Not available.Key words: Big Bang NucleosynthesisThe Himalayan Physics Vol.1, No.1, May, 2010 Page: 79-82 Uploaded Date: 29 July, 2011

Along with global economic development and population growth, the discharge of highly toxic and corrosive anthropogenic byproducts into the atmosphere or aquatic habitats creates a serious threat to human health. In order to remove such byproducts, more attention should be paid to innovative materials with high uptake capacity and performance. Metal-organic frameworks (MOFs) are crystalline, porous, hybrid materials that are made up of organic ligands as linkers and metal cluster-based nodes. Because of their beneficial features such as their large surface area, tailorable pore sizes, structural diversity, catalytic activity, and wide range of chemical and physical properties, MOFs offer significant potential as adsorbents. As a result, these materials have drawn a significant amount of attention for the capture and/or detoxification of hazardous and toxic chemicals. This review will focus on recent advancements on MOF based experimental and computational studies related to the capture of toxic gases including hydrogen sulfide (H2S), ammonia (NH3) sulfur dioxide (SO2) carbon monoxide (CO), and nitrogen oxides (NOx).

A controllable and targeted drug delivery system development is imperative and important to reduce side effects and enhance the therapeutic efficacy of drugs. Metal-organic frameworks (MOFs), an emerging type of hybrid porous materials synthesized from metal ions or clusters abridged by organic linkers. They have attracted increasing attention in the recent years owing to the unique physical structures possessed, and the potential for wide range of applications. The superior properties of MOFs, such as well-defined pore aperture, tailorable composition and structure, tunable size, versatile functionality, high agent loading, and improved biocompatibility, have made them promising candidates as drug delivery hosts. MOFs for drug encapsulation and delivery is of great interest and many very promising results have been found, indicating that these porous solids exhibit several advantages over existing systems. This review highlights the recent advances in the synthesis, functionalization, and applications of MOFs in nanodrug delivery, and has classified them using drug loading strategies.

Photochromism in some diarylethene molecules have been studied by using hybrid density functional theory using the ground state energy consideration. In particular, B3LYP functional and all electron basis set 6-311G (2d,2p) as implemented in Gaussian09 suites of program has been used to investigate the energy difference of two stable isomers of stilbene, azobenzene, cyclooctane, and 1,2, dimethylcyclohexane molecules. The energy difference is corroborated to calculate the frequencies of photons that are required to induce photochromism in these molecules in vacuum and in solvation state. The study found that the molecules exhibit photochromism at various frequency range from infra-red to ultraviolet. The binding energy per atom, charge distribution, HOMO-LUMO (Highest Occupied Molecular Orbital and Lowest Unoccupied Molecular Orbital) gap are also calculated for all the molecules in vacuum, water and ethanol solvent. The results obtained are in accordance with the experimental observations.

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