Metalloligands: Rhodium(III) cyclometallated compounds containing multitopological binucleating ligands

Article abstract of DOI:10.1002/ejic.200900165

The reaction of [Rh(2-phenylpyridine)₂Cl]₂ with secondary dithiooxamides H₂R₂C₂N ₂S₂ (R = isoamyl, isopropyl, {S}-phenylethyl, meso-phenylethyl) affords the contact ion pair [Rh(2-phenylpyridine) ₂(H₂R₂C₂N₂S₂ κ-S,S-Rh)]⁺Cl^-, which can be transformed into the neutral complexes [Rh(2-phenylpyridine)₂(HR₂C ₂N₂S₂ κ-S,S-Rh)]. The HCl exchange between the ion pairs and the corresponding neutral complexes has been studied by means of dynamic NMR spectroscopy techniques, and a mechanism for this exchange has been proposed. [Rh(2-phenylpyridine)₂{H(isoamyl) ₂C₂N₂S₂ κ-S,S-Rh}] reacts with chlorido-bridged dimers [ML_nCl]₂ {ML_n = Pd(η³-allyl), Rh(cyclooctadiene), (n-propyl)₃PClPd} and provides the heterobimetallic complexes [Rh(2-phenylpyridine) ₂{μ-(isoamyl)₂C₂N₂S ₂}ML_n]. Heterobimetallic complexes having the same formula and the same structure are obtained by reaction of [ML_n{H(isoamyl) ₂C₂N₂S₂ κ-S,S-M}] species [ML_n = Rh(1,5-cyclooctadiene), Pd(η³-allyl), PdCl(tri-n-propylphosphane), PtCl(diphenyl-2-pyridylphosphane)] with [Rh(2-phenylpyridine)₂Cl]₂. The connectivity of the binucleating ligand diisoamyldithiooxamidate within the bimetallic complexes has been assessed. The linkage isomer obtained is [Rh(2-phenylpyridine) ₂{μ-(isoamyl)₂C₂N₂S ₂}ML_n] (κ-N,N-Rh^III, κ-S,S-M). Wiley-VCH Verlag GmbH & Co. KGaA, 2009.

Full text of DOI:10.1002/ejic.200900165

FULL PAPER
DOI: 10.1002/ejic.200900165
Metalloligands: Rhodium(III) Cyclometallated Compounds Containing
Multitopological Binucleating Ligands
Santo Lanza,*[a] Antonino Giannetto,[a] Giuseppe Bruno,[a] Franco Nicolò,[a] and
Giuseppe Tresoldi[a]
Keywords: Rhodium / Metalloligands / Heterometallic complexes / Coordination modes / NMR spectroscopy
The reaction of [Rh(2-phenylpyridine)2Cl]2 with secondary
dithiooxamides H2R2C2N2S2 (R = isoamyl, isopropyl, {S}-
phenylethyl, meso-phenylethyl) affords the contact ion pair
[Rh(2-phenylpyridine)2(H2R2C2N2S2 κ-S,S-Rh)]+Cl–, which
can be transformed into the neutral complexes [Rh(2-phenyl-
pyridine)2(HR2C2N2S2 κ-S,S-Rh)]. The HCl exchange be-
tween the ion pairs and the corresponding neutral complexes
has been studied by means of dynamic NMR spectroscopy
techniques, and a mechanism for this exchange has been
proposed. [Rh(2-phenylpyridine)2{H(isoamyl)2C2N2S2 κ-S,S-
{µ-(isoamyl)2C2N2S2}MLn]. Heterobimetallic complexes hav-
ing the same formula and the same structure are obtained by
reaction of [MLn{H(isoamyl)2C2N2S2 κ-S,S-M}] species [MLn
=
Rh(1,5-cyclooctadiene), Pd(η3-allyl), PdCl(tri-n-propyl-
phosphane), PtCl(diphenyl-2-pyridylphosphane)] with [Rh(2-
phenylpyridine)2Cl]2. The connectivity of the binucleating li-
gand diisoamyldithiooxamidate within the bimetallic com-
plexes has been assessed. The linkage isomer obtained
is [Rh(2-phenylpyridine)2{µ-(isoamyl)2C2N2S2}MLn] (κ-N,N-
RhIII, κ-S,S-M).
Rh}] reacts with chlorido-bridged dimers [MLnCl]2 {MLn
=
Pd(η3-allyl), Rh(cyclooctadiene), (n-propyl)3PClPd} and pro-
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2009)
vides the heterobimetallic complexes [Rh(2-phenylpyridine)2-
ated fragment, an interesting photoelectrochemical probe,[5]
and in exploring their reactivity toward other metal frag-
ments. The aim is to get heteropolymetallic complexes in
which the electronic communication between the metals is
propagated through bridging atoms. Molecules containing
different metals with diverse electronic properties are key
structures that could display peculiar electronic[6–9] and
magnetic properties[10] and are therefore potentially useful
for developing molecular-based devices.[11]
We report in this paper: (i) the synthesis of the mononu-
clear [Rh(2-phenylpyridine)2(H2R2C2N2S2 κ-S,S-Rh)]+Cl–
species (H2R2C2N2S2 = diisoamyldithiooxamide, 1; di-
isopropyldithiooxamide, 2; di-{S}-phenylethyldithiooxam-
ide, 3; meso-phenylethyldithiooxamidate, 4) and of their de-
hydrohalogenated counterparts [Rh(2-phenylpyridine)2-
(HR2C2N2S2 κ-S,S-Rh)] (HR2C2N2S2 = diisoamyldithioox-
amidate, 5; diisopropyldithiooxamidate, 6; di-{S}-phenyl-
ethyldithiooxamidate, 7; meso-phenylethyldithiooxamidate,
8); (ii) the reaction of [Rh(2-phenylpyridine)2{H(isoamyl)2-
C2N2S2 κ-S,S-Rh}] with some chlorido-bridged dimers
[MLnCl]2 (M = di or trivalent metal ion, Ln = set of neutral
and anionic ligands such that the charge of the MLn frag-
ment is 1+); (iii) the reaction of [MLn{H(isoamyl)2C2N2S2
κ-S,S-M}] [MLn = (1,5-cod)rhodium(I), 9 (cod = cyclooc-
tadiene); (η3-allyl)palladium(II), 10; (tri-n-propylphos-
phane)palladium(II), 11; (diphenyl-2-pyridylphosphane)-
(chlorido)platinum(II), 12] with the chlorido-bridged
[Rh(2-phenylpyridine)2Cl]2; (iv) the assessment of the struc-
Introduction
A number of donor sites conveniently placed in a molec-
ular skeleton can give rise to a binucleating ligand, i.e. a
multitopological ligand that can link metal fragments in a
sequential way. In other words, when a metal coordinates
one or more of the said donor sites, a mononuclear complex
is formed with other uncoordinated donor atoms, which
could link another metal fragment in a successive step. This
is the essence of the synthetic strategy to achieve heteropo-
lymetallic systems based on the use of “metalloligands” (i.e.
metal complexes used as ligands). We have favoured the
strategy of using “metal–dithiooxamidate” building blocks
as a ligand to synthesize various heteropolymetallic com-
plexes,[1–4] by taking advantage of the fact that metal frag-
ments coordinated to the donor sulfur atoms of a deproton-
ated secondary dithiooxamide can function as a ligand
complex. In fact, the N–H···N frame of an S,S-coordinated
dithiooxamidate is nucleophilic enough to split chlorido-
bridged dimers so that heterobimetallic complexes can eas-
ily be obtained.
