Hydrophobic Chromophores in Aqueous Micellar Solution Showing Large Two‐Photon Absorption Cross Sections

Abstract

A series of new hydrophobic two‐photon absorbing (2PA) chromophores with varied electron‐donating groups in quasi‐linear and multibranched structures are synthesized to correlate their structure/photophysical property relationships. The feasibility of using these large two‐photon absorption cross‐sectional (δ, expressed in GM = 1 × 10–50 cm4 s photon–1 molecule–1) materials in aqueous solution is also explored. All four hydrophobic 2PA materials can be encapsulated into micelles generated by dispersing an amphiphilic block copolymer, poly(methacrylic acid)‐block‐polystyrene (PMAA‐b‐PS), into water. The micellar nanostructures are characterized using dynamic light scattering, atomic force microscopy, and transmission electron microscopy. After these dyes are incorporated into micelles, they exhibit strong fluorescence in water. It is found that the quantum yield and δ values of these chromophores are strongly dependent on the diameters of the micelles, concentrations of the PMAA‐b‐PS, and molecular structures of the 2PA chromophores. One of the compounds that has a strong triarylamino donor and a multibranched structure exhibits a large δ value of 2790 GM and high quantum yield (0.56) in micelle‐containing water. Although this value is smaller than the original value of 5300 GM in toluene, it is still substantially larger than the values of most water‐soluble 2PA materials, which have δ values of less than 100 GM.

Study of Linear and Nonlinear Optical Properties of Four Derivatives of Substituted Aryl Hydrazones of 1,8‐Naphthalimide

“…[1][2][3][4][5][6][7][8][9][10] Current research on them focuses on improving the optical properties and synthesizing new materials exhibiting better NLO properties compared to the conventional materials. [1][2][3][4][5][6][7][8][9][10] Current research on them focuses on improving the optical properties and synthesizing new materials exhibiting better NLO properties compared to the conventional materials.…”

Synthesis, Characterization, Two‐Photon Absorption, and Optical Limiting Properties of Ladder‐Type Oligo‐p‐phenylene‐Cored Chromophores

“…In the past decade, a number of chromophores have been designed and characterized as highly two-photon active materials with TPA cross-sections up to several thousand GM (1 GM ¼ 10 À50 cm 4 s photon À1 ). [10][11][12][13][14] Recently, it has become clear that for the two-photon technology to realize its full potential, the development of more two-photon-active chromophores, which also possess other useful optical or chemical properties such as high fluorescence quantum yields, easy processability, good photostability and durability, will play a vital role. Although chromophores with extended conjugation length would have enhanced TPA due to their extended intramolecular charge transfer, they are often compromised with decreased fluorescence quantum yields and decreased photostability.…”

The photophysics and two-photon absorption of a series of quadrupolar and tribranched molecules: The role of the edge substituent

“…Although, a huge amount of research has been devoted to the design and study of organic materials with enhanced TPA properties, this field remains highly attractive as it is obvious by the large number of recent reports [4][5][6][7][8][9][10][11]. The ultimate goal of the research efforts is to understand how the chemical structure affects the TPA properties and to find chemically stable, inexpensive organic materials with large TPA cross sections, d [12,13].…”