, JH,H = 7.2 Hz, 2H, CH2), 4.77 (d. sept,
3
3JPOCH = 10.6 Hz, JH,H = 6.1 Hz, 2H, OCH), 6.62 (br. s, 1H,
3
PNH), 7.83 (br. s, 1H, alkylNH) ppm. 31P{1H} NMR: δ =
52.7 ppm. Calc. for C9H21N2O2PS2 (284.37): C, 38.01; H, 7.44;
N, 9.85. Found: C, 38.07; H, 7.39; N, 9.89%.
3·Et2NH. Yield: 0.733 g (76%). IR ν (cm−1): 617 (PvS), 970
1
3
(POC), 1504 (SCN). H NMR: δ = 1.15 (t, JH,H = 7.1 Hz, 6H,
3
+
CH3, Et), 1.23 (t, JH,H = 7.3 Hz, 6H, CH3, Et2NH2 ), 1.29 (d,
3JH,H = 6.2 Hz, 12H, CH3, iPr), 2.88 (q, JH,H = 7.3 Hz, 4H,
3
+
3
CH2, Et2NH2 ), 3.62 (br. s, 4H, CH2), 4.79 (d. sept, JPOCH
=
3
10.6 Hz, JH,H = 6.2 Hz, 2H, OCH), 8.91 (br. s, 2H, NH2,
+
The thioureas 1–10 have been investigated for their transport
properties towards the CoII, NiII, CuII, ZnII, AgI, CdII and PbII
cations. It was established, that the ligands 6 and 10 are the most
Et2NH2 ) ppm. 31P{1H} NMR: δ = 58.5 ppm. Calc. for
C15H36N3O2PS2 (385.56): C, 46.73; H, 9.41; N, 10.90. Found:
C, 46.68; H, 9.49; N, 10.81%.
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4. Yield: 1.658 g (92%). IR ν (cm−1): 638 (PvS), 955
(POC), 1525 (SvC–N), 3084, 3365 (NH). H NMR: δ = 1.39
10. Yield: 1.520 g (94%). IR ν (cm−1): 637 (PvS), 977
1
1
(POC), 1535 (SvC–N), 3098, 3264 (NH). H NMR: δ = 1.24
3
3
3
3
(d, JH,H = 6.2 Hz, 6H, CH3, iPr), 1.41 (d, JH,H = 6.2 Hz, 6H,
CH3, iPr), 2.28 (s, 3H, CH3, Me), 2.34 (s, 3H, CH3, Me), 4.89
(d, JH,H = 6.2 Hz, 6H, CH3, iPr), 1.29 (d, JH,H = 6.1 Hz, 6H,
3
3
CH3, iPr), 4.71 (d. sept, JPOCH = 10.7 Hz, JH,H = 6.1 Hz, 2H,
OCH, iPr), 7.18 (br. s, 1H, PNH), 8.72 (s, 1H, arylNH), 8.93 (s,
2H, CH, triazole) ppm. 31P{1H} NMR: δ = 53.1 ppm. Calc. for
C9H18N5O2PS2 (323.37): C, 33.43; H, 5.61; N, 21.66. Found: C,
33.49; H, 5.56; N, 21.58%.
3
3
(d. sept, JPOCH = 10.5 Hz, JH,H = 6.2 Hz, 2H, OCH, iPr), 7.05
(d. d, JH,H = 7.9 Hz, JH,H = 1.2 Hz, 1H, p-H, C6H3), 7.10 (br.
3
4
3
s, 1H, PNH), 7.16 (d, JH,H = 7.8 Hz, 1H, m-H, C6H3), 7.22 (br.
s, 1H, o-H, C6H3), 9.30 (s, 1H, arylNH) ppm. 31P{1H} NMR: δ
= 52.7 ppm. Calc. for C15H25N2O2PS2 (360.47): C, 49.98; H,
6.99; N, 7.77. Found: C, 49.92; H, 7.04; N, 7.71%.
