The lowest excited states of copper porphyrins

Abstract

Temperature dependence of conformation, chemical state, and metal-directed assembly of tetrapyridylporphyrin on Cu (111) Two-dimensional localization of adsorbate/substrate charge-transfer excited states of molecules adsorbed on metal surfaces

Mechanism of exciplex formation between Cu-porphyrin and calf-thymus DNA as revealed by saturation resonance Raman spectroscopy

“…All the other Cu(TMpy-P4) molecules, predominantly intercalated at GC sites, were postulated to behave as copper porphyrins in a non-complexing environment. 17,21,22 They participate in intramolecular processes of the excitation relaxation via the triplet-state manifold T 1 [left-hand relaxation scheme in Fig. 6(B)].…”

Effects of the Peripheral Substituents, Central Metal, and Solvent on the Photochemical and Photophysical Properties of 5,15‐Diazaporphyrins

“…The relatively short triplet lifetimes observed for MDAP-COOH could be partly caused by the intrinsic solvation of the chromophore and/or solvent coordination onto the central metal ion. [16] More importantly, the τ T values of MDAP-COOH were almost identical to the τ T0 values, and the rate constant of the 1 O 2 -generation process (k q [O 2 ]) observed for MDAP-COOH was about one hundredth of that for MDAP-COOEt. These results indicate that most of the MDAP-COOH molecules are present as a monomeric form inside the micelle and could not react with dioxygen outside of the micelle.…”

“…The triplet lifetimes of MDAP‐COOH in micelles were shorter than those of MDAP‐COOEt in toluene. The relatively short triplet lifetimes observed for MDAP‐COOH could be partly caused by the intrinsic solvation of the chromophore and/or solvent coordination onto the central metal ion . More importantly, the τ T values of MDAP‐COOH were almost identical to the τ T0 values, and the rate constant of the 1 O 2 ‐generation process ( k q [O 2 ]) observed for MDAP‐COOH was about one hundredth of that for MDAP‐COOEt.…”

“…It is worth noting that the τ T0 value of 1Cu was significantly longer than that of the Cu II complex of 5,10,15,20‐tetraphenylporphyrin (CuTPP; τ T0 =0.03 μs) . CuTPP has a relaxation process to the ground state ( 2 S) via a tripdoublet ( 2 T) state located at Δ E T higher than the lowest tripquartet ( 4 T) state . Hence the long τ T0 of 1Cu can be understood by its large Δ E T , which inhibits the thermal activation of 4 T→ 2 T. The relatively short Cu−N bond length of 1Cu (1.95 Å) causes the increase in Δ E T that is mostly determined by the exchange interaction between d x2−y2 orbital of copper and 2p z orbitals on the coordinating nitrogen atoms of porphyrin.…”

Quasi-line phosphorescence spectra of the copper complex of meso-tetrapropylporphin at liquid helium temperature

“…Refs [18,19]) that the two lower triplet levels of a metalloporphyrin molecule have close energies and correspond to practically pure configurations 3 (1a 1u 4e g ) and 3 (3a 2u 4e g ). There are various and substantial reasons to consider that in metal complexes of meso-tetraarylporphyrins and mesotetraalkylporphyrins, in particular, in copper complexes as well, the T 1 state of the macrocycle has the configuration 3 (3a 2u 4e g ) [1][2][3][4][5][6][7][20][21][22]. As an example, we give the data [20] that a typical picture of thermally activated phosphorescence absent in CuTPP appears when five atoms of fluorine that decrease the energy of the orbital 3a 2u are introduced in each phenyl ring of a CuTPP molecule.…”