Coordination of a hemilabile N,N,S donor ligand in the redox system [CuL2]+/2+, L = 2-pyridyl-N-(2′-alkylthiophenyl) methyleneimine

Article abstract of DOI:10.1002/ejic.201001183

The new copper(I) complexes [Cu(L¹)₂](BF ₄), L¹ = 2-pyridyl-N-(2′-methylthiophenyl) methyleneimine, and [Cu(L²)₂]-(ClO₄), L ² = 2-pyridyl-N-(2′-benzylthiophenyl)methyleneimine, have been prepared and structurally characterized. In contrast to the known [Cu(L ¹)₂](ClO₄)₂, which exhibits partial thioether S binding to effect five-coordinate Cu²⁺, the copper(I) compounds reported here contain four-coordinate metal ions with exclusively N-donor binding. Cyclic voltammetry reveals a fully reversible oxidation of the Cu^I species, which suggests a small barrier for reorganization. The reduction at negative potentials is irreversible for compounds [Cu(L) ₂](X) and for the structurally characterized new compound [Cu(L ¹)(PPh₃)₂](ClO₄). UV/Vis spectroelectrochemistry shows the typical low-energy absorption bands of copper(I) (MLCT transition) and copper(II) (ligand-field transition) in the visible region; the Cu^II form develops an intense band at 350 nm attributed to a S-to-Cu ligand-to-metal charge transfer (LMCT).

Full text of DOI:10.1002/ejic.201001183

FULL PAPER
DOI: 10.1002/ejic.201001183
Coordination of a Hemilabile N,N,S Donor Ligand in the Redox System
[CuL2]+/2+, L = 2-Pyridyl-N-(2Ј-alkylthiophenyl)methyleneimine
Johannes Schnödt,[a] Jorge Manzur,[b] Ana-Maria García,[b] Ingo Hartenbach,[a]
Cheng-Yong Su,[c] Jan Fiedler,[d] and Wolfgang Kaim*[a]
Keywords: Copper / Diimines / Ligand effects / S ligands / Redox chemistry
The new copper(I) complexes [Cu(L1)2](BF4), L1 = 2-pyridyl-
which suggests a small barrier for reorganization. The re-
duction at negative potentials is irreversible for compounds
[Cu(L)2](X) and for the structurally characterized new com-
pound [Cu(L1)(PPh3)2](ClO4). UV/Vis spectroelectrochemis-
try shows the typical low-energy absorption bands of cop-
per(I) (MLCT transition) and copper(II) (ligand-field transi-
tion) in the visible region; the CuII form develops an intense
band at 350 nm attributed to a S-to-Cu ligand-to-metal
charge transfer (LMCT).
N-(2Ј-methylthiophenyl)methyleneimine, and [Cu(L2)2]-
(ClO4), L2
= 2-pyridyl-N-(2Ј-benzylthiophenyl)methylene-
imine, have been prepared and structurally characterized. In
contrast to the known [Cu(L1)2](ClO4)2, which exhibits partial
thioether S binding to effect five-coordinate Cu2+, the cop-
per(I) compounds reported here contain four-coordinate
metal ions with exclusively N-donor binding. Cyclic voltam-
metry reveals a fully reversible oxidation of the CuI species,
Introduction
The strikingly different coordination properties of the
neighbouring oxidation states CuI and CuII have provided
a fruitful subject of investigation for electron transfer re-
search, both within biochemistry (type 1 Cu of “blue” cop-
per centres)[1] and outside.[2] The role of neutral thioether
ligands mimicking the side chain of methionine has been
studied for certain electron-transferring blue copper pro-
teins and for recently characterized monooxygenase en-
zymes such as PHM (α-peptidylglycine hydroxylating
monooxygenase)[3,4] or DβM (dopamine-β-monooxygen-
ase).[4] In a more recent development, a copper(I) com-
pound with a N3S donor set including pyridine N and neu-
tral S was found to react with CO2 from air with oxidation
to Cu2+ and formation of oxalate.[5]
On the basis of a minimal model system involving cop-
per(II) in combination with thioether-containing pyridyl-
methyleneimines,[6] we are now adding information on the
copper(I) complex structures [CuL2]+, with ligands L =
pmtpm or pbtpm, and on the electrochemical and spectro-
electrochemical aspects of the CuI/CuII transition.