Membrane transport
5. Yield: 1.6718 g (89%). IR ν (cm−1): 632 (PvS), 974
(POC), 1529 (SvC–N), 3051, 3215 (NH). H NMR: δ = 1.39
1
An aqueous source phase (10 mL), containing an equimolar
mixture of the seven metal ions CoII, NiII, CuII, ZnII, AgI, CdII
and PbII as their nitrate salts dissolved in a pH 5.5 buffer solution
(CH3COOH/NaOOCCH3), and an aqueous receiving phase
(30 mL of 0.1 mol dm−3 HNO3, pH = 1.0) were separated by a
water presaturated chloroform membrane phase containing the
ligand (50 mL) and 4 × 10−3 mol dm−3 palmitic acid. The con-
centration of the metal ions was 1 × 10−2 mol dm−3 and that of
the chosen ligand was 2 × 10−3 mol dm−3. The mentioned pH
values of the source and receiving phases, as well as the ligand
concentration in the membrane phase, were found to be the
optimum for the use of the NTTU ligands as ionophores.5c,d The
slightly modified cell details are the same as those described by
Lindoy et al.15 The membrane phase, the source phase and the
receiving phase were then transferred in this respective order into
the cells. The cells were thermostated at 25 °C and stirred at 10
rpm. Under these conditions, not only was the stirring process
consistent, but also the interfaces between the organic membrane
and the two aqueous phases remained flat and well defined and
transport allowed to take place, against a back gradient of
protons. The cells were covered with cover slips in order to
prevent evaporation of solvents over the 24 h period and then
entirely covered by aluminium foil in order to prevent the light-
induced reduction of AgI in the source phase. All transport
experiments were terminated after 24 h and the amount of metal
ion transported from the source phase to the receiving phase
over this period was determined by atomic absorption spec-
troscopy (AAS). Small samples for analysis were taken from
both the source and receiving phases of each duplicate run after
each experiment and analyzed. The average flux rate, J (mol per
24 h), for each transport experiment was calculated based on the
quantity of metal ions transported into the receiving phase in a
24 h period. The transport results are quoted as the average
values obtained from the duplicate runs carried out in parallel; in
all cases the flux values obtained did not differ by more than
5%. J values equal to or less than 2.2 × 10−8 mol per 24 h were
assumed to be within experimental error of zero and have been
ignored in the analysis of results.
3
3
(d, JH,H = 6.1 Hz, 6H, CH3, iPr), 1.40 (d, JH,H = 6.1 Hz, 6H,
3
CH3, iPr), 2.96 (s, 6H, CH3, Me), 4.87 (d. sept, JPOCH = 10.6
Hz, 3JH,H = 6.1 Hz, 2H, OCH, iPr), 6.71 (d, 3JH,H = 8.7 Hz, 2H,
o-H, C6H4), 6.98 (d, 3JPNH = 9.1 Hz, 1H, PNH), 7.29 (d, 3JH,H
=
8.6 Hz, 2H, m-H, C6H4), 9.34 (s, 1H, arylNH) ppm. 31P{1H}
NMR: δ = 52.6 ppm. Calc. for C15H26N3O2PS2 (375.48): C,
47.98; H, 6.98; N, 11.19. Found: C, 48.05; H, 7.07; N, 11.13%.
6. Yield: 1.874 g (96%). IR ν (cm−1): 647 (PvS), 964
1
(POC), 1528 (SvC–N), 1707 (CvO), 3151 (NH). H NMR: δ
3
3
= 1.39 (d, JH,H = 6.2 Hz, 6H, CH3, iPr), 1.41 (d, JH,H = 6.2
3
Hz, 6H, CH3, iPr), 3.92 (s, 3H, CH3, Me), 4.91 (d. sept, JPOCH
= 10.6 Hz, 3JH,H = 6.2 Hz, 2H, OCH, iPr), 7.23 (d. t, 3JH,H = 7.8
4
3
Hz, JH,H = 1.5 Hz, 1H, m-H, C6H4), 7.54 (d. t, JH,H = 7.9 Hz,
4JH,H = 1.6 Hz, 1H, p-H, C6H4), 7.18 (br. s, 1H, PNH), 7.98 (d.
