Metal-free catalysis for electrocatalytic hydrogen evolution from water is very demanding for the production of sustainable and clean fuel. Herein, we report the synthesis of a porphyrin-based metal-free covalent organic polymer (TpPAM) through a simple condensation between triformyl phloroglucinol (Tp) and 5,10,15,20-tetra(4-aminophenyl)-21H,23H-porphyrin (PAM). The as-prepared porous TpPAM exhibited superior activity for the hydrogen evolution reaction (HER) current density of 10 mA cm −2 at a low overpotential of 250 mV and a small Tafel slope of 106 mV decade −1 , which are better than those of related metal-free electrocatalysts. The high HER activity of TpPAM was investigated in-depth via theoretical density functional theory (DFT) calculations. The theoretical findings were correlated with the experimental results, and these were in good agreement for high HER catalytic efficiency of the porous TpPAM polymer. The Faradaic efficiency of the TpPAMbased electrode was found to be 98%, which is very close to the ideal value of 100%, reflecting its potential for practical implementation. Moreover, the as-synthesized catalyst showed good stability by retaining 91% of the initial current density after 1000 cycles.

A [2 + 2] Schiff base type condensation between 5,10,15,20-tetrakis(4-aminophenyl)porphyrin (TAP) and 1,3,6,8-tetrakis (4-formylphenyl) pyrene (TFFPy) under solvothermal condition yields a crystalline, quasi-two-dimensional covalent organic framework (SB-PORPy-COF). The porphyrin and pyrene units are alternatively occupied in the vertex of 3D triclinic crystal having permanent microporosity with moderately high surface area (∼869 m g) and promising chemical stability. The AA stacking of the monolayers give a pyrene bridged conducting channel. SB-PORPy-COF has been exploited for metal free hydrogen production to understand the electrochemical behavior using the imine based docking site in acidic media. SB-PORPy-COF has shown the onset potential of 50 mV and the Tafel slope of 116 mV dec. We expect that the addendum of the imine based COF would not only enrich the structural variety but also help to understand the electrochemical behavior of these class of materials.

Covalent organic frameworks (COFs) promise several benefits as materials in terms of gas adsorption, for use in optoelectronic devices, etc.

With the aim of opening an efficient access to large and sterically crowded polycyclic arenes as well as improving insight into the geometrical preferences of the Scholl reaction, a versatile synthesis strategy has been developed to form a family of flexible yet strongly crowded substrates for multiple dehydrocyclizations. Their intramolecular Scholl reactions lead with high selectivity either to considerably twisted species where the initial C3 symmetry is maintained, or to strongly rearranged products where the formation of multiple [6]helicene fragments is avoided by the formation of unusual hexa[7]circulene moieties under loss of the C3 symmetry.