Temperature-dependent analysis of thermal motion, disorder and structures of tris(ethylenediamine)zinc(II) sulfate and tris(ethylenediamine)copper(II) sulfate.
The crystal structures of the title compounds have been determined in the temperature range 140-290 K for the zinc complex, and 190-270 K for the copper complex. The two structures are isostructural in the trigonal space group P31c with the sulfate anion severely disordered on a site with 32 (D(3)) symmetry. This sulfate disorder leads to a disordered three-dimensional hydrogen-bond network, with the N-H atoms acting as donors and the sulfate O atoms as acceptors. The displacement parameters of the N and C atoms in both compounds contain disorder contributions in the out-of-ligand plane direction owing to ring puckering and/or disorder in hydrogen bonding. In the Zn compound the vibrational amplitudes in the bond directions are closely similar. Their differences show no significant deviations from rigid-bond behaviour. In the Cu compound, a (presumably) dynamic Jahn-Teller effect is identified from a temperature-independent contribution to the displacement ellipsoids of the N atom along the N-Cu bond. These conclusions derive from analyses of the atomic displacement parameters with the Hirshfeld test, with rigid-body models at different temperatures, and with a normal coordinate analysis. This analysis considers the atomic displacement parameters (ADPs) from all different temperatures simultaneously and provides a detailed description of both the thermal motion and the disorder in the cation. The Jahn-Teller radii of the Cu compound derived on the basis of the ADP analysis and from the bond distances in the statically distorted low-temperature phase [Lutz (2010). Acta Cryst. C66, m330-m335] are found to be the same.
Bijvoet Center for Biomolecular Research, Crystal and Structural Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
Stef
S
Smeets
Pascal
P
Parois
Hans-Beat
HB
Bürgi
Martin
M
Lutz
D003300:Copper / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D008024:Ligands; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D013696:Temperature; D015032:Zinc / Q000737:chemistry*
D008024:Ligands; D009942:Organometallic Compounds; C554373:tris(ethylenediamine)copper(II) sulfate; C554372:tris(ethylenediamine)zinc(II) sulfate; D003300:Copper; D015032:Zinc