We are now interested in preparing “metal–dithioox-
amidate” synthons containing a rhodium(III) cyclometall-
[a] Dipartimento di Chimica Inorganica, Chimica Analitica e Chi-
mica Fisica, Università di Messina,
Vill. S. Agata, Salita Sperone 31, 98166 Messina, Italy
Fax: +39-090-393756
E-mail: Lanza@unime.it
Eur. J. Inorg. Chem. 2009, 2647–2654
© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
2647

S. Lanza, A. Giannetto, G. Bruno, F. Nicolò, G. Tresoldi
FULL PAPER
ture of the heterobimetallic compounds [Rh(2-phenylpyr- the ion pair II. It is worth mentioning that the reversible
idine)2{µ-(isoamyl)2C2N2S2}MLn] [MLn = (1,5-cod)rhodi- loss of HCl from complex ion pairs similar to II has already
um(I), 13; (η3-allyl)palladium(II), 14; (tri-n-propylphos- been exploited to obtain molecular systems capable of exhi-
phane)palladium(II), 15; (diphenyl-2-pyridylphosphane)- biting the on/off switching of luminescence both in the solid
(chlorido)platinum(II), 16].
state and in solution.[16]
Results and Discussion
Mononuclear Complexes
We prepared the metalloligands III according to
Scheme 1. It is not surprising that treatment of I with bi-
dentate sulfur ligands results in the cleavage of the chlorido-
bridges and the formation of mononuclear complexes.[12]
However, the HN(R)C–C(R)NH frame of a secondary di-
thiooxamide should work more as a chelating system; thus
the reaction of H2C2N2S2 with a chlorido-bridged dimer
often results in reaction products that depend on the steric
hindrance on the amidic nitrogen atom,[13a] on the nature
of the chlorido-bridged dimers and on the reaction tem-
perature and time.[13b] Actually, treatment of [(phpy)2-
MCl]2 (phpy = 2-phenylpyridine; M = RhIII, IrIII, I) with a
secondary dithiooxamide H2R2C2N2S2 in chloroform pro-
vides II, and III after dehydrohalogenation, independently
of the structural complexity of the alkyl substituent R in
H2R2C2N2S2, of the reaction duration and of the reaction
Scheme 1.
The reversible exchange of HCl was investigated by
temperature. In the absence of structural data, we can infer means of VT 1H NMR experiments. Thus, equimolar quan-
that the neutral dithiooxamide in II, as well as the anionic tities of [Rh(2-phpy)2(H2R2C2N2S2 κ-S,S-Rh)]+Cl– and [(2-
rubeanate in III, is bound to a MIII central ion through phpy)2Rh(µ-R2C2N2S2 κ-S,S-Rh)] were dissolved in deuter-
1
the S,S-chelating system of the ligand on the basis of the iochloroform, and the H NMR spectra were recorded at
following. (i) Both type II and type III complexes have a various temperatures. When R = isoamyl, the signals corre-
C2 symmetry axis. This is evidenced by the NMR spectra, sponding to one species appear in the spectrum at room
which exhibit only one set of signals in all complexes, except temperature, but the frequencies of such signals differ from
in 4 and in 8. In these complexes, the twofold axis is lost as those of both the [Rh(2-phpy)2{H2(isoamyl)2dithiooxamide
a result of the meso ligand so that all resonances appear κ-S,S-Rh}]+Cl– ion pair and the [Rh(2-phpy)2{H(isoamyl)2-
doubled. The NMR signals are doubled also in the spectra dithiooxamide κ-S,S-Rh}] neutral complex. By lowering the
of compounds 3 and 7, but these compounds are equimolar temperature, the signals broadened, but coalescence was not
1
mixtures of ∆-(S,S) and Λ-(S,S) diastereomers. (ii) The H reached, even at a temperature as low as 190 K. The isopro-
NMR shift of the NH signal indicates that amidic hydrogen pyl complexes 2 and 6 gave the results shown in Figure 1.
atoms are engaged in a strong hydrogen bond of the type The doublet, which is quite broadened at room temperature,
+N–H···Cl–.[14] (iii) The IR absorptions at 3400 and at first coalesces and then splits into two well-resolved dou-
3180 cm–1 in complexes 1–4 and at 3350 and 3180 cm–1 blets by lowering the temperature. These doublets corre-
(shoulder) in complexes 5–8 are typical of N–H stretching spond to the H6 2-phenylpyridine proton in 2 and 6.
frequencies. (iv) NMR NOESY experiments do not show
The room-temperature spectrum of the equimolar mix-
dipolar interactions between the α-hydrogen atoms of the ture of the {S}-phenylethyl complexes (3 and 7) exhibits
alkyl substituents and H6 of the 2-phenylpyridine system well-resolved signals for both species 3 and 7. This mixture
that is N,C-chelated to the MIII central ions. These interac- was warmed up to 330 K, but the signals of each dia-
tions should have been detectable if the dithiooxamide li- stereomer were scarcely affected; nevertheless, HCl ex-
gand had been bound to MIII through the N,N-chelating change between species 3 and 7 was evidenced by means of
system; actually, this is the case for heterobimetallic com- a NOESY experiment.
plexes [(phpy)2Rh(µ-R2C2N2S2 κ-N,N-Rh, κ-S,S-M)MLn]
Activation parameters for the above exchange processes
(vide infra). (iv) The nitrogen chelating system of the di- were achieved only for isopropyl derivatives, as the other
thiooxamide ligands, being uncoordinated, is engaged in a processes were too fast (species 1 and 5) or too slow (species
N–H···Cl interaction, which plays an important role in the 3 and 7). It has been found that ∆H = 27.1Ϯ 1.0 kJ/mol,
stabilization of contact ion pairs such as [Rh(phpy)2- ∆G = 59.9Ϯ0.1 kJ/mol, ∆S = –110.0Ϯ3.8 J/Kmol. The
(H2R2C2N2S2 κ-S,S-Rh)]+Cl–.[15] Such an ion pair can negative value for the activation entropy, as well as the low-
easily be dehydrohalogenated to give the neutral complexes ering of the exchange rate as a result of the progressively
III; species III can incorporate gaseous HCl, thus restoring bulkier α-carbon atoms on going from isoamyl to phenyl-
2648
www.eurjic.org
© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2009, 2647–2654

Rhodium(III) Cyclometalated Complexes with Multitopological Ligands
Binuclear Complexes
We have already synthesized a number of binuclear het-
erobimetallic,[1,2,4] trinuclear heterobimetallic[3,4] and trinu-
clear heterotrimetallic complexes[4] by using [LnM-
(HR2C2N2S2)] (M = bi- or trivalent metal ion; Ln = various
ligands, including dithiooxamidate, that leave a positive
charge in the fragment MLn). All the complexes were ob-
tained in one step or in a sequential synthesis, and in all
cases, the metal fragment MЈLЈn was added to the
[LnM(HR2C2N2S2)] ligand complex according to the fol-
lowing process ([MЈLЈnCl]2 is any symmetrical chlorido-
bridged dimer).
[LnM(HR2C2N2S2 κ-S,S-M)] +1/2[MЈLЈnCl]2 Ǟ
[LnM(µ-R2C2N2S2 κ-S,S-M, κ-N,N-MЈ)MЈLЈn] + HCl
Thus, one could expect that a bis(2-phenylpyridine)rho-
dium(III) moiety could be connected to a MLn fragment
through a binucleating dithiooxamide ligand in two ways,
so that the following linkage isomers A and B could be
formed (Scheme 2). The formation of isomer A, rather than
isomer B, depends on whether bis(2-phenylpyridine)rhodi-
um(III) [(phpy)2Rh(HR2C2N2S2 κ-S,S-Rh)] is added to
[MLnCl]2 in
a
ratio of 1:0.5 [procedure (a)] or
[MLn(HR2C2N2S2 κ-S,S-M)] is added to [(phpy)2RhCl]2 in
the same ratio [procedure (b)].
[(phpy)2Rh(HR2C2N2S2 κ-S,S-Rh)] + 0.5[MLnCl]2 Ǟ A + HCl(a)
[MLn(HR2C2N2S2 κ-S,S-M)] + 0.5[(phpy)2RhCl]2 Ǟ B + HCl (b)
Figure 1. Variable-temperature spectra of an equimolar mixture of
[Rh(phpy)2{H2(isopropyl)2C2N2S2 κ-S,S-Rh}]+Cl– (2) and [Rh-
(phpy)2{H(isopropyl)2C2N2S2 κ-S,S-Rh}] (6) in the 6.1–6.4 ppm re-
gion. Computer-synthesized spectra are shown on the right.
Scheme 2.
ethyl groups, agrees with an exchange mechanism, which
implies a congested transition state in which two [(2-phenyl-
pyridine)2Rh(HR2C2N2S2)] units interact with a HCl mole-
cule as suggested in Figure 2.
