Abstract :
The potential applicabilities of B40 cluster and encapsulated B40 with Lithum atom (Li@B40) as chemical sensors for NOx pollutants detection are investigated by employing DFT calculations. The results indicate that NO2 and NO molecules are remarkably chemisorbed on the surface of both B40 and Li@B40 clusters. However the adsorption energies of NO2 molecule are somewhat greater than those values for NO adsorption onto the B40 cluster. Also the electronic properties of B40 and Li@B40 clusters change remarkably after NO2 chemisorption. The HOMO-LUMO energy gap of B40 cluster is considerably decreased after NO2 and NO chemisorption, but the gap energies of Li@B40 cluster are significantly enhanced after adsorption of these pollutants. Thus, B40 and Li@B40 clusters are introduced as novel promising chemical sensor for NO2 and NO pollutants due to appreciable adsorption energies and producing electronical signals
 

The electro-optical features of functionalized sumanenes with BH, NH, O or S groups is studied theoretically. The effects of substitution on the sumanene CH2 groups with hetero groups are studied using density functional theory computations. Thereafter, the lithiation effect are investigated to reveal the impact of these modifications on their electro-optical properties. Also, the electro-optical characteristics of the bowl shaped lithiated corannulene (C_20 H_10) and quadrannulene (C_16 H_8) are scrutinized through density functional theory (DFT) computations.
The obtained results show that the multilithiation of heterosubstituted sumanenes, corannulene (C_20 H_10) and quadrannulene (C_16 H_8) buckybowls is an efficient approach to enhance their nonlinear optical response and narrow their highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) energy gaps. The present results will be beneficial for further theoretical and experimental studies on the nonlinear optical (NLO) properties of lithiated buckybowl compounds.

Abstract
In this work, different isoelectronic models of C2n(BN)12-n, n=1-11 hetero-nanoclusters, are systematically investigated through DFT calculations to explore their electro-optical features. These structures are generated by replacing B-N bonds of B12N12 nanocluster by C-C segments. All of the 54 possible structures are optimized and the most stable ones are determined. The encapsulation of alkali metals (Li, Na, K) inside the stable hetero-nanoclusters are studied. The results indicate that the encapsulation of potassium atom inside them could be an effective approach to improve their electro-optical properties including HOMO-LUMO gap and first static hyperpolarizability. Thus, introducing the diffuse excess electron together with π-electron are proposed to be efficient approaches to improve their electro-optical properties. The results might open new perspectives for further development of designing novel electro-optical hybrid carbon-boron-nitride based nanomaterials.
 

The adsorption