Although [Ag(en)]ClO 4 involves a normally bidentate ligand, in this case the structure is polymeric and the silver ion still retains a CN=2 with the N atoms (from different ligands) at ~180 degrees to each other. The cis- isomer is a powerful anti-cancer drug whereas the trans- is inactive. The classic example of optical isomerism in octahedral coordination complexes (H atoms not shown).
For a typical spin-allowed but Laporte (orbitally) forbidden transition in an octahedral complex, expect ε < 10 m 2 mol -1 . Extinction coefficients for tetrahedral complexes are expected to be around 50-100 times larger than for octrahedral complexes. B for first-row transition metal free ions is around 1000 cm -1 . Depending on the position of the ligand in the nephelauxetic series, this can be reduced to as low as 60% in the complex.
Based on the radius ratio, it can be seen that the bigger the charge on the central ion, the more attraction there will be for negatively charged ligands, however at the same time, the bigger the charge the smaller the ion becomes which then limits the number of groups able to coordinate.
Elongation Jahn-Teller distortions occur when the degeneracy is broken by the stabilization (lowering in energy) of the d orbitals with a z component, while the orbitals without a z component are destabilized (higher in energy) as shown in Figure 2 below:
Pay attention to definitions: a number of texts may refer to \(\beta_4\) as the instability constant or the dissociation constant of coordination complexes (e.g., termed \(\beta'_4\) below) , which corresponds to the reciprocal of the formation constant (\(K_4\)), since the reactions referred to are those where fully formed complexes break down to the aqua ion and free ligands.
The mer isomer is where the ligands are not on the same plane and there exists a 90-90-180 degree bond angle between the 3 same ligands. The fac isomer is where the ligands are on the same plane and there exists a 90-90-90 degree bond angle between the 3 same ligands. Using either the symmetry method or the mirror image method, one can observe that this molecule has a chiral center and that the mirror image is not superimposable on the original molecule.
Canada is the world's leading nickel producer and the Sudbury Basin of Ontario contains one of the largest nickel deposits in the world. In the first step of the process, nickel oxide is reacted with water gas, a mixture of H 2 and CO, at atmospheric pressure and a temperature of 50 °C. The primary use of nickel is in the preparation of alloys such as stainless steel, which accounts for approximately 67% of all nickel used in manufacture.