114737-73-4Relevant articles and documents
Anisotropic exchange in dinuclear complexes with polyatomic bridges. 2. Crystal and molecular structure and EPR spectra of tetraphenylphosphonium bis(μ-pyrazolato)bis[dihydrobis(1-pyrazolyl)borato](μ-chloro)dicuprate(II) . Magneto-structural correlations in bis(μ-pyrazolato)-bridged copper(II) complexes
Ajò, David,Bencini, Alessandro,Mani, Fabrizio
, p. 2437 - 2444 (2008/10/08)
The X-ray crystal structure of [Cu2(H2B(pz)2)2(pz) 2(Cl)](PPh4)-0.5(CH3)2CO (H2B(pz)2 = dihydrobis(1-pyrazolyl)borate; pz = pyrazolate) was determined at room temperature. The crystals are monoclinic, space group C2/c, with a - 17.598 (7) ?, b = 19.681 (9) ?, c = 15.324 (6) ?, β = 117.1 (2)°, and Z = 4. The least-squares refinement of the structure leads to a conventional R factor of 0.078. The temperature dependence of the magnetic susceptibility showed that the copper atoms of the dinuclear complex are antiferromagnetically coupled with a singlet-triplet separation of = ?240 cm-1. Single-crystal EPR spectra were recorded at X-band (9 GHz) frequency at room temperature. The measured zero-field splitting tensor was found to be misaligned from the g tensor, showing that exchange contributions to the anisotropic spin-spin interaction are operative. The singlet-triplet energy gap in bis(μ-pyrazolato)-bridged copper(II) dimers has been correlated to geometrical distortions by using the orbital model of the Isotropic exchange interaction.
