Four novel mononuclear and polynuclear Cu(I) thiosaccharinates with triphenylphosphane and bis(diphenylposphino)methane. Synthesis and structural study of Cu4(tsac)4(PPh3)3, Cu(tsac)(PPh3)2, Cu4(tsac)4(dppm)2, and Cu2(tsac)2(dppm)2

Article abstract of DOI:10.1016/j.ica.2009.01.014

Four new ternary complexes of copper(I) with thiosaccharin and phosphanes were prepared. The reaction of [Cu₄(tsac)₄(CH₃CN)₂] (1) (tsac: thiosaccharinate anion) with PPh₃ in molar ratios Cu(I)/PPh₃ 1:075 and 1:2 gave the complexes [Cu₄(tsac)₄(PPh₃)₃] · CH₃CN (2) and Cu(tsac)(PPh₃)₂ (3), respectively. The reaction of 1 with Ph₂PCH₂PPh₂ (dppm) in molar ratios Cu(I)/dppm 2:1 and 1:1 gave the complexes [Cu₄(tsac)₄(dppm)₂] · 2CH₂Cl₂ (4) and [Cu₂(tsac)₂(dppm)₂] · CH₂Cl₂ (5), respectively. All the compounds have been characterized by spectroscopic and X-ray crystallographic methods. Complex 2 presents a tetra-nuclear arrangement with three metal centers in distorted tetrahedral S₂NP environments, the fourth one with the Cu(I) ion in a distorted trigonal S₂N coordination sphere, and the tsac anions acting as six electron donor ligands in μ₃-S₂N coordination forms. Complex 3 shows mononuclear molecular units with copper(I) in a distorted trigonal planar coordination sphere, built with the exocyclic S atom of a mono-coordinated thiosaccharinate anion and two P-atoms of triphenylphosphane molecules. With dppm as secondary ligand the structures of the complexes depends strongly on the stoicheometry of the preparation reaction. Complex 4 has a centrosymmetric structure. Two triply bridged Cu₂(tsac)₂(dppm) units are joined together by the exocyclic S-atoms of two tsac anions acting effectively as bridging tridentate ligands. Complex 5 is conformed by asymmetric dinuclear moieties where the two dppm and one tsac ligands bridge two Cu(I) atoms and the second tsac anion binds one of the metal centers through its exocyclic S-atom.

Full text of DOI:10.1016/j.ica.2009.01.014

Inorganica Chimica Acta 362 (2009) 2900–2908
Contents lists available at ScienceDirect
Inorganica Chimica Acta
journal homepage: www.elsevier.com/locate/ica
Four novel mononuclear and polynuclear Cu(I) thiosaccharinates
with triphenylphosphane and bis(diphenylposphino)methane. Synthesis
and structural study of Cu4(tsac)4(PPh3)3, Cu(tsac)(PPh3)2, Cu4(tsac)4(dppm)2,
and Cu2(tsac)2(dppm)2
b
Mariana Dennehy a, Gabriela P. Tellería a, Oscar V. Quinzani a, , Gustavo A. Echeverría ,
*
Oscar E. Piro b, Eduardo E. Castellano c
a INQUISUR, Departamento de Química, Universidad Nacional del Sur, Avda. Alem 1253, B8000CPB, Bahía Blanca, Buenos Aires, Argentina
b Departamento de Física and Instituto IFLP (Conicet), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, C.C. 67, 1900 La Plata, Argentina
c Instituto de Física de São Carlos, Universidade de São Paulo, CP. 369, 13560 São Carlos (SP), Brazil
a r t i c l e i n f o
a b s t r a c t
Article history:
Four new ternary complexes of copper(I) with thiosaccharin and phosphanes were prepared. The reaction
of [Cu4(tsac)4(CH3CN)2] (1) (tsac: thiosaccharinate anion) with PPh3 in molar ratios Cu(I)/PPh3 1:075 and
1:2 gave the complexes [Cu4(tsac)4(PPh3)3] ꢀ CH3CN (2) and Cu(tsac)(PPh3)2 (3), respectively. The reaction
of 1 with Ph2PCH2PPh2 (dppm) in molar ratios Cu(I)/dppm 2:1 and 1:1 gave the complexes [Cu4
(tsac)4(dppm)2] ꢀ 2CH2Cl2 (4) and [Cu2(tsac)2(dppm)2] ꢀ CH2Cl2 (5), respectively. All the compounds have
been characterized by spectroscopic and X-ray crystallographic methods.
Complex 2 presents a tetra-nuclear arrangement with three metal centers in distorted tetrahedral S2NP
environments, the fourth one with the Cu(I) ion in a distorted trigonal S2N coordination sphere, and the
tsac anions acting as six electron donor ligands in l3-S2N coordination forms. Complex 3 shows mono-
Received 26 September 2008
Received in revised form 8 January 2009
Accepted 14 January 2009
Available online 23 January 2009
Keywords:
Copper(I)
Thiones
Thionates
nuclear molecular units with copper(I) in a distorted trigonal planar coordination sphere, built with
the exocyclic S atom of a mono-coordinated thiosaccharinate anion and two P-atoms of triphenylphos-
phane molecules. With dppm as secondary ligand the structures of the complexes depends strongly on
the stoicheometry of the preparation reaction. Complex 4 has a centrosymmetric structure. Two triply
bridged Cu2(tsac)2(dppm) units are joined together by the exocyclic S-atoms of two tsac anions acting
effectively as bridging tridentate ligands. Complex 5 is conformed by asymmetric dinuclear moieties
where the two dppm and one tsac ligands bridge two Cu(I) atoms and the second tsac anion binds one
of the metal centers through its exocyclic S-atom.
Phosphanes
X-ray crystal structure
Spectra
Ó 2009 Elsevier B.V. All rights reserved.
1. Introduction
good reducing agents for Cu(II), giving rise to little soluble Cu(I)
complexes [8,10,12].
The heterocyclic thioamides (thiones) are systems of chemical
and biological interest because they are good chelating agents for
a great number of metal ions in different oxidation states [1–8].
They show tautomeric equilibrium in solution hence making them
versatile complexing agents, especially for heavy metals [9]. Partic-
ular attention has been devoted in the last decades to the synthesis
of copper complexes, in both the mono and divalent oxidation
states, due to the great variety and flexibility of their coordination
spheres [1c,10]. The relative stability of the Cu(I) and Cu(II) oxida-
tion states depends on various factors such as the redox potentials
of the ligands (L), the solubility of Cu(I)–L and Cu(II)–L adducts and
the solvent polarity [10,11]. In particular thiolate compounds are
Among the studied ligands, the heterocyclic thioamides and its
deprotonated counterparts, thioamidates (thionates) have at-
tracted attention because the exocyclic sulfur and/or the endocy-
clic nitrogen atoms of the thioamido group may be involved in
metal coordination, making then potentially mono- to poly-func-
tional donor agents. These versatile S,N ligands are capable to bind
metals in a great variety of coordination forms: N- or S-monoden-
tate, N,S-chelate, and
l2-S, l2-N,S, l3-N,S (g g l4-N,S
2-S, 1-N) or
(g
3-S, 1-N) bridges. As a consequence, a rich field of mononu-
g
clear, binuclear and complex poly-nuclear coordination com-
pounds has developed. There are several reviews in the literature
dealing with heterocyclic thioamide–metal coordination [1,10].
Ternary and quaternary Cu(I)-halide complexes with neutral
thiones and mono- or diphosphanes have been extensively studied
by several research groups [4,5,13]. In these complexes Cu(I)
* Corresponding author. Fax: +54 291 4595159.
E-mail address: quinzani@criba.edu.ar (O.V. Quinzani).
0020-1693/$ - see front matter Ó 2009 Elsevier B.V. All rights reserved.
doi:10.1016/j.ica.2009.01.014

M. Dennehy et al. / Inorganica Chimica Acta 362 (2009) 2900–2908
2901
presents distorted trigonal or tetrahedral coordination spheres
M
M
M
S
with the heterocyclic thiones bond to the metal as mono-dentate
or bridging bi-dentate ligands through the thiocarbonilic sulfur
A
S
S
B
E
C
F
M
C
C
C
atom (g l2-S coordination forms, respectively). Among
1-S and
N
N
N
the chemistry of Cu(I) with thionates most of the research effort
has been focused on the tetra-nuclear [6,14,15] or hexa-nuclear
binary complexes [2,3,16] and also on the ternary Cu(I)–thioami-
date–diphosphane complexes [7,17]. Copper–phosphane binding
produces a large diversity of structural arrangements, with ligand
to copper ratios from 1:1 to 4:2 [17,18]. Among them, the use of
dppm as a bridging ligand between Cu(I) centers has developed a
very rich structural chemistry of di-nuclear [19], tri-nuclear [20]
and poly-nuclear [21] complexes.
