Syntheses of Organic Semiconductors in Water. Recent Advancement in the Surfactants Enhanced Green Access to Polyconjugated Molecules

Abstract

Organic semiconductors have been at the center of intense investigation for decades. The efficiencies of the most performing candidates, along with the compatibility with solution processing and printing led to relevant technological breakthrough. The development of market applications for Organic Light Emitting Devices (OLEDs), Organic Thin film transistors (OTFTs), and Organic Photovoltaics (OPVs) poses a relevant question regarding to the scaling up and overall sustainability of synthetic protocols employed for the preparation of active compounds. This review summarizes the role that the emerging field of micellar catalysis and surfactant enhanced chemistry can play in dramatically improving the sustainability of established and emerging performing organic semiconductors.

Sustainable Access to π-Conjugated Molecular Materials via Direct (Hetero)Arylation Reactions in Water and under Air

“…Such methods already contributed to the green chemistry-compliant access to relevant organic-conjugated derivatives [ 42 , 43 , 44 , 45 , 46 ]. In particular, the use of the industrial grade, FDA-approved surfactant Kolliphor EL (K-EL)—a complex mixture obtained by the reaction of castor oil with 35 equivalents of ethylene oxide—in S–M and Buchwald–Hartwig (B–H) amination protocols, enabled the high yield and low E-factor preparation of several classes of molecular semiconductors, including perylenediimides, isoindigos, oligothiophenes and benzothiadiazoles, having applications in organic field effect transistors, organic solar cells and luminescent solar concentrators [ 47 ].…”

Taming Troublesome Suzuki–Miyaura Reactions in Water Solution of Surfactants by the Use of Lecithin: A Step beyond the Micellar Model

“…22,25 Acetone and THF in particular are recognized as efficient cosolvents for the SM coupling. 16 However, such an approach improved only modestly the behavior of the reaction (entry [9][10][11][12] and, at the same time, does not honor the commitment to clear away organic solvents.…”

“…Literature shows that the addition of surfactants to water can drastically change such a scenario. [5][6][7][8][9] Several different chemical processes can be profitably performed in water with high yield, irrespective to the solubility of reagents and products. [10][11][12][13][14] Gathered under the banner of "micellar catalysis" (MC) such methods witnessed an enormous boost in scope, generality and synthetic usefulness in the last 10 years, even at the industrial scale.…”

“…The development of improved synthetic methods offering selectivity, high yield, and short reaction times while providing moderate or no heating is a cornerstone of modern sustainable chemistry. , Unfortunately, the need for organic solvents remains the elephant in the room. , Despite the obvious benefits, their replacement with water in homogeneous phase reactions is troublesome as the vast majority of fine chemicals and/or precursors are water insoluble. The literature shows that the addition of surfactants to water can drastically change such a scenario. − Several different chemical processes can be profitably performed in water with high yield, irrespective to the solubility of reagents and products. − Gathered under the banner of “micellar catalysis” (MC), such methods witnessed an enormous boost in scope, generality, and synthetic usefulness in the last 10 years, even at the industrial scale. − …”

Sustainable, Efficient, and Scalable Preparation of Pure and Performing Spiro-OMeTAD for Perovskite Solar Cells

“…Water would be the ideal substitute, if not for the hydrophobicity of most organic species. Yet, the last 20 years witnessed a dramatic increase in the number of processes based on water as the solvent, regardless of the water solubility of reagents and products. − Solventless reactions are also becoming increasingly relevant …”