Copper and silver complexes bearing flexible hybrid scorpionate ligand mpBm.

The addition of flexible scorpionate ligand, [mpBm]⁻{i.e. HB(mt)2(mp), where mt = methyl-2-mercaptoimidazole and mp = 2-mercaptopyridine} to group eleven centres is reported for the first time. The coordination of this hybrid ligand to copper(I) and silver(I) centres in the presence of triphenylphosphine and trialkylphosphine co-ligands has been investigated. The trialkylphosphines coordinates to both copper and silver centres while the less basic triarylphosphine only successfully coordinates to the copper centre. Structural characterisation of [Cu{HB(mt)₂(mp)}(PPh₃)], [Cu{HB(mt)₂(mp)}(PCy₃)] and [Ag{HB(mt)₂(mp)}(PCy₃)] confirm κ³-SSH coordination modes for ligand where one of the mt 'arms' and the mp 'arm' of the scorpionate ligand are coordinated to the metal centre. The second mt 'arm' remains uncoordinated in all three complexes. A comparison has been made with the parent sulfur based scorpionate ligand, [Tm]⁻{HB(mt)₃}.