Syntheses, structures and ligand conformations of Cu(II), Co(II) and Ag(I) complexes containing the phosphinic amide ligands

The syntheses, structures and ligand conformations of the complexes trans-Cu(L1)2(ClO4)2, (L1 = N-(2-pyrimidinyl)-P,P-diphenyl-phosphinic amide), 1, [trans-Co(L1)2(CH3OH)2](ClO4)2·O(C2H5)2, 2, [trans-Co(L2)2(H2O)2](ClO4)2·2CH3OH, (L2 = N-(2-pyridinyl)-P,P-diphenyl-phosphinic amide), 3, [cis-Co(L2)2(NO3)](NO3), 4, and [Ag(L3)(NO3)(CH3CN)]∞, (L3 = N-(6-methyl-2-pyridinyl)-P,P-diphenyl-phosphinic amide), 5, are reported. The L1 and L2 ligands in the monomeric complexes 1–4 chelate the metal centers through the pyrimidyl/pyridyl nitrogen atoms and the phosphinic amide oxygen atoms, whereas the L3 ligands in complex 5 bridge the metal centers, forming a 1-D zigzag chain. The chelating L2 ligands in complexes 3 and 4 adopt cis conformations and the bridging L3 ligand in complex 5 adopts a trans conformation, respectively.

Graphical abstractThe syntheses, structures and ligand conformations of five new Cu(II), Co(II) and Ag(I) complexes containing three phosphinic amide ligands (L1–L3) with the nitrogen donors located in different positions are reported. In the monomeric Cu(II) and Co(II) complexes, the L1 and L2 ligands chelate the metal centers through the pyrimidyl/pyridyl nitrogen atoms and the phosphinic amide oxygen atoms, whereas the L3 ligands in the polymeric Ag(I) complex bridge the metal centers, forming a 1-D zigzag chain. The chelating L2 ligand adopts the cis conformations and the bridging L3 ligand adopts the trans conformation, respectively.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► We report five new complexes containing three phosphinic amide ligands. ► The ligands coordinate to metal ions through pyrimidyl/pyridyl nitrogen atoms and the phosphinic amide oxygen atoms. ► The chelating ligand adopts the cis conformation, whereas the bridging one adopts the trans conformation.