Controlling the Physical and Electrochemical Properties of Arylamines Through the Use of Simple Silyl Ethers: Liquid, Waxy and Glassy Arylamines

Abstract

The effect of silyl ether substitution on the physical and electrochemical properties of single and two-nitrogen centered arylamines was explored. It was found that this substitution can significantly lower the T g and suppress crystallization of these compounds. This resulted in arylamines that were isolated as liquids, waxes, glasses, and in some cases crystalline solids at ambient conditions. Additionally, these silyl ether groups were found to be relatively strong electron donating groups with similar donating potentials to the well known methyl ether group. It is concluded that silyl ether substitution is a synthetic handle to greatly alter the physical properties of arylamines without substantially changing their basic electronic properties.

Synthetic Studies Probing Elansolid Biosynthesis: A para‐Quinone‐Methide‐Triggered Intramolecular Diels–Alder Reaction

“…Roche ester 31 is commercially available. Building blocks and reagents 14 , 16 ,[10a] 17 ,[10a] 18 , 30 ,[10a] 32 ,[10a] 35 , 38a ,[10a] and 38b [10a] were prepared according to known procedures.…”

The use of siloxanes, silsesquioxanes, and silicones in organic semiconducting materials

“…The Piers-Rubinsztajn reaction 9 is a relatively new process to join siloxane-silicone functionalities with organic molecules, including organic semiconducting materials. [10][11][12][13] This reaction takes place between a silane and an aryl or alkyl hydroxyl or alkoxy group (Scheme 1) and is catalysed by tris(pentafluorophenyl)borane (B(C 6 F 5 ) 3 or simply BCF), a strong and water tolerant Lewis acid. Like hydrosilylation, the Piers-Rubinsztajn reaction proceeds with low catalyst loadings and there are no significant by-products beyond gaseous hydrocarbons which are easily dealt with on a laboratory scale.…”

“…), some degree of caution must be exercised when dealing with this process. Despite this minor downside, the reaction is compatible with a variety of different silanes including small molecules [11][12][13] and polymers. 10 It should be noted that alkoxy-silanes will also react under these conditions.…”

“…The general synthesis of free flowing liquid organic semiconductors has been achieved by our group by modifying the periphery of well-known triarylamine structures with either simple silyl ethers (of which 2TIPS, 15, Fig. 6 is a representative example) 11 or discrete siloxane chains. 12,13 The former strategy was accomplished through common C-N coupling reactions of the silyl ether functionalized components.…”

Charge Carrier Mobility of Siliconized Liquid Triarylamine Organic Semiconductors by Time-of-Flight Spectroscopy.

“…8 While unmodified triarylamines tend to be brittle, crystalline materials, 9 siliconized triarylamines take on the physical characteristics of waxes or liquids, depending on the length and arrangement of the silicone fragment(s) attached. 8,10,11 We have shown that the incorporation of silicone fragment(s) into a triarylamine has little effect on the electrochemical properties of the triarylamine. 12 More recently we have also shown that the charge transport properties of a single model liquid triarylamine (referred to as 2-TIPS) follows the same general model of charge transport as standard solid triarylamines.…”