Search results
Results from the WOW.Com Content Network
Charge-transfer bands of transition metal complexes result from shift of charge density between molecular orbitals (MO) that are predominantly metal in character and those that are predominantly ligand in character. If the transfer occurs from the MO with ligand-like character to the metal-like one, the transition is called a ligand-to-metal ...
In chemistry, charge-transfer (CT) complex, or electron donor-acceptor complex, describes a type of supramolecular assembly of two or more molecules or ions. The assembly consists of two molecules that self-attract through electrostatic forces, i.e., one has at least partial negative charge and the partner has partial positive charge, referred ...
Once a metal complex undergoes metal-to-ligand charge transfer, the system can undergo intersystem crossing, which, in conjunction with the tunability of MLCT excitation energies, produces a long-lived intermediate whose energy can be adjusted by altering the ligands used in the complex.
Consequently X-ray crystallography above and below transition temperatures will generally reveal changes in metal-ligand bond lengths. Transitions from a HS to a LS state cause a decrease in and a strengthening of the metal-ligand bond. These changes are also manifested in FT-IR and Raman spectra.
This is commonly known as ligand-to-metal charge transfer or LMCT. In some cases, low-lying unoccupied ligand orbitals (π*) can receive back-donation (or backbonding) from the occupied metal orbitals. This has the opposite effect on the system, resulting in metal-to-ligand charge transfer, MLCT, and commonly appears as an additional L-edge ...
[5] [6] This electron transfer strengthens the metal–ligand bond and weakens the C–C bonds within the ligand. [7] In the case of metal-alkenes and alkynes, the strengthening of the M–C 2 R 4 and M–C 2 R 2 bond is reflected in bending of the C–C–R angles which assume greater sp 3 and sp 2 character, respectively.
Complexes have been described for all of the transition metals. [citation needed] Although few have any practical value, these complexes have been influential. [1] 2,2'-Bipyridine (bipy) is classified as a diimine ligand. Unlike the structures of pyridine complexes, the two rings in bipy are coplanar, which facilitates electron delocalization ...
The intense blue color of Prussian blue is a consequence of an intervalence charge transfer band. In chemistry, intervalence charge transfer, often abbreviated IVCT or even IT, is a type of charge-transfer band that is associated with mixed valence compounds. It is most common for systems with two metal sites differing only in oxidation state.