236386-04-2Relevant articles and documents
Synthesis, crystal structure, optical, magnetic, and thermal properties of the new heteroleptic chromium complex [Ph4P][Cr(en)(S5)2]
Rijnberk, Herme,Naether, Christian,Bensch, Wolfgang
, p. 1172 - 1176 (2008/10/08)
The new heteroleptic chromium complex [Ph4P][Cr(en)(S5)2] has been synthesised under mild solvothermal conditions by the reaction of chromium trichloride, sulfur, and tetraphenylphosphoniumbromide in a solution of ethylendiamine (en) in water. The crystal structure consists of isolated tetraphenylphosphonium cations and [Cr(en)(S5)2]- anions. The Cr3+ cations are in an octahedral coordination of two bidentate S52- polysulfide anions and one bidentate en ligand. The N atoms of the en ligand and the terminal S atoms of the S52- anions bonded to the Cr3+ ions are in a cis-position. The six-membered CrS5 rings are in a chair conformation. The three dimensional arrangement of the cations and anions is achieved via intermolecular hydrogen bonds. Investigations with differential thermal analysis (DTA) combined with thermogravimetry (TG) show a stepwise decomposition. In the first step the en ligand is removed completely followed by the emission of a part of the tetraphenylphosphonium cations and the sulfur atoms in the second step. The temperature dependence of the magnetic susceptibility exhibits a Curie-Weiss behaviour with an effective magnetic moment typical for a Cr3+ (d3) ion and a value for the Weiss constant of 1.3(2) K. Fourier transform infra-red spectroscopy (FTIR) was also performed to characterise the optical properties.
