Superatoms, due to their various applications in redox and materials chemistry, have been a major topic of study in cluster science. Superhalogens constitute a special class of superatoms that mimic...

2374 C12H9C1N2OSuent to the desired position in the benzene ring. The results of the calculations are depicted in Figs. 2(a) and 2(b) for compounds (1) and (2), respectively.Independent of the alkylation position, the general profiles of the E=f(¢) curves are similar in both diagrams. Therefore, the conformers corresponding to a planar arrangement of the benzene and thiohydantoin rings (~ about 0 and 180 °) are in energy maxima. The two absolute minima-energy conformations are those in which the benzene ring is inclined to the thiohydantoin ring at almost 90 ° for all analyzed compounds. As is clearly visible, the effect of para and meta substitution is similar and both energy minima have similar heights. The heights of maxima in ortho-substituted compounds are different; those at ~ about 180 ° being much greater. The corresponding planar arrangement of both molecules with an ortho substituent is especially unfavourable.The differences in the conformational analysis results also depend on the dialkylation position (1,2-or 2,3-). The energy differences in 1,2-dialkylation products ( Fig. 2a) are much bigger and also the positions of the extremes are slightly shifted in comparison with 2,3-analogues (Fig. 2b).Summarizing, the energy differences between the conformers and the profiles of the curves suggest that the non-planar conformations for free molecules are preferred for all 1,2-dialkylated compounds. The para and meta substitutions in 2,3-dialkylated compounds generate no restrictions in the preferences of the conformations while for ortho substitution a planar molecule (~o = 180 °) is not favoured. The planar conformation for (2p) in the solid state should therefore be a consequence of molecular packing in the crystal.

In the current decade, all countries are going to launch their National Hydrogen Energy Mission with ambitious targets in the renewable energy sector and the push for hydrogen energy will steer the world in the promising direction towards green energy. Scientists, technologists, and industrialists are searching for a suitable hydrogen storage system. Influenced by our promising recent findings on Li doped aromatic N-heterocyclic (ANH) six-membered Py-Li systems; (Py = Pyrazine, Pyrimidine, Pyridazine, and Triazine), here we have focused on isomeric oxadiazole-xLi + (x = 1, 2) templates. The hydrogen trapping ability of the systems has been studied carefully with the density functional theory (DFT) approach. The aromaticity of the systems prevails even after hydrogen adsorption and the process is quasi-molecular in nature. It justifies these templates as potential hydrogen storage material. The charge on the Li atom decreases gradually with each successive H 2 adsorption, and a charge transfer type interaction occurs from the bonding orbital (BD) of H 2 molecules to the antibonding lone pair orbital (LP*) of lithium-ion (Li + ). It is found that the molecular H 2 interacts with oxadiazole-xLi + template through ionic type bonding. Gibbs free energy changes suggest that the H 2 adsorption process is spontaneous at or below 200 K.

New Frustrated Lewis Pairs (FLPs) are designed and are attempted to activate molecular hydrogen. The new FLPs are modeled by changing the ligands in the Lewis acid (LA) part of the TPFPB (Tris(pentafluorophenyl)borane) molecule. The modifications are done by replacing the phenyl group in TPFPB with three different aromatic heterocyclic ligands. The stability and reactivity of FLPs: [(C 2 BNSHF 2 )] 3 BÀ P( t Bu) 3 , [(C 2 BNSF 3 )] 3 BÀ P-( t Bu) 3 and [C 2 BNO(CN) 3 ] 3 BÀ P(tBu) 3 is analysed in terms of the dual descriptors, NBO/Hirshfeld charges, VDE, hardness (η) and electrophilicity (ω). Although all three modeled FLPs show their capability towards activating molecular hydrogen, the [C 2 BNO (CN) 3 ] 3 BÀ P( t Bu) 3 shows better performance than the conventionally used FLP: (C 6 F 5 ) 3 BÀ P( t Bu) 3 .