Results and Discussion
Copper(I) complexes [Cu(L1)2](BF4) and [Cu(L2)2](ClO4)
were obtained by reacting the corresponding ligands with
the precursor [Cu(CH3CN)4](X), X = BF4– or ClO4 , in the
–
appropriate 2:1 molar ratio (Scheme 1). A 1:1 ratio between
L1 and [Cu(CH3CN)4](ClO4) yielded [Cu(L1)(CH3CN)]-
(ClO4).
The structure determination of [CuI(L1)2](BF4) and
[CuI(L2)2](ClO4) showed solely N-coordinated metal, in
contrast to the corresponding copper(II) complex [Cu(L1)2]-
(ClO4)2 with one coordinated thioether sulfur atom (Fig-
ures 1 and 2).
Bonding parameters are listed in Tables 1 and 2, crystal
data are presented in Table 4. Within the bonding distance
range of the metal, the difference between the nonbonding
distances Cu···S·3.35 Å and the sole Cu–S bond of 2.43 Å
in [Cu(L1)2](ClO4)2 are most conspicuous. This result
clearly illustrates the coordination expansion on going from
CuI (N4 coordination) to CuII (N4S coordination). In agree-
ment with the typical Jahn–Teller distortion for d9 systems,
the latter was shown to exhibit a predominantly square-
pyramidal configuration with an imine N at the apex (long-
est Cu–N bond to N2). Since the mer configuration is typi-
cally favoured over the fac form with unsaturated rigid tri-
dentate ligands such as pyridine–Schiff base systems,[7]
[a] Institut für Anorganische Chemie, Universität Stuttgart,
Pfaffenwaldring 55, 70550 Stuttgart, Germany
E-mail: kaim@aic.uni-stuttgart.de
[b] Departamento de Ciencias de los Materiales, Facultad de
Ciencias Físicas y Matemáticas, Universidad de Chile,
Tupper 2069, Santiago de Chile, CEDENNA, Chile
[c] MOE Laboratory of Bioinorganic and Synthetic Chemistry,
State Key Laboratory of Optoelectronic Materials and
Technologies, School of Chemistry and Chemical Engineering,
Sun Yat-Sen University,
Guangzhou, 510275, China
[d] J. Heyrovský Institute of Physical Chemistry, v.v.i., Academy of
Sciences of the Czech Republic,
Dolejsˇkova 3, 18223 Prague, Czech Republic
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Eur. J. Inorg. Chem. 2011, 1436–1441

A Hemilabile N,N,S Donor Ligand in the Redox System [CuL2]+/2+
Scheme 1.
Table 1. Selected structure parameters for complexes [Cu(L)2](BF4)
and [Cu(L)2](ClO4).[a]
[Cu(L2)
2](ClO4)
[Cu(L1)
2](ClO4)2
[Cu(L1)2](BF4)
Distances [Å]
Cu–N1
Cu–N2
Cu–N3
Cu–N4
Cu–S1
Cu–S2
2.079(3)
2.035(2)
2.030(3)
2.104(2)
3.402(1)
3.405(2)
2.028(5)
2.050(5)
2.000(5)
2.091(5)
3.384(2)
3.362(2)
1.954(5)
2.153(6)
2.007(5)
1.952(5)
3.699(3)
2.431(2)
Angles [°]
N1–Cu–N2
N1–Cu–N3
N1–Cu–N4
N2–Cu–N3
N2–Cu–N4
N3–Cu–N4
N1–Cu–S
N2–Cu–S
N3–Cu–S
N4–Cu–S
80.63(10)
116.28(11)
109.27(10)
136.20(11)
134.50(10)
80.51(10)
–
–
–
–
80.6(2)
122.1(2)
134.55(2)
143.9(2)
103.42(2)
80.88(19)
–
–
–
–
80.2(2)
100.7(2)
176.2(2)
117.0(2)
101.5(2)
81.5(2)
95.92(17)
97.49(15)
143.61(18)
80.57(16)
Figure 1.Molecularstructureof[Cu(L1)2]+ inthecrystalof[Cu(L1)2]-
(BF4), L1 = 2-pyridyl-N-(2Ј-methylthiophenyl)methyleneimine.
