Dinuclear platinum complexes with designer thiolate ligands from the monoalkylation of [Pt2(μ-S)2(PPh3)4]

Abstract

a b s t r a c tAlkylation reactions of the nucleophilic platinum(II) sulfide complex [Pt 2 (l-S) 2 (PPh 3 ) 4 ] with functionalised alkylating agents have been investigated as a versatile synthetic route to dinuclear, cationic sulfidethiolate complexes of the type [Pt 2 (l-S)(l-SR)(PPh 3 ) 4 ] + , extending the range of thiolate complexes that can be prepared using this methodology. A wide range of functional groups can be incorporated, using appropriate alkylating agents, and include ketone, ester, amide, hydrazone, semicarbazone, thiosemicarbazone, oxime, guanidine, urea and thiourea groups.

Towards the water solubilization of [Pt2(μ-S)2(PPh3)4] derivatives by polyether functionalization – a synthetic and mass spectrometric investigation

“…The urea carbon was observed at δ 157.5 and (as expected) was absent in the DEPT135 spectrum. The remaining two CH 2 groups were assigned using the same methodology, with the thiolate carbon appearing at δ 40.1 in the 13 C spectrum (carbon f, overlapping with carbon c), and giving a rather broad 1 H NMR signal at δ 2.1, the broadness being ascribed to unresolved 31 P and 195 Pt couplings, as observed previously in related compounds [8]. The CH 2 group (H 6 ) appeared at δ 2.9, which correlated to carbon e at δ 41.5 in the 13 C spectrum.…”

“…The 31 P{ 1 H} NMR spectrum of 4·PF 6 showed a very pure complex, with a single central resonance as a complex multiplet at δ 24.5, with two sets of satellites due to coupling to [8,25]. In addition to the expected complex set of signals due to PPh 3 ligands, a number of peaks at δ < 5 were observed in the proton NMR spectrum.…”

“…By reaction with organic electrophiles, it is possible to convert either one or both bridging sulfides (μ-S 2− ) into bridging thiolates (μ-SR − ), allowing a facile methodology for synthesis of a diverse range of functionalized thiolate complexes of platinum(II) [2][3][4]. Using this chemistry, it has been possible to synthesize a wide range of dinuclear platinum(II) thiolate complexes which include simple alkyl or aryl substituents [5], dithiolates [6], fluorinated groups [7], carbonyl-containing compounds [8], and heterocycles [9]. However, these compounds, as a result of the presence of highly lipophilic PPh 3 (or other aryl phosphines) and the thiolate substituent, are typically soluble only in polar organic solvents such as methanol and dichloromethane.…”

Alkylation of [Pt2(μ-S)2(PPh3)4] with boronic acid derivatives

“…[12][13][14][15] Recently, the rudimentary reactivity of 1 with simple mild alkylating agents 13 has been extended to functionalized alkylating agents (electrophiles). 16,17 The alkylation of 1 provides a facile route for the generation of functionalized thiolate ligands . 21 An electrospray ionization mass spectrometry (ESI-MS) based screening of the reactions of 1 with a variety of alkylating agents indicates the possibility of generating dinuclear platinum complexes containing a range of thiolate ligands.…”

“…16 This methodology has been used to generate coordinated functionalized thiolate ligands (-SR) on 1. 17 Notably, any desired functionality can be incorporated into 1 through a suitable electrophile.…”