Thiosaccharinate (1,2-benzoisothiazol-3-thionate-1,1-dioxide),
the anion of thiosaccharin which is the thione form of saccharin,
behaves as a versatile coordination agent for heavy metals. The an-
ion has adopted a variety of coordination forms (Scheme 1) in the
ternary metal thiosaccharinates with azines or phosphanes previ-
ously reported [22]. As part of a research to elucidate the coordina-
tion properties of metal thiosaccharinates, we present here the
synthesis and the spectroscopic and X-ray diffraction study of four
new Cu(I) complexes which exhibit different types of interaction
between the thionate ligand and the metal centers: [Cu4(tsac)4
S
S
S
O
S
O
O
M
O
O O
M
M
M
S
S
D
M
C
C
S
C
N
M
N
N
M
S
S
O
O
O
O
O
O
Scheme 1. Coordination forms of thiosaccharinate ligand.
(PPh3)3] ꢀ MeCN, [Cu(tsac)(PPh3)2], [Cu4(tsac)4(dppm)2] ꢀ 2CH2Cl2,
and [Cu2(tsac)2(dppm)2]ꢀCH2Cl2.
S
(3)
(2)
(4)
(1)
NCMe
N
=
N
S
(5)
Cu1
S
(7)
N
(6)
O
O
Cu3
S
N
S
tsac
S
N
N
Cu2
1
Cu4
S
MeCN
dppm (
)
P
P
PPh3 (P)
P
P
P
Cu
Cu1
N
N
N
Cu3
S
S
Cu
S
S
S
S
S
N
Cu
N
N
N
Cu2
N
Cu
Cu4
P
P
S
4
2
P
P
dppm
PPh3
P
P
P
N
Cu
Cu
P
P
Cu
S
S
P
S
N
3
5
N
Scheme 2. Copper thiosaccharinates obtained with increasing amounts of phosphanes.

2902
M. Dennehy et al. / Inorganica Chimica Acta 362 (2009) 2900–2908
2.2.3. Tetrakis(thiosaccharinato)bis{bis(diphenylphosphino)methane}
2. Experimental
tetracopper(I) bis(dichloromethane), [Cu4(tsac)4(dppm)2] ꢀ 2CH2Cl2
(4)
2.1. General remarks
A solution of 1 (0.012 g, 0.010 mmol) in acetonitrile (5 mL) was
slowly added with constant mechanical stirring to a solution of
bis(diphenylphosphino)methane (dppm) (0.0078 g, 0.020 mmol)
in the same solvent (3 mL) (Cu/dppm molar ratio = 1/0.5). The
resulting orange solution was evaporated to dryness at 40 °C.
Dichloromethane (4 mL) was used to dissolve the solid and diethyl
ether was allowed to slowly diffuse into the solution, at room tem-
perature. The orange crystals obtained loosed their quality after
exposure to moisture. The best crystals were kept in the mother li-
quor until they were mounted on a goniometric head for the X-ray
diffraction study. To ensure the analytical composition of the sub-
stance, it was grinding and heated at 40 °C until constant weight
was reached. Anal. Calc. for C78H60Cu4N4O8P4S8: C, 51.6; H, 3.3;
N, 3.1. Found: C, 51.9; H, 3.0; N, 2.6%. IR (freshly prepared solid,
Nujol mulls, cmꢁ1): 1482w, 1436m, 1409m, 1338m, 1325m,
1244m, 1171s, 1154m, 1123m, 1020m, 1007m, 822m, 801m,
771m, 736m, 694m, 624w, 596m, 561m, 552m, 517w, 500vw,
428w. IR (solid, KBr, cmꢁ1): 3053w, 2923w, 1459s, 1437m,
1399m, 1323m, 1243s, 1169vs, 1123m, 1020m, 1004w, 818w,
739m, 694m, 595m, 560s, 437w. 1H NMR (DMSO-d6, d in ppm): d
8.03–7.92 (m, 2H, H6), 7.90–7.70 (m, 2H, H3), 7.70–7.48 (m, 4H,
H4/H5); 7.15–6.70 (m, 8H, Ha), 7.45–7.15 (m, 12H, Hb, c), 3.48
(s, 2H, CH2). 31P{1H} NMR (DMSO-d6, d in ppm): d 48.95 (dppm).
All chemicals and solvents were of analytical reagent grade
and used as purchased. Thiosaccharin in its solid
a-form and
[Cu4(tsac)4(MeCN)2] ꢀ 2MeCN (1) were prepared following the
techniques published previously [15]. The elemental composition
analysis of C, H, and N were performed with a Carlo Erba
EA1108 instrument at INQUIMAE (FCEyN, UBA, Argentina). The
IR spectra in KBr pellets and Nujol mulls were recorded on a
Nicolet Nexus FTIR spectrometer. The electronic spectra of solu-
tions and solid spectra in BrK discs, were registered using a Cecil
CE 2021 UV–Vis spectrophotometer. The 1H, and 31P{1H} RMN
spectra were recorded on a multinuclear Bruker ARX-300 equip-
ment. The chemical shift data were measured by the replace-
ment methods and are given relative to TMS and external
H3PO4 (85%) standards. The numbering of the compounds can
be seen above in Scheme 2. Conductivity measurements of ace-
tonitrile (MeCN) solutions of compounds 2 and 3 were per-
formed with an OAKTON digital conductimeter calibrated
against aqueous solutions of twice re-crystallized KCl
(744.7 ppm, 1413 lS).
2.2. Synthesis of the complexes
2.2.1. Tetrakis(thiosaccharinato)tris(triphenylphosphane)tetra-
copper(I) monoacetonitrile, [Cu4(tsac)4(PPh3)3] ꢀ MeCN (2)
2.2.4. Bis(thiosaccharinato)bis{bis(diphenylphosphino)methane}
dicopper(I)dichloromethane, [Cu2(tsac)2(dppm)2] ꢀ CH2Cl2 (5)
Complex 5 was prepared at room temperature by the reaction
Over a solution of complex 1 (0.010 g, 0.009 mmol) in aceto-
nitrile (11 mL), a solution of PPh3 (0.007 g, 0.03 mmol) in aceto-
nitrile (10 mL) was slowly added with continuous stirring (Cu/
PPh3 molar ratio = 1/0.8). The final red solution was left to slowly
evaporate at room temperature until half of its original volume
was reached. The red single crystals obtained were filtered out,
washed with diethyl ether and air dried. They showed light
and air stability. Yield: 0.006 g (40%). Anal. Calc. for C84H64Cu4-
N5O8P3S8: C, 53.8; H, 3.4; N, 3.7. Found: C, 54.2; H, 3.4; N,
of complex
1
(0.012 g, 0,010 mmol) and dppm (0.016 g,
0,040 mmol) in dried acetonitrile (2.5 mL) at room temperature
(Cu/dppm molar ratio = 1/1). The resulting yellow solution was
evaporated to dryness and the residual solid further dried in the
oven at 40 °C. The yellow solid obtained was dissolved in dichloro-
methane (2 mL) and small amounts of well formed crystals were
obtained by slow diffusion of dried diethyl ether. Yield: variable,
around 10%. Anal. Calc. for C65H54Cu2Cl2N2O4P4S4: C, 56.7; H, 4.0;
N, 2.0. Found: C, 57.3; H, 4.1; N, 2.3%. IR (KBr, cmꢁ1): 3054w,
2924w, 1482w, 1458s, 1434s, 1403s, 1364m, 1313s, 1300s,
1244m, 1166vs, 1151vs, 1121s, 1097m, 1022m, 1001s, 834w,
822m, 783m, 770m, 739vs, 693vs, 588m, 561m, 553m, 517m,
432s. Due to the low yield of the preparation, the NMR spectra
were obtained dissolving corresponding amounts of complex 1
and dppm in DMSO-d6, checking the resulting solutions by UV–
Vis spectroscopy. 1H NMR (DMSO-d6, d in ppm): d 7.44–7.37 (m,
1H, H6), 7.19–7.11 (m, 1H, H3), 7.09–6.98 (m, 2H, H4/H5); 6.83–
6.63 (m, 8H, Ha), 6.52-6.42 (m, 4H, Hc), 6.40–6.28 (m, 8H, Hb);
2.92 (s, 2H, CH2). 31P{1H} NMR (DMSO-d6, d in ppm): d 46.35
(dppm).
3.6%. Molar conductance
(
X
ꢁ1 molꢁ1 cmꢁ1): 33 (3.0 ꢂ 10ꢁ4
M
solutions in MeCN). IR: (KBr, cmꢁ1): 3072w, 3053w, 1480m,
1461s, 1435s, 1399s, 1325s, 1236s, 1170vs, 1124s, 1095s,
1003s, 820m, 792m, 768m, 746m, 694s, 586m, 557s, 520m,
431m. 1H NMR (DMSO-d6, d in ppm): d 7.82–7.76 (m, 4H, H6);
7.72–7.65 (m, 4H, H3); 7.62–7.48 (m, 8H, H4/H5); 7.36–7.15
(m, 45 H, PPh3); 2.05 (s, 3H, MeCN). 31P{1H} NMR (DMSO-d6, d
in ppm): d 53.22 (PPh3).