In contrast to what we expected, either procedure (a) or
procedure (b) gave the same compound, which can be for-
mulated as a heterobimetallic compound with the formula
[Rh(phpy)2(µ-R2C2N2S2)MLn]. In such a compound, the
binucleating dithiooxamide group could be linked through
the sulfur atoms to rhodium and through the nitrogen
atoms to the MLn fragment as in isomer A or vice versa as
in isomer B. Finally, the unique compound obtained could
be isomer C, which contains the binucleating dithiooxamide
group in an N,S coordination mode (Scheme 3). Complexes
in which a dithiooxamide group links two metals in an N,S
coordination mode are well known.[17–20] Structure C can
be ruled out because the NMR spectrum of 13 evidences a
twofold axis in the RhIII–RhI bimetallic complex. Further-
more, the 2D NOESY spectrum shows polar interactions
between the α protons of the alkyl substituents of the di-
thiooxamide group and both the H6 and H6Ј protons of the
N,C-chelated 2-phenylpyridine (Figure 3).
Figure 2. Proposed transition state for the HCl exchange process
between the ion pair [Rh(phpy)2(H2R2C2N2S2 κ-S,S-Rh)]+Cl–
(H2R2C2N2S2
=
dialkyldithiooxamide) and [Rh(phpy)2-
(HR2C2N2S2 κ-S,S-Rh)].
Eur. J. Inorg. Chem. 2009, 2647–2654
© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
2649

S. Lanza, A. Giannetto, G. Bruno, F. Nicolò, G. Tresoldi
FULL PAPER
Scheme 3.
Figure 4. Schematic view of the polar interactions between the α
hydrogen atoms of the alkyl substituents of the dithiooxamide li-
gand and the H6 and H6Ј protons of the N,C-coordinated 2-phenyl-
pyridine. Each N–CH2 group is equidistant from the H6 and H6Ј
protons of both 2-phenylpyridine moieties. Irradiation of the N–
CH2 protons enhances the signal for H6 (ca. 3.7%) and that for
H6Ј (ca. 1.7%) in all the bimetallic complexes 13–16.
Figure 3. NOESY spectrum of [Rh(phpy)2{µ-(isoamyl)2-
C2N2S2}Pd(η3-allyl) κ-N,N-Rh κ-S,S-Pd)] (14). Cross peaks
marked with horizontal arrows indicate the proximity of the N–
CH2 protons to H6 of 2-phenylpyridine; the peaks indicated by
vertical arrows refer to the polar interaction between N–CH2 and
H6Јof 2-phenylpyridine.
Figure 5. Asymmetric unit of the crystal model of 16 obtained by
single-crystal X-ray diffraction, showing the molecular geometry
and co-crystallized chloroform in a ratio of 1:1. Thermal ellipsoids
are at the 25% probability level, while the H size is arbitrary. Se-
lected bond lengths [Å] and angles [°]: Pt–P = 2.258(6), Pt–S1 =
2.271(5), Pt–S2 = 2.315(5), Pt–Cl = 2.336(5), Rh–C35 = 1.97(2),
Rh–N4 = 2.00(2), Rh–N7 = 2.01(2), Rh–C41 = 2.01(2), Rh–N1 =
2.15(2), Rh–N2 = 2.17(1), S1–Pt–S2 = 89.6(2), N1–Rh–N2 =
75.9(6), N7–Rh–C41 = 84.3(8), C35–Rh–N4 = 84.2(8), S1–C1 =
1.74(2), S2–C2 = 1.77(2), C1–N1 = 1.33(2), C1–C2 = 1.44(2), S1–
C1–C2–S2 = 2(2).
Such interactions are not present in the mononuclear
complex [(phpy)2Rh(HR2C2N2S2 κ-S,S-Rh)], in which the
dithiooxamide ligand is chelated in an S,S fashion to rho-
dium and the NCH2 protons are too far from H6 of the 2-
phenylpyridine rings. These facts suggest that the probable
structure of the heterobimetallic species is B (Figure 4).
In order to strengthen the theory proposed by NMR
spectroscopy, several attempts to obtain crystals of com-
plexes 13–16 suitable for an X-ray analysis were made. Un-
fortunately, very thin needles of the only Ru–Pt complex
(16) were obtained, which provided diffraction data of very
poor quality. Nevertheless such data appeared to be suf-
occurs when the bimetallic complexes 13–15 were prepared
according to the following reaction.
[(phpy)2Rh(HR2C2N2S2 κ-S,S-Rh)] + 0.5[MLnCl]2 Ǟ
[(phpy)2Rh(µ-R2C2N2S2 κ-N,N-Rh κ-S,S-M)] + HCl
(1)
This implies that a favourable hard–hard interaction be-
ficient in providing us with some information, i.e. the binu- tween the nitrogen chelating system of the binucleating li-
cleating dithiooxamide ligand is linked to platinum through gand and the proton in the mononuclear [(phpy)2Rh-
the sulfur atoms and to rhodium through the nitrogen (HR2C2N2S2 κ-S,S-Rh)] changes with a probable stable N–
atoms, as shown in Figure 5.
RhIII–N interaction in the binuclear complexes. At the same
As a matter of fact, a change in the connectivity of the time, the rearrangement of the binucleating ligand also pro-
dithiooxamide ligand on going from the mononuclear spe- duces a stable S–M(Ln)–S soft–soft interaction, since all
+
cies [κ-S,S-RhIII] to the binuclear complex [κ-N,N-RhIII
]
MLn are soft metal fragments.[21]
2650
www.eurjic.org
© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2009, 2647–2654

Rhodium(III) Cyclometalated Complexes with Multitopological Ligands
Finally, it should be noted that in [(phpy)2Rh-
(HR2C2N2S2 κ-S,S-Rh)], the high trans influence exerted
by the σ-bonded C1Ј atom destabilizes the RhIII–S bond.[22]
This could be a concomitant cause favouring the change in
the coordination mode of the binucleating ligand observed
Scheme 4.
in process (1).
[Rh(phpy)2(H2R2C2N2S2 κ-S,S-Rh)]+Cl– (H2R2C2N2S2 = N,NЈ-di-
isoamyldithiooxamide) (1): The chloridobis(2-phenyl-pyridine)rho-
dium(III) dimer (446.7 mg, 0.5 mmol) was suspended in chloro-
form (75 mL) and a twofold quantity of N,NЈ-diisoamyldithioox-
amide (260.5 mg, 1 mmol) was added to the resulting suspension.
The mixture was magnetically stirred for 24 h at room temperature.
After this period, the resulting red solution was concentrated to
10 mL, after which petroleum ether (50 mL) was added. The ion
pair [Rh(2-phpy)2(H2R2C2N2S2 κ-S,S-Rh)]+Cl– precipitated as an
orange–red powder; the solvent removed by filtration, and the pow-
der was allowed to dry in air. Yield: 495.0 mg (70%).
C34H40ClN4RhS2 (707.21): calcd. H 5.70, C 57.75, N 7.92, S 9.07;
Conclusions
This work shows that metalloligand [(2-phenylpyridine)2-
Rh{H(isoamyl)2C2N2S2 κ-S,S-Rh}] changes the coordina-
tion mode of the dithiooxamide group when it is linked to
a second metal fragment. Such a change mainly depends on
the stability of the interaction between each of the metals
and the different chelating sites of the binucleating ligand,
other than on the trans influence, and presumably, on the
trans effect of the ancillary ligands surrounding both metal
centres. Steric effects have not been investigated in the
course of the present study, although one can suppose that
bulkier alkyl groups in the species H2R2C2N2S2 causes fur-
ther effects either in the reactions indicated as procedure (a)
or in those indicated as procedure (b). Consequently, fur-
ther studies are required to achieve a complete comprehen-
sion of the stereoelectronic factors that rule the step-wise
formation of polymetallic complexes.
