Syntheses and ligand interconversions of copper(ii) derivatives of the metalloligand [Pt2(µ-S)2(PPh3)4]

Abstract

The reactivity of the metalloligand [Pt2(micro-S)2(PPh3)4] towards a variety of copper(II)-ligand systems has been studied. Reaction of [Pt2(mu-S)2(PPh3)4] with copper(II) halide complexes [CuCl2L](L = 2,2'-bipyridine and 1,10-phenanthroline) gave trinuclear dicationic products [Pt2(mu-S)2(PPh3)4CuL]2+, and the 8-hydroxyquinolinate (hq) complex [Cu(hq)2] gave [Pt2(mu-S)2(PPh3)4Cu(hq)]+, isolated as their BPh4- or PF6- salts. Related cationic complexes with other ancillary amine ligands (1,2-diaminoethane, 1,2-diaminopropane, 1,2-diaminocyclohexane) were obtained by reactions of [Pt2(mu-S)2(PPh3)4] with CuCl2 and the amine. In contrast, reaction of [Pt2(mu-S)2(PPh3)4] with CuCl2 and NH3 in methanol gave the intensely blue methoxy-bridged dicopper complex [{Pt(2)(mu-S)2(PPh3)4Cu(OMe)}2]2+, isolated as its hexafluorophosphate salt. Copper beta-diketonate complexes reacted with [Pt2(mu-S)2(PPh3)4] giving [Pt2(mu-S)2(PPh3)4Cu(beta-diketonate)]+PF6- complexes, with the CH3COCHCOCH3(acac) and CF3COCHCO(2-thienyl)(tta) derivatives characterised by X-ray structure determinations. The local Cu(II) environment ranges from distorted square-planar to an intermediate form of square-planar and tetrahedral. The beta-diketonate derivatives show varying stability towards methanolysis, giving [{Pt2(mu-S)2(PPh3)4Cu(OMe)}2]2+.

Tuning the sulfur–heterometal interaction in organolead(IV) complexes of [Pt2(μ-S)2(PPh3)4]

“…This results in a five-coordinate Pb atom with pseudo trigonal bipyramidal coordination, the I and S(2) atoms occupying the axial positions [I-Pb-S(2) angle 156.6°]. A similar arrangement was also found for the corresponding Me 2 ClSn + and (PhCH 2 ) 2 BrSn + analogues [1]. Related systems are known in the literature, for example the complex [Ph 2 Pb(dmit)]…”

“…General experimental procedures were as described in recent publications from these laboratories [1][2][3][4]. ESI mass spectra were recorded on a VG Platform II instrument in positive-ion mode, using methanol as the mobile phase.…”

“…In a series of recent papers we have been applying the technique of electrospray ionisation mass spectrometry (ESI MS) to probe the coordination chemistry of the metalloligand [Pt 2 (l-S) 2 (PPh 3 ) 4 ] [1][2][3][4]. This methodology allows the rapid screening of reaction systems on a small scale, with promising systems then being investigated on a more traditional macroscopic scale for full characterisation [5].…”

Thallium(III) complexes of the metalloligands [Pt2(μ-S)2(PPh3)4] and [Pt2(μ-Se)2(PPh3)4]

“…Although the platinum(II) sulfido complex [Pt 2 (-S) 2 (PPh 3 ) 4 ] 1 has been known for over 30 years [1], investigations on the chemistry of complexes containing the enigmatic {Pt 2 S 2 } core are continuing [2,3], particularly in areas of sulfide oxidation [4], hydrogen-bonding [5] and protonation, [6] alkylation and arylation reactions [7,8,9,10,11,12,13,14] and coordination chemistry. [15,16,17] With the exception of the very hardest metals, 1 acts as a very general metalloligand towards a diverse range of metal centres. [18] While a number of complexes of [Pt 2 (-S) 2 (PPh 3 ) 4 ] with main group metal centres are known [19], such as lead [20], indium and gallium [21] and bismuth [22,23,24], organometallic derivatives are limited to organo-tin [25] and organo-lead [26] compounds.…”

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

“…2 The bridging sulfides are electron-rich and the reactivity towards metal fragments has been exploited in the synthesis of multimetallic aggregates. [3][4][5][6][7][8][9][10][11] Alkylation reactions of 1 with mild electrophiles was realised in the early preliminary studies. [12][13][14][15] Recently, the rudimentary reactivity of 1 with simple mild alkylating agents 13 has been extended to functionalized alkylating agents (electrophiles).…”