[a] N1,N3: pyridyl N; N2,N4: imine N.
plex. On the other hand, the two copper(I) ions [Cu(L1)2]+
and [Cu(L2)2]+ show quite irregular four-coordination, the
former with a typical[7,8] propensity towards a trigonal-py-
ramidal arrangement with a pyridine N (N1) at the apex
(N1 is not involved in large N–Cu–N angles). The variation
of the other Cu–N distances is marginal, with slightly
longer bonds to the imine N atoms.
Table 2. Selected structure parameters for [Cu(L1)(PPh3)2](BF4).
Distances [Å]
Cu–N1
Cu–N2
Cu–P1
Cu–P2
Cu–S1
2.124(2)
2.107(2)
2.261(1)
2.264(1)
3.502(9)
Figure 2. Molecular structure of [Cu(L2)2]+ in the crystal of [Cu-
(L2)2](ClO4).
Angles [°]
N1–Cu–N2
N1–Cu–P1
N1–Cu–P2
N2–Cu–P1
N2–Cu–P2
P1–Cu–P2
78.43(9)
108.65(7)
112.74(7)
121.50(7)
103.83(6)
123.15(3)
hexacoordination would imply cis-positioned thioether
groups. In such a situation, the two weak Cu–S bonds can-
not occupy the two apex sites of an elongated octahedron,
leaving the square-pyramidal structure for the CuII com-
Eur. J. Inorg. Chem. 2011, 1436–1441
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W. Kaim et al.
FULL PAPER
Scheme 2.
Employing the copper(I) stabilizing effect of phosphane
ligands, we also obtained compound [Cu(L1)(PPh3)2](ClO4)
by the standard route (Scheme 2) and determined its struc-
ture (Figure 3, Tables 2 and 4).
Figure 4. Cyclic voltammograms at different scan rates of
[Cu(L1)2](BF4) in CH2Cl2/0.1 m Bu4NPF6.
Table 3. Electrochemical data from cyclic voltammetry.[a]
Figure 3. Molecular structure of [CuL1(PPh3)2]+ in the crystal of
[CuL1(PPh3)2](ClO4)·CH2Cl2.
[Cu(L1)2](BF4)
–0.07[b]
[Cu(L2)2](ClO4) [Cu(L1)(PPh3)2](ClO4)
[d]
E1/2(ox1)
–0.08[c]
–1.35
+0.57 (Epa)
–
Epa(ox2)[d] +1.38
Epc(red)[e]
–1.62
The coordination around copper(I) is regular with a sym-
metrically binding N,NЈ-chelate system and two equivalent
triphenylphosphane ligands. The asymmetry frequently noted
in such (N–N)CuI(PR3)2 situations[8] is not observed here.
Considering the structural change for [Cu(L1)2]+ and
[Cu(L1)2]2+ ions as evident from solid-state structures, we
investigated the electron transfer behaviour of the redox
systems [CuL2]+/2+ by cyclic voltammetry at scan rates be-
tween 20 and 200 mVs–1. A typical example is shown in
Figure 4, and the results are summarized in Table 3. Stan-
dard reversible behaviour is observed under the conditions
employed. A second oxidation, presumably of the coordi-
nated thioether, occurs irreversibly at higher potentials.
These results suggest that the CuI/CuII equilibrium de-
picted in Scheme 3 is attained very rapidly and requires only
a small reorganization energy, in spite of the notable geome-
try change.
–1.63
–1.75
[a] In CH2Cl2/0.1 m Bu4NPF6 at 100 mVs–1 scan rate; potentials in
V vs. Fc+/o. [b] At –45 °C –0.09 V (reversible). [c] At –45 °C –0.11 V
(reversible). [d] Epa: anodic peak potential for irreversible process.
