Manoj Kumar Pandey

Do aziridines require Lewis acids for cleavage with ionic nucleophiles

A variety of activated aziridines were cleaved by sodium azide and sodium cyanide in aqueous acetonitrile at reflux, in the absence of any Lewis acid, to provide ring-opened products in quantitative yields. However, the reaction was sluggish in the ring opening of unactivated aziridines with sodium azide where the yields could be increased by adding 50 mol% CuCl2·2H2O. The reaction was used to synthesize chiral diamines.

Photo-induced characteristic study of the smallest fullerene fragment, 1,6,7,10-tetramethylfluoranthene as an acceptor

In the present study, a novel solution-processable 1,6,7,10-tetramethylfluoranthene (1), as the smallest fragment of fullerene, is synthesized and systematically studied for use as a non-fullerene acceptor in an organic solar cell (OSC). Molecule 1 has the potential to be synthesized on a large scale. Optical and electrochemical studies revealed that 1 has a high absorption range and an appropriate band gap, which is compatible with poly(3-hexylthiophene-2,5-diyl) (P3HT) as a donor. The morphology showed high intermixed blend with uniform distribution of donor–acceptor molecules. Steady state and time resolved photoluminescence studies showed efficient charge separation from the donor and acceptor. These studies can be confirmed by the conventional OSC device structure employing a blend of P3HT:1, which gives a power conversion efficiency (PCE) of up to 0.71% with an open circuit voltage (VOC) of 0.52 V and a fill factor (FF) of 44.89%. Despite this, the significant stability of the device, even after 60 h in open air, demonstrates that this molecule shows promising output and the result can be enhanced in the future with further optimization.

Zinc oxide nanorod clusters deposited seaweed cellulose sheet for antimicrobial activity

Seaweed cellulose was isolated from green seaweed Ulva fasciata using a common bleaching agent. Sheet containing porous mesh was prepared from the extracted seaweed crystalline cellulose along with zinc oxide (ZnO) nanorod clusters grown over the sheet by single step hydrothermal method. Seaweed cellulose and zinc oxide nanorod clusters deposited seaweed cellulose sheet was characterized by FT-IR, XRD, TGA, and SEM-EDX. Morphology showed that the diameter of zinc oxide nanorods were around 70nm. Zinc oxide nanorod clusters deposited on seaweed cellulose sheet gave remarkable antibacterial activity towards gram-positive (Staphylococcus aureus, Bacillus ceresus, Streptococcus thermophilis) and gram-negative (Escherichia coli, Pseudomonas aeruginous) microbes. Such deposited sheet has potential applications in pharmaceutical, biomedical, food packaging, water treatment and biotechnological industries.