Arrangement of Rh³⁺ions infac-triamminetrichloridorhodium from powder data and infac-triamminetrinitratorhodium crystals twinned by merohedry

Abstract

The rhodium complexes [RhCl3(NH3)3], (I), and [Rh(NO3)3(NH3)3], (II), are built from octahedral RhX3(NH3)3 units; in (I) they are isolated units, while in (II) the units are stacked in columns with partially filled sites for the Rh atoms. The octahedra of monoclinic crystals of (I) are linked by N-H···Cl hydrogen bonds and the Rh(3+) ions are located on the mirror planes. In the trigonal crystals of (II), the discontinuous `columns' along the threefold axis are linked by N-H···O hydrogen bonds. The structure of (I) has been solved using laboratory powder diffraction data, the structure of (II) has been solved by single-crystal methods using data from a merohedrally twinned sample. Both compounds possess low solubility in water.

Synthesis and Crystal Chemistry of Octahedral Rhodium(III) Chloroamines

“…Due to the low trans-effect of coordinated ammonia, in comparison to Cland NO2 -, reaction of [RhCl6] 3-or [Rh(NO2)6] 3-with ammonia, results in a formation of cis-[Rh(NH3)2Cl4] -and cis-[Rh(NH3)2(NO2)4] -, respectively [3]. Further nitration should result in a formation of fac-[Rh(NH3)3Cl3] and fac-[Rh(NH3)3(NO2)3], which was confirmed experimentally [6][7][8]. Due to the high stability of [Rh(NH3)5Cl]Cl2, its deamination cannot be performed to access mer-[Rh(NH3)3Cl3].…”

“…According to [6,14], fac-[Rh(NH 3 ) 3 Cl 3 ] can be prepared by heating of fac-[Rh(NH 3 ) 3 (NO 2 ) 3 ] with HCl (25 mL of 1:1 aqueous solution), for 3 h. After cooling the solution to room temperature, a light-yellow powder is isolated with a 91% yield. The crystalline structure of fac-[Rh(NH 3 ) 3 Cl 3 ] was solved and refined using powder X-ray diffraction data (PXRD).…”

“…The crystalline structure of fac-[Rh(NH 3 ) 3 Cl 3 ] was solved and refined using powder X-ray diffraction data (PXRD). Fac-[Rh(NH 3 ) 3 (NO 2 ) 3 ] can be prepared according to [19] Cl 3 ], the IR-spectrum (cm -1 ) was: 1590 (δ a (NH 3 )); 1318 (δ s (NH 3 )); 837 (ρ r (NH 3 )) [6].…”

“…Crystal structure of fac-[Rh(NH3)3Cl3] has been solved and refined using powder X-ray diffraction data [6]. The monoclinical crystal structure was solved using the direct space approach and was refined using the Rietveld method.…”

“…Rhodium(III) coordinated with Cl and NH 3 ligands can form 7 possible types of octahedral species [3] 5 Cl]Cl 2 seems to be the first investigated Rh(III) coordination compound [4] and was one of the first Rh(III) compound that was structurally characterized [5]. Crystal structures of fac-[Rh(NH 3 ) 3 Cl 3 ] and diverse salts with [Rh(NH 3 ) 6 ] 3+ cations, as well as the first complexes with known anions [Rh(NH 3 )Cl 5 ] 2and cis-[Rh(NH 3 ) 2 Cl 4 ] − were just recently reported [6][7][8]. No previous study have looked at the crystal structures of complexes with known cis-[Rh(NH 3 ) 4 Cl 2 ] + .…”