[e] Epc: cathodic peak potential for irreversible process.
Scheme 3.
The potentials of the CuI/CuII transition are not unusual; ines,[9c] the reduced “copper(0)” states are more stable and
however, the reduction of the pyridylimino function to a can be correctly identified as radical ion complexes
radical anion[9a,9b] occurs at rather negative values of about [CuI(L)(L·–)].
–1.6 V vs. Fc+/o and is not reversible, neither for [Cu(L)2]+
The seemingly clean reversibility of the CuI/CuII transi-
nor for [Cu(L1)(PPh3)2]+. With more rigid and sterically tion prompted us to monitor this process for the [Cu(L1)2]+/
better protected bis(α-diimine)copper complexes, for exam- [Cu(L1)2]2+ system by UV/Vis spectroelectrochemistry (Fig-
ple those involving 2,9-disubstituted 1,10-phenanthrol- ure 5).
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Eur. J. Inorg. Chem. 2011, 1436–1441

A Hemilabile N,N,S Donor Ligand in the Redox System [CuL2]+/2+
oxidation state assignments. While the precursor solvate
system [Cu(L1)(CH3CN)](ClO4) is air-sensitive, the new
[10]
copper(I) compounds do not react with O2.
It may be noted that the increase of the coordination
number upon oxidation by thioether S binding is not only
restricted to metal-centred electron removal as shown here
but also via indirect effects from non-innocent ligand
oxidation as exemplified recently in the system
[Ir(Q)(C5Me5)]o/+, Q = 4,6-di-tert-butyl-(2-methylthiophen-
ylimino)-o-benzoquinone, Scheme 4].[11] In that case, how-
ever, the rearrangement involving a change in the metal co-
ordination number leads to nonreversible behaviour in the
cyclovoltammetric experiment, in contrast to the situation
shown here.
Figure 5. UV/Vis/NIR spectroelectrochemical oxidation of
[Cu(L1)2](BF4) in CH2Cl2/0.1 m Bu4NPF6.
While the [CuI(L1)2]+ ion exhibits the expected metal-to-
ligand charge transfer (MLCT) absorptions in the visible
region [650 nm (sh), 500 nm, (sh) 395 nm], which occur be-
tween the d10 level of copper(I) and the π* orbitals of the
iminopyridine conjugated π system, the oxidized form,
[Cu(L1)2]2+, has lost those absorptions but shows two new
features: the expected very weak ligand–field (d–d) absorp-
tion around 900 nm and an intense new band at 355 nm,
attributed to a sulfur-to-copper(II) ligand-to-metal charge
transfer (LMCT). Since the sulfur is part of a neutral thio-
ether function and not of a thiolate group,[1] the LMCT
transition occurs at high energy and the oxidized form dis-
Scheme 4.
Experimental Section
Instrumentation: EPR spectra in the X band were recorded with a
Bruker System EMX. H NMR spectra were taken with a Bruker
1
AC 250 spectrometer. IR spectra were obtained with a Nicolet 6700
FTIR instrument; solid-state IR measurements were performed
with an ATR unit (smart orbit with diamond crystal). UV/Vis/NIR
absorption spectra were recorded with J&M TIDAS and Shimadzu
UV 3101 PC spectrophotometers. Cyclic voltammetry was carried
out in 0.1 m Bu4NPF6 solutions by using a three-electrode configu-
ration (glassy carbon working, Pt counter and Ag/AgCl reference
electrode) and a PAR 273 potentiostat and function generator. The
ferrocene/ferrocenium (Fc/Fc+) couple served as internal reference.
