Pt2–Pt4/Pt3–Pt5, 72.1(2)◦; Pt1/Pt2–Pt4, 83.3(2)◦; Pt1/Pt3–Pt5,
63.17(9)◦).
The reaction of complex 2 with different P- or S-donor
ligands results in facile cleavage of the PtII–S bridge, leading to
different mononuclear species, such as [PtCl(PyDT)(PPh3)] (3) or
[PtCl(PyDT)(DMSO)] (4) (ESI‡).
crystallography, Dr. S. Sitran (CNR Padova) for DTA analyses and
Prof. ssa G. Faraglia (Universita’ di Padova) for useful discussions
are kindly acknowledged.
Notes and references
§ [PtCl(PyDT)]5·2CH3ClCH3Cl (2): C29H48Cl9N5Pt5S10, M = 2081.82,
Crystals of 3 suitable for X-ray analysis were obtained by the
slow addition of n-pentane to a dichloromethane solution.¶ The
structure of complex 3 is somewhat related to that of the monomers
of 2, including the PyDT and chloride ligands, and a PPh3 group,
which formally substitutes the second bridged PyDT ligand (Fig.
2). Both S atoms of the PyDT ligand in 3 act only as chelates, thus
no sp3 hybridization is expected for the sulfur atoms, contrary to
the situation observed in 2. This is clearly observable in the C–S
¯
orange blocks, triclinic, space group P1, a = 11.862(2)◦, b = 14.543(3),
˚
c = 16.207(3) A, a = 80.60(3), b = 78.97(3), g = 74.89(3) , V = 2630.3(9)
3
-3
˚
A , Z = 2, Dc = 2.629 g cm , T = 150(2) K, with Mo-Ka (l = 0.71073),
9497 reflections collected, 9147 unique (Rint = 0.0363), R1 [I > 2s(I)] =
0.0533, wR2 (F, all data) = 0.1254, GoF = 0.990.‡
¶ [PtCl(PyDT)(PPh3)]·0.5CH2Cl2 (3): C47H48Cl4N2P2Pt2S4, M = 1363.03,
¯
colorless blocks, triclinic, space group P1, a = 9.571(2), b = 10.278(3), c =
◦
3
˚
˚
14.367(3) A, a = 89.79(3), b = 86.21(3), g = 62.91(3) , V = 1254.9(5) A ,
Z = 1, Dc = 1.804 g cm-3, T = 150(2) K, with Mo-Ka (l = 0.71073), 6366
reflections collected, 6015 unique (Rint = 0.0212), R1 [I > 2s(I)] = 0.0397,
wR2 (F, all data) = 0.0975, GoF = 0.994.‡
˚
distances, which are almost identical (C16–S17, 1.738(7) A; C16–
˚
S18, 1.716(7) A). The distances and angles around Pt1 and within
1 G. Hogarth, Prog. Inorg. Chem., 2005, 53, 71–561.
2 J. Cookson and P. D. Beer, Dalton Trans., 2007, 1459–1472.
3 M. S. Vickers, J. Cookson, P. D. Beer, P. T. Bishop and B. Thiebaut, J.
Mater. Chem., 2006, 16, 209–215.
the molecule are normal (ESI‡) and similar to related complexes,
such as [M(S2CNEt2)(PPh3)Cl] (M = Pd, Pt).16
4 (a) K. Lemma, S. K. C. Elmroth and L. I. Elding, J. Chem. Soc., Dalton
Trans., 2002, 1281–1286; (b) R. Mital, N. Jain and T. S. Srivastava,
Inorg. Chim. Acta, 1989, 166, 135–140.
5 See, for example: Cisplatin—Chemistry and Biochemistry of
a
Leading Anticancer Drug, ed. B. Lippert, VHCA/Wiley-VCH,
Zu¨rich/Weinheim, 1999.
6 (a) G. Faraglia, D. Fregona, S. Sitran, L. Giovagnini, C. Marzano, F.
Baccichetti, U. Casellato and R. Graziani, J. Inorg. Biochem., 2001, 83,
31–40; (b) G. Faraglia, D. Longo, V. Cherchi and S. Sitran, Polyhedron,
1999, 14, 1939–1914; (c) G. Faraglia, D. Montagner and S. Sitran, Inorg.
Chim. Acta, 2005, 358, 971–980.
7 (a) L. Cattaruzza, D. Fregona, M. Mongiat, L. Ronconi, A. Fassina;,
A. Colombatti and D. Andinucci, Int. J. Cancer, 2011, 128, 206–215;
(b) L. Ronconi, D. Aldinucci, Q. P. Dou and D. Fregona, Anti-Cancer
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Fig. 2 View of [PtCl(PyDT)(PPh3)] (3).
8 L. Giovagnini, E. Mancinetti, L. Ronconi, S. Sitran, L. Marchio`, I.
Castagliuolo, P. Brun, A. Trevisan and D. Fregona, J. Inorg. Biochem.,
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9 (a) J. D. E. T. Wilton-Ely, D. Solanki and G. Hogarth, Eur. J. Inorg.
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1984, 54, 23–98.
In conclusion, the self-assembly of five PtCl(PyDT) monomers
of different chirality results in a unique Pt5 metallacyclic structure,
[PtCl(PyDT)]5 (2), with two possible enantiomers (K,K,K,D,D and
D,D,D,K,K). With this PyDT chelating ligand, a pentamer is the
smallest possible construction, stabilizing the two different (sp2
and sp3) hybridizations of the S atoms. This work also extends
the existing examples of discrete PtII metallacycles, with potential
applications based on a dithiocarbamate-platinum tandem.
10 See, for example: (a) B. Lippert and P. J. Sanz Miguel, Chem. Soc. Rev.,
2011, 40, 4475–4487; (b) V. K. Jain and L. Jain, Coord. Chem. Rev.,
2010, 254, 2848–2903 and references cited therein.
11 G. Mezei, C. M. Zaleski and V. L. Pecoraro, Chem. Rev., 2007, 107,
4933–5003.
12 S. G. Nyburg, Acta Crystallogr., Sect. B: Struct. Sci., 1996, 52, 328–331.
13 (a) A. B. Goel, S. Goel, D. van Derveer and C. G. Brinkley, Inorg. Chim.
Acta, 1982, 64, L173–174; (b) S. Sokolov, H. Imoto and T. Saito, Inorg.
Chem. Commun., 1999, 2, 422–423.
Acknowledgements
14 D. A. Clemente, G. Faraglia, L. Sindellari and L. Trincia, J. Chem. Soc.,
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15 P. J. Stang and B. Olenyuk, Acc. Chem. Res., 1997, 30, 502–518.
16 L. T. Chan, H. W. Chen, J. P. Fackler, A. F. Masters and W. H. Pan,
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This work was supported by the Consorzio Interuniversitario per
la Ricerca Chimica dei Metalli nei Sistemi Biologici (CIRCMSB)
and the Spanish Ministerio de Ciencia e Inovacio´n (Ramo´n y
Cajal Program). Dr. F. Benetollo (CNR Padova) for help with the
This journal is
The Royal Society of Chemistry 2011
Dalton Trans., 2011, 40, 10809–10811 | 10811
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