Sources and processes affecting the abundances of atmospheric NH using δN over northwestern Indo-Gangetic plain.

Ammonia (NH) is the major constituent among all the reactive nitrogen species present in the atmosphere, and the most essential species for secondary inorganic aerosol formation. Recent satellite-based observations have identified the Indo-Gangetic Plain (IGP) as a major hotspot of global NH emission; however, the major sources and atmospheric processes affecting its abundance are poorly understood. The present study aims to understand the wintertime sources of NH over a semi-urban site (Patiala, 30.

Optical source apportionment of aqueous brown carbon (BrC) on a daytime and nighttime basis in the eastern Indo-Gangetic Plain (IGP) and insights from C and N isotopic signatures.

This study reports day-night and seasonal variations of aqueous brown carbon (BrC) and constituent humic-like substances (HULIS) (neutral and acidic HULIS: HULIS-n and HULIS-a) from the eastern Indo-Gangetic Plain (IGP) of India during 2019-2020. This is followed by the application of the receptor model positive matrix factorization (PMF) for optical source apportionment of BrC and the use of stable isotopic ratios (δC and δN) to understand atmospheric processing. Nighttime BrC absorption and mass absorption efficiencies (MAE) were enhanced by 40-150 % and 50-190 %, respectively, compared to the daytime across seasons, possibly as a combined effect from daytime photobleaching, dark-phase secondary formation, and increased nighttime emissions.

Bismuth(iii)-catalyzed regioselective alkylation of tetrahydroquinolines and indolines towards the synthesis of bioactive core-biaryl oxindoles and CYP19 inhibitors.

Bismuth(iii)-catalyzed regioselective functionalization at the C-6 position of tetrahydroquinolines and the C-5 position of indolines has been demonstrated. For the first time, one pot symmetrical and unsymmetrical arylation of isatins with tetrahydroquinolines was accomplished giving a completely new product skeleton in good to excellent yields. Most importantly, this protocol leads to the formation of a highly strained quaternary carbon stereogenic center, which is a challenging task.