Di-μ-cyanato-bis[(cyanato-κN)(tetramethylethylenediamine-κ2N,N′)-copper(II)] and catena-poly[[μ3-cyanato-κ3O:N:N-bis[(cyanato-κN)(1,3-di- aminopropane-κ2N,N′)copper(II)]]μ3-cyanato-κ3N:N:O]

The two title Cu-II complexes, [Cu-2(NCO)(4)(tmeda)(2)] (tmeda is tetramethylethylenediamine, C6H16N2), (I), and [Cu(NCO)(2)(pn)](n) (pn is 1,3-diaminopropane, C3H10N2), (II), have been synthesized and their crystal structures determined. In (I), which lies about an inversion centre, each Cu centre possesses a distorted tetragonal-pyramidal geometry with four basal N atoms from two cyanate anions [Cu-N=1.945 (2) and 1.948 (3) Angstrom] and one tmeda molecule [Cu-N=2.053 (2) and 2.071 (2) Angstrom], and one axial O atom [Cu-O=2.737 (3) Angstrom] from another cyanate anion. The two neighbouring Cu atoms in (I) are joined by a pair of cyanates in an end-to-end fashion, forming a dimer. In (II), each Cu centre adopts a distorted square-bipyramidal geometry, with four equatorial N atoms from two cyanates [Cu-N=1.988 (2) and 2.007 (3) Angstrom] and a pn ligand [Cu-N=1.996 (3) and 2.011 (3) Angstrom], and one apical N atom [Cu-N=2.437 (3) Angstrom] and an apical O atom [Cu-O=2.900 (3) Angstrom] from two cyanates. In contrast with (I), the two neighbouring Cu atoms in (II) are bridged by two cyanates in an end-on fashion, to form a centrosymmetric dimeric unit. These units are further crosslinked, forming a two-dimensional network structure, via weak interactions between the bridging cyanate O atom and a neighbouring Cu atom, plus interactions of the amine H atoms with the cyanate O atoms and the terminal cyanate N atom.