1
found H 5.70, C 57.90, N 7.90, S 9.00. H NMR (CDCl3, 27 °C):
δ = 0.83,0.86 [2d, J = 6.60 Hz, 12 H, NCH2CH2CH(CH3)2], 1.58
[seven lines, J = 6.6 Hz, 2 H, NCH2CH2CH(CH3)2], 1.74 [m, 4 H,
NCH2CH2CH(CH3)2], 3.70 [m, 4 H, NCH2CH2CH(CH3)2], 6.21
(d, J = 7.8 Hz, 2 H, H6Ј), 6.83 (t, J = 7.8 Hz, 2 H, H5Ј), 6.95 (t, J
= 7.8 Hz, 2 H, H4Ј), 7.19 (t, J = 6.2 Hz, 2 H, H5), 7.63 (d, J =
7.8 Hz, 2 H, H3Ј), 7.84 (t, J = 8.2 Hz, 2 H, H4), 7.87 (d, J = 8.2 Hz,
2 H, H3), 8.84 (d, J = 6.0 Hz, 2 H, H6), 12.43 (br. s, 2 H, NH···Cl)
ppm. 13C{1H} NMR (CDCl3, 27 °C):
δ = 22.21, 22.33
[NCH2CH2CH(CH3)2], 26.34 [NCH2CH2CH(CH3)2], 35.00
[NCH2CH2CH(CH3)2], 48.20 [NCH2CH2CH(CH3)2], 118.40 (C3),
122.50 (C4Ј), 123.10 (C5), 124.00 (C3Ј), 129.80 (C5Ј), 132.00 (C6Ј),
2
137.27 (C4), 143.23 (C2Ј), 150.66 (C6), 153.96 (d, JRh-C = 2.1 Hz,
Experimental Section
C2), 166.86 (d, JRh-C = 31.6 Hz, C1Ј) ppm.
General Remarks: Solvents were purified by standard procedures
[Rh(phpy)2(H2R2C2N2S2 κ-S,S-Rh)]+Cl– (H2R2C2N2S2 = N,NЈ-di-
isopropyldithiooxamide) (2): This orange compound was obtained
according to the above procedure by using N,NЈ-diisopropyldi-
thiooxamide (204.4 mg, 1 mmol) in place of N,NЈ-diisoamyldi-
thiooxamide. Yield: 462.3 mg (71%). C30H32ClN4RhS2 (651.09):
calcd. H 4.95, C 55.34, N 8.61, S 9.85; found H 5.00, C 55.80, N
8.50, S 9.90. 1H NMR (CDCl3, 27 °C): δ = 1.37, 1.46 [2d, J =
6.20 Hz, 12 H, NCH(CH3)2], 4.50 [m, 2 H, NCH(CH3)2], 6.21 (d,
J = 7.7 Hz, 2 H, H6Ј), 6.84 (t, J = 7.8 Hz, 2 H, H5Ј), 6.96 (t, J =
7.7 Hz, 2 H, H4Ј), 7.19 (t, J = 6.2 Hz, 2 H, H5), 7.63 (d, J = 7.8 Hz,
2 H, H3Ј), 7.82 (t, J = 8.2 Hz, 2 H, H4), 7.85 (d, J = 8.2 Hz, 2 H,
H3), 8.77 (d, J = 6.0 Hz, 2 H, H6), 12.31 (br. s, 2 H, NH···Cl) ppm.
13C{1H} NMR (CDCl3, 27 °C): δ = 20.28, 20.40 [NCH(CH3)2],
52.62, [NCH(CH3)2], 119.20 (C3), 122.50 (C4Ј), 123.04 (C5), 123.97
(C3Ј), 129.80 (C5Ј), 132.06 (C6Ј), 137.26 (C4), 143.20 (C2Ј), 150.71
and distilled before use. Secondary dithiooxamides,[23] cis-
[24]
Pt(Me2SO)2Cl2
phane)Cl2
and cis-Pt(Me2SO)(diphenyl-2-pyridylphos-
[25]
[26]
and [Pd(tri-n-propylphosphane)Cl2]2
were pre-
pared according to literature methods. [Rh(1,5-cyclooctadiene)-
Cl]2, [(η3-allyl)PdCl]2 and [Rh(2-phenylpyridine)2Cl]2 were ob-
tained commercially and were used as purchased. The reactions
were performed under laboratory atmosphere, since both reagents
and reaction products are stable in air. 1H NMR and
13C{1H}NMR spectra were recorded at 298°K on a Bruker ARX-
300, equipped with a broad band probe operating at 300.13 and
75.56 MHz, respectively. Chemical shifts (δ, ppm) were referenced
to SiMe4. The simulation of static and dynamic spectra was per-
formed with a gNMR program. IR spectra were obtained as Nujol
mulls on KBr plates by using a Perkin–Elmer FTIR 1720 spectrom-
eter. Diffraction analysis was performed with a four-circle single-
crystal Siemens P4 diffractometer by using graphite monochro-
mated Mo-Kα radiation. Thin needles of complex 16 were obtained
by slow evaporation of the solvent from a chloroform/petroleum
ether solution. The diffraction data were collected up to 2θ = 50º,
and the reflection intensities were evaluated by a learnt-profile pro-
cedure[27] among 2θ shells and then corrected for Lorentz-polariza-
tion and absorption effects. Data collection and reduction were
performed with a SHELXTL[28] package, but the quality of the
9036 independent reflection set was very poor [R(int) = 0.124]. The
atom labelling scheme for 2-phenylpyridine– is shown in Scheme 4.
CCDC-730891 contains the supplementary crystallographic data
for this paper. These data can be obtained free of charge from The
Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/
data_request/cif.
2
(C6), 165.37 (d, JRh-C = 2.1 Hz, C2), 166.90 (d, JRh-C = 31.6 Hz,
C1Ј) ppm.
[Rh(phpy)2(H2R2C2N2S2 κ-S,S-Rh)]+Cl– (H2R2C2N2S2 = N,NЈ-di-
{S}-phenylethyldithiooxamide) (3): This orange compound was pre-
pared as described for 1 by using N,NЈ-di-{S}-phenylethyldithioox-
amide (328.5 mg, 1 mmol) in place of N,NЈ-diisoamyldithiooxam-
ide. Yield: 535.0 mg (69%). C40H36ClN4RhS2 (775.23): calcd. H
4.68, C 61.97, N 7.23, S 8.27; found H 4.70, C 62.50, N 7.40, S
1
8.20. H NMR (CDCl3, 27 °C): δ = 1.88, 1.93 [2d, J = 7.04 Hz, 6
H, NCH(C6H5)CH3], 5.33, 5.94 [2sl, J = 7.0 Hz, 2 H, NCH(C6H5)
CH3], 5.92, 6.14 (2d, J = 7.8 Hz, 2 H, H6Ј), 6.7–7.84 (overlapping
signals due to H3, H4, H5, H3Ј, H4Ј, H5Ј, 22 H, phenylethyl-C6H5),
8.59, 9.19 (2d, J = 6.0 Hz, 2 H, H6), 12.88, 13.04 (2d, J = 6.2 Hz,
2 H, NH···Cl) ppm. 13C{1H} NMR (CDCl3, 27 °C): δ = 21.33,
Eur. J. Inorg. Chem. 2009, 2647–2654
© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
2651

S. Lanza, A. Giannetto, G. Bruno, F. Nicolò, G. Tresoldi
FULL PAPER
22.08 [NCH(C6H5)CH3], 60.04, 60.34 [NCH(C6H5)CH3], 119.24
[Rh(phpy)2(HR2C2N2S2 κ-S,S-Rh)] (HR2C2N2S2 = N,NЈ-di-{S}-
(C3), 122.25 (C4Ј), 122.90 (C5), 123.90 (C3Ј), 127.70 (meta-C6H5), phenylethyldithiooxamidate) (7): This yellow compound was ob-
128.01 (para-C6H5), 128.40, 128.60 (ortho-C6H5), 129.70 (C5Ј), tained according to the procedure described for 5 by using 3
131.38, 132.04 (C6Ј), 137.06, 137.18 (C4), 140.10, 141.00 (C2Ј), (387.6 mg, 0.5 mmol) in place of 1. Yield: 229.6 mg (62%).
150.50 (C6), 165.30 (2JRh-C = 2.1 Hz, C2), 166.50, 166.90 (2d,
1JRh-C = 31.6 Hz, C1Ј) ppm.
