Mono- and dinitrosyls on copper(I) site in a zeolite model: effects of static correlation
1Faculty of Chemistry, Jagiellonian University, Kraków, Poland.
Abstract:
Multiconfigurational RASSCF/RASPT2 approach has been applied to investigate bonding of one and two nitric oxide (NO) molecules to a simple model of Cu(I) site in zeolite environment, Cu(I)[Al(OH)(4)]. Two binding modes were considered for the mononitrosyls and four alternative structures for the dinitrosyls (each one in either singlet or triplet state). Stabilities of the mono- and dinitrosyl complexes obtained from the multireference calculations were compared to the previously reported coupled cluster CCSD(T) results, as well as to DFT calculations performed here with various functionals, either hybrid or nonhybrid ones. RASSCF calculations provided also a qualitative insight into the electronic structure of the studied complexes, concerning mainly the interaction between the Cu and the NO ligand, and between the two NO fragments. Whereas the electronic structure of the mononitrosyls is dominated by a single configuration, the dinitrosyls have a considerably multireference character. Various effects of nondynamical correlation have been pointed out for these interesting species, trying to assess their impact on performance of the tested DFT methods.
Related Concept Videos
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,...
02:58Crystal 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...
01:19Complexation Equilibria: The Chelate Effect
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 be...
02:42Valence Bond Theory
02:51Metal-Ligand Bonds
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...