Biomimetic Photodegradation of Glyphosate in Carborane-Functionalized Nanoconfined Spaces.

The removal of organophosphorus (OP) herbicides from water has been studied using adsorptive removal, chemical oxidation, electrooxidation, enzymatic degradation, and photodegradation. The OP herbicide glyphosate (GP) is one of the most used herbicides worldwide, leading to excess GP in wastewater and soil. GP is commonly broken down in environmental conditions to compounds such as aminomethylphosphonic acid (AMPA) or sarcosine, with AMPA having a longer half-life and similar toxicity to GP. Metal-organic frameworks (MOFs) are excellent materials for purifying OP herbicides from water due to their ability to combine adsorption and photoactivity within one material. Herein, we report the use of a robust Zr-based MOF with a meta-carborane carboxylate ligand (mCB-MOF-2) to examine the adsorption and photodegradation of GP. The maximum adsorption capacity of mCB-MOF-2 for GP was determined to be 11.4 mmol/g. Non-covalent intermolecular forces between the carborane-based ligand and GP within the micropores of mCB-MOF-2 are thought to be responsible for strong binding affinity and capture of GP. After 24 h of irradiation with ultraviolet-visible (UV-vis) light, mCB-MOF-2 selectively converts 69% of GP to sarcosine and orthophosphate, following the C-P lyase enzymatic pathway and biomimetically photodegrading GP. Circumventing the production of AMPA is desirable, as it has a longer half-life and similar toxicity to GP. The exceptional adsorption capacity of GP by mCB-MOF-2 and its biomimetic photodegradation to non-toxic sarcosine make it a promising material for removing OP herbicides from water.

Photoactive Organo-Sulfur Polymers for Hydrogen Generation.

Herein, we report the synthesis of photoactive polymeric organo-sulfur (POS) materials. These polymers absorb light in the ultraviolet/visible and near-infrared region of the solar spectrum, and upon irradiation, they reduce water to hydrogen (H2 ). The decoration of POS materials with nitrile (-CN) groups is found to be the critical factor for enhanced interactions with the co-catalyst, Ni2 P, leading to greater H2 evolution rates compared to the nitrile-free POS material.

Sustainable and Chemoselective Synthesis of α-Aminonitriles Using Lewis and Brønsted Acid-Functionalized Nanoconfined Spaces.

α-Aminonitriles are significant components in the synthesis of biological compounds and complex drugs. Although efficient, procedures for synthesizing α-aminonitriles suffer from high loadings of expensive catalysts, long reaction times, energy-intensive conditions, and expensive, toxic solvents. Herein, we report the use of metal-organic framework Cr-MIL-101-SO3H as a catalyst for the facile synthesis of eight α-aminonitriles, five of which are reported as new molecules. We found that the presence of both open Cr3+ Lewis and -SO3H Brønsted acids in the MIL-101 pores is vital for the one-pot synthesis of α-aminonitriles. The catalytic reaction is conducted under solvent-free conditions at room temperature and a Cr-MIL-101-SO3H loading of 1% by the total mass, which is considered a sustainable synthetic pathway of α-aminonitriles. Additionally, we demonstrated for the first time that Cr-MIL-101-SO3H exhibits a high degree of catalytic chemoselectivity, differing substrates with sterically hindered and electronically withdrawn functional groups. Our study expands the existing family of α-aminonitriles and provides an intelligent strategy for the development of catalysts that can be used to synthesize functional α-aminonitriles with potential in therapeutics and health applications.