C40H35N4RhS2 (738.77): calcd. H 4.78, C 65.03, N 7.58, S 8.68;
1
found H 4.90, C 64.90, N 7.50, S 8.65. H NMR (CDCl3, 27 °C):
δ = 1.45, 1.55 [2d, J = 6.7 Hz, 6 H, NCH(C6H5)CH3], 5.39, 5.38
[2q, J = 6.7 Hz, 2 H, NCH(C6H5)CH3], 6.20, 6.28 (2d, J = 7.8 Hz,
2 H, H6Ј), 6.62–7.83 (overlapping signals due to H3, H4, H5, H3Ј,
H4Ј, H5Ј, 22 H, phenylethyl-C6H5), 8.86, 9.12 (2d, J = 5.9 Hz, 2 H,
H6) ppm. 13C{1H} NMR (CDCl3, 27 °C): δ = 21.75, 21.93
[NCH(C6H5)CH3], 58.15, 58.20 [NCH(C6H5)CH3], 118.73, 118.84
(C3), 121.74 (C5), 122.05, 122.10 (C4Ј), 123.43, 123.60 (C3Ј), 126.47,
126.65 (meta-C6H5), 126.99 (para-C6H5), 128.47 (ortho-C6H5),
129.19, 129.21 (C5Ј), 132.25 (C6Ј), 136.10, 136.20 (C4), 143.40,
144.00 (C2Ј), 151.91 (C6), 165.69, 170.00 (C2), 169.92, 170.00 (2d,
JRh-C = 31.6 Hz, C1Ј) ppm.
[Rh(phpy)2(H2R2C2N2S2 κ-S,S-Rh)]+Cl– (H2R2C2N2S2 = N,NЈ-
meso-diphenylethyldithiooxamide) (4): This orange compound was
obtained according to the procedure described for 1 by using N,NЈ-
meso-diphenylethyldithiooxamide (328.5 mg, 1 mmol) in place of
N,NЈ-diisoamyldithiooxamide.
Yield:
503.9 mg
(65%).
C40H36ClN4RhS2 (775.24): calcd. H 4.68, C 61.97, N 7.23, S 8.27;
1
found H 4.65, C 62.40, N 7.20, S 8.15. H NMR (CDCl3, 27 °C):
δ = 1.86, 1.94 [2d, J = 7.04 Hz, 6 H, N-CH(C6H5)CH3], 5.34, 5.56
[2sl, J = 7.0 Hz, 2 H, NCH(C6H5)CH3], 6.04, 6.17 (2d, J = 7.8 Hz,
2 H, H6Ј), 6.68–7.90 (overlapped signals due to H3, H4, H5, H3Ј,
H4Ј, H5Ј, 22 H, phenylethyl-C6H5), 8.03, 8.76 (2d, J = 6.0 Hz, 2 H,
H6), 12.90, 13.07 (2d, J = 6.2 Hz, 2 H, NH···Cl) ppm. 13C{1H} [Rh(phpy)2(HR2C2N2S2 κ-S,S-Rh)] (HR2C2N2S2 = N,NЈ-di-meso-
NMR (CDCl3, 27 °C): δ = 21.62, 22.10 [NCH(C6H5)CH3], 60.30 phenylethyldithiooxamidate) (8): This yellow compound was ob-
[NCH(C6H5)CH3], 119.30, 119.50 (C3), 122.40, 122.60 (C4Ј), 122.97
(C5), 123.90, 124.01 (C3Ј), 127.68 (meta-C6H5), 127.89 (para-C6H5),
tained according to the procedure described for 5 by using 4
(387.6 mg, 0.5 mmol) in place of 1. Yield: 248.0 mg (67%).
128.50, 128.60 (ortho-C6H5), 129.70 (C5Ј), 131.90, 132.1 (C6Ј), C40H35N4RhS2 (738.77): calcd. H 4.78, C 65.03, N 7.58, S 8.68;
1
137.16, 137.34 (C4), 140.10, 141.00 (C2Ј), 150.47, 150.51 (C6),
found H 4.70, C 65.00, N 7.50, S 8.50. H NMR (CDCl3, 27 °C):
δ = 1.49, 1.67 [2d, J = 6.7 Hz, 6 H, NCH(C6H5)CH3], 5.38, 5.39
[2q, J = 6.7 Hz, 2 H, NCH(C6H5)CH3], 6.20, 6.23 (2d, J = 7.8 Hz,
2 H, H6Ј), 6.66–7.93 (overlapping signals due to H3, H4, H5, H3Ј,
H4Ј, H5Ј, 22 H, phenylethyl-C6H5), 8.69, 9.24 (2d, J = 5.9 Hz, 2 H,
H6) ppm. 13C{1H} NMR (CDCl3, 27 °C): δ = 21.73, 22.46
[NCH(C6H5)CH3], 58.00, 58.17 [NCH(C6H5)CH3], 118.74, 118.86
(C3), 121.74 (C5), 122.06 (C4Ј), 123.56 (C3Ј), 126.35, 126.54 (meta-
C6H5), 126.83126.95 (para-C6H5), 128.50 (ortho-C6H5), 129.19,
129.21 (C5Ј), 132.17, 132.35 (C6Ј), 136.25 (C4), 143.40, 144.00 (C2Ј),
151.91 (C6), 166.25 (C2), 169.32, 169.74 (2d, JRh-C = 31.6 Hz, C1Ј)
ppm.
165.05, 165.45 (C2), 166.64, 167.01 (2d, 1JRh-C = 31.6 Hz, C1Ј) ppm.
[Rh(phpy)2(HR2C2N2S2 κ-S,S-Rh)] (HR2C2N2S2 = N,NЈ-diisoamyl-
dithiooxamidate) (5): Compound 1 (353.6 mg, 0.5 mmol) was dis-
solved in chloroform (75 mL), and the resulting orange solution
was treated with sodium hydrogen carbonate (2 g). The mixture
soon turned yellow and was left to stir for 0.5 h. After this time,
the solution was filtered, concentrated to 10 mL and purified by
chromatography [alumina column, chloroform/petroleum ether
(4:1, v/v) as eluent]. The pure yellow product was finally obtained
by precipitation from the addition of petroleum ether (40/60) to a
concentrated portion (about 10 mL) of the eluate. Yield: 228.1 mg
(68%). C34H39N4RhS2 (670.73): calcd. H 5.86, C 60.88, N 8.35, S
9.56; found H 5.90, C 61.00, N 8.25, S 9.50. 1H NMR (CDCl3,
27 °C): δ = 0.88, 0.89 [2d, 12 H, NCH2CH2CH(CH3)2], 1.60 [m, 6
[Rh(1,5-cyclooctadiene)(HR2C2N2S2 κ-S,S-Rh)] (HR2C2N2S2
=
N,N-diisoamyldithiooxamidate) (9): [Rh(1,5-cyclooctadiene)Cl]2
(123.3 mg, 0.25 mmol) was dissolved in chloroform (40 mL), and
H, NCH2CH2CH(CH3)2], 3.58 [m, 4 H, NCH2CH2CH(CH3)2], sodium hydrogen carbonate (1.0 g) and N,NЈ-diisoamyldithiooxam-
6.27 (d, J = 7.3 Hz, 2 H, H6Ј), 6.79 (t, J = 7.3 Hz, 2 H, H5Ј), 6.88 ide (130.2 mg, 0.5 mmol) were then added. The mixture was kept
(t, J = 7.3 Hz, 2 H, H4Ј), 7.09 (t, J = 6.6 Hz, 2 H, H5), 7.59 (d, J
under magnetic stirring for 1 h. Sodium hydrogen carbonate was
= 8.0 Hz, 2 H, H3Ј), 7.72 (t, J = 8.0 Hz, 2 H, H4), 7.82 (d, J = then removed, and the resulting solution was concentrated to a
8.0 Hz, 2 H, H3), 9.08 (d, J = 6.0 Hz, 2 H, H6) ppm. 13C{1H}
NMR (CDCl3, 27 °C): δ = 22.58 [NCH2CH2CH(CH3)2], 26.41
small volume (about 5 mL). Finally, petroleum light was added,
and a pure yellow compound was obtained. Yield: 198.0 mg (84%).
