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 ...
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 ...
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 ...
[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.
6,6'-Substituents tend to protect the metal center. [8] The related N,N-heterocyclic ligand phenanthroline forms similar complexes. With respective pK a 's of 4.86 and 4.3 for their conjugate acids, phenanthroline and bipy are of comparable basicity. [9] 2,2'-Biquinoline is closely related to bipy as a ligand.
As a ligand approaches the metal ion, the electrons from the ligand will be closer to some of the d-orbitals and farther away from others, causing a loss of degeneracy. The electrons in the d-orbitals and those in the ligand repel each other due to repulsion between like charges.
Spin crossover is commonly observed with first row transition metal complexes with a d 4 through d 7 electron configuration in an octahedral ligand geometry. [1] Spin transition curves typically plot the high-spin molar fraction against temperature. [ 3 ]
In addition to containing A- and B-terms, this example demonstrates the effects of spin-orbit coupling in metal to ligand charge transfer (MLCT) transitions. As shown in figure 1, the molecular orbital diagram of [(n-C 4 H 9) 4 N] 2 Pt(CN) 4 reveals MLCT into the antibonding π* orbitals of cyanide.