2.2.2. Thiosaccharinato-bis(triphenylphosphane)copper(I),
[Cu(tsac)(PPh3)2] (3)
A solution of PPh3 (0.042 g, 0,16 mmol) in acetonitrile (2 mL)
was added to a red solution of copper thiosaccharinate (1)
(0.024 g, 0,021 mmol) in acetonitrile (20 mL) under continuous
stirring at room temperature (Cu/PPh3 molar ratio = 1/2). A clear
yellow solution was produced. After 4 days of slow evaporation
of the solvent at room temperature, bright yellow crystals suitable
for X-ray diffraction analysis were formed. The crystalline product
was filtered out, washed with diethyl ether and dried in air. Yield:
0.043 g (68 %). Anal. Calc. for C43H34CuNO2P2S2: C, 65.7; H, 4.4; N,
1.8. Found: C, 65.4; H, 4.7; N, 2.1%. Molar conductance
2.3. X-ray structure determination of complexes 2–5
Crystal data, structure solution methods and refinement results
are summarized in Table 1. The hydrogen atoms were stereochem-
ically positioned and refined with the riding model, adopting an
isotropic thermal parameter 20% greater than the equivalent iso-
tropic displacement parameter of the corresponding C-atom to
which they are bonded. This percentage was set to 50% for the
methyl hydrogen atoms of the acetronitrile molecule in 2, which
were refined as a rigid group allowed to rotate around the corre-
sponding C–CN bond.
Tables containing complete information on atomic coordinates
and equivalent isotropic parameters, full intra-molecular bond dis-
tances and angles, anisotropic thermal parameters and hydrogen
atomic positions are available from the authors upon request and
(
X
ꢁ1 molꢁ1 cmꢁ1): 35 (1.0 ꢂ 10ꢁ3 M solutions in MeCN). IR (KBr,
cmꢁ1): 3074w, 3061w, 1480m, 1461s, 1434s, 1403s, 1305vs,
1238s, 1153vs, 1123s, 1094s, 1008s, 8067s, 753m, 739m, 694vs,
590m, 555m, 518s, 509s, 432s. 1H NMR (DMSO-d6, d in ppm): d
8.19–8.14 (m, 1H, H6); 8.06–8.00 (m, 1H, H3); 7.97–7.88 (m, 2H,
H4/H5); 7.72–7.54 (m, 30 H, PPh3). 31P{1H} NMR (DMSO-d6, d in
ppm): d 53.06 (PPh3).

M. Dennehy et al. / Inorganica Chimica Acta 362 (2009) 2900–2908
2903
Table 1
Crystal data and structure solution methods and refinement results for [Cu4(tsac)4(PPh3)3] ꢀ MeCN (2), [Cu(tsac)(PPh3)2] (3), [Cu4(tsac)4(dppm)2] ꢀ 2CH2Cl2 (4), and
[Cu2(tsac)2(dppm)2] ꢀ CH2Cl2 (5).
(2)
(3)
(4)
(5)
Empirical formula
Formula weight
Temperature (K)
Crystal system
Space group
Unit cell dimensiona
a (Å)
C84H64Cu4N5O8P3S8
1875.08
296(2)
C43H34CuNO2P2S2
786.37
293(2)
monoclinic
Pn
C82H68Cl8Cu4N4O8P4S8
1077.8
293(2)
C65H54Cl2Cu2N2O4P4S4
1377.31
296(2)
triclinic
triclinic
triclinic
ꢀ
ꢀ
ꢀ
P1
P1
P1
13.1400(10)
16.5840(10)
19.7850(10)
91.650(10)
94.120(10)
107.380(10)
4098.2(4)
2
11.1510(17)
12.6190(11)
13.4310(18)
90.00
94.870(11)
90.00
1883.1(4)
2
1.387
12.6360(6)
13.5520(5)
14.3610(6)
89.568(2)
71.953(2)
71.385(2)
2204.49(16)
2
13.1210(10)
13.335(2)
19.9020(10)
93.910(10)
104.440(10)
107.310(10)
3181.1(6)
2
b (Å)
c (Å)
a
(°)
b (°)
c
(°)
V (Å3)
Z
DCalc (Mg/m3)
Absorption coefficient (mmꢁ1
F(000)
1.503
1.344
1890
1.624
1.513
1092
1.438
4.166
1412
)
2.957
812
Crystal size (mm)
Crystal color/shape
Diffractometer/scan
0.21 ꢂ 0.11 ꢂ 0.04
0.32 ꢂ 0.2 ꢂ 0.06
yellow/polyhedral
Enraf-Nonius CAD4/
scan
0.19 ꢂ 0.14 ꢂ 0.12
0.32 ꢂ 0.24 ꢂ 0.24
red/polyhedral
orange/polyhedral
yellow/polyhedral
KappaCCD/u and
Mo K , k = 0.71073
2.80–25.0
x
x
ꢁ 2h KappaCCD/u and
x
Enraf-Nonius CAD4/
Cu K k = 1.54184
2.32–67.99
x ꢁ 2h scan
Radiation, graphite
monochramated (Å)
h Range data collection (°)
Index ranges
a
Cu K
a
k = 1.54184
Mo K , k = 0.71073
a
a
3.50–72.05
2.69–25.00
ꢁ15 6 h 6 15, ꢁ19 6 k 6 18,
ꢁ23 6 l 6 23
35643/14357
0.0595
ꢁ13 6 h 6 13, ꢁ1 6 k 6 15, ꢁ15 6 h 6 15, ꢁ16 6 k 6 16,
ꢁ15 6 h 6 15,0 6 k 6 16,ꢁ23 6 l 6 23
0 6 l 6 16
3890/3872
0.0177
ꢁ17 6 l 6 15
17628/7715
0.0560
Reflections collected/unique
R(int)
12112/11572
0.0259
Observation reflections
9705
3851
5614
9874
[I > 2r(I)]
Completeness (%)
Maximum and minimum
transmission
99.3
0.9444/0.8203
99.7
0.9603/0.8576
99.5
0.8672/0.7838
99.9
0.3783/0.4647
Data collection
COLLECT [23]
DENZO and SCALEPACK [24]
CAD4 express
XCAD4
COLLECT [23]
DENZO and SCALEPACK [24]
CAD4 express
XCAD4
Data reduction and
correctionb
Absorption correction
Structure solutionc
Structure refinementd
Refinement method
PLATON [25]
SHELXS-97 [26]
SHELXL-97 [27]
Full-matrix least-squares on F2
Full-matrix least-squares
full-matrix least-squares on F2
full-matrix least-squares on F2
on F2
Weights,
[r
2(Fo2) + (0.0374P)2 + 5.66P]ꢁ1
[r
2(Fo 2) + (0.0586P)2
+
[r
2(Fo2) + (0.1180P)2 + 6.2764P]ꢁ1
[r
2(Fo2)+(0.0971P)2 + 3.1349P]ꢁ1
w(P = [Max(Fo2,0) + 2Fc2]/3)
Data/restraints/parameters
Goodness-of-fit on F2
0.31P]ꢁ1
3872/2/461
1.101
14357/0/995
1.017
7715/0/532
0.932
11572/0/769
1.051
Final R-index [I > 2
R1/wR2
r
(I)]e
0.0469/0.1122
0.0820/0.1311
0.550/ꢁ0.589
0.0306/0.0802
0.0307/0.0803
0.449/ꢁ0.442
0.0574/0.1548
0.0839/0.1797
2.942/ꢁ2.356
0.0568/0.1510
0.0651/0.1619
0.756/ꢁ0.710
R índices (all data)R1/wR2
Largest peak and hole (e Aꢁ3
)
a
Least-squares refinement of the angular settings for 35643 reflections in the 2.80 < h < 25.00° range for 2, 25 reflections in the 32.23 < h < 67.32° range for 3, 17628
reflections in the 2.69 < h < 25.00° range for 4, and 25 reflections in the 19.34 < h < 51.60° range for 5.
b
Corrections: Lorentz, polarization and absorption.
Structure solved by direct and Fourier methods.
Neutral scattering factors and anomalous dispersion corrections. Final molecular model obtained by anisotropic full-matrix least-squares refinement of the non-hydrogen
c
d
atoms.
e
2
R-indices defined as: R1
=
R
||Fo| ꢁ |Fc||/
R
|Fo|, wR2 = [
R
w(Fo ꢁ Fc2)2/
R .
w(Fo2)2]1/2
have been deposited at the Cambridge Crystallographic Data Cen-
tre, under deposition numbers CCDC 700159 (2), 700160 (3),
700161 (4), and 700162 (5).
The molecular complex is built over four Cu(I) cations held to-
gether by four thiosaccharinate anions, each one bridging three
metals in a tripodal
l3-N,S (g g
2-S, 1-N) coordination form. Three
PPh3 molecules bonded to three of the copper atoms of the tetra-
mer completes the non-symmetric structure. Then all copper
atoms are surrounded by two sulfur atoms and one nitrogen atom
belonging to tsac anions and three of them are also bounded to one
phosphorous atom of the phosphane molecules. The Cuꢀ ꢀ ꢀCu dis-
3. Results and discussion
3.1. Structural results and discussion
tances are too long to be considered as bond distances and only
3.1.1. Crystal and molecular structure of [Cu4(tsac)4(PPh3)3] ꢀ MeCN
(2)
Selected bond lengths and angles in [Cu4(tsac)4(PPh3)3] ꢀ MeCN
are listed in Table 2 and an ORTEP [28] molecular diagram of the
complex is shown in Fig. 1.