[NCH2CH2CH(CH3)2], 37.99 [NCH2CH2CH(CH3)2], 48.55 C20H35N2RhS2 (470.54): calcd. H 7.50, C 51.05, N 5.95, S 13.63;
1
[NCH2CH2CH(CH3)2], 118.89 (C3), 121.81 (C4Ј), 122.15 (C5), found H 7.60, C 51.10, N 6.00, S 13.50. H NMR (CDCl3, 27 °C):
123.63 (C3Ј), 129.22 (C5Ј), 132.26 (C6Ј), 136.27 (C4), 143.39 (C2Ј),
δ = 0.92 [d, J = 6.3 Hz, 12 H, NCH2CH2CH(CH3)2], 1.57–1.63 [m,
6 H, NCH2CH2CH(CH3)2], 2.03 (m, 4 H, CH2-cod), 2.44 (m, 4 H,
CH2-cod), 3.60 [t, J = 7.2 Hz, 4 H, NCH2CH2CH(CH3)2], 4.43 (br.
s, 4 H, CH-cod) ppm. 13C{1H} NMR (CDCl3, 27 °C): δ = 22.47,
[NCH2CH2CH(CH3)2], 26.23 [NCH2CH2CH(CH3)2], 31.30 (CH2-
cod), 37.64 [NCH2CH2CH(CH3)2], 47.64 [NCH2CH2CH(CH3)2],
82.65 (JRh-C = 11.0 Hz, CH-cod) ppm.
150.91 (C6), 165.70 (C2), 169.90 (d, JRh-C = 31.9 Hz, C1Ј) ppm.
[Rh(phpy)2(HR2C2N2S2 κ-S,S-Rh)] (HR2C2N2S2 = N,NЈ-diisopro-
pyldithiooxamidate) (6): This yellow compound was obtained ac-
cording to the above procedure by using 2 (325.6 mg, 0.5 mmol) in
place of 1. Yield: 215.1 mg (70%). C30H31N4RhS2 (614.63): calcd.
H 5.08, C 58.63, N 9.12, S 10.43; found H 5.00, C 58.90, N 9.20,
1
S 10.50. H NMR (CDCl3, 27 °C): δ = 1.13, 1.26 [2d, J = 6.10 Hz,
[Pd(η3-allyl)(HR2C2N2S2 κ-S,S-Pd)] (HR2C2N2S2 = N,NЈ-diiso-
amyldithiooxamidate) (10): This yellow compound was obtained ac-
12 H, NCH(CH3)2], 4.33 [m, 2 H, NCH(CH3)2], 6.27 (d, J =
7.50 Hz, 2 H, H6Ј), 6.76 (t, J = 7.78 Hz, 2 H, H5Ј), 6.87 (t, J = cording to the above procedure by using [Pd(η3-allyl)Cl]2 (91.5 mg,
7.7 Hz, 2 H, H4Ј), 7.08 (t, J = 6.16 Hz, 2 H, H5), 7.59 (d, J =
0.25 mmol) in place of [Rh(1,5-cyclooctadiene)Cl]2. Yield:
7.8 Hz, 2 H, H3Ј), 7.75 (t, J = 8.2 Hz, 2 H, H4), 7.8 (d, J = 8.22 Hz, 175.0 mg (86%). C15H28N2PdS2 (406.94): calcd. H 6.94, C 44.27,
2 H, H3), 9.12 (d, J = 6.0 Hz, 2 H, H6) ppm. 13C{1H} NMR N 6.88, S 15.76; found H 6.90, C 44.20, N 6.80, S 15.60. H NMR
1
(CDCl3, 27 °C): δ = 21.75, 21.93 [NCH(CH3)2], 50.27, [NCH-
(CDCl3, 27 °C):
δ
=
0.90 [d,
J
=
6.45 Hz, 12 H,
(CH3)2], 118.80 (C3), 121.63 (C4Ј), 121.96 (C5), 123.55 (C3Ј), 129.14 NCH2CH2CH(CH3)2], 1.60–1.70 [m, 6 H, NCH2CH2CH(CH3)2],
(C5Ј), 132.27 (C6Ј), 136.19 (C4), 143.37 (C2Ј), 150.91 (C6), 165.00 (d, 3.00 (d, J = 12.7 Hz, 2 H, allyl anti), 3.68 [d, J = 7.2 Hz, 1 H,
2JRh-C = 2.1 Hz, C2), 170.00 (d, JRh-C = 31.8 Hz, C1Ј) ppm.
2652
NCH2CH2CH(CH3)2], 4.15 (d, J = 6.9 Hz, 2 H, allyl syn), 5.32 (m,
www.eurjic.org
© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2009, 2647–2654

Rhodium(III) Cyclometalated Complexes with Multitopological Ligands
4 H, CH-allyl) ppm. 13C{1H} NMR (CDCl3, 27 °C): δ = 22.50,
[Rh(phpy)2{µ-(isoamyl)2C2N2S2}Pd(η3-allyl) κ-N,N-Rh κ-S,S-Pd]
[NCH2CH2CH(CH3)2],
26.3
[NCH2CH2CH(CH3)2],
37.6 (14): This orange compound was prepared by procedures (a) and
[NCH2CH2CH(CH3)2], 48.30 [NCH2CH2CH(CH3)2], 61.80 (allyl- (b). (a) This product was obtained from 5 (134.2 mg, 0.2 mmol)
CH2), 113.8 (allyl-CH) ppm.
and [(η3-allyl)PdCl]2 (36.6 mg, 0.1 mmol) according to procedure
(a) above. Yield: 65 mg (40%). C37H43N4PdRhS2 (817.20): calcd.
(817.22): H 5.30, C 54.38, N 6.86, S 7.85; found H 5.35, C 54.45,
N 6.90, S 7.80. (b) This product was obtained from 10 (81.4 mg,
0.2 mmol) and [Rh(2-phpy)Cl]2 (89.3 mg, 0.1 mmol) according to
procedure (b) above. Yield: 80 mg (49%). Found H 5.25, C 54.50,
[PdCl(tri-n-propylphosphane)(HR2C2N2S2 κ-S,S-Pd)] (HR2C2N2S2
= N,NЈ-diisoamyldithiooxamidate) (11): This yellow compound was
obtained according to the procedure described for 9 by using
[Pd(tri-n-propylphosphane)Cl2]2 (168.8 mg, 0.25 mmol) in place of
[Rh(1,5-cyclooctadiene)Cl]2.
C21H44ClN2PPdS2 (561.56): calcd. H 7.90, C 44.92, N 4.99, S
Yield:
235.9 mg
(84%).
1
N 6.80, S 7.80. H NMR (CDCl3, 27 °C): δ = 0.43, 0.47 [2d, J =
6.6 Hz, 12 H, NCH2CH2CH(CH3)2], 1.06 [m,
2
H,
1
11.42; found H 7.90, C 44.20, N 4.80, S 11.60. H NMR (CDCl3,
NCH2CH2CH(CH3)2], 1.25 [m, 4 H, NCH2CH2CH(CH3)2], 2.91
(d, 2 H, CH2-allyl), 3.60 [m, 4 H, NCH2CH2CH(CH3)2], 3.95 (d, 2
H, CH2-allyl), 5.27 (m, 1 H, CH-allyl), 6.16 (d, J = 7.5 Hz, 2 H,
H6Ј), 6.78 (t, J = 7.5 Hz, 2 H, H5Ј), 6.89 (t, J = 7.5 Hz, 2 H, H4Ј),
7.15 (m, 2 H, H5), 7.57 (d, J = 8.0 Hz, 2 H, H3Ј), 7.85 (m, 2 H,
H4), 7.85 (m, 2 H, H3), 8.15 (d, J = 5.5 Hz, 1 H, H6), 8.19 (d, J =
5.7 Hz, 1 H, H6) ppm. 13C{1H} NMR (CDCl3, 27 °C): δ = 21.86,
21.99 [NCH2CH2CH(CH3)2], 26.42 [NCH2CH2CH(CH3)2], 34.60
[NCH2CH2CH(CH3)2], 54.11 [NCH2CH2CH(CH3)2], 60.28 (CH2-
allyl), 112.75 (CH-allyl), 118.58 (C3), 122.12 (C4Ј), 122.30 (C5),
123.37 (C3Ј), 129.42 (C5Ј), 132.19 (C6Ј), 136.82 (C4), 143.24 (C2Ј),
150.15 (C6), 165.63 (C2), 170.98 (2d, JRh-C = 31.64 Hz, C1Ј) ppm.
