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In a very recent article, atomically thin two-dimensional MoS2xSe2(1-x) nanosheets have been synthesized with complete composition tunability using a temperature gradient assisted chemical vapor deposition technique [J. Am. Chem. Soc., 2014, 136, 3756]. To have a better understanding of the composition dependent tunability of the properties of this class of materials we here perform first principles calculations on the detailed electronic structure of single layered transition metal dichalcogenides MoS2(1-x)Se2x and MoS2(1-x)Te2x. The positive value of mixing energy of both MoS2(1-x)Se2x and MoS2(1-x)Te2x 2D sheets at various composition confirms their formation at some energy cost. The analysis of the composition dependent band structure and the density of states of these 2D sheets reveals certain interesting features. The band gap variation of the MoS2(1-x)Se2x nanosheets is almost linear with composition while that of MoS2(1-x)Te2x deviates slightly from linearity. We have also calculated the optical absorption spectrum of these nanosheets as a function of composition and found that the optical transitions are mainly metal d-d type spin forbidden transitions.

Phosphorus carbide (PC) has been the subject of major research efforts in recent years. In this regard, very recently, a stoichiometric metallic phosphorus carbide (β-PC) monolayer has been proposed as locally stable with one lone nonbonding electron in each C atom. Therefore, the ambiguity of coexistence of a nonbonding electron with metallic properties for β-PC is reported and hence deserves further explanation. Herein, using first-principles calculations, we have explored the stability and electronic properties of β-PC to resolve this ambiguity. The metallic behavior of β-PC is explained on the basis of electron delocalization involving P and C atoms along a zigzag chain of β-PC. We have also explored the possibility of getting a β-PC monolayer via homogeneous doping of C (P) into phosphorene (graphene) and layer exfoliation of 3D bulk PC with β-InS-like structure, which has been experimentally synthesized.

Host-guest interaction of two significant drugs, phenylephrine hydrochloride and synephrine with α and β-cyclodextrins were studied systematically. Initially two simple but reliable physicochemical techniques namely conductance and surface tension were employed to find out saturation concentration for the inclusion and its stoichiometry. The obtained 1:1 stoichiometry was further confirmed by two spectrometric methods, UV-Vis study and spectrofluorimetry. Significant shifts in IR stretching frequency also support the inclusion process. Relative stabilities of the inclusion complexes were established by the association constants obtained from UV-Vis spectroscopic measurements, program based mathematical calculation of conductivity data. Calculations of the thermodynamic parameters dictates thermodynamic feasibility of the inclusion process. Spectrofluorometric measurement scaffolds the UV-Vis spectroscopic measurement validating stability of the ICs once again. Mass spectroscopic measurement gives the molecular ion peaks corresponding to the inclusion complex of 1:1 molar ratio of host and guest molecules. The mechanism of inclusion was drawn by 1H-NMR and 2D ROESY spectroscopic analysis. Surface texture of the inclusion complexes was studied by SEM. Finally, the cytotoxic activities of the inclusion complexes were analyzed and found, Cell viability also balances for non-toxic behavior of the ICs. Moreover, all the studies reveal the formation of inclusion complexes of two ephedra free, alternatively emerging drugs (after their banned product having ephedra) SNP, PEH with α and β-CD which enriches the drug delivery system with their regulatory release without any chemical modification.

Uncertainty quantification, Bayesian statistics, the reported experimental literature, and density functional theory are synthesized to identify the active sites for the non-oxidative propane dehydrogenation on platinum catalysts. This study tests three different platinum surface models as active sites, Pt(100), Pt(111), and Pt(211), and two different methodologies for generating uncertainty, using data from four density functional theory functionals and data from the BEEF−vdW ensembles. By comparing these three surface facets using two uncertainty sources, a total of six different computational models were evaluated. Three experimental data sets, with varying numbers of reported observables, such as turnover frequencies, selectivity to propylene, apparent activation energy, and reaction orders, are calibrated and validated for these six models. This study finds no evidence for Pt(100) as the dominant active facet and finds that Pt(211) has some evidence for being the most relevant active site on the catalyst. In addition, all four functional models were excluded from final data analysis due to poor "goodness-of-fit". In contrast, the BEEF−vdW model with ensembles (BMwEs) was found to pass "goodness-of-fit" for most of the models tested. Finally, for both Pt(111) and Pt( 211), this study finds that the majority of simulations found the kinetically rate-controlling step the first dehydrogenation step from propane to C 3 H 7 *.