2013. 54, 3 – UDC 541.6:541.49:546.92 A ZWITTERIONIC MONOALKYLATED DERIVATIVE OF [Pt2(-S)2(PPh3)4] FROM 1,3-PROPANESULTONE O.T. Ujam, W. Henderson, B.K. Nicholson Department of Chemistry, University of Waikato, Hamilton, New Zealand E-mail: w.henderson@waikato.ac.nz Received February, 8, 2012 Reaction of dinuclear platinum(II) sulfido complex [Pt2(-S)2(PPh3)4] with 1,3-propanesultone gives the novel zwitterionic monoalkylated thiolate complex [Pt2(-S){-S(CH2)3SO3}(PPh3)4], which was characterized by NMR spectroscopy, electrospray ionisation mass spectrometry, and a single crystal X-ray structure determination. <...> The dinuclear platinum(II) sulfido complex [Pt2(-S)2(PPh3)4] 1 has been known for many years to contain highly nucleophilic sulfide centers [ 1 ]. <...> This reactivity can be harnessed in the assembly of multi-metallic sulfide-bridged aggregates [ 2—5] or alternatively alkyl- or aryl-thiolate ligands can be generated by alkylation [ 6—11] or arylation [ 12, 13 ] reactions using suitable electrophiles. <...> In recent years we have been exploiting this reactivity using electrospray ionisation mass spectrometry [ 14 ] which offers advantages in terms of efficiency and simplicity [ 15 ]. <...> A wide range of alkylated and arylated derivatives of [Pt2(-S)2(PPh3)4] is now known, where one or both sulfide groups are converted into bridging thiolate ligands, namely [Pt2(-S)(-SR)(PPh3)4]+ and [Pt2(-SR)(-SR)(PPh3)4]+. <...> The vast majority of such alkylated and arylated derivatives are cationic, with counteranions (such as PF6 or BPh4 ) added to effect precipitation and isolation of the complexes. <...> In this contribution we report investigations into the synthesis and characterization of a novel zwitterionic alkylated derivative of [Pt2(-S)2(PPh3)4], formed by alkylation with 1,3-propanesultone 2 (a well-known alkylating agent [ 16 ]) giving a product where the resulting sulfonate (—SO3 ) counterion is retained as part of the alkylthiolate group. <...> Electrospray mass spectra were recorded in positive-ion mode using a Bruker MicrOTOF instrument, typically using a capillary exit voltage of 20 V. Isolated solid products (ca. 0.5 mg) were <...>