Coordination chemistry of the ditopic ligand 4-[6-(2-pyridyl)-2-pyridyl]-6-(2-pyridyl)pyrimidine:: Encapsulation of nitrate by [2x2] grid complexes

We describe herein the synthesis, physical properties and crystal structures of metal complexes with the new ligand 6(2-pyridyl)-4-[6-(2-pyridyl)-2-pyridyl]pyrimidine (L). Reactions of L with Ni-II, Co-II, Fe-II, Zn-II and Cu-II nitrates in a 1:1 ratio leads to the self-assembled tetranuclear [2 x 2] grid complexes 1-5 with encapsulated NO3- ions, as confirmed by the X-ray crystal structures of [Ni4L4(DMSO)(2)(H2O)(2)](NO3) (ClO4)(7)center dot 4DMSO center dot 6H(2)O (1) and [Co4L4(DMF)(4)](NO3)(ClO4)(7) (2). The mononuclear copper(I) complex [CuL(PPh3)(2)]ClO(4)center dot 2(CH3CN) (6) and the binuclear [Cu2L2(CN)(PPh3)(2)]ClO4 (7) were synthesized from L and [Cu(PPh3)(3)]Cl. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005).