Search results
Results From The WOW.Com Content Network
The inversion centre is preserved after the distortion. In octahedral complexes, the Jahn–Teller effect is most pronounced when an odd number of electrons occupy the e g orbitals. This situation arises in complexes with the configurations d 9, low-spin d 7 or high-spin d 4 complexes, all of which have doubly degenerate ground states.
Second-order Jahn-Teller distortion provides a rigorous and first-principles approach to the distortion problem. The interactions between the HOMOs and LUMOs to afford a new set of molecular orbitals is an example of second-order Jahn-Teller distortion.
In their early 1957 paper on what is now called pseudo Jahn–Teller effect (PJTE), Öpik and Pryce [2] showed that a small splitting of the degenerate electronic term does not necessarily remove the instability and distortion of a polyatomic system induced by the Jahn–Teller effect (JTE), provided that the splitting is sufficiently small (the two split states remain "pseudo degenerate ...
The term can also refer to octahedral influenced by the Jahn–Teller effect, which is a common phenomenon encountered in coordination chemistry. This reduces the symmetry of the molecule from O h to D 4h and is known as a tetragonal distortion.
In this structure, the copper centers are octahedral. Most copper(II) compounds exhibit distortions from idealized octahedral geometry due to the Jahn-Teller effect , which in this case describes the localization of one d-electron into a molecular orbital that is strongly antibonding with respect to a pair of chloride ligands.
Known for his "life-long years of experience in theoretical chemistry" [1] working on the electronic structure and properties of coordination compounds, Isaac B. Bersuker is “one of the most widely recognized authorities” [2] in the theory of the Jahn–Teller effect (JTE) and the pseudo-Jahn–Teller effect (PJTE).
Six-coordinate complexes of the Cu(II) ion, with the generic formula [CuL 6] 2+, are subject to the Jahn-Teller effect so that the symmetry is reduced from octahedral (point group O h) to tetragonal (point group D 4h). Since d orbitals are centrosymmetric the related atomic term symbols can be classified in the subgroup D 4.
Pd(III) has a d 7 electronic configuration, which leads to a Jahn–Teller distorted octahedral geometry. The geometry could also be viewed as being intermediate between square-planar and octahedral. These complexes are low-spin and paramagnetic. The first Pd(III) complex characterized by X-ray crystallography was reported in 1987. [3]