Heterometallic Porphyrin Conjugated Polymer Thin Films-A Gas-Phase Approach for the Engineering of New Fused Porphyrin Systems

For the first time, the simultaneous synthesis and deposition of heterometallic porphyrin conjugated polymer thin films from a simple and scalable gas-phase approach are reported. The oxidative chemical vapor deposition (oCVD) reaction of 5,15-(diaryl) porphyrins chelated with different metal cations (M = Co(II), Ni(II), Zn(II), Cu(II), Pd(II)) readily yields the formation of new hetero-metalated fused porphyrin tapes, such as evidenced by in-depth high-resolution mass spectrometry studies. The impact of the coreactants on the regioselectivity of the intermolecular dehydrogenative coupling reaction and the formation of double or triple bonds between the porphyrin units is demonstrated. The oCVD reaction of multiple porphyrins brings the possibility to easily engineer the chemical features and the electronic and optoelectronic properties of these highly conjugated porphyrin polymers. Particularly, it is demonstrated that porphyrin conjugated polymers having different chelated metal cations can achieve higher electrical conductivities and promote narrower bandgaps. The gas-phase approach presented herein overcomes the main limitations of the conventional solution-based approaches and opens the path to the engineering of a novel class donor-acceptor heterometallic polymers with high interest in several fields including multimetallic electrocatalysis, photocatalysis, sensing, and nonlinear optics applications.

Automated summary

This study reports a simple and scalable gas-phase approach for the simultaneous synthesis and deposition of heterometallic porphyrin conjugated polymer thin films. The oxidative chemical vapor deposition (oCVD) reaction of different metal cations chelated with 5,15-(diaryl) porphyrins readily forms new hetero-metalated fused porphyrin tapes. Multiple porphyrins react to easily engineer the chemical features and electronic and optoelectronic properties of the resulting highly conjugated porphyrin polymers. This gas-phase approach overcomes the limitations of conventional solution-based approaches and has potential applications in various fields.