Header menu link for other important links
Discrete 0D and polymeric 2D and 3D derivatives assembled from [(CuL) 2 Zn] 2+ and dicyanamide blocks (H 2 L = salen type Schiff bases): Genuine supramolecular isomers with distinct topologies
Published in -
Volume: 16
Issue: 14
Pages: 3029 - 3039
Three new hetero-metallic Cu(ii)-Zn(ii) compounds [(CuL 1 ) 2 Zn(N(CN) 2 ) 2 ] (1), 2 ∞ [(CuL 2 ) 2 Zn(μ 1,5 -N(CN) 2 ) 2 ] n (2A) and 3 ∞ [(CuL 2 ) 2 Zn(μ 1,5 -N(CN) 2 ) 2 ] n (2B) have been synthesized by reacting a [CuL 1 ] or [CuL 2 ] "metalloligand" (where H 2 L 1 = N,N′-bis(α-methylsalicylidene)-1,3- propanediamine and H 2 L 2 = N,N′-bis(salicylidene)-1, 3-propanediamine) with zinc perchlorate hexahydrate and sodium dicyanamide, using various molar ratios of the reactants. All three products have been characterized by IR and UV-Vis spectroscopies, ESI-MS, elemental, powder and single crystal X-ray diffraction analyses. Complex 1 is a discrete 0D trinuclear species in which two "metalloligands" coordinate to a zinc(ii) ion through phenoxido oxygen atoms along with two terminal dicyanamido ligands. In contrast, products 2A and 2B are 2D and 3D coordination polymers, respectively, which bear a common [(CuL 2 ) 2 Zn(N(CN) 2 ) 2 ] trinuclear unit wherein, however, dicyanamido moieties adopt a μ l,5 -bridging coordination mode. The coordination networks have been formed via the linkage, in different manners, of the trinuclear nodes [(CuL 2 ) 2 Zn] 2+ through Zn and Cu centres with the help of divergent dicyanamido spacers. These two isomeric coordination polymers represent a rare example of "genuine supramolecular isomerism". The coordination networks in 2A and 2B have been classified from the topological viewpoint, revealing a binodal 3,4-connected underlying net with the 3,4L21 topology in 2A and a uninodal 4-connected underlying net with the qtz (quartz, 4/6/h1) topology in 2B. Electronic spectra and ESI mass spectra show that all three complexes lose their solid state identity in solution. This journal is © the Partner Organisations 2014.
About the journal
Open AccessNo