Structural variations in polynuclear copper(II) complexes based on salicylaldimine type ligands along with dicyanamido co-ligand

Use of Cu(II)-di-Schiff bases as metalloligands in the formation of complexes with Cu(II), Ni(II) and Zn(II) perchlorate

“…However, if only one monodentate ligand coordinates to an axial position of the central copper, its geometry may distort towards trigonal bipyramidal and consequently the structure becomes bent [23]. The structure can also be bent if the anionic coligands are strongly coordinating and occupy the equatorial positions [24,42]. On the other hand, when the central metal ion is not a Cu(II) and is hexa-coordinated, the coordination of two ligands other than the four phenoxido atoms determine its geometry.…”

“…Among the divalent first transition elements, Cu(II) forms the most stable complexes with these Schiff bases [10][11][12][13] and therefore, these neutral Cu-chelates have been used frequently to form complex with another metal ions. In most of these complexes, the oxygen atoms of two ''metalloligands'' coordinate to a second ion to result in trinuclear complexes [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28]. These trinuclear complexes can be homonuclear i.e.…”

“…it is other than Cu(II) ion. The molecular shapes of the trinuclear complexes show an interesting trend; the homonuclear Cu(II) complexes are usually linear [25][26][27][28] with some exceptions [23,24]. However, in the hetero trinuclear complexes when the bridging anionic co-ligands (nitrate, acetate, perchlorate etc.)…”

Designing a heterotrinuclear CuII—NiII—CuIIcomplex from a mononuclear CuIISchiff base precursor with dicyanamide as a coligand: synthesis, crystal structure, thermal and photoluminescence properties

“…Complexes of Schiff base ligands containing various donor atoms (N, O, S etc.) Salen-type Schiff base ligands derived from 2,2 0 -[propane-1,3-diylbis(nitrilomethanylylidene)]diphenol (H 2 L) are widely used to form multinuclear complexes (Biswas & Ghosh, 2012). There has also been considerable interest in designing polynuclear complexes, due to their facile preparations and varied synthetic, structural and magnetic properties (Heinicke et al, 2005;Shi et al, 2009;Tao et al, 2004).…”

“…The O atoms of the coordinated Schiff base ligand are capable of bridging to another metal ion to form polynuclear complexes. Salen-type Schiff base ligands derived from 2,2 0 -[propane-1,3-diylbis(nitrilomethanylylidene)]diphenol (H 2 L) are widely used to form multinuclear complexes (Biswas & Ghosh, 2012). Additionally, salen ligands have been widely used in many fields, such as microbiology, magnetochemistry and photochemistry (Chakraborty et al, 2015;Kara, 2007;Gungor & Kara, 2012;Erkarslan et al, 2016).…”