Related Experiment Video
Updated: Mar 29, 2026
X-ray Powder Diffraction in Conservation Science: Towards Routine Crystal Structure Determination of Corrosion Products on Heritage Art Objects
Published on: June 8, 2016
Crystal structure of tetra-kis-(μ-caproato-κ(2) O:O')bis-[(4-cyano-pyridine-κN (1))copper(II)]
Sukanya Baruah1, Zinnatara Islam1, Sanjib Karmakar2
1Department of Chemistry, Gauhati University, Guwahati 781 014, India.
Abstract:
The title dinuclear complex, [Cu2(C6H11O2)4(C6H4N2)2], has a paddle-wheel structure. The two crystallographically independent Cu(II) atoms are each in a distorted square-pyramidal environment, in which four O atoms from the four bridging caproate ligands form the basal plane and the pyridine N atom of the 4-cyano-pyridine ligand occupies the apical position. The Cu⋯Cu distance is 2.6055 (9) Å. One of the alkyl chains of the caproate ligands is disordered over two sets of sites, with occupancies of 0.725 (5) and 0.275 (5). In the crystal, two pairs of C-H⋯N hydrogen bonds connect the mol-ecules into chains along [11-1] and C-H⋯O hydrogen bonds link the chains into a three-dimensional network.
Related Concept Videos
02:57Coordination Number and Geometry
02:46Crystal 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 the dxy,...
02:42Ionic 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...
02:58Crystal 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...
02:42Valence Bond Theory
02:34Structural 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, SCN− can...