Self-Assembled Organic Nanocrystals with Strong Nonlinear Optical Response

Abstract

Facile molecular self-assembly affords a new family of organic nanocrystals that, unintuitively, exhibit a significant nonlinear optical response (second harmonic generation, SHG) despite the relatively small molecular dipole moment of the constituent molecules. The nanocrystals are self-assembled in aqueous media from simple monosubstituted perylenediimide (PDI) molecular building blocks. Control over the crystal dimensions can be achieved via modification of the assembly conditions. The combination of a simple fabrication process with the ability to generate soluble SHG nanocrystals with tunable sizes may open new avenues in the area of organic SHG materials.

Self‐Assembly of Conjugated Metallopolymers with Tunable Length and Controlled Regiochemistry

“…[13] Polymer growth is favored by the strong mutual reinforcement between these two linkages,w hich allows the self-assembly of functional and persistent structures. Controlling the structure and conjugation length of the organic portion of metallopolymers is crucial to optimizing their electronic properties.P olymer length also determines the morphology of the material, impacting device performance,scalability of preparation, and solution processability, [15] which are essential considerations for bespoke device fabrication. Controlling the structure and conjugation length of the organic portion of metallopolymers is crucial to optimizing their electronic properties.P olymer length also determines the morphology of the material, impacting device performance,scalability of preparation, and solution processability, [15] which are essential considerations for bespoke device fabrication.…”

Composites of hydrophilic polymers and organic nanocrystals enable enhanced robustness

“…Organic solvents were of spectroscopic or HPLC grade, dried over molecular sieves (3 Å), and filtered over 0.2‐μm PTFE syringe filters prior to use. Syntheses of the PDI derivatives followed literature procedures …”

“…Hence, organic nanocrystals (ONCs), whose solubility and morphology are difficult to control, have not been employed in polymer/nanohybrids. Aromatic ONCs can be robust and exhibit useful photonic properties, [11][12][13][14][15][16] yet their fabrication is based mostly on empirical methods. 17 Addressing this challenge, we have recently demonstrated that rational design based on hydrophobicity tuning can be applied to control structure and morphology, resulting in soluble and tunable ONCs.…”

“…14,18,19 We have also reported on a new family of ONCs that possess strong nonlinear optical (NLO) response (second harmonic generation, SHG). 14…”

Nitro-Perylenediimide: An Emerging Building Block for the Synthesis of Functional Organic Materials

“…The functionalization with amine and alcohol through The mononitration of PDI 1 is more selective, owing to the electron-withdrawing inductive and mesomeric effects of the nitro group, which sufficiently deactivates the PDI core towards the second electrophilic substitution. The reaction was initially performed by Langhals and colleagues, who attained 98% yield using a solution of N 2 O 4 gas (prepared by strong heating of Pb(NO 3 ) 2 ) and methanesulfonic acid (CH 3 SO 3 H) as the catalyst in CH 2 Cl 2 [38,39], and this was achieved more easily using nitric acid in the presence of cerium (IV) ammonium nitrate (CAN) in CH 2 Cl 2 with nearly quantitative yields [30,31,[40][41][42][43][44][45][46]. The kinetics of the reaction were reported to be higher using a mixture of HNO 3 and H 2 SO 4 [47][48][49].…”