New Ternary Complexes of Copper(II) with 2,2′‐Bipyridine (Bpy) and Phosphocholine (PCh–) or the Quaternary 1‐(2‐Phosphonomethoxy)ethyl Derivative of 2,4‐Diaminopyrimidine (PMEDAPy–)

The polynuclear Cu-II complexes [Cu4Cl2 (bpy)(4)(PCh(-))(2)] (ClO4)(4)center dot H2O (1) and [Cu-6(bpy)(6)(PMEAPy(-))(4)](ClO4)(8)center dot 2H(2)O (2), where bpy = 2,2`-bipyridine, PCh(-) = phosphocholine ([2-(phosphonooxy)ethyl]trimethylammonium) and PMEDAPy(-) = 1-[2(phosphonomethoxy) ethyl]-2,4-diaminopyrimidine, have been synthesized and characterized by X-ray single-crystal analysis. Compound 1 crystallizes in the triclinic system (P-1 space group) and consists of tetranuclear Cu-II units, which are threefoldly bridged by mu(3)-O, O`, O``-phosphate groups in a square arrangement around the copper atoms. Complex 2 crystallizes in the monoclinic system (P2(1)/c space group) and consists of hexanuclear Cu-II units containing the same kind of mu(3)-phosph(on)ate bridges like 1 and in addition mu(4)-O, O`, O`` -phosphonate bridges. The topology of compound 2 can be envisaged as two triangular subunits linked by means of a double Cu–O–Cu bridge provided by the μ4-phosphonate unit. Magnetic susceptibility measurements of the two complexes in the temperature range of 2–300 K show weak antiferromagnetic couplings mediated by the phosph(on)ate bridges.