Spectroelectrochemistry was performed with an optically trans-
parent thin-layer electrode (OTTLE) cell. A two-electrode capillary
served to generate intermediates for X band EPR studies.
plays the standard CuII EPR spectrum (g1 = 2.17, g2,3
2.02, A1 = 15 mT).[1]
=
Conclusions
The potentially tridentate ligand 2-pyridyl-N-(2Ј-methyl-
thiophenyl)methyleneimine, which was previously reported
to form a copper(II) complex ion [Cu(L1)2]2+ with one
N,NЈ- and one N,NЈ,S- coordinating ligand L1, yielded a
new copper(I) species, [Cu(L1)2]+, with only N-coordinated
ligands. Similarly, the structurally characterized analogue,
[Cu(L2)2]+, with the related ligand 2-pyridyl-N-(2Ј-benzyl-
thiophenyl)methyleneimine (L2) and the compound
[Cu(L1)(PPh3)2](ClO4) do not show any bonding between
CuI and the thioether function (Cu–S distances Ͼ 3.35 Å).
The two described complex ions [CuL2]+ (L = L1, L2) exhi-
bit differently distorted four-coordination at the d10-config-
ured metal. The transition [CuL2]+/2+ was monitored elec-
trochemically by using cyclic voltammetry, EPR and UV/
Vis spectroelectrochemistry, showing a fully reversible CuI/
CuII conversion despite the rather different molecular struc-
tures found in the crystals, that is, a distorted trigonal pyra-
mid with pyridyl apex for [Cu(L1)2]+ and a square pyramid
with a thioether S atom at the apex for [Cu(L1)2]2+. The
[Cu(pmtpm)(CH3CN)](ClO4):
A solution of pmtpm (95 mg,
0.397 mmol)[6] in dichloromethane (3 mL) was added to
[Cu(CH3CN)4](ClO4) (130 mg, 0.397 mmol) dissolved in dichloro-
methane (15 mL). The mixture turned red and was stirred for 1 h
at room temperature. The complex was precipitated as a red brown-
ish solid by reducing the amount of solvent in vacuo. For purifica-
tion, the resulting powder was washed with toluene several times.
Yield: 144 mg, 84.2%. C15H15ClCuN3O4S (432.36): calcd. C 41.67,
H 3.50, N 9.72; found C 41.94, H 3.64, N 9.42. 1H NMR
(400 MHz, CD2Cl2): δ = 2.19 (s, 3 H, CH3CN), 2.63 (s, 3 H, CH3),
7.48 (s, 3 H, HPh, HC=N), 7.60–7.68 (m, 2 H, HPh), 8.03–8.10
(m, 2 H, HPy), 8.74 (s, 1 H, HPy), 8.83 (s, 1 H, HPy) ppm. 1H-
13C-HSQC NMR (250 MHz, CD2Cl2): δ = 20.3 (CH3), 120.3
(CPh), 129.5 (CPh), 130.7 (CPy), 132.7 (CPy), 136.5 (CPy), 143.0
(CPh), 171.5 (C=N) ppm. HRMS: calcd. for [Cu(pmtpm)]+
(C13H12CuN2S, [M]+) 291.00; found 291.00.
[Cu(pmtpm)(PPh3)2](ClO4):
To
[Cu(CH3CN)2(PPh3)2](ClO4)
spectroelectrochemical results are in agreement with the (140 mg, 0.182 mmol) dissolved in dichloromethane (8 mL) was
Eur. J. Inorg. Chem. 2011, 1436–1441
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1439