27 °C): δ = 0.93 [d, J = 6.1 Hz, 12 H, NCH2CH2CH(CH3)2], 1.05
(t, 3JH-H
=
6.6 Hz, PCH2CH2CH3), 1.562–1.925 [m,
NCH2CH2CH(CH3)2, PCH2CH2CH3], 3.5 [t, JH-H = 7.2 Hz,
NCH2CH2CH(CH3)2], 3.67 [t, JH-H = 7.2 Hz NCH2CH2CH(CH3)
2] ppm. 13C{1H} NMR (CDCl3, 27 °C): δ = 15.88 (PCH2CH2CH3),
17.85 (PCH2CH2CH3), 22.28, 22.58 [NCH2CH2CH(CH3)2], 25.20
(d,
JP-C
=
28.0 Hz,
PCH2CH2CH3),
26.1,
26.4
[NCH2CH2CH(CH3)2], 36.2, 38.9 [NCH2CH2CH(CH3)2], 43.9,
49.7 [NCH2CH2CH(CH3)2] ppm.
[PtCl(diphenyl-2-pyridylphosphane)(HR2C2N2S2 κ-S,S-Pt)] (HR2-
C2N2S2 = N,NЈ-diisoamyldithiooxamidate) (12): This yellow com-
pound was obtained according to the procedure described for 9 by
[Rh(phpy)2{µ-(isoamyl)2C2N2S2}PdCl(tri-n-propylphosphane) κ-N,N-
Rh κ-S,S-Pd] (15): This compound was prepared by procedures (a)
and (b). (a) 5 (0.2 mmol, 134.2 mg) was dissolved in chloroform
(50 mL). To the solution were added [PdClP(n-propyl)3]2 (60.4 mg,
0.1 mmol) and methanol (10 mL). The reaction mixture was heated
at reflux for 6 h, concentrated to 10 mL and purified by chromatog-
raphy [alumina column, chloroform/petroleum ether (4:1, v/v) as
eluent]. The orange solid was obtained by addition of petroleum
ether (40/60) to a concentrated portion (about 10 mL) of the eluate.
Yield: 97.2 mg (50%). C43H59ClN4PPdRhS2 (971.82): calcd.
(971.84): H 6.12, C 53.14, N 5.77, S 6.60; found H 6.20, C 53.50,
N 5.55, S 6.50. (b) This product was obtained from 11 (112.3 mg,
0.2 mmol) and [Rh(phpy)Cl]2 (89.3 mg, 0.1 mmol) according to
procedure (b) described for 13. Yield: 118.0 mg (61%). Found H
using
[Pt(diphenyl-2-pyridylphosphane)Cl2]2
(264.6 mg,
0.25 mmol) in place of [Rh(1,5-cyclooctadiene)Cl]2.Yield: 320.0 mg
(85%). C29H37ClN3PPtS2 (753.26): calcd. H 4.95, C 46.24, N 5.58,
1
S 8.51; found H 4.90, C 46.20, N 5.60, S 8.60. H NMR (CDCl3,
27 °C): δ = 0.92, 0.93 [2d, J = 7.2 Hz, 12 H, NCH2CH2CH-
(CH3)2], 1.596–1.691 [m, 6 H, NCH2CH2CH(CH3)2], 3.71, 3.28 [2t,
J = 7.0 Hz, 4 H, NCH2CH2CH(CH3)2] ppm. 13C{1H} NMR
(CDCl3, 27 °C): δ = 22.30, 21.92 [NCH2CH2CH(CH3)2], 25.8, 26.4
[NCH2CH2CH(CH3)2], 35.8, 38.4 [NCH2CH2CH(CH3)2], 43.0,
48.9 [NCH2CH2CH(CH3)2], 124,9–150.5 (ArC, PyC) ppm.
[Rh(phpy)2{µ-(isoamyl)2C2N2S2}Rh(1,5-cyclooctadiene) κ-N,N-RhIII
κ-S,S-RhI] (13): This orange compound was prepared by pro-
cedures (a) and (b). (a) 5 (134.2 mg, 0.2 mmol) was dissolved in
chloroform (40 mL). To the solution were added [(1,5-cyclooc-
tadiene)RhCl]2 (49.3 mg, 0.1 mmol) and methanol (10 mL). The re-
action mixture was heated at reflux for 2 h, concentrated to 10 mL
and purified by chromatography [alumina column, chloroform/pe-
troleum ether (4:1, v/v) as eluent]. The solid pure product was ob-
tained by the addition of petroleum ether (40/60) to a concentrated
portion (about 10 mL) of the eluate. Yield: 72 mg (41%).
C42H50N4Rh2S2 (880.82): calcd. H 5.72, C 57.27, N 6.36, S 7.28;
found H 5.75, C 57.50, N 6.35, S 7.20. (b) 9 (94.1 mg, 0.2 mmol)
was dissolved in chloroform (40 mL). To the solution were added
[Rh(phpy)Cl]2 (89.3 mg, 0.1 mmol) and methanol (10 mL). The re-
action mixture was treated as above. Yield: 93 mg (53%). Found H
1
6.15, C 53.60, N 5.60, S 6.45. H NMR (CDCl3, 27 °C): δ = 0.37
0.40 0.43, 0.45 [4d, J = 6.6 Hz, 12 H, NCH2CH2CH(CH3)2], 0.88
[m, 9 H, P(CH2CH2CH3)3], 1.01 [m, 6 H, P(CH2CH2CH3)3], 1.19
[m, 2 H, NCH2CH2CH(CH3)2], 1.19 [m, 4 H, NCH2CH2CH-
(CH3)2], 1.58 [m,
6 H, P(CH2CH2CH3)3], 3.43 [m, 4 H,
NCH2CH2CH(CH3)2], 6.10, 6.12 (d, J = 6.1 Hz, 2 H, H6Ј), 6.76 (t,
J = 6.1 Hz, 2 H, H5Ј), 6.87 (t, J = 6.1 Hz, 2 H, H4Ј), 7.20 (m, 2 H,
H5), 7.54 (d, J = 8.0 Hz, 2 H, H3Ј), 7.83 (m, 2 H, H4), 7.83 (m, 2
H, H3), 8.12 (m, 2 H, H6) ppm. 13C{1H} NMR (CDCl3, 27 °C): δ
=
21.95,
22.65
[NCH2CH2CH(CH3)2],
26.38,
26.49
[NCH2CH2CH(CH3)2], 26.76, 26.87 [P(CH2CH2CH3)3], 34.71,
34.89 [NCH2CH2CH(CH3)2], 35.90 [P(CH2CH2CH3)3], 51.90
[P(CH2CH2CH3)3], 52.28, 52.78 [NCH2CH2CH(CH3)2], 118.73
(C3), 122.37 (C4Ј), 122.60 (C5), 123.52 (C3Ј), 129.56 (C5Ј), 132.21
(C6Ј), 137.11 (C4), 143.29 (C2Ј), 150.14 (C6), 165.57 (C2), 170.20,
170.45 (2d, JRh-C = 31.6 Hz, C1Ј) ppm.
1
5.80, C 57.40, N 6.35, S 7.30. H NMR (CDCl3, 27 °C): δ = 0.40,
0.44 [2d, J = 6.46 Hz, 12 H, NCH2CH2CH(CH3)2], 1.56 [m, 6 H,
NCH2CH2CH(CH3)2], 2.00 (m, 4 H, CH2-cod), 2.45 (m, 4 H, CH2-
cod), 3.51 [m, 4 H, NCH2CH2CH(CH3)2], 4.88 (m, 4 H, CH-cod),
6.11 (d, J = 7.5 Hz, 2 H, H6Ј), 6.75 (t, J = 7.5 Hz, 2 H, H5Ј), 6.88 (Rh(phpy)2{µ-(isoamyl)2C2N2S2}PtCl(diphenyl-2-pyridylphosphane)
(t, J = 7.5 Hz, 2 H, H4Ј), 7.18 (t, J = 6.0 Hz, 1 H, H5), 7.19 (t, J =
6.0 Hz, 1 H, H5), 7.55 (d, J = 8.0 Hz, 2 H, H3Ј), 7.84 (m, 2 H, H4),
7.84 (m, 2 H, H3), 8.16 (d, J = 5.7 Hz, 2 H, H6) ppm. 13C{1H}
κ-N,N-Rh κ-S,S-Pt](16): This compound was obtained as an
orange solid according to procedure (b) described for 13 starting
from 12 (150.6 mg, 0.2 mmol) and [Rh(phpy)Cl]2 (89.3 mg,
NMR (CDCl3, 27 °C): δ = 21.91, 22.13 [NCH2CH2CH(CH3)2], 0.1 mmol). Yield: 116.5 mg (50%). C51H52ClN5PPtRhS2 (1163.54):
26.40 [NCH2CH2CH(CH3)2], 31.10, 31.34 (CH2-cod), 34.92 H 4.50, C 52.65, N 6.02, S 5.51; found H 4.55, C 52.70, N 6.10, S
[NCH2CH2CH(CH3)2], 53.54 [NCH2CH2CH(CH3)2], 80.99, 81.09 5.60. 1H NMR (CDCl3, 27 °C): δ = 0.29 0.30 0.38, 0.42 [4d, J =
(JRh-C = 8.32 Hz, CH-cod), 118.00 (C3), 122.20 (C4Ј), 122.47 (C5),
123.37 (C3Ј), 129.51 (C5Ј), 132.20 (C6Ј), 136.83 (C4), 143.33 (C2Ј),
150.50 (C6), 165.67 (C2), 170.93 (d, JRh-C = 31.9 Hz, C1Ј) ppm.
