16 research outputs found
Crystallographic coincidence of two bridging species in a dinuclear CoIII ethynylbenzene complex
In the title compound, trans,trans-[μ-(m-phenylene)bis(ethyne-1,2-diyl)]bis[chlorido(1,4,8,11-tetraazacyclotetradecane)cobalt(III)]–trans,trans-[μ-(5-bromo-m-phenylene)bis(ethyne-1,2-diyl)]bis[chlorido(1,4,8,11-tetraazacyclotetradecane)cobalt(III)]–tetraphenylborate–acetone (0.88/0.12/2/4), [Co2(C12H4)Cl2(C10H24N4)2]0.88[Co2(C10H3Br)Cl2(C10H24N4)2]0.12(C24H20B)2·4C3H6O, with the exception of the acetylene and bromine groups, all atomic postitions are the same in the two compounds and are modeled at full occupancy. The CoIII ions are six-coordinate with acetylide and chloride ligands bound to the axial sites and the N atoms from the cyclam rings coordinated at the equatorial positions. N—H⋯O and N—H⋯Cl hydrogen-bonding interactions help to consolidate the crystal packing
Nickel(II) complexes with bridged polyamines
Three nickel(II) complexes [Ni2(μ-trien)(trien)2](ClO4)4 (1), {[Ni2(μ-tren)2(tren)](ClO4)4·3,25H2O}n (2) and [Ni3(μ-tren)2(tren)2(H2O)2]Cl6·2H2O (3) (trien = N,N′-bis(2-aminoethyl)ethane-1,2-diamine, tren = N,N′-bis(2-aminoethyl)-1,2-ethanediamine) were synthesized and structurally characterized. Complex 1 consists of dimeric [Ni2(μ-trien)(trien)2]4+ cation and perchlorate anions, compound 2 contains polymer chain of cation {[Ni2(μ-tren)2(tren)]4+}n, perchlorate anions and uncoordinated water molecules, and structure of 3 consists of [Ni3((μ-tren)2(tren)2(H2O)2]6+ cation, chloride anions and uncoordinated water molecules. All compounds exhibit octahedrally coordinated nickel atoms. Two nickel(II) atoms of [Ni2(μ-trien)(trien)2]4+ cation in 1 are bridged through one trien ligand, which is bidentate to both nickel(II) atoms. The central Ni(II) atom in complex 3 is associated with peripheral atoms with one arm of tren ligand bonded in tridentate fashion, similarly as two nickel(II) atoms in polymer of complex 2. The magnetic behaviour of 1 and 2 complexes have been investigated in terms of magnetic susceptibility and magnetization. The magnetic analyses confirmed weak antiferromagnetic exchange between paramagnetic Ni(II) centres. The experimental observations were further confirmed and studied by DFT method at B3LYP/def2-TZVP level of theory for all compounds