Old Molecule, New Chemistry: Exploring Silicon Phthalocyanines as Emerging N-Type Materials in Organic Electronics

Abstract

Efficient synthesis of silicon phthalocyanines (SiPc) eliminating the strenuous reaction conditions and hazardous reagents required by classical methods is described. Implementation into organic thin-film transistors (OTFTs) affords average electron field-effect mobility of 3.1 × 10−3 cm2 V−1 s−1 and threshold voltage of 25.6 V for all synthetic routes. These results demonstrate that our novel chemistry can lead to high performing SiPc-based n-type OTFTs.

Silicon phthalocyanines: synthesis and resurgent applications

“…25 Brusso and co-workers recently proposed an alternate route to synthesize DII from phthalonitrile by using air-stable lithium bis(trimethylsilyl)amide etherate, LiN(TMS)2•Et2O in dry toluene at room temperature for 5 h, followed by exposure to gaseous hydrochloric acid at ice bath temperature. 26 The dichloride salt, H2DIICl2, thus formed when refluxed with SiCl4 in quinoline afforded 1 (yield ~ 51%). Among all these synthetic pathways, route B of Scheme 2 remains the most convenient and preferred choice for the construction of SiPcs.…”

“…Like other nitrogen heterocycle-based compounds, 123,124 certain SiPcs also possess electronic properties of n-type semiconductors. 26 Additionally, the readily tunable axial ligands, high field-effect mobility, robust environmental stability and ease of processability make them ideal to perform as organic thin film transistors (OTFTs).…”

From chemical curiosity to versatile building blocks: unmasking the hidden potential of main-group phthalocyanines in organic field-effect transistors

“…122 However, an alternative approach to the classical preparative route for DIII was recently reported by Brusso and co-workers (Scheme 3) that employs LiN(TMS) 2 ÁEt 2 O as a nucleophilic source of nitrogen. 125 This new route eliminates the undesired expenses attributed to the strenuous reaction conditions required and the hazardous reagents employed in the preparation of DIII, thus it is anticipated that other derivatives with modified molecular frameworks can now be explored.…”

“…Scheme 3 Synthetic routes in the preparation of Cl 2 -SiPc, including the preparation of DIII. 125 phthalocyanine (Cl 2 -GePc). 123,126 Alternatively, Cl 2 -GePc can also be prepared by mixing powdered germanium metal with phthalonitrile under a stream of ICl vapor at B160 1C.…”

High Voc Fullerene-Free Organic Photovoltaics Composed of PTB7 and Axially-Substituted Silicon Phthalocyanines

“…18 Axially substituted silicon phthalocyanines (R 2 -SiPc) are ideal candidates for low-cost, high-VOC acceptor materials. [21][22][23] While metal phthalocyanine (MPc) have been investigated in organic electronic applications for more than 50 year, R 2 -SiPcs are relatively understudied, having emerged in recent years 24 and successfully incorporated in multiple new application, including organic thin-lm transistors (OTFTs), [25][26][27][28][29][30] organic light-emitting diodes (OLEDs) [31][32][33] and in OPVs 21,31,34−37 . The synthetic complexity (SC) index 38 of R 2 -SiPcs have been calculated to be at least three times lower (SC = 12) 23 than that of several prominent OPV acceptors materials, such as PC 61 BM (SC = 36) 39 , Y6 (SC = 59) 40 and ITIC (SC = 67) 41 .…”