A novel N(3),N(4)-bridging coordination mode of 1-R-tetrazole-5-thiolates - Synthesis, X-ray diffraction, magnetic properties and quantum-chemical study of a macrocyclic dinickel complex coligated by 1-methyltetrazole-5-thiolate

摘要

The dinuclear nickel(II) complex [Ni_2L(μ-ClO _4)]ClO_4, where L~(2-) represents a 24-membered macrocyclic bis(triamine-thiophenolate) ligand, reacts with 1-methyltetrazole-5- thiol and triethylamine to give the complex [Ni2L(μ-SCN _4Me)]ClO_4, which was subjected to metathesis with NaBPh_4 yielding [Ni_2L(μ-SCN_4Me)]BPh _4. This new complex was characterized by elemental analysis, UV/Vis/NIR and IR spectroscopy. The structure of [Ni_2L(μ-SCN _4Me)]BPh_4 was determined by X-ray crystallography, showing the 1-methyltetrazole-5-thiolate ligand in an N(3),N(4)-bridging mode generating a bis(octahedral) N_3Ni(μ-S)_2(μ-SCN _4Me)NiN_3 core. Quantum chemical calculations of the molecular electrostatic potential, natural population analysis and total energies of possible structures of [Ni_2L(μ-SCN_4Me)] ~+ are in agreement with the structural data obtained. Temperature-dependent magnetic susceptibility measurements revealed that the NiII ions in the dinuclear complex are weakly ferromagnetically coupled showing a coupling constant J of 19.5 cm~(-1) (H = -2JS _1S_2).