0
for the Cu(1)–Cu(3) separation (2.9844(8) ÅA) a weak inter-metallic
interaction can be considered. The tetra-nuclear unit of Cu(I) atoms
resembles that of complex 1. The inter-metallic distances are
shorter in the last substance (between 2.6033(7) and

2904
M. Dennehy et al. / Inorganica Chimica Acta 362 (2009) 2900–2908
0
4.4909(9) ÅA) and the Cu–S bonds (between 2.2291(1) and
2.5319(1) ÅA) are longer than in complex 2 [15]. These structural
changes are not the most important upon the coordination of the
PPh3 molecules. In the more asymmetric tetra-nuclear cluster of
complex 1, two Cu atoms are surrounded by two S atoms and
one N atom of tsac anions and one N atom of a MeCN molecule,
one of the metals is coordinated by three S atoms and with weak
interactions to other two Cu atoms, and the forth Cu(I) center is
surrounded by two N atoms of tsac anions and with a weak inter-
action to a S atom. These characteristics are indicating that a struc-
tural reorganization takes place in solution and complex 2 is not
formed by coordination of the phosphane molecules over complex
1. Both compounds 1 and 2 are bright red in the solid state and in
solution, which can indicate that each complex retains its molecu-
lar arrangement in solution.
0
Table 2
Bond distances (Å) and angles (°) around copper in [Cu4(tsac)4(PPh3)3] ꢀ MeCN (2).
Bond distances
Cu(1)–N(2)
Cu(1)–P(5)
Cu(1)–S(41)
Cu(1)–S(11)
Cu(2)–N(4)
Cu(2)–P(7)
Cu(2)–S(31)
Cu(2)–S(21)
2.055(3)
2.288(1)
2.342(1)
2.425(1)
2.038(3)
2.299(1)
2.389(1)
2.445(1)
Cu(2)–Cu(3)
Cu(3)–N(3)
Cu(3)–S(21)
Cu(3)–S(11)
Cu(4)–N(1)
Cu(4)–P(6)
Cu(4)–S(41)
Cu(4)–S(31)
2.9207(7)
2.001(3)
2.186(1)
2.228(1)
2.062(3)
2.301(1)
2.341(1)
2.349(1)
The molecular structure of solid complex 2 is very similar to
that observed for Ag4(tsac)4(PPh3)3 complex [22b]. In this sub-
stance all the tsac anions are also coordinated to three metal
Bond angles
centers in
l3-S,N coordination mode and only three silver atoms
N(2)–Cu(1)–P(5)
N(2)–Cu(1)–S(41)
P(5)–Cu(1)–S(41)
N(2)–Cu(1)–S(11)
P(5)–Cu(1)–S(11)
S(41)–Cu(1)–S(11)
N(2)–Cu(1)–Cu(3)
P(5)–Cu(1)–Cu(3)
S(41)–Cu(1)–Cu(3)
S(11)–Cu(1)–Cu(3)
N(4)–Cu(2)–P(7)
N(4)–Cu(2)–S(31)
P(7)–Cu(2)–S(31)
N(4)–Cu(2)–S(21)
P(7)–Cu(2)–S(21)
S(31)–Cu(2)–S(21)
N(4)–Cu(2)–Cu(3)
P(7)–Cu(2)–Cu(3)
123.19(9)
109.50(9)
105.18(4)
112.68(10)
96.58(4)
108.44(4)
79.78(9)
143.84(4)
89.80(3)
47.27(3)
124.9(1)
106.97(9)
98.76(4)
S(31)–Cu(2)–Cu(3)
S(21)–Cu(2)–Cu(3)
N(3)–Cu(3)–S(21)
N(3)–Cu(3)–S(11)
S(21)–Cu(3)–S(11)
N(3)–Cu(3)–Cu(2)
S(21)–Cu(3)–Cu(2)
S(11)–Cu(3)–Cu(2)
N(3)–Cu(3)–Cu(1)
S(21)–Cu(3)–Cu(1)
S(11)–Cu(3)–Cu(1)
Cu(2)–Cu(3)––Cu(1)
N(1)–Cu(4)–P(6)
N(1)–Cu(4)–S(41)
P(6)–Cu(4)–S(41)
N(1)–Cu(4)–S(31)
P(6)–Cu(4)–S(31)
S(41)–Cu(4)–S(31)
74.25(3)
47.07(3)
118.3(1)
108.3(1)
130.90(4)
90.11(9)
54.96(3)
142.37(4)
144.77(9)
91.58(3)
53.08(3)
93.12(2)
122.87(9)
108.1(1)
100.52(4)
110.3(1)
102.12(4)
112.65(4)
are coordinated by PPh3 molecules. As a difference with the copper
complex, obtained by the reaction with PPh3, the silver thiosaccha-
rinate needs the presence of a weak nitrogenous base to be
obtained. There is only one closed tetra-nuclear copper–thio-
nate–PPh3 complex reported in the literature, namely the
Cu4(tzdt)4(PPh3)2 (tzdt = thiazolidine-2-thione) complex. Like
other binary copper thionates it crystallizes as butterfly-shaped
Table 3
Bond distances (Å) and angles (°) around copper in [Cu(tsac)(PPh3)2] (3).
102.06(9)
106.59(4)
119.00(4)
103.54(9)
130.42(4)
Bond distances
Cu–P(2)
Cu–P(1)
Cu–S(1)
2.2504(8)
2.2658(8)
2.2753(9)
S(1)–C(1)
N–C(1)
1.689(3)
1.320(4)
Bond angles
P(2)–Cu–P(1)
P(2)–Cu–S(1)
P(1)–Cu–S(1)
122.38(3)
124.78(3)
112.73(3)
C(1)–S(1)–Cu
N–C(1)–S(1)
98.1(1)
124.6(2)
Fig. 1. Molecular plot of Cu4(tsac)4(PPh3)3 (2) showing the labeling scheme of the
non-H atoms. For clarity, the carbon atoms are indicated by small gray disks and
only the bonded-to-phosphorous C-atom of the phenyl groups are included in the
plot. Displacement ellipsoids of the other non-H atoms are drawn at the 30%
probability level. Copper-ligand bonds are indicated by dashed lines.
Fig. 2. Molecular plot of Cu(tsac)(PPh3)2 (3) showing the labeling scheme of the
non-H atoms. For clarity, the carbon atoms are indicated by small gray disks and
only the bonded-to-phosphorous C-atom of the phenyl groups are included in the
plot. Displacement ellipsoids of the other non-H atoms are drawn at the 30%
probability level. Copper-ligand bonds are indicated by dashed lines.

M. Dennehy et al. / Inorganica Chimica Acta 362 (2009) 2900–2908
2905
units with smaller copper–copper distances (between 2.741 and
was already pointed out by Cotton and col. for ‘Cu2(dppm)2’ di-
bridged frameworks [19b]. Cu(2) binds to three exocyclic S-atoms
from three thiosaccharinates, to one P atom belonging to one dppm
molecule and to the Cu(1) atom in a fivefold coordination. Cu(1) is
surrounded by two N atoms from two thionates, one P atom of the
dppm molecule and the Cu(2) atom, in a trigonal pyramidal geom-
etry. The major deviations from the ideal values (120° and 90°) are
the angles in the trigonal plane, which range from 105.4(2)° to
137.5(1)°. It should be observed that the asymmetric coordination
of the tsac ligands in each ‘Cu2(tsac)2(dppm)’ subunit (two S atoms
over Cu(2) and two N atoms over Cu(1)), named head-to-head [1b],
is unknown in the chemistry of copper(I) thionates. Such type of
dinuclear arrangements have been observed for [Ag2(tsac)2(py)]
[22a], and more examples exist of dinuclear metal thionates with
the symmetric head-to-tail arrangement [32]. These type of coordi-
nation form of the tsac anions might have synergic effects with the
existence of the S-atom bridges between the ‘Cu2(tsac)2(dppm)’
subunits.
0
2.992 ÅA) and very similar Cu–S bond lengths (between 2.191 and
0
2.424 ÅA) [14d].
3.1.2. Crystal and molecular structure of [Cu(tsac)(PPh3)2] (3)
Complex 3 crystallizes as a mononuclear molecular compound.
A selection of bond distances and angles of 3 are listed in Table 3
and its molecular plot is presented in Fig. 2.
