Synthesis, crystal structure and magnetic properties of the cyano-bridged heteropolynuclear complex [{(Cu(dien))2Co(CN)6} ][Cu(dien)(H2O)Co(CN)6] ·5nH2O

New Cu(II) complexes with polydentate chelating Schiff base ligands: Synthesis, structures, characterisations and biochemical activity studies

“…There is apparent strain in the butyl chain shown by torsion angles differing markedly from normal gauche-and trans-angles. The bond angles and bond distances of 1 are close to the value in other related penta-coordinated complexes[31,32,34]. The transangles N(2)-Cu(1)-N(4), N(3)-Cu(1)-N(1) have values of 138.41(7) and 167.16(8) • , respectively and are not close to linearity.…”

“…Distortion from ideal geometry may have arisen from the asymmetric nature of the Schiff base. The propylenic part of the Schiff base N(2)-C(8)-C(9)-C(10)-N(3) is to some extent puckered due Cu (1) [31,32]. Addison et al [33] have introduced an angular structural parameter τ (index of trigonality) for distinguishing between a trigonal bipyramidal and square pyramidal geometry in five coordinated metal complexes τ = (β − α)/60, where α and β are the two largest coordination angles.…”

Funktionale poröse Koordinationspolymere

“…[58][59][60][61] Cyanometallat-Anionen können vielfältige Geometrien einnehmen: z. B. lineare wie bei [M(CN) 2 ] À (M = Au, [62,63] Ag [64][65][66] ), trigonale wie bei [Cu(CN) 3 ] 2À , [67] tetraedrische wie bei [Cd(CN) 4 ] 2À , [68][69][70][71] quadratisch-planare wie bei [M(CN) 4 ] 2À (M = Ni, [41] Pd, [72][73][74] Pt [72,75] ), oktaedrische wie bei [M(CN) 6 ] 3À (M = Fe, [76][77][78][79][80] Co, [76,81,82] Cr, [83][84][85] Mn [86,87] ) und pentagonal-bipyramidale wie bei [Mo (CN) 7 ] 4À . [88][89][90][91] Insbesondere das Octacyanometallat-Ion [M(CN) 8 ] nÀ (M = Mo, W) bildet mehrere unterschiedliche Geometrien aus (quadratisch-antiprismatische, dodekaedrische, zweifach über-dachte trigonal-prismatische).…”

Synthesis, Characterisation and Crystal Structure of a Copper(II) Dichromate Complex with the N,N’-Bis(2-pyridylmethylene)butane- 1,4-diamine Schiff Base Ligand

“…This coordination is common for Cu(II) with either square pyramidal (spy) or trigonal bipyramidal (tbp) geometry. Recently, some complexes have been reported in which the Cu(II) ion adopts a geometry that is intermediate between spy and tbp [18,19]. Addison et al [20] have introduced an angular structural parameter τ (index of trigonality) for distinguishing between a trigonal bipyramidal and a square pyramidal geometry in five-coordinate metal complexes, τ = (β − α)/60, where α and β are the two largest coordination angles.…”