Two Mononuclear Compounds with bis(Pyrimidin-2-yl)amine as a Ligand and as a Hydrogen-bonded Lattice Molecule. Synthesis, Structure and Spectroscopy of {[M(dipm)(H2O)(A)](dipm)(A)(H2O)} (M = Cd with A = ClO4; and Zn with A = BF4)

Abstract

Two isostructural mononuclear compounds with formula {[Cd(dipm)(H2O)(ClO4)](dipm)(ClO4)(H2O)} (1) {[Zn(dipm)(H2O)(BF4)](dipm)(BF4)(H2O)} (2) and (in which dipm = bis(pyrimidin-2-yl)amine) have been synthesised and characterised by X-ray crystallography and infrared spectroscopy. The structure of compound 1 has been solved in the space group P21/n with a = 18.860(4), b = 8.579(2), c = 20.917(4) A, β = 101.33(3)°, V = 3318.4(12) A3, Z = 4 with final R = 0.0454. The structure of compound 2 has also been solved in the space group P21/n with a = 19.026(4), b = 8.389(1), c = 20.720(4) A, β = 101.37(3)°, V = 3242.2(10) A3, Z = 4 with final R = 0.0689. The geometry around the metal ions is octahedral, and is constituted by four nitrogen atoms from two dipm molecules, an oxygen atom from a water molecule and a semi-coordinating anion atom ( $$ O_{{\rm ClO}_{4}} $$ for compound 1 and $$ F_{{\rm BF}_{4}} $$ for compound 2). In the lattice are also present: a non-coordinating water molecule, an anion molecule and a dipm molecule. For compound 1, the Cd–N distances are between 2.296 and 2.328 A. The $$ \hbox{Cd}{-}\hbox{O}_{{\rm H}_{2}{\rm O}} $$ distance is 2.310 A and the $$ \hbox{Cd}{-}\hbox{O}_{{\rm ClO}_{4}} $$ is 2.477 A. The Zn–N distances in compound 2 are between 2.121 and 2.164 A. The $$ \hbox{Zn}{-}\hbox{O}_{{\rm H}_{2}{\rm O}} $$ distance is 2.147 A and the $$ \hbox{Zn}{-}\hbox{F}_{{\rm BF}_{4}} $$ distance is 2.373 A. A hydrogen bond interaction of the Watson–Crick type is observed between the amine N atom of a dipm ligand to a pyrimidyl N atom and a non-coordinating dipm ligand with N···N distances, which vary from 3.066(5) to 3.109(5) A. Furthermore medium to strong hydrogen bond interactions are present between oxygen atoms of the water molecules and the anions of the compounds. Two isostructural mononuclear compounds with formula {[Cd(dipm)(H2O)(ClO4)](dipm)(ClO4)(H2O)} (1) {[Zn(dipm)(H2O)(BF4)](dipm)(BF4)(H2O)} (2) and (in which dipm = bis(pyrimidin-2-yl)amine) have been synthesised and characterised by X-ray crystallography and infrared spectroscopy. .