Influence of synthesis conditions on the properties of 2-pyrimidinecarbonitrile in complexing reactions: Synthesis and structure of the coordination polymer [Ag(C4H3N2CN)NO3] and mononuclear complex [Ag(C4H3N2COOH)2]NO3·H2O

Abstract

The coordination polymer [Ag(C4H3N2CN)NO3] (I) and mononuclear complex [Ag(C4H3N2COOH)2]NO3 · H2O (II) have been synthesized and characterized by X-ray crystallography. The crystals of I are monoclinic, space group Pm, a = 5.364(1) A, b = 6.631(1) A, c = 5.648(1) A, β = 105.68(3)°, V = 193.42(6) A3, d calcd = 2.361 g/cm3, Z = 1. The crystals II are triclinic, space group \(P\bar 1\), a = 6.859(1) A, b = 8.872(2) A, c = 12.825(3) A, α = 81.29(3)°, β = 86.33(3)°, γ = 69.66(3)°, V = 723.3(3) A3, d calcd = 2.002 g/cm3, Z = 2. The structure of I is built of polymeric chains [Ag(C4H3N2CN)] ∞ + linked through coordinated anions NO 3 − into layers (a 2D polymer) perpendicular to the [001] direction. The formation of II is a result of hydrolysis of the carbonitrile group to the carboxyl group (in the presence of metal ions in the solution) and coordination of the ligand to the metal. In II, mononuclear cationic complexes [Ag(N2H3C5OOH)2]+ are linked through H-bonds into supramolecular chains along direction [010]. Hydrogen bonds are also formed between free NO 3 − anions and water molecules.