6.60 Hz, 12 H, NCH2CH2CH(CH3)2], 0.66–1.32 [m, 6 H,
NCH2CH2CH(CH3)2], 3.06, 3.50 [m, 4 H, NCH2CH2CH(CH3)2],
6.06 (d, J = 7.70 Hz, 2 H, H6Ј), 6.73, 6.75 (2t, J = 7.7 Hz, 2 H,
Eur. J. Inorg. Chem. 2009, 2647–2654
© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
2653

S. Lanza, A. Giannetto, G. Bruno, F. Nicolò, G. Tresoldi
FULL PAPER
H5Ј), 6.84, 6.87 (2t, J = 7.7 Hz, 2 H, H4Ј), 7.0–7.86 (m), 8.04 (d, J
= 5.5 Hz, 2 H, H4), 8.13 (d, J = 5.50 Hz, 2 H, H6), 8.54 (t, J =
7.2 Hz, 2 H, H6), 8.70 (d, J = 6.6 Hz, 2 H, H6) ppm. 13C{1H}
NMR (CDCl3, 27 °C): δ = 21.87, 22.00, 22.10 [NCH2CH2CH-
(CH3)2], 26.40 [NCH2CH2CH(CH3)2], 34.57, 34.67 [NCH2CH2CH-
(CH3)2], 52.51, 53.12 [NCH2CH2CH(CH3)2], 122.5–136.0, 118.70
(C3), 122.36 (C4Ј), 122.45 (C5), 123.43, 123.52 (C3Ј), 129.51, 129.60
(C5Ј), 132.16 (C6Ј), 137.08 (C4), 143.22 (C2Ј), 149.75, 149.93 (C6-
PyP) 150.20, 150.34 (C6), 165.46, 165.54 (C2), 170.17, 170.41 (2d,
JRh-C = 30.5 Hz, C1Ј) ppm.
[12] M. K. Lau, K. M. Cheung, O. F. Zhang, Y. Song, W. T. Wong,
I. D. Williams, W. H. Leung, J. Organomet. Chem. 2004, 689,
2401–2410.
[13] a) S. Lanza, G. Bruno, F. Nicolò, A. Rotondo, G. Tresoldi, Eur.
J. Inorg. Chem. 2002, 65–72; b) S. Lanza, unpublished results.
[14] J. Emsley, J. Chem. Soc. Rev. 1980, 9, 91–124.
[15] a) G. Rosace, G. Bruno, L. Monsù Scolaro, F. Nicolò, S. Sergi,
S. Lanza, Inorg. Chim. Acta 1993, 208, 59–65; b) R. Karaman,
T. C. Bruice, Inorg. Chem. 1992, 31, 2455–2459.
¨
[16] a) F. Nastasi, F. Puntoriero, N. Palmeri, S. Yerseroo, S. Cam-
pagna, S. Lanza, Chem. Commun. 2007, 4740–4742; b) G. Ros-
ace, G. Giuffrida, M. Saitta, G. Guglielmo, S. Campagna, S.
Lanza, Inorg. Chem. 1996, 35, 6816–6822.
[17] a) J. J. Girerd, S. Jeannin, Y. Jeannin, O. Kahn, Inorg. Chem.
1978, 17, 3034–3040; b) C. Chauvel, J. J. Girerd, Y. Jeannin, O.
Kahn, G. Lavigne, Inorg. Chem. 1979, 18, 3015–3020; c) R.
Veit, J. J. Girerd, O. Kahn, F. Robert, Y. Jeannin, N. El Murr,
Inorg. Chem. 1984, 23, 4448–4454.
[18] F. A. Cotton, Z. Li, C. Y. Liu, C. A. Murillo, Inorg. Chem.
2007, 46, 9294–9302.
[1]
[2]
[3]
[4]
S. Lanza, G. Bruno, F. Nicolò, R. Scopelliti, Tetrahedron:
Asymmetry 1996, 7, 3347–3350.
S. Lanza, G. Bruno, F. Nicolò, A. Rotondo, R. Scopelliti, E.
Rotondo, Organometallics 2000, 19, 2462 –2469.
S. Lanza, G. Bruno, F. Nicolò, G. Callipari, Inorg. Chem. 2003,
42, 4545–4552.
4; a) S. Lanza, G. Callipari, F. Loiseau, S. Serroni, G. Tresoldi,
Inorg. Chem. 2005, 44, 6717–6724; b) S. Lanza, F. Loiseau, G.
Tresoldi, S. Serroni, S. Campagna, Inorg. Chim. Acta 2007, 360,
1929–1934.
[19] T. Halder, H. D. Hausen, J. Weidlein, Z. Naturforsch., B: Chem.
Sci. 1980, 35, 773–774.
[20] A. Castineiras, M. C. F. Vidal, J. Romero, R. Saez, A. Matilla,
¨
J. Niclos, J. M. Yersero, Z. Anorg. Allg. Chem. 2001, 627, 1553–
1559.
[5]
M. T. Indelli, C. Chiorboli, F. Scandola, Top. Curr. Chem.
2007, 280, 215–255.
[21] R. G. Pearson, J. Am. Chem. Soc. 1963, 85, 3533–3539.
[22] R. G. Pearson, Inorg. Chem. 1973, 12, 712–713.
[23] R. N. Hurd, G. De La Mater, C. G. McElheny, R. J. Turner,
V. H. Vallingford, J. Org. Chem. 1961, 26, 3980–3987.
[24] Y. N. Kukushkin, Y. E. Viaz’menskii, L. I. Zorina, Y. L. Pazhu-
kina, Russ. J. Inorg. Chem. 1968, 13, 835–838.
[25] C. G. Arena, G. Bruno, G. De Munno, E. Rotondo, D.
Drommi, F. Faraone, Inorg. Chem. 1993, 32, 1601–1606.
[26] R. J. Goodfellow, P. L. Goggin, L. M. Venanzi, J. Chem. Soc.
A 1967, 1897–1900.
[27] R. Diamond, Acta Crystallogr., Sect. A 1969, 25, 43–55.
[28] G. M. Sheldrick, SHELXTL, VMS version 5.05, Siemens Ana-
lytical X-ray Instruments Inc., Madison Wisconsin, 1991.
Received: February 17, 2009
[6] V. Balzani, F. Scandola, Supramolecular Photochemistry, Ellis-
Horwood, Chichester, 1991.
[7] V. Balzani, M. Juris, S. Venturi, S. Campagna, S. Serroni,
Chem. Rev. 1996, 96, 759–834.
[8] S. Serroni, A. Juris, S. Campagna, M. Venturi, G. Denti, V.
Balzani, J. Am. Chem. Soc. 1994, 116, 9086–9091.
[9] U. Maeder, A. Von Zelewsky, H. Stoeckli-Evans, Helv. Chim.
Acta 1992, 75, 1320–1332.
[10] a) O. Kahn, Struct. Bonding (Berlin) 1987, 68, 89; b) O. Kahn,
Angew. Chem. Int. Ed. Engl. 1985, 24, 834–850.
[11] V. Balzani, A. Credi, M. Venturi, Molecular Devices and Ma-
chines: A Journey into the Nano World, Wiley-VCH, Weinheim,
Germany, 2003.
Published Online: May 15, 2009
2654
www.eurjic.org
© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2009, 2647–2654