The iron complex shown below forms the basis for many catalysts.[cite]10.1002/anie.200502985[/cite] With iron, the catalytic behaviour very much depends on the spin-state of the molecule, which for the below can be either high (hextet) or medium (quartet) spin, with a possibility also of a low spin (doublet) state. Here I explore whether structural information in crystal structures can reflect such spin states.
Posts Tagged ‘Organometallic chemistry’
Chemistry rich diagrams: do crystal structures carry spin information? Iron-di-imine complexes.
Sunday, June 18th, 2017Tags:catalysis, Catalysts, Chemistry, energy, energy separations, energy span, Fe complex, Homogeneous catalysis, Kumada coupling, Organometallic chemistry, spin-state energy separations, Synergistic catalysis
Posted in crystal_structure_mining | 1 Comment »
What’s in a name? Carbenes: a reality check.
Sunday, September 11th, 2016To quote from Wikipedia: in chemistry, a carbene is a molecule containing a neutral carbon atom with a valence of two and two unshared valence electrons. The most ubiquitous type of carbene of recent times is the one shown below as 1, often referred to as a resonance stabilised or persistent carbene. This type is of interest because of its ability to act as a ligand to an astonishingly wide variety of metals, with many of the resulting complexes being important catalysts. The Wiki page on persistent carbenes shows them throughout in form 1 below, thus reinforcing the belief that they have a valence of two and by implication six (2×2 shared + 2 unshared) electrons in the valence shell of carbon. Here I consider whether this name is really appropriate.
Tags:Carbenes, chemical bonding, energy barrier, free energy, Functional groups, Ligand, Mesoionic carbene, Organometallic chemistry, Persistent carbene, quantum mechanical solution, Reactive intermediates, Transition metal carbene complex, Valence, Valence electron
Posted in crystal_structure_mining, General | No Comments »