Nonlinear Optical Properties of Porphyrins

Abstract

Porphyrins and phthalocyanines have outstanding chemical and thermal stability. The macrocyclic structure and chemical reactivity of tetrapyrroles offers architectural flexibility and facilitates the tailoring of chemical, physical and optoelectronic parameters. The specific optical properties of the tetrapyrrole macrocycle combined with the synthetic methodologies now available and the already available theoretical and spectroscopic knowledge on their optical behavior make porphyrins a target of choice for this area. They are versatile organic nanomaterials with a rich photochemistry and their excited state properties are easily modulated through conformational design, molecular symmetry, metal complexation, orientation and strength of the molecular dipole moment, size and degree of conjugation of the π‐systems, and appropriate donor‐acceptor substituents. Here we review the structural chemistry and optical properties of recently synthesized porphyrin derivatives that offer potential for nonlinear optical (NLO) applications and complement existing studies on phthalocyanines. Classes of interest include the classic A4 symmetric tetrapyrroles, while optimized systems include push‐pull porphyrins, oligomeric and supramolecular self‐assembled systems, films and nanoparticle systems, and highly conjugated porphyrin arrays.

Bottom-Up Hierarchical Self-Assembly of Chiral Porphyrins through Coordination and Hydrogen Bonds

“…[8][9][10][11][12] Self-assembled chiral systems based on synthetic porphyrins present a broad range of potential applications in areas such as photovoltaic cells, 13 sensors, 14 optoelectronics 15 and nanoelectronic devices 16 and also non-linear optical materials. 17 The number and position of the stereogenic centers in molecules united by covalent or non-covalent bonds directly affect the chiral transfer from the molecular level up to the supramolecular aggregates that they form in solution and consequently their optical activity can be modified. [18][19][20] The self-assembly of porphyrins in supramolecular stacked systems can be controlled by a combination of non-covalent interactions such as hydrogen-bonding, van der Waals interactions and π-π-interactions between the porphyrin cores.…”

Photoinitiated charge separation in a hybrid titanium dioxide metalloporphyrin peptide material

“…(PPIX)Zn was found to be sensitive to room light and would decompose in less than 24 h. With this knowledge, the porphyrin (DPP)Zn replaced the (PPIX)Zn molecule. This non-natural molecule was intentionally chosen because it serves as a basic building block in more complex porphine systems that have a wide array of functionalities and applications such as: nonlinear optics, molecular beacons, biomolecular imaging reagents and lightharvesting antennae [34][35][36][37][38][39] .…”

Nonlinear absorption properties of 5,10-A2B2porphyrins—correlation of molecular structure with the nonlinear responses

“…13,35 Introduction of bromine atoms at both the meso and β positions was reported to enhance the ISC rate and the quantum yield for triplet states up to unity. 31 (2,3,7,8,12,13,17,18-Octabromo-5,10,15,20-tetraphenylporphyrinato)zinc(II) was shown to have especially strong positive NLA with an OL efficiency comparable to the advanced phthalocyanine chloro{tetra(tert-butyl)-phthalocyaninato}indium(III). 35 Compared to TMS-ethynyl substituted 5,10-A 2 B 2 compounds the brominated porphyrins exhibited weaker OL efficiency and thus have less potential for green light OL.…”

“…1,2 Porphyrins, along with phthalocyanines and other related macrocyclic dyes, constitute a promising group of NLO compounds due to high nonlinearities upon irradiation with high intense laser light. 3,4 Their main advantage is their chemical versatility which provides a tool for tailoring the linear and NLO properties for specific applications. One field of potential use of NLO active macrocyclic dyes is broadband optical limiting (OL), which aims for the protection of human eyes and sensitive optical elements against accidental exposure to high energy laser beams.…”