Nickel(II), Copper(II), and Silver(I) complexes of the thiophene containing ligand tris[4-(2-thienyl)-3-aza-3-butenyl]amine (TTME)

摘要

The nickel(II), copper(II), and silver(I) complexes of the ligand tris[4-(2-thienyl)-3-aza-3-butenyl]amine (TTME) have been prepared and characterized. The nickel(II) complex, [Ni(TTME)(NO_3)](PF _6), is six-coordinate, the copper(II) complex, [Cu(TTME)(NO _3)](PF_6), five-coordinate and the silver(I) complex, [Ag(TTME)](PF_6)·H_2O, four-coordinate. The silver(I) complex, unlike the complexes of Ni(II) and Cu(II), exhibits an apical nitrogen to silver distance that is significantly longer than the distance from the metal atom to the equatorial nitrogen donors. [Ag(TTME)](PF_6) ·H_2O has the sulfur atoms of the thiophene oriented towards the silver ion in the center of the molecule. The EPR spectrum of the copper(II) complex is typical of tetragonally elongated Cu(II) complexes with the unpaired electron in the d_(x2)-_(y2) orbital (g|| > gτ (2.236 and 2.055, respectively); A||A (172.0 and 10.0, respectively). The fully-decoupled 109Ag spectrum of [Ag(TTME)](PF_6).H2_O displays a single positively phased peak (+585.58 ppm). Decoupling of the resonance at 3.80 ppm in the proton NMR allowed the elucidation of the 109Ag-1H coupling constant (8.57 Hz).