W. Kaim et al.
FULL PAPER
added a yellow pmtpm solution (42 mg, 0.182 mmol) in dichloro-
methane (2.5 mL). After the mixture turned orange, it was stirred
for another 30 min at room temperature. The amount of solvent
was reduced in vacuo, and a brown solid precipitated after adding
hexane. The solid was filtered off, and the orange solution was
concentrated to dryness. For a further purification, the orange
powder was washed five times with hexane (3 mL) and finally
recrystallized from a dichloromethane solution. Yield: 33 mg,
(0.033 mmol, 18.1%). C49H42ClCuN2O4P2S (915.88): calcd. C
[Cu(pbtpm)2](ClO4):
A
yellow solution of pbtpm (221 mg,
0.727 mmol) in dichloromethane (5 mL) was added to
[Cu(CH3CN)4](ClO4) (119 mg, 0.364 mmol) dissolved in dichloro-
methane (13 mL). After the brown solution was stirred for 2 h at
room temperature, the amount of solvent was reduced in order to
precipitate the brown complex. For purification, the solid was
recrystallized by dissolving in dichloromethane layered with tolu-
ene. Yield: 214 mg, (0.277 mmol, 76.1%). C38H32ClCuN4O4S2
(771.81): calcd. C 59.13, H 4.18, N 7.26; found C 58.17, H 4.04, N
1
64.26, H 4.62, N 3.06; found C 63.12, H 4.52, N 3.01. 1H NMR 6.93. H NMR (250 MHz. CD2Cl2): δ = 3.84 (s, 4 H, CH2), 6.73
3
3
3
(250 MHz. CD2Cl2): δ = 1.86 (s, 3 H, CH3), 6.39 (d, J = 7.6 Hz, (d, J = 7.7 Hz, 2 H, HPh), 6.92 (d, J = 7.6 Hz, 4 H, HPh), 7.04–
3
3
3
1 H, HPh), 6.98 (m, 1 H, HPh), 7.06 (t, J = 8.8 Hz, 12 H, CH), 7.23 (m, 10 H, HBz), 7.28 (d, J = 6.5 Hz, 2 H, HPh), 7.57 (t, J
7.19 (t, 3J = 7.5 Hz, 12 H, CH), 7.25–7.28 (m, 1 H, HPh), 7.30–
= 5.0 Hz, 2 H, HPy), 7.83 (d, J = 7.7 Hz, 2 H, HPy), 8.04 (t, J
3
3
3
3
7.33 (m, 1 H, HPh), 7.38 (t, J = 7.6 Hz, 6 H, CH), 7.48–7.54 (m, = 7.7 Hz, 2 H, HPy), 8.38 (s, 2 H,HC=N), 8.42 (d, J = 4.9 Hz, 2
1 H, HPy), 8.03–8.18 (m, 2 H, HPy), 8.27 (d, 3J = 4.7 Hz, 1 H, H, HPy) ppm. H-13C-HSQC NMR (250 MHz; CD2Cl2): δ = 37.4
1
HPy), 8.57 (s, 1 H,HC=N) ppm. 31P{1H} NMR (250 MHz, (CH2), 120.5 (CPh), 128.6 (CPh), 126.6 (CBz), 126.7 (CPh), 128.3
CD2Cl2): δ = 1.00 ppm. HRMS: calcd. for [Cu(pmtpm)(PPh3)2]+
(CPy), 128.0 (CPy), 138.3 (CPy), 148.4 (CPy), 170.4 (C=N) ppm.
HRMS: calcd. for [Cu(pbtpm)]+ (C19H16CuN2S, [M]+) 367.03;
found 367.0.
(C49H42CuN2P2S, [M]+) 815.18; found 815.18.
[Cu(pmtpm)2](BF4): To pmtpm (174 mg, 0.763 mmol) dissolved in
dichloromethane (3 mL) was added dropwise
a solution of
X-ray Crystallography
[Cu(CH3CN)4](BF4) (120 mg, 0.382 mmol) in dichloromethane
(11 mL). After being stirred at room temperature for 1.5 h, the deep
red solution was concentrated in vacuo. The red solid, which pre-
cipitated after addition of toluene, was purified by recrystallization
from a dichloromethane solution layered with toluene. Yield:
158 mg, (0.261 mmol, 68.4%). C26H24BCuF4N4S2 (606.98): calcd.
Single crystals of the compounds were obtained by layering a solu-
tion in dichloromethane with toluene [for Cu(L)2 complexes] or by
cooling saturated solutions to –10 °C. Diffraction data were ob-
tained by using Cu-Kα radiation (λ = 1.54178 Å) with an Oxford
Gemini S Ultra diffractometer [for Cu(L)2 complexes] or with Mo-
Kα radiation (λ 0.71073 Å) with a Bruker Nonius Kappa-CCD in-
strument {for [Cu(L)(PPh3)2](ClO4)}. The structures were solved
with the SHELXS program (Patterson method) and refined with
SHELXL97.[12] All H atoms were introduced at the appropriate
positions with isotropic temperature factors (Table 4).
