Synthesis of a tritopic, third-generation bis(1-pyrazolyl)methane ligand and its silver(I) complex: Unexpected structure with high coordination numbers

The reaction of the new tritopic ligand C6H3[CH2OCH2CH(pz)2]3 (Ltri, pz = pyrazolyl ring), prepared to determine the types of complex architectures its metal complexes will form, with Ag(O3SCF3) yields {[AgLtri](O3SCF3)}n. The solid-state structure of this complex is a two-dimensional sheet in which each of the three bis(pyrazolyl)methane units coordinate three different symmetry equivalent Ag(I) cations, with each Ag(I) bonding to three different ligands. Because of a significant disorder in one “arm” of the ligand, approximately half of the Ag(I) cations are six-coordinate and the other half are five-coordinate. In the six-coordinate case, the Ag(I) is in a trigonal prismatic geometry and in the five-coordinate case the disordered bis(pyrazolyl)methane unit is in an unusual κ1-coordination mode. These structural types are very different from those observed with analogous multitopic poly(pyrazolyl)methane ligands, where cages and mononuclear metallacycles are observed.

The new tritopic ligand C6H3[CH2OCH2CH(pz)2]3 (Ltri, pz = pyrazolyl ring) forms the Ag(I) complex {[AgLtri](O3SCF3)}n, which has a two-dimensional sheet structure where three bis(pyrazolyl)methane units coordinate three different Ag(I) cations, each bonding to three different ligands.Figure optionsDownload as PowerPoint slide