Electric Literature of 72287-26-4, Chemistry is the science of change. But why do chemical reactions take place? Why do chemicals react with each other? The answer is in thermodynamics and kinetics.In a document type is Article, and a compound is mentioned, 72287-26-4, [1,1′-Bis(diphenylphosphino)ferrocene]dichloropalladium(II), introducing its new discovery.
Topological Effects on Intramolecular Electron Transfer via Quantum Interference
The three isomers of diferrocenylbenzenes (ortho, 1o; meta, 1m; para, 1p) as well as 5-substituted derivatives of m-diferrocenylbenzene with R = NH2 (2), Cl (3), CH3 (4), CN (5), NO2 (6), and N(CH3)33+ (7) have been prepared. Crystal structures of 1o, 3, and 5 have been solved. In 3 and 5, the cyclopentadienyl rings are nearly parallel to the benzene mean planes with angles ranging from 9.99(5) to 14.74(5). One ferrocene group is above and the other below the mean molecular plane. For 1o, there is an important twist between the benzene and cyclopentadiene rings (68.6(8) and 32.5(8)) for steric reasons. Controlled potential electrolysis yields the mixed-valence ferrocene/ ferrocenium species in comproportionation equilibrium with homovalent species. Intervalence transitions have been observed and corrected from comproportionation. From the intervalence band parameters, metal-metal couplings (Vab) are calculated using Hush’s equation. The values are much higher for 1o (0.025 eV) and 1p (0.043 eV) than for 1m (0.012 eV) and exhibit little or no variation for the substituted m-diferrocenylbenzenes 2-6. These results are rationalized by extended Hueckel molecular orbital calculations. The weakness of the interaction in 1m can be ultimately traced to a quantum Interference effect, i.e., a cancellation of the contributions of two electron transfer paths. This cancellation occurs because each path implies a mixing of metal orbitals with a different ligand orbital, and the resulting molecular orbitals exhibit different symmetries.
Balanced chemical reaction does not necessarily reveal either the individual elementary reactions by which a reaction occurs or its rate law.Electric Literature of 72287-26-4. In my other articles, you can also check out more blogs about 72287-26-4
Reference£º
Chapter 1 An introduction to palladium catalysis,
Palladium/carbon catalyst regeneration and mechanical application method