The Cu(I) ion is in a slightly distorted trigonal planar coordina-
tion sphere, bonded by the exocyclic sulfur atom of a thiosacchari-
nate anion and by two phosphorous atoms of two
triphenylphosphane molecules. The Cu–S bond length is shorter
than the average values obtained for complexes 1 and 2 (2.341(1)
0
and 2.338(1) ÅA, respectively), in accordance with the change of
coordination mode from tri-coordinated bridge to mono-coordi-
nated. As far as we know the molecular structure of complex 3 is
quite unique. There are many examples of poly-nuclear copper thi-
onates reported in the literature [14–21], but only one report of a
mononuclear copper-thionate-triphenylphosphane structure, the
[Cu(pymt)(PPh3)2] (pymt: pyrimidine-2-thionato) complex of Ruan
and Shi [17a]. The pymt ions act as
j
2-S,N chelating ligands (Cu–S
Table 4
0
and Cu–N distances of 2.4023(7) and 2.139(2) ÅA, respectively) and
the exocyclic sulfur atoms have distal interactions with other cop-
per atoms of neighbor complexes, making a two-dimensional net-
work. More common are the tetracoordinated CuX(PPh3)2HL
complexes (X: halide, HL: neutral thione) [13]. As can be expected,
Bond distances (Å) and angles (°) around copper in [Cu4(tsac)4(dppm)2] ꢀ 2CH2Cl2 (4).
Bond distances
P(2)–Cu(2)
S(11)–Cu(2)
S(21)–Cu(2)
S(21)i–Cu(2)
2.241(2)
2.272(2)
2.371(2)
2.503(1)
Cu(2)–Cu(1)
P(1)–Cu(1)
N(1)–Cu(1)
N(2)–Cu(1)
2.8494(9)
2.205(1)
1.985(4)
2.057(5)
the Cu–S distance in complex 3 is shorter than those reported for
0
Bond angles
neutral thione complexes, as CuI(PPh3)2(bzimtH2) (2.3692(8) ÅA)
0
P(2)–Cu(2)–S(11)
P(2)–Cu(2)–S(21)
P(2)–Cu(2)–S(21)i
P(2)–Cu(2)–Cu(1)
S(11)–Cu(2)–S(21)
S(11)–Cu(2)–S(21)i
S(11)–Cu(2)–Cu(1)
S(21)–Cu(2)–S(21)i
130.49(6)
104.31(6)
118.37(5)
86.03(4)
119.52(6)
88.12(5)
80.96(4)
86.01(5)
S(21)–Cu(2)–Cu(1)
S(21)i –Cu(2)–Cu(1)
P(1)–Cu(1)–N(1)
P(1)–Cu(1)–N(2)
P(1)–Cu(1)–Cu(2)
N(1)–Cu(1)–N(2)
N(1)–Cu(1)–Cu(2)
N(2)–Cu(1)–Cu(2)
79.29(4)
154.17(4)
137.5(1)
116.7(1)
95.44(4)
105.4(2)
92.6(1)
and CuI(PPh3)2(bztztH) (2.3660(6) ÅA) (bzimtH2: benzimidazole-
2-thione, and bztztH: benzothiazole-2-thione) [13g], CuCl(PPh3)2
0
(pytH) (2.381(2) ÅA) (pytH: pyridine-2-thione) [13h], or CuCl
0
(PPh3)2(pymtH) (2.3875(7) ÅA) (pymtH: pyrimidine-2-thione)
[13f]. The Cu–P bond lengths are very similar to those reported
0
for [Cu(pym2S)(PPh3)2] (2.2417(7) and 2.2557(7) ÅA) [17a] and
87.0(1)
shorter than the distances observed in related copper-thione com-
0
Symmetry codes: (i) ꢁx + 1, ꢁy + 1, ꢁz + 2.
plexes, such as CuCl(PPh3)2(pytH) (2.300(2) and 2.288(2) ÅA) [13h],
0
or CuCl(PPh3)2(pymtH) (2.2899(6) and 2.2978(6) ÅA) [13f].
The triphenylphosphane ligands show internal bond lengths
and angles typical for this molecule coordinated to Cu(I) metal cen-
ters [13f–h,17a]. For the thionate anion the C–S bond distance is
longer and the C–N bond shorter than the corresponding parame-
ters of free thiosaccharin (1.624(2) and 1.384(3) Å, respectively
[29]), showing the expected electronic charge delocalization upon
deprotonation and coordination [30]. These parameters are very
close to that observed for metal thiosaccharinates in which the thi-
onates are mono-coordinated through the exocyclic S atom (C–S
and C–N) distances of 1.7022/1.6965 and 1.312/1.314 Å, respec-
tively for Cd(tsac)2(bim)2 [22e] and 1.673(5) and 1.334(6) Å,
respectively, for Ag(tsac)(PPh3)2 [22b].
3.1.3. Crystal and molecular structure of [Cu4(tsac)4(dppm)2] ꢀ 2CH2Cl2
(4)
Complex 4 has a very curious structure consisting on centro-
symmetric tetranuclear molecules. Selected bond lengths and an-
gles are listed in Table 4 and a molecular diagram of the
compound is presented in Fig. 3.
The two halves of each molecule are copper dimers, ‘Cu2-
(tsac)2(dppm)’, bridged through the exocyclic
S atoms of
thiosaccharinate anions, in a Cu2S2 dinuclear planar arrange-
ment (S(21)–Cu(2)–S(21)i = 86.01(5) and Cu(2)–S(21)–Cu(2)i =
93.99(5)°). Thus, only half of the molecule will be discussed. The
Cu2ꢀ ꢀ ꢀCu2i distance is 3.566(1) Å, too long for significant metal–
metal interaction. In the ‘Cu2(tsac)2(dppm)’ subunits the Cu(2)–
Cu(1) distance (2.8494(9) Å) is in the order of the sum of the van
der Waals radii of copper atoms (2.80 Å) [31] and therefore sug-
gesting the existence of interaction between the Cu(I) centers, as
Fig. 3. Molecular plot of Cu4(tsac)4(dppm)2 (4) showing the labeling scheme of the
non-H atoms. For clarity, the carbon atoms are indicated by small gray disks and
only the bonded-to-phosphorous C-atom of the phenyl groups are included in the
plot. Displacement ellipsoids of the other non-H atoms are drawn at the 30%
probability level. Copper-ligand bonds are indicated by dashed lines.

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M. Dennehy et al. / Inorganica Chimica Acta 362 (2009) 2900–2908
As far as we know there are only two reports of triply-bridged
3.1.4. Crystal and molecular structure of complex
dinuclear Cu(I) complexes with one bridging dppm molecule.
One of them is a copper thionate, [Cu2(tBuMe2Si-py2S)2(dppm)2]
(tBuMe2Si-py2S = 6-tert-butyldimethylsilyl-pyridine-2-thionate)
[Cu2(tsac)2(dppm)2] ꢀ CH2Cl2 (5)
Selected bond distances and angles for the dinuclear complex 5
are listed in Table 5 and a molecular diagram of the molecule is
shown in Fig. 4.
[17b], in which the two thionate anions made the remaining two
0
bridges of the structure. The Cuꢀ ꢀ ꢀCu distance (2.711(2) ÅA) is one
of the shortest distances reported for a dinuclear ‘Cu2(dppm)’
framework. It has a very asymmetric structure, with the second
dppm molecule mono-coordinated to only one of the Cu ions by
a P-atom and with the two thionates bridging the Cu(I) centers
[Cu2(tsac)2(dppm)2] complex shows also a uncommon asym-
metric triply bridged di-copper(I) core, with different environ-
ments around each metal center due to the different
coordination forms of the anions, one as a
l2-N,S coordinating
and the other as a S-monocoordinating ligand. Cu(1) atom binds
to two P-atoms of different dppm molecules, and the two exocyclic
S atoms of the thiosaccharinates, one belonging to the bridging
thionate and the other to the mono-coordinated one, in a highly
distorted tetrahedral environment. Cu(2) binds to one N atom of
the bridging thiosaccharinate ligand and to the other two P-atoms
in different coordination forms, one in a
l2-S, and the other in a
l2-N,S arrangement [17b]. The second related complex is a copper
dithiocarboxilate with a very similar structure to complex 4. It also
consists of tetra-nuclear molecular units [Cu2(S2CT)2(dppm)]2
(S2CT = dithio-o-toluato-j2-S,S0) build by two dinuclear halves.
Each ‘Cu2(S2CT)2(dppm)’ subunit has a dppm and two S2CT bridges,
of the diphosphanes, in a distorted trigonal planar arrangement.
0
0
with a bit longer Cuꢀ ꢀ ꢀCu distance of 2.874(4) ÅA. One of the S atoms
of one of the dithio-o-toluate anions is also coordinated to the cor-
responding Cu atoms of the other subunit, defining a centrosym-
metric tetranuclear molecule [107b]. The Cu–S bond lengths of the
bridges (2.341(4) and 2.565(5) AÅ) are in the order of the observed
distances for complex 4.
