Synthesis and coordination chemistry of an alkyne functionalised bis(pyrazolyl)methane ligand

The alkyne functionalised bidentate N-donor ligand (2-propargyloxyphenyl)bis(pyrazolyl)methane was prepared in high yield from the reaction of (2-hydroxyphenyl)bis(pyrazolyl)methane with propargyl bromide in the presence of base. A series of transition-metal complexes including MCl2] (M=Cu, Co, Ni, Zn, Pt), M2](NO3)2 (M=Cu, Co, Ni, Zn), Ag]NO3 and Pd(dppe)](OTf)2 were prepared and characterised by spectroscopic techniques. In addition, ligand as well as the Co(II) and Zn(II) complexes CoCl2]2, ZnCl2] were structurally characterized by single-crystal X-ray diffraction. The organometallic gold(I) and platinum(II) acetylide complexes Pz2CH(C6H(4)-2-OCH2Ctriple bond, length as m-dash]CAuPPh3)] and trans-{Pz2CHC6H(4)-2-OCH2Ctriple bond, length as m-dash]C}2Pt(PPh3)2] were prepared from and AuCl(PPh3)] and trans-PtCl2(PPh3)2], respectively. Treatment of these complexes with Pd(OTf)2(dppe)] or Cu(MeCN)4]PF6 results in formation of the cationic, mixed-metal complexes, which were isolated (Pt/Pd, Au/Pt) or detected by electrospray mass spectrometry (Au/Cu, Pt/Cu).