3
4
3
d, JH,H = 7.9 Hz, JH,H = 1.6 Hz, 1H, o-H, C6H4), 8.39 (d, JH,
= 8.0 Hz, 1H, m-H, C6H4), 11.03 (s, 1H, arylNH) ppm. 31P
H
{1H} NMR: δ = 53.9 ppm. Calc. for C15H23N2O4PS2 (390.45):
C, 46.14; H, 5.94; N, 7.17. Found: C, 46.08; H, 5.98; N, 7.12%.
7. Yield: 1.517 g (91%). IR ν (cm−1): 639 (PvS), 962
1
(POC), 1530 (SvC–N), 3182, 3216 (NH). H NMR: δ = 1.41
3
3
(d, JH,H = 6.2 Hz, 6H, CH3, iPr), 1.42 (d, JH,H = 6.2 Hz, 6H,
3
3
CH3, iPr), 5.00 (d. sept, JPOCH = 10.6 Hz, JH,H = 6.2 Hz, 2H,
OCH, iPr), 6.87–7.08, 7.61–7.76, 8.13–8.24 (m, 4H, Py), 9.39
(s, 1H, PyNH), 13.31 (br. s, 1H, PNH) ppm. 31P{1H} NMR: δ =
57.5 ppm. Calc. for C12H20N3O2PS2 (333.40): C, 43.23; H,
6.05; N, 12.60. Found: C, 43.29; H, 6.11; N, 12.53%.
8. Yield: 1.511 g (87%). IR ν (cm−1): 643 (PvS), 969
1
3
(POC), 1534 (SvC–N), 3167 (NH). H NMR: δ = 1.31 (d, JH,
3
= 6.1 Hz, 6H, CH3, iPr), 1.37 (d, JH,H = 6.1 Hz, 6H, CH3,
H
3
3
iPr), 4.83 (d. sept, JPOCH = 10.5 Hz, JH,H = 6.1 Hz, 2H, OCH,
iPr), 4.91 (d, 3JHCNH = 4.1 Hz, 2H, CH2), 6.95 (br. s, 1H, PNH),
7.17–7.39, 7.63–7.78, 8.48–8.61 (m, 4H, Py), 8.96 (br. s, 1H,
alkylNH) ppm. 31P{1H} NMR: δ = 53.8 ppm. Calc. for
C13H22N3O2PS2 (347.43): C, 44.94; H, 6.38; N, 12.09. Found:
C, 44.86; H, 6.42; N, 12.14%.
Under the experimental conditions employed, no metal ion
transport was observed when only palmitic acid was present in
the membrane phase.
9. Yield: 1.372 g (79%). IR ν (cm−1): 646 (PvS), 978
1
(POC), 1537 (SvC–N), 3179, 3248 (NH). H NMR: δ = 1.26
3
3
(d, JH,H = 6.1 Hz, 6H, CH3, iPr), 1.27 (d, JH,H = 6.1 Hz, 6H,
3
3
CH3, iPr), 4.75 (d. sept, JPOCH = 10.5 Hz, JH,H = 6.1 Hz, 2H,
OCH, iPr), 4.85 (d, 3JHCNH = 4.6 Hz, 2H, CH2), 7.22 (br. s, 1H,
PNH), 7.17–7.37, 7.61–7.81, 8.52–8.65 (m, 4H, Py), 8.31 (br. s,
1H, alkylNH) ppm. 31P{1H} NMR: δ = 52.7 ppm. Calc. for
C13H22N3O2PS2 (347.43): C, 44.94; H, 6.38; N, 12.09. Found:
C, 45.02; H, 6.33; N, 12.02%.
