Synthesis, structure and magnetic properties of a mononuclear Cu(ii) complex with a NNO donor Schiff base ligand and its oxalato- and oxamidato-bridged dinuclear complexes

Mononuclear and Dinuclear NiII and CuII Complexes with a Pyrrolecarboxamide Ligand: Core Conversions and Unusual Presence of a Dimer and Two Monomers in the Same Unit Cell

“…Interestingly, the solution spectrum is quite complex presumably due to the presence of both dimeric as well as monomeric units (Figure 2). [13] The complex 5 was crystallographically characterized and reveals a number of interesting features. The crystal structure of complex 5 is shown in Figure 5 whereas the important crystallographic details and bond angles and bond lengths are contained in Tables 3 and 2, respectively.…”

μ2-Oxalato-bridged tricopper(II) complex derived from 1,4,8,12-tetraazacyclopentadecane: Synthesis, structure and magnetic characterization

“…In most cases, dinuclear metal(II) complexes were obtained where the oxalate ligand is binding the two metals in bis-bidentate bridging mode [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. In the dinuclear oxalato-bridged Cu(II) complexes where the separation distance between the two Cu(II) ions is in the range of 5-6 Å , moderate to strong antiferromagnetic interactions were observed with the singlet-triplet energy gap, J value is as large as À386 cm À1 in [Cu 2 (tmen) 2 (H 2 O) 2 (C 2 O 4 )](ClO 4 ) 2 Á 1.25H 2 O (tmen = N, N,N 0 ,N 0 -tetramethylethylenediamine) [7][8][9][10][11][12][13][14][15]20]. The great plasticity of the coordination sphere of the Cu(II) center (four, five and six coordination sphere) which allows the variation of the orientation and symmetry of the molecular orbital describing its unpaired electron (magnetic orbital) is believed to be a crucial parameter for the presence of such enormous number complexes.…”

“…Many oxalato-nickel(II) and -copper(II) compounds have been isolated, and magnetically and structurally characterized [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. In most cases, dinuclear metal(II) complexes were obtained where the oxalate ligand is binding the two metals in bis-bidentate bridging mode [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. In the dinuclear oxalato-bridged Cu(II) complexes where the separation distance between the two Cu(II) ions is in the range of 5-6 Å , moderate to strong antiferromagnetic interactions were observed with the singlet-triplet energy gap, J value is as large as À386 cm À1 in [Cu 2 (tmen) 2 (H 2 O) 2 (C 2 O 4 )](ClO 4 ) 2 Á 1.25H 2 O (tmen = N, N,N 0 ,N 0 -tetramethylethylenediamine) [7][8][9][10][11][12][13][14][15]20].…”

Interplay of thermochemistry and Structural Chemistry, the journal (volume 17, 2006) and the discipline

“…The first paper of the last issue of the 2007 volume was written by Rahaman et al [305] and focuses on the complexes with Schiff bases because of their ease of synthesis, structural diversity, and varied denticities [306][307][308]. Three new Schiff bases, all N,N'-bis N,N'-pyridin-2-yl(alkylidene)butane-1,4-diamines, were synthesized and used as staring compounds for the synthesis of six new doubly endon bridged cadmium(II) azido complexes of the type [Cd(L)(N 3 )] 2 (Y) 2 (L = newly synthesized Schiff bases, Y = ClO 4 -, PF 6 -) which represent new examples of luminous materials.…”