In the present study, the proton affinity (PA) and the gas phase basicity have been calculated for a series of azine heterocycles bearing phosphazene motif by using the B3LYP/6-31 + G(d,p) method. The results indicate that the designed compounds meet remarkable superbasicity. The calculated PAs are in the range of 931-1117 kJ mol À 1 . The studied molecules have flexible structure and can be used as anion receptors through strong hydrogen bonding. The interaction of superbases 7-9 with F À , Cl À and NO 3 À anions has been also investigated using the Density Functional Theory. The anion receptors show a high affinity toward F À anion, therefore, they may be considered as selective F À receptors.

The asymmetric cross-aldol reaction of simple ketones (acetone, cyclohexanone) with isatin derivatives in the presence of crude extract from earthworms as green and effective biocatalyst proceeds easily in MeCN/H 2 O (1:1) as solvent to afford 3-hydroxy-2-oxindoles derivatives. Ten compounds were synthesized in high yields (62-88%) and moderate ee (29-42%). Structure of the synthesized compounds has been characterized on the basis of NMR spectra and CHN analysis. The ee of the obtained compounds was determined by chiral phase HPLC analysis.

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DFT calculations have been performed to study the He adsorption on the surface of Mo-doped graphene and Nb-doped graphene nanoflakes in order to evaluate the capability of studied doped graphene sheets as effective gas sensor materials. The ωB97XD (including dispersion)/6-311++G(d,p) (LanL2DZ for Mo and Nb) level of theory were utilized in this investigation. The HOMO-LUMO gap (Eg) of the Mo-doped and Nb-doped graphene structures decreased upon He adsorption on both sheets (-37.77% and -8.33%, respectively). Therefore, the electrical conductivity of both surfaces have increased. However, alteration of the Eg value in Mo-doped graphene is very higher than that of Nb-doped graphene. So, the Mo-doped graphene is more sensitive to He molecule in comparison with Nb-doped graphene and it could be used as a gas sensor material to detect He gas. Variety analyses such as natural bond orbital (NBO), density of states (DOS), electron density distribution (ED), electron localization function (ELF) and non-covalent interaction-reduced density gradient (NCI-RDG) have been carried-out in order to better evaluate the He adsorption nature on the investigated surfaces.