Addition of alkynes and osmium carbynes towards functionalized d\u03c0\u2013p\u03c0 conjugated systems

Shiyan Chen,Feng He,Haiping Xia,Longzhu Liu,Yuanzhi Tan,Yuhui Hua,Lixia Peng,Xiang Gao,Liulin Yang,Ying Zhang

doi:10.1038/s41467-020-18498-2

Abstract

The metal-carbon triple bonds and carbon-carbon triple bonds are both highly unsaturated bonds. As a result, their reactions tend to afford cycloaddition intermediates or products. Herein, we report a reaction of M≡C and C≡C bonds that affords acyclic addition products. These newly discovered reactions are highly efficient, regio- and stereospecific, with good functional group tolerance, and are robust under air at room temperature. The isotope labeling NMR experiments and theoretical calculations reveal the reaction mechanism. Employing these reactions, functionalized dπ-pπ conjugated systems can be easily constructed and modified. The resulting dπ-pπ conjugated systems were found to be good electron transport layer materials in organic solar cells, with power conversion efficiency up to 16.28% based on the PM6: Y6 non-fullerene system. This work provides a facile, efficient methodology for the preparation of dπ-pπ conjugated systems for use in functional materials.

Highlights

The metal-carbon triple bonds and carbon-carbon triple bonds are both highly unsaturated bonds
Because of the electron transport feature enhanced by osmium, these dπ–pπ conjugated complexes have been proved to be feasible as electron transport layers (ETLs) to enhance device performance
PM6: Y6-based non-fullerene solar cells with complex 30 as an ETL have acquired a power conversion efficiency (PCE) as high as 16.28%. This value is much higher than that in devices lacking ETL, but is dramatically elevated compared with commonly used ETLs, such as the PDINO discussed below. This reveals that the dπ–pπ conjugated complexes have great potential as interfacial layer materials, especially when combined with good electron transport capability and solubility in alcohol to facile orthogonal solvent processing, which could open a window into the capabilities of these newly developed dπ–pπ conjugated complexes

Summary

Introduction

The metal-carbon triple bonds and carbon-carbon triple bonds are both highly unsaturated bonds. We report a reaction between metal carbynes and terminal alkynes in the presence of acid, which gives rise to acyclic addition products. A solution of the complex (1a) was treated with HCl·Et2O solution in dichloromethane (DCM), producing a carbyne triple bond shifted product (2a) (Fig. 1a).

Results

Conclusion