Synthesis, Crystal Structure, Optical, Magnetic, and Thermal Properties of the New Heteroleptic Chromium Complex [Ph4P][Cr(en)(S5)2]
✍ Scribed by Herme Rijnberk; Christian Näther; Wolfgang Bensch
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- German
- Weight
- 135 KB
- Volume
- 625
- Category
- Article
- ISSN
- 0372-7874
No coin nor oath required. For personal study only.
✦ Synopsis
The new heteroleptic chromium complex [Ph 4 P][Cr(en)(S 5 ) 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)(S 5 ) 2 ] ± anions. The Cr 3+ cations are in an octahedral coordination of two bidentate S 5
2± polysulfide anions and one bidentate en ligand. The N atoms of the en ligand and the terminal S atoms of the S 5 2± anions bonded to the Cr 3+ ions are in a cis-position. The six-membered CrS 5 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 analy-sis (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 Cr 3+ (d 3 ) ion and a value for the Weiss constant of 1.3(2) K. Fourier transform infrared spectroscopy (FTIR) was also performed to characterise the optical properties.