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A unique π-conjugated benzothiadiazole-ortho-vanillin ligand (HL), characterized by single crystal X-ray diffraction and DFT calculations, has been prepared by condensation between 4-amino-benzothiadiazole (BTD) and ortho-vanillin. Its reaction with cobalt(II) acetate afforded the complex of formula [CoL2]·CH2Cl2 (1), for which the coordination environment of the cobalt centre is a distorted octahedron and the ligand acts as a monoanionic tridentate NNO chelate in its phenolate form. Intermolecular π–π stacking interactions between the π-conjugated BTD units provide an antiferromagnetic coupling pathway, as indicated by the analysis of the dc magnetic measurements of a crystalline sample of the complex and supported by DFT type calculations. The static magnetic behaviour of 1 is analysed according to spin–orbit coupling and zero-field splitting models. Remarkably, the complex exhibits slow relaxation of the magnetization under dc applied magnetic fields being thus a new example of field-induced mononuclear single-molecule magnet (SMM). [ABSTRACT FROM AUTHOR]

Abstract: A new complex [Ni(L)Fe(CN)5NO]·2H2O (L=4,6,6-trimethyl-1,9-diamino-3,7-di-aza-nona-3-ene) has been obtained and characterized by means of X-ray crystallographic analysis and magnetochemistry. The Fe(CN)5NO2− anion links to the Ni(L)2+ cation through two bridging cyanide groups in a bent fashion. The intrachain Ni⋯Ni and interchain Ni⋯Ni distances are equal to 9.81(8) and 7.75(1) Å, respectively. The magnetic behaviour of the complex indicates the zero field splitting parameter D higher than 3cm−1 and the average exchange parameter (intra- and interchain) corresponding to direct Ni–Ni magnetic interaction in the crystal lattice equals ∼−0.2cm−1. [Copyright &y& Elsevier]

Abstract: A series of new heterometallic CuIIZnII and NiIIZnII complexes with N- and N,O open-chain multidentate ligands (L1 =4,6,6-trimethyl-1,9-diamino-3,7-diazanon-3-ene; L2 =3,7-bis(2-aminoethyl)-1,3,5,7-tetraazabicyclo[3.3.1]nonane; L3 =1,15-dihydroxy-7,9,9-trimethyl-3,6,10,13-tetraazapentadec-6-ene and L4 =1-hydroxy-9-oxy-4,6,6-trimethyl-3,7-diazanon-3-ene) have been prepared through the “direct template synthesis” approach, which is a combination of classical template reactions of amines with acetone/formaldehyde and the “direct synthesis” method based on using elemental metals as starting materials. There is a significant decrease in the reaction time when the “direct synthesis” method is used compared to the conventional template condensation methods. X-ray crystallographic analyses of the complexes with the general formula M(L)ZnX4 and [CuL4ZnCl3]2 (M=Cu2+, Ni2+; L=L1-L3; X=Cl−, NCS−) reveal the presence of long intermolecular distance interactions, such as semi-coordination, S⋯S and H-bonding, in their crystal organization. [Copyright &y& Elsevier]

Four new heterobimetallic complexes [CuL 1 ][MnCl 4 ] ( 1 ), [CuL 2 ][MnCl 4 ] ( 2 ), [NiL 1 ][MnCl 4 ] ( 3 ), [NiL 2 ][MnCl 4 ] ( 4 ) (L 1 = 4,6,6-trimethyl-1,9-diamino-3,7-di-aza-nona-3-ene; L 2 = 1,15-dihydroxy-7,9,9-trimethyl-3,6,10,13-tetra-aza-pentadeca-6-ene) have been prepared from elemental metals, ethylenediamine dihydrochloride or its N-(2-hydroxyethyl) derivative and acetone by the template condensation reaction. All complexes have been characterized by elemental analysis, IR and UV-Visible spectroscopy. The structures of 2 and 3 have been determined by X-ray crystallography ( 2 : Orthorhombic, Pna2 1, a = 20.136(4), b = 11.185(2), c = 10.251(2)Å, Z = 4; 3 : Orthorhombic, Pca2 1, a = 14.335(2), b = 11.405(2), c = 11.154(2)Å, Z = 4 ). Both crystals consist of alternating complex cations [ML] 2+ and anions [MnCl 4 ] 2- linked together by N-H···Cl-Mn and O-H···Cl-Mn hydrogen bonds forming 2D corrugated sheets in ( 2 ) and 1D helical chains in ( 3 ). Complex 2 represents the first single crystal structure elucidation of the complex containing L 2 . [ABSTRACT FROM AUTHOR]