X-Ray crystallography
The X-ray data of 1 and 4–7 were collected on a STOE IPDS-II
diffractometer with graphite-monochromatised Mo-Kα radiation
generated by a fine-focus X-ray tube operated at 50 kV and
3230 | Dalton Trans., 2012, 41, 3223–3232
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View Article Online
40 mA. The reflections of the images were indexed, integrated
and scaled using the X-Area data reduction package.16 Data were
corrected for absorption using the PLATON program.17 The X-
ray data for 8 were collected on a Mar345 image plate detector
using Mo-Kα radiation (Zr-filter). The data were integrated with
the crysAlisPro software.18 The structures were solved by direct
methods using the SHELXS97 program19 and refined first isotro-
pically and then anisotropically using SHELXL-97.19 Hydrogen
atoms of 1 and 4–7 were revealed from Δρ maps and those
bonded to C were refined using appropriate riding models. H
atoms bonded to N were freely refined. Non-hydrogen atoms of
8 were anisotropically refined and the hydrogen atoms were
placed on calculated positions in riding mode with temperature
factors fixed at 1.2 times Ueq of the parent atoms and 1.5 times
Ueq for methyl groups. Figures were generated using the
program Mercury.20
Acknowledgements
This work was partly funded by the Fonds National de la
Recherche Scientifique-FNRS (FRFC N°2.4508.08, IISN
4.4507.10) and the IAP-VI (P6/17) INANOMAT program. We
thank the F.R.S.-FNRS (Belgium) for a post-doctoral position
allocated to D. A. S. We thank Dr K. Robeyns for recording
X-ray data of 8.
Notes and references
1 B. Moulton and M. J. Zaworotko, Chem. Rev., 2001, 101, 1629 and refer-
ences therein.
2 (a) J. M. Lehn, Supramolecular Chemistry, VCH, Weinheim, Germany,
1995; (b) L. Brunsveld, B. J. B. Folmer, E. W. Meijer and R. P. Sijbesma,
Chem. Rev., 2001, 101, 4071.
3 G. A. Jeffery, An Introduction To Hydrogen Bonding, Oxford University
Press, 1997.
4 (a) M. D. Hollingsworth and K. D. M. Harris, Urea, Thiourea and Sele-
nourea, in Comprehensive Supramolecular Chemistry, ed. J. L. Atwood,
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5 For examples: (a) F. D. Sokolov, V. V. Brusko, N. G. Zabirov and R.
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Crystal data for 1. C10H23N2O2PS2, Mr = 298.39 g mol−1
,
ˉ
triclinic, space group P1, a = 8.7411(4), b = 9.4953(4),
c = 10.2409(5) Å, α = 94.511(2), β = 99.974(2), γ = 94.849(2)°,
V = 830.37(7) Å3, Z = 2, ρ = 1.193 g cm−3, μ(Mo-Kα) =
0.411 mm−1, reflections: 21707 collected, 6020 unique, Rint
0.0171, R1(all) = 0.0322, wR2(all) = 0.0811.
=
Crystal data for 4. C15H25N2O2PS2, Mr = 360.46 g mol−1
,
monoclinic, space group P21/c, a = 9.6981(5), b = 16.1422(10),
c = 13.1345(6) Å, β = 111.037(3)°, V = 1919.14(18) Å3, Z = 4,
ρ = 1.248 g cm−3, μ(Mo-Kα) = 0.368 mm−1, reflections: 31989
collected, 3640 unique, Rint = 0.0974, R1(all) = 0.0937, wR2(all)
= 0.1351.
Crystal data for 5. C15H26N3O2PS2, Mr = 375.48 g mol−1, tri-
ˉ
clinic, space group P1, a = 10.2581(6), b = 13.1606(7), c =
14.9343(8) Å, α = 90.718(3), β = 107.751(3), γ = 93.285(2)°, V
= 1916.07(18) Å3, Z = 4, ρ = 1.302 g cm−3, μ(Mo-Kα) =
0.373 mm−1, reflections: 33787 collected, 6750 unique, Rint
0.0567, R1(all) = 0.0781, wR2(all) = 0.1522.
=
6 (a) N. G. Zabirov, A. Yu. Verat, F. D. Sokolov, M. G. Babashkina,
D. B. Krivolapov and V. V. Brusko, Mendeleev Commun., 2003, 13, 163;
(b) A. Y. Verat, F. D. Sokolov, N. G. Zabirov, M. G. Babashkina,
D. B. Krivolapov, V. V. Brusko and I. A. Litvino, Inorg. Chim. Acta,
2006, 359, 475; (c) F. D. Sokolov, M. G. Babashkina, D. A. Safin,
N. G. Zabirov and R. A. Cherkasov, Russ. J. Gen. Chem., 2006, 76,
1340.
