Related Experiment Video
Updated: Apr 19, 2026

The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes
Published on: April 10, 2015
Crystal structure of bis-(2,2':6',2''-terpyridine-κ(3) N,N',N'')nickel(II) dicyanidoaurate(I)
Frankie White1, Richard E Sykora1
1University of South Alabama, Department of Chemistry, Mobile, AL 36688, USA.
Abstract:
The title compound, [Ni(C15H11N3)2][Au(CN)2]2, is an ionic compound composed of bis-(2,2':6',2''-terpyridine)-nickel(II) dications and dicyanidoaurate(I) anions in a 1:2 ratio. The two tridentate terpyridine ligands define the coordination of the Ni(2+) cation, resulting in a nearly octa-hedral coordination sphere, although there is not any imposed crystallographic symmetry about the Ni(2+) site. The two nearly linear dicyanidoaurate(I) anions [C-Au-C = 179.0 (2) and 178.2 (2)°] contain a short aurophilic inter-action of 3.1017 (3) Å. The structure does not demonstrate any π-π stacking. Non-classical C-H⋯N inter-actions between the cations and anions build up a three-dimensional network.
Related Concept Videos
Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than...
Valence Bond Theory
Coordination Number and Geometry
Ionic Crystal Structures
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
Structural Isomerism
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly,...