1
C 51.45, H 3.99, N 9.23; found C 51.39, H 4.03, N 9.24. H NMR
3
(400 MHz, CD2Cl2): δ = 2.16 (s, 6 H, CH3), 6.85 (d, J = 7.8 Hz,
2 H, HPh), 7.10 (t, 3J = 7.8 Hz, 2 H, HPh), 7.18–7.30 (m, 4 H,
3
3
HPh), 7.70 (t, J = 5.0 Hz, 2 H, HPy), 7.93 (d, J = 7.7 Hz, 2 H,
HPy), 8.1 (t, 3J = 7.7 Hz, 2 H, HPy), 8.57 (d, 3J = 4.7 Hz, 2 H,
HPy), 8.64 (s, 2 H, HC=N) ppm. H-13C-HSQC NMR (250 MHz,
1
CD2Cl2): δ = 15.6 (CH3), 119.5 (CPh), 125.7 (CPh), 126.1 (CPh),
CCDC-800172, -800173 and -800174 contain the supplementary
127.7 (CPy), 128.3 (CPy), 138.6 (CPy), 148.3 (CPy), 171.2 (CN) crystallographic data for this paper. These data can be obtained
ppm. HRMS: calcd. for [Cu(pmtpm)2]+ (C26H24CuN4S2, [M]+) free of charge from The Cambridge Crystallographic Data Centre
519.07; found 519.1.
via http://www.ccdc.cam.ac.uk/data_request/cif.
Table 4. Crystallographic data for the copper(I) complexes.
[Cu(L1)2](BF4)
[Cu(L2)2](ClO4)
[Cu(L1)(PPh3)2](ClO4)·CH2Cl2
Empirical formula
Formula mass [gmol–1]
Crystal system
Space group
a [Å]
b [Å]
c [Å]
C26H24BCuF4N4S2
606.96
Monoclinic
C2/c
27.984(2)
14.2186(7)
15.8971(12)
117.466(10)
5612.3(7)
8
C38H32ClCuN4O4S2
771.79
Monoclinic
P21/n
9.1487(3)
19.5317(7)
20.7615(7)
97.354(3)
3679.3(2)
4
C50H44Cl3CuN2O4P2S
1000.76
Monoclinic
P21/n
15.1636(4)
12.6726(3)
24.0858(6)
98.404(2)
4578.7(2)
4
β [°]
V [Å3]
Z
Dcalcd [g cm–3]
T [K]
1.437
100(1)
1.393
100(1)
1.452
100(1)
λ [Å]
θ range [°]
F(000)
1.54178
3.56–63.55
2480
1.54178
3.12–62.45
1592
0.71073
1.49–27.89
2064
Parameters
343
2.921
532
2.935
745
0.816
μ [mm–1]
Refl. collected
Indep. refl.
Refl. [IϾ2σ(I)]
R1/wR2 [all data]
R1/wR2 [IϾ2σ(I)]
Goodness of fit
Δρ [eÅ–3]
21539
4582
3435
0.0602/ 0.1654
0.0484/0.1566
1.055
11551
5629
3421
0.1101/0.2032
0.0682/0.1834
1.024
20121
10897
7265
0.0925/0.1318
0.0507/0.1180
1.054
0.573/–0.417
0.551/–0.410
1.283/–1.035
1440
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© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2011, 1436–1441

A Hemilabile N,N,S Donor Ligand in the Redox System [CuL2]+/2+
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Acknowledgments
Support from Deutsche Forschungsgemeinschaft (SFB 706), Fonds
der Chemischen Industrie (Germany), COST D35 (European
Union), Grant Agency of the Czech Republic (Grant 203/09/0705)
and from Proyecto Basal CEDENNA-FB0807 (Chile) is gratefully
acknowledged.
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Received: November 8, 2010
Published Online: February 18, 2011
Eur. J. Inorg. Chem. 2011, 1436–1441
© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
1441