Nonlinear Absorption Dynamics in Tetrapyridyl Metalloporphyrins

Abstract

Nonlinear absorption dynamics of Zn(2+), Cu(2+), and Ni(2+) tetrapyridyl porphyrins in chloroform/methanol solutions were investigated at 532 nm with the Z-scan technique. Additional techniques such as UV-vis absorption spectroscopy and time-resolved fluorescence were used to obtain parameters that are important for the analysis of the population dynamics. A marked difference was observed in the nonlinear absorption and excited-state dynamics of closed (ZnTPyP)- and open-shell metalloporphyrins (CuTPyP and NiTPyP). ZnTPyP presents a reverse saturable absorption whose dynamics can be completely described by means of a simple five-energy-level diagram. On the other hand, CuTPyP and NiTPyP have a different excited-state dynamics, presenting a saturable absorption behavior and faster relaxation rates that were attributed to the presence of unfilled d shells of the central ion.

Investigation of the photophysical and eletrochemical properties of a free base tetrapyridyl porphyrin with meso carbon linked ruthenium(II) groups

“…Efforts in this direction have been made through changes of the central ion [11,12], aggregate formation [13,14], insertion of lateral and axial ligands [15,16], oligomers [17], supramolecular isomeric structures [10,[18][19][20], presence of cationic groups [21,22], and others. In order to better understand the impact of structural modification on porphyrins systematic studies of their photophysical and photochemical properties is highly necessary.…”

Investigation of Ground- and Excited-State Photophysical Properties of 5,10,15,20-Tetra(4-pyridyl)-21H,23H-porphyrin with Ruthenium Outlying Complexes

“…Efforts in this direction have been made through changes of the central ion, 10,11 aggregate formation, 12 insertion of lateral and axial ligands, 13À15 oligomers, 16 isomeric structures, 17 cationic porphyrins, 18 and others.…”

Self-assembled monolayers formed by 5,10,15,20-tetra(4-pyridyl)porphyrin and cobalt 5,10,15,20-tetra(4-pyridyl)-21H,23H-porphine on iodine-passivated Au(111) as observed using electrochemical scanning tunneling microscopy and cyclic voltammetry

“…Cobalt 5,10,15,20-tetra(4-pyridyl)-21H,23H-porphine (CoTPyP) was prepared by metallating TPyP using a procedure from the literature [26]. Briefly, tetrapyridylporphyrin was refluxed for 3 h with an excess of cobalt chloride in a 1:1 acetic acid and dimethyl formamide solution.…”