The Cu(2)ꢀ ꢀ ꢀCu(1) distance (3.0351(9) ÅA) is greater than the sum
0
of the van der Waals radii of copper atoms (2.80 ÅA) [31] and there-
fore too long to qualify as a metal–metal bond. The Cuꢀ ꢀ ꢀCu dis-
tance in
5 falls between the 3.757(3) Å value observed for
[Cu2(dppm)2(MeCN)4](ClO4)2, a complex without coordinated an-
0
ions [19f], and the 2.7883(11), 2.707(1), and 2.679(6) ÅA values re-
ported for [Cu2(dppm)2(MeCOO)](BF4) [19c], [{Cu2(dppm)2}2
(OOCC6H4COO)] (PF6)2 [19b], and [Cu2(dppm)2(MeC5H3NO)](ClO4)
(MeC5H3NO = 6-methyl-pyridin-2-olate) [19e], respectively. In
the last complexes the organic anions strongly coordinate the
Cu(I) nuclei of the ‘Cu2(dppm)2’ frameworks acting as third bridg-
ing ligands, and for them weak Cuꢀ ꢀ ꢀCu interaction are to be ex-
pected [19b]. The Cuꢀ ꢀ ꢀCu separation in complex 5 is very similar
to the 3.1003(9) Å distance observed for [Cu2(dppm)2(CNt-
Bu)3](BF4)2 where one of the isonitrile ligands binds the copper
Table 5
Bond distances (Å) and angles (°) around copper in [Cu2(tsac)2(dppm)2] ꢀ CH2Cl2 (5).
Bond distances
Cu(2)–N(1)
Cu(2)–P(2)
Cu(2)–P(4)
1.988(3)
2.2333(9)
2.2695(9)
Cu(1)–P(1)
Cu(1)–S(11)
Cu(1)–P(3)
Cu(1)–S(21)
2.2961(9)
2.3065(10)
2.3212(9)
2.4095(11)
centers in a l2-C arrangement [19a].
Bond angles
N(1)–Cu(2)–P(2)
N(1)–Cu(2)–P(4)
P(2)–Cu(2)–P(4)
N(1)–Cu(2)–Cu(1)
P(2)–Cu(2)–Cu(1)
P(4)–Cu(2)–Cu(1)
P(1)–Cu(1)–S(11)
P(1)–Cu(1)–P(3)
128.39(9)
115.41(9)
115.28(4)
90.76(8)
96.54(3)
92.05(3)
121.32(4)
110.25(4)
S(11)–Cu(1)–P(3)
P(1)–Cu(1)–S(21)
S(11)–Cu(1)–S(21)
P(3)–Cu(1)–S(21)
P(1)–Cu(1)–Cu(2)
S(11)–Cu(1)–Cu(2)
P(3)–Cu(1)–Cu(2)
S(21)–Cu(1)–Cu(2)
119.50(4)
96.76(4)
97.20(4)
106.40(4)
79.42(3)
77.51(3)
83.36(3)
170.24(4)
The presence of the bridging dppm ligands in complexes of this
kind imparts unusual stability to the ‘Cu2(dppm)2’ framework
[19b]. The Cu–P bond lengths are quite similar to those reported
for other copper diphosphane complexes, like [Cu2(dppm)2-
(MeCN)4](ClO4)2 (2.270(3) and 2.283(3) Å) [19f], but longer than
the bond lengths reported for [Cu2(dppm)2(MeCOO)](BF4) (from
2.258(2) to 2.241(2) Å), a complex with a shorter Cuꢀ ꢀ ꢀCu distance
[19c].
As mentioned above, there are two different coordination
modes for the thiosaccharinate ligands. One of them bridges the
Cu atoms in a
one of the Cu atoms as a mono-coordinated
l
2-N,S coordination form. The other one binds only
g
1-S ligand. The differ-
ent coordination modes are reflected in the internal bond distances
of the tsac anions. The bridging one has a shorter exocyclic C–S
bond distance (1.664(4) Å) than the mono-coordinated anion
(1.686(4) Å), indicating a greater negative charge delocalization
over the thiocarbonilic functional group in the later ligand.
3.2. Vibrational and electronic spectra of solid complexes
The solid state FT-IR spectra of the complexes 1–5, recorded be-
tween 4000 and 400 cmꢁ1 in KBr pellets or in Nujol mulls, provide
information regarding the coordination mode of the thiosacchari-
nate ligand and confirm the presence of the phosphanes. Table 6
shows the IR assignments for the most important bands related
to vibrations of the five-membered ring of the thionate anion in
the complexes. Those assignments are based on general informa-
tion of thiosaccharin and thiosaccharinate anion analyzed and dis-
cussed in previous papers [22b,33]. The disappearance of the
band of the free thiosaccharin is verified in combination with the
lack of any
(SH) bands at 2600–2500 cmꢁ1, indicating that the thi-
one ligand is in the deprotonated form in these complexes. Among
the observed bands (Table 6), those principally belonging to the
stretching motion of the thiocarbonyl and imino bonds of the
m(NH)
Fig. 4. Molecular plot of Cu2(tsac)2(dppm)2 (5) showing the labeling scheme of the
non-H atoms. For clarity, the carbon atoms are indicated by small gray disks and
only the bonded-to-phosphorous C-atom of the phenyl groups are included in the
plot. Displacement ellipsoids of the other non-H atoms are drawn at the 30%
probability level. Copper-ligand bonds are indicated by dashed lines.
m

M. Dennehy et al. / Inorganica Chimica Acta 362 (2009) 2900–2908
2907
thiosaccharinate anion,
the coordination mode of the thionate. For the simplest structure
of complex 3 with a two electron coordination of the tsac ligand
m
(CS) and
m
(CN), bring information about
NMR spectra in DMSO-d6 show only one set of signals (for tsac,
1H NMR: d 8.17–7.99 (m, 1H, H6); 7.95–7.83 (m, 1H, H3); 7.83–
7.69 ppm (m, 2H, H4/H5); 13C NMR: tsac: d 183.3 (C1); 134.9
(C7); 133.1(C4); 132.6(C5); 131.6 (C2); 124.8(C6); 119.8(C3)) [15]
(see numbering code in Scheme 2). Complex 1 is a poly-nuclear
species also in solutions of low coordinating solvents. In the pres-
ence of increasing amounts of PPh3 or dppm, the original red solu-
through the exocyclic
S atom, two sharp bands (1008 and
1403 cmꢁ1, respectively) have been observed. As a comparison,
the bands of the ‘free’ tsac anion in the (PNP)tsac (PNP: bis(trip-
henylphosphino)iminium cation) lie at 1010,
m
(CS), and 1365,
m
(CN), cmꢁ1. In the tetranuclear complex 2, all the tsac anions have
tions of complex
1
change to red–orange, at medium
a tripodal
l
3-N,S2 coordination with longer C–S bonds (average va-
concentrations, and finally to bright yellow when a excess of phos-
phanes exists. At stoichiometric or quasi-stoichiometric molar ra-
tios Cu:PPh3 (or dppm) crystalline solids with the composition of
the solutions can be isolated (see Scheme 2). With the aim to
reproduce with Cu(I) thiosaccharinate the same structure reported
for Ag(I), the [Ag(tsac)(PPh3)3] compound [22b], synthetic routes
with higher amounts of PPh3 were used. Complex 3 was always
recovered.
lue of 1.704 Å). It correlates with a
wavenumbers (Table 6).
As can be expected, more complex vibrational patterns are ob-
served for complexes 4 and 5. For the former, freshly prepared
samples were dispersed in Nujol to obtain its IR spectra. As was
discussed previously, two coordination forms of the tsac anions
m(CS) band located at lower
are present in complex 4. The
l2-N,S (one under a Nujol band,
1020, and 822 cmꢁ1 bands) and the
l
3-N,S2 (1409, 1007, and
The four complexes, 2–5, also show single sets of signals in their
1H, and 31P{1H} NMR spectra in DMSO-d6 solutions, hence indicate
the existence of only one species. The molar conductances of com-
801 cmꢁ1 bands) bridging forms can be characterized. The IR spec-
tra of complex 5 are in accord with the observed molecular struc-
ture too. The
l
2-N,S bridging thiosaccharinate display bands at
plexes
2 and 3, similar to that reported for complex 1
different wavenumbers (1364, 1022, and 834 cmꢁ1) than the g1
-
(27
X
ꢁ1 molꢁ1 cmꢁ1) [15] are in accord with that picture. For com-
S coordinated anion (1403, 1001, and 822 cmꢁ1).
plexes 2 and 3 the signal of the PPh3 molecules appears low-field
shifted against the free ligand and at the same position (ca.
53 ppm) in the 31P NMR of both complexes. The low-field shifting
indicates that the PPh3 molecules are still coordinated to the Cu
atoms in solution. The solvation of the more accessible Cu center
in complex 3 could be responsible of the similarity in the NMR re-
sponses between both complexes. They have small differences in
Cu–P bond orders in the solid state (Tables 2 and 3), and the Cu–
PPh3 bonds could be weakened by the solvent in complex 3. The
1H NMR signals of the tsac anion in complex 3 appears low-field
shifted against complex 2, indicating that in solution a different
coordination mode of the ligands also exists. The 1H-NMR signals
of 3 have chemical shifts similar to the neutral thiosaccharin. For
Htsac: 1H NMR: d 8.17 (H6); 8.04 (H3); 8.02 (H5), 7.81 (H4) and
6.02 ppm (H1), which is in its thiol tautomeric form in DMSO-d6
solutions [33]. This is in accordance with an anion monoco-
ordinated to the Cu atom through the thiocarbonilic S atom. The
1H NMR chemical shifts of complex 2 indicate a great delocaliza-
tion of the negative electronic charge on the thioamidate
functional groups. Therefore, the substance might be also a tetra-
nuclear species in solution. As was already pointed out with the
crystal discussions, the molecular structures of the ‘Cu4(tsac)4’ tet-
ramers in complexes 1 and 2 are different. A structural reorganiza-
tion of complex 1 takes place in solution prior to or as a
consequence of the Cu–P bonds formation.
