Silver(I) derivatives with new functionalised acylpyrazolonates

Silver(I) acylpyrazolonate derivatives of formula [Ag(Q)(R3P)]2 and [Ag(Q)(R3P)2], (QH=1-phenyl-3-methyl-4-R′(CO)-pyrazol-5-one; QOH, R′=furane; QSH, R′=thiophene; R=Ph, Cy, o-tol), have been synthesised and characterised, both in the solid state and in solution. The derivatives [Ag(Q)(R3P)]2 contain dinuclear AgO2NP units with the acylpyrazolonate coordinating in a bridging O,O′-Q-N fashion. The [Ag(Q)(R3P)2] are tetrahedral species, with the distortion from ideal geometry increasing with the bulk of the phosphine. The [Ag(Q)(R3P)2] derivatives are fluxional in chloroform solution when R3P is sterically hindered (R=Cy or o-tol), dissociating partially to the [Ag(Q)(R3P)] fragment and free R3P. [Ag(QS)(Ph3P)]2 reacts with 1-methyl-2-mercaptoimidazole (Hmimt) affording the compound [Ag(Hmimt)(Ph3P)(QS)] and [Ag(QO)(Ph3P)]2 reacts with 1-methyl-imidazole (Meim) affording the compound [Ag(Meim)(Ph3P)(QO)], whereas [Ag(QS)(Ph3P)]2 reacts with 1,10-phenanthroline (phen), affording the compound [Ag(phen)(Ph3P)](QS). Finally [Ag(QS)(Ph3P)2] reacts with phen producing the ionic species [Ag(phen)(Ph3P)2](QS).