7 (a) E. G. Yarkova, N. R. Safiullina, I. G. Chistyakova, N. G. Zabirov,
F. M. Shamsevaleev and R. A. Cherkasov, Zh. Obshch. Khim., 1990, 60,
1790; (b) N. G. Zabirov, V. N. Soloviev, F. M. Shamsevaleev, R.
A. Cherkasov, A. N. Chechlov, A. G. Tsyfarkin and I. V. Martynov, J.
Gen. Chem. USSR, 1991, 61, 597.
8 (a) M. G. Babashkina, D. A. Safin, M. Bolte and A. Klein, Polyhedron,
2009, 28, 2693; (b) D. A. Safin, M. G. Babashkina, M. Bolte and
A. Klein, Inorg. Chim. Acta, 2010, 363, 1791.
9 Y. Garcia, P. J. van Koningsbruggen, G. Bravic, D. Chasseau and
O. Kahn, Eur. J. Inorg. Chem., 2003, 356.
10 J. Kim, A. J. Leong, L. F. Lindoy, J. Kim, J. Nachbaur, A. Nezhadali,
G. Rounaghi and G. Wei, J. Chem. Soc., Dalton Trans., 2000, 3453.
11 M. Akhond and M. Shamsipur, J. Membr. Sci., 1996, 117, 221.
12 A. Safavi and S. Rastegarzadeh, Talanta, 1995, 42, 2039.
13 J. Kim, T. H. Ahn, M. Lee, A. J. Leong, L. F. Lindoy, B. R. Rumbel,
B. W. Skelton, T. Strixner, G. Wei and A. H. White, J. Chem. Soc.,
Dalton Trans., 2002, 3993.
14 (a) F. D. Sokolov, M. G. Babashkina, D. A. Safin, A. I. Rakhmatullin,
F. Fayon, N. G. Zabirov, M. Bolte, V. V. Brusko, J. Galezowska and
H. Kozlowski, Dalton Trans., 2007, 4693; (b) F. D. Sokolov,
Crystal data for 6. C15H23N2O4PS2, Mr = 390.44 g mol−1
,
monoclinic, space group P21/n, a = 7.7008(9), b = 20.249(3), c
= 12.5512(17) Å, β = 95.990(6)°, V = 1946.5(5) Å3, Z = 4, ρ =
1.332 g cm−3, μ(Mo-Kα) = 0.376 mm−1, reflections: 52859 col-
lected, 5030 unique, Rint = 0.0388, R1(all) = 0.0411, wR2(all) =
0.0845.
Crystal data for 7. C12H20N3O2PS2, Mr = 333.40 g mol−1
orthorhombic, space group Pbca, a = 14.3388(7), b = 6.9545(4),
,
c = 33.6884(18) Å, V = 3359.4(3) Å3, Z = 8, ρ = 1.318 g cm−3
,
μ(Mo-Kα) = 0.416 mm−1, reflections: 68595 collected, 4341
unique, Rint = 0.0820, R1(all) = 0.0697, wR2(all) = 0.1030.
Crystal data for 8. C13H22N3O2PS2, Mr = 347.43 g mol−1
,
monoclinic, space group P21/n, a = 7.6949(8), b = 17.153(2), c
= 13.2985(13) Å, β = 90.175(10)°, V = 1755.3(3) Å3, Z = 4, ρ =
1.315 g cm−3, μ(Mo-Kα) = 0.401 mm−1, reflections: 8683 col-
lected, 3210 unique, Rint = 0.028, R1(all) = 0.0394, wR2(all) =
0.1073.
This journal is © The Royal Society of Chemistry 2012
Dalton Trans., 2012, 41, 3223–3232 | 3231

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3232 | Dalton Trans., 2012, 41, 3223–3232
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