For all the complexes reported here, strong bands due to the
coordinated triphenylphosphane or dppm ligands are observed in
the medium IR region, in some cases masking less intense thiosac-
charinate bands [34].
The solid state electronic absorption spectra of the complexes
consist in three very broad bands appearing in the 220–250,
270–290, and 340–360 nm regions. The first two intense bands
*
are unresolved mixtures that belong to
p ? p transitions of the
phenyl rings of the phosphane ligands and of the benzene rings
of the thiosaccharinate anions [35]. The weak lower energy bands
lie in the region where free thiones absorb, and can be assigned to
p
? p* and n ? p* transitions of the thiocarbonilic (C = S) bonds
[36] but they are little sensitive to the coordination forms of the
tsac ligands.
3.3. NMR spectra of complexes and reactivity of copper
thiosaccharinate with phosphanes
As was previously mentioned, the red solid complex 1 brings
also red solutions in MeCN or DMSO solvents. Its 1H and 13C
Table 6
FT-IR spectra and assignments for a selection of thiosaccharinate absorption bands in
solid complexes [Cu4(tsac)4(PPh3)3] ꢀ MeCN (2), [Cu(tsac)(PPh3)2] (3), [Cu4(tsac)4
(dppm)2] ꢀ 2CH2Cl2 (4), and [Cu2(tsac)2(dppm)2] ꢀ CH2Cl2 (5).
The 31P NMR signals of the dppm molecules of complexes 4 and
of the mixtures with complex 5 stoichiometry appear low-field
shifted against the free ligand (48.95 and 46.35 ppm, respectively).
The low-field shifting confirms that in solution the two P atoms of
the dppm molecules are both coordinated to the Cu atoms and
that the dimeric ‘Cu2(dppm)’ and ‘Cu2(dppm)2’ frameworks exist
also in the DMSO-d6 solutions. The pattern and the chemical shifts
of the 1H NMR signals of the tsac anions of complex 4 indicate that
its molecular structure doesn’t change in solution. The 1H NMR sig-
nals of complex 5 appear low field shifted compared to complex 4.
They resemble those of the free thiosaccharinate (for DMSO-d6
solutions of NBut4(tsac): 1H NMR: d 7.71 (H6); 7.45 (H3); and
7.40 (H4/H5) ppm) [33]. This would agree with the presence of
two equivalent not coordinated anions in solution.
Assignments
1a
2
3
4
5
Nujol
KBr
m
(CN),
m
(/S)b
1417mc
1405m
1338s
1409m
Nd
1403s
1364m
1313s
1300s
1244m
1166vs
1151vs
1121s
1022m
1001s
1399s
1325s
1403s
1305vs
1399m
1323m
mas(SO2)
1338m
1325m
1244m
1171s
1154m
1123m
1020m
1007m
m
m
as(/CN), d(CH)
s(SO2), (CC)
1237s
1176vs
1236s
1170vs
1238s
1153vs
1243s
1169vs
m
m
m
s(SO2), d(/SN)
(CS), d(CNS)
1126m
1124s
1003s
1123s
1008s
1123
1020m
1004w
1006m
998w
809w
800m
m(NS), d(CCC)
822m
801m
818w
834w
822m
792m
806s
a
Nujol mulls [15].
4. Conclusions
b
m:
stretching; d: in-plane deformation;
c: out-of-plane deformation; as:
asymmetric; s: symmetric; /: bencenic ring.
c
A wide range of mono and polymeric Cu(I)–thosaccharinate–
phosphane complexes have been prepared and characterized,
vs: very strong; s: strong; m: medium; w: weak; vw: very weak.
Strong Nujol band.
d

2908
M. Dennehy et al. / Inorganica Chimica Acta 362 (2009) 2900–2908
68 (1995) 793;
showing different coordination modes for the thionate ligands and
different nuclearities. When enough triphenylphosphane is pres-
ent, the simple mononuclear Cu(tsac)(PPh3)2 complex is formed.
When the amount of the P-donor ligand is not enough to fill the
coordination sphere of the metal atoms, then the poly-nuclear
complex Cu4(tsac)4(PPh3)3 is obtained.
When a rigid diphosphane like dppm is used as a second ligand,
poly-nuclear copper arrangements are always produced. As in the
case of triphenylphosphane, when there is a lack of dppm the Cu
nuclearity is high and a new and interesting tetra-nuclear Cu(I)
complex is isolated.
(e) E.S. Raper, J.R. Creighton, W. Clegg, Inorg. Chim. Acta 237 (1995) 87;;
(f) J.P. Fackler Jr., C.A. Lopez, R.J. Staples, S. Wang, R.E.P. Winnipenny, R.P.
Lattimer, J. Chem. Soc., Chem. Commun. (1992) 146;
(g) E.S. Raper, J.R. Creighton, W. Clegg, Inorg. Chim. Acta 183 (1991) 179.
[15] M. Dennehy, G.P. Tellería, S.H. Tarulli, O.V. Quinzani, S.D. Mandolesi, J.A. Güida,
G.A. Echeverría, O.E. Piro, E.E. Castellano, Inorg. Chim. Acta 360 (2007) 3169.
[16] (a) J.A. García-Vázquez, J. Romero, A. Souza-Pedrares, M.L. Louro, A. Souza, J.
Zubieta, J. Chem. Soc., Dalton Trans. (2000) 559;
(b) E.C. Constable, S.M. Elder, C.A. Palmer, P.R. Raithby, D.A. Tocher, Inorg.
Chim. Acta 252 (1996) 281;
(c) R. Castro, M.L. Durán, J.A. García-Vázquez, J. Romero, A. Souza, E.E.
Castellano, J. Zukerman-Schpector, J. Chem. Soc., Dalton Trans. (1992) 2559;
(d) S. Kitagawa, M. Munakata, H. Shimono, S. Matsuyama, H. Masuda, J. Chem.
Soc., Dalton Trans. (1990) 2105;
(e) E. Block, M. Gernon, H. Kang, J. Zubieta, Angew. Chem., Int. Ed. Engl. 27
(1988) 1342.
[17] (a) C.-X. Ruan, W.-J. Shi, Acta Crystallogr. E63 (2007) m2412;
(b) P. Perez-Lourido, J. García–Vazquez, J. Romero, M.S. Louro, A. Souza, J.
Zubieta, Inorg. Chim. Acta 271 (1998) 1;
5. Supplementary material
CCDC 700159, 700160, 700161 and 700162 contains the supple-
mentary crystallographic data for 2, 3, 4 and 5. These data can be
obtained free of charge from The Cambridge Crystallographic Data
Centre via www.ccdc.cam.ac.uk/data_request/cif.
(c) R. Castro, J. Romero, J.A. García-Vázquez, A. Souza, Y.D. Chang, J. Zubieta,
Inorg. Chim. Acta 345 (1996) 119;
(d) E.W. Ainscough, E.N. Baker, A.G. Bingham, A.M. Brodie, C.A. Smith, J. Chem.
Soc., Dalton Trans. (1989) 2167.
[18] C. di Nicola, C. Pettinari, M. Ricciutelli, B. Skelton, N. Somers, A.H. White, Inorg.
Chim. Acta 358 (2005) 4003.
[19] (a) E. Fournier, F. Lebrun, M. Drouin, A. Decken, P.D. Harvey, Inorg. Chem. 43
(2004) 3127;
Acknowledgements
We thank financial support from CONICET, Argentina and FA-
PESP, Brazil. Part of the X-ray diffraction experiments were con-
ducted at LANADI (CONICET). M.D. and O.V.Q. thank SGCyT-UNS
for financial support of Project M24/Q025. G.A.E. and O.E.P. are re-
search fellows of CONICET. We thank Dra. Sandra D. Mandolesi for
the gathering of NMR spectroscopic data.
(b) P. Angaridis, F.A. Cotton, M.A. Petrukhina, Inorg. Chim. Acta 324 (2001)
318;
(c) P.D. Harvey, M. Drouin, T. Zhang, Inorg. Chem. 36 (1997) 4998;
(d) D. Li, C.-M. Che, W.-T. Wong, S.-J. Shieh, S.-M. Peng, J. Chem. Soc., Dalton
Trans. (1993) 653;
(e) J. Diez, M.P. Gamasa, J. Gimeno, M. Manfranchi, A. Tiripicchio, J. Chem. Soc.,
Dalton Trans. (1990) 1027;
(f) J. Diez, M.P. Gamasa, J. Gimeno, A. Tiripicchio, M. Tiripicchio, J. Chem. Soc.,
Dalton Trans. (1987) 1275;
(g) A.M. Manotti Lanfredi, F. Ugozzoli, A. Camus, N. Marsich, Inorg. Chim. Acta
99 (1985) 111.
References
[20] (a) W. Tan, H. Zheng, Q. Jin, G. Jin, W. Ji, D. Long, X. Xin, Polyhedron 19 (2000)
1545;
(b) D. Li, H.-K. Yip, C.-M. Che, Z.-Y. Zhou, T.C.W. Mak, S.-T. Liu, J. Chem. Soc.,
Dalton Trans. (1992) 2445.
[21] (a) O. Fuhr, L. Fernandez-Recio, A. Castiñeiras, D. Fenske, Z. Anorg. Allg. Chem.
633 (2007) 700;
(b) P.C. Ford, E. Cariati, J. Bourassa, Chem. Rev. 99 (1999) 3625;
(c) T.A. Annan, R. Kumar, D.G. Tuck, J. Chem. Soc., Chem. Commun. (1988) 446.
[22] (a) M. Dennehy, O.V. Quinzani, R.M. Ferullo, S.D. Mandolesi, N. Castellani, M.
Jennings, Polyhedron 27 (2008) 2243;
[1] (a) E.S. Rapper, Coord. Chem. Rev. 153 (1996) 199;
(b) E.S. Rapper, Coord. Chem. Rev. 165 (1997) 475;
(c) J.A. García-Vázquez, J. Romero, A. Sousa, Coord. Chem. Rev. 193–195 (1999)
691;
(d) P.D. Akrivos, Coord. Chem. Rev. 181–210 (2001) 213.
[2] A. Castiñeiras, I. García-Santos, S. Dehnen, P. Sevillano, Polyhedron 25 (2006)
3653.
[3] E. López-Torres, M. Mendiola, C.J. Pastor, Inorg. Chem. 45 (2006) 3103.
[4] P. Aslanidis, S. Divanidis, P.J. Cox, P. Karagiannidis, Polyhedron 24 (2005) 853.
[5] T.S. Lobana, R. Sharma, R. Sharma, S. Mehra, A. Castiñeiras, P. Turner, Inorg.
Chem. 44 (2005) 6.
[6] J.A. García-Vazquez, A. Souza-Pedrares, M. Carabel, J. Romero, A. Souza,
Polyhedron 24 (2005) 2043.
[7] L.M. Nguyen, M.E. Dellinger, J.T. Lee, R.A. Quinlan, A.L. Rheingold, R.D. Pike,
Inorg. Chim. Acta 358 (2005) 1331.
[8] B. Krebs, G. Henkel, Angew. Chem., Int. Ed. Engl. 30 (1991) 769.
[9] (a) S. Stoyanov, T. Stoyanova, I. Antonov, P. Karagiannidis, P.D. Akrivos,
Monatsch. Chem. 127 (1996) 495;
(b) S. Stoyanov, T. Stoyanova, P.D. Akrivos, Trends Appl. Spectrosc. 2 (1998) 89.
[10] E.S. Rapper, Coord. Chem. Rev. 129 (1994) 91.
[11] L.-O. Klotz, U. Weser, in: K.D. Rainsford, R. Milanino, J.R.J. Sorenson, G.P. Velo
(Eds.), Copper and Zinc in Inflammatory and Degenerative Diseases, Kluwer
Academic Publication, Dordrecht, 1998, p. 19.
(b) M. Dennehy, S.D. Mandolesi, O.V. Quinzani, M. Jennings, Z. Anorg. Allg.
Chem. 633 (2007) 2746;
(c) D.R. Pérez, S.H. Tarulli, O.V. Quinzani, J. Dristas, R. Faccio, L. Suescun, A.
Mombrú, Z. Anorg. Allg. Chem. 633 (2007) 1066;
(d) M. Dennehy, O.V. Quinzani, M. Jennings, J. Mol. Struct. 841 (2007) 110;
(e) S.H. Tarulli, O.V. Quinzani, O.E. Piro, E.E. Castellano, E.J. Baran, J. Mol. Struct.
797 (2006) 56.
[23] Enraf-Nonius. COLLECT. Nonius BV, Delft, The Netherlands, 1997–2000.
[24] Z. Otwinowski, W. Minor, in: C.W. Carter Jr., R.M. Sweet (Eds.), Methods in
Enzymology, vol. 276, Academic Press, New York, 1997, pp. 307–326.
[25] PLATON, A Multipurpose Crystallographic Tool, Utrecht University, Utrecht,
The Netherlands, A.L. Spek, 1998.
SHELXS-97, Program for Crystal Structure Resolution, University
[26] G.M. Sheldrick,
of Göttingen, Göttingen, Germany, 1997.
[27] G.M. Sheldrick, SHELXL-97, Program for Crystal Structure Analysis, University of
Göttingen, Göttingen, Germany, 1997.
[12] I.G. Dance, Polyhedron 5 (1986) 1037.
[13] (a) T.S. Lobana, R. Sultana, G. Hundal, Polyhedron 27 (2008) 1008;
(b) M. Mamais, P.J. Cox, P. Aslanidis, Polyhedron 27 (2008) 175;
(c) P.J. Cox, A. Kaltzoglou, P. Aslanidis, Inorg. Chim. Acta 359 (2006) 3183;
(d) K. Marjani, S.C. Davies, M.C. Durrant, D.L. Hughes, N. Khodamorad, Acta
Cryst. Sect. E 62 (2006) 774;
[28] C.K. Johnson, ORTEP-II.
A Fortran Thermal-Ellipsoid Plot Program. Report
ORNL-5318, Oak Ridge National Laboratory, TN, USA, 1976.
ˇ
´
[29] O. Grupce, M. Penavic, G. Jovanovski, J. Chem. Crystallogr. 24 (1994) 581.
ˇ
[30] (a) G. Jovanovski, A. Cahil, O. Grupce, L. Pejov, J. Mol. Struct. 784 (2006) 7;
(e) A. Kaltzoglou, P.J. Cox, P. Aslanidis, Inorg. Chim. Acta 358 (2005) 3048;
(f) D. Li, W.-J. Shi, T. Wu, S.W. Ng, Acta Cryst. Sect. E 60 (2004) 776;
(g) P. Aslanidis, P.J. Cox, P. Karagiannidis, S.K. Hadjikakou, C.D. Antoniadis, Eur.
J. Inorg. Chem. (2002) 2216;
(h) T. Lobana, A. Castiñeiras, Polyhedron 21 (2002) 1603;
(i) P.J. Cox, P. Aslanidis, P. Karagiannidis, Polyhedron 19 (2000) 1615;
(j) P.J. Cox, P. Aslanidis, P. Karagiannidis, S.K. Hadjikakou, Polyhedron 18
(1999) 1501;
(b) M.M. Branda, N.J. Castellani, S.H. Tarulli, O.V. Quinzani, E.J. Baran, R.H.
Contreras, Int. J. Quant. Chem. 89 (2002) 525;
(c) Y.I. Binev, C. Petkov, L. Pejov, Spectrochim. Acta Part A 56 (2000) 1949.
[31] A. Bondi, J. Phys. Chem. 68 (1964) 441.
[32] (a) W. Wei, D. Di, W. Chu, Q. Zhu, R. Huang, Inorg. Chim. Acta 361 (2008) 1819;
(b) M. Dennehy, O.V. Quinzani, R.A. Burrow, Acta Cryst. Sect. C 63 (2007)
m395.
[33] M. Dennehy, O.V. Quinzani, S.D. Mandolesi, J. Guida, G.A. Echeverría, O.E. Piro,
Monatshefte Chem. 138 (2007) 669.
[34] (a) R. Pikl, F. Dushek, C. Fickert, R. Finsterer, W. Kiefer, Vib. Spectrosc. 14 (1997)
189;
(b) R.J.H. Clark, C.D. Flint, A.J. Hempleman, Spectrochim. Acta 43A (1987) 805;
(c) R.G. Inskeep, J. Inorg. Nucl. Chem. 24 (1962) 763.
[35] C. Kutal, Coord. Chem. Rev. 99 (1990) 213.
(k) P. Aslanidis, S.K. Hadjikakou, P. Karagiannidis, P.J. Cox, Inorg. Chim. Acta
271 (1998) 243;
(l) T. Shibahara, S. Kobayashi, D. Long, X. Xin, Acta Cryst. Sect. C53 (1997) 58.
[14] (a) M. Shi, J.-K. Jiang, Chirality 15 (2003) 605;
(b) E.S. Raper, J.R. Creighton, W. Clegg, L. Cucurull-Sanchez, M.N. Stuart Hill,
P.D. Akrivos, Inorg. Chim. Acta 271 (1998) 57;
(c) J.A. García-Vázquez, J. Romero, R. Castro, A. Souza, D.J. Rose, J. Zubieta,
Inorg. Chim. Acta 260 (1997) 221;
[36] M. Petiau, J. Fabian, J. Mol. Struct. Theochem. 538 (2001) 253.
(d) C.A. Lopez, J.P. Fackler, R.J. Staples, S. Wang, R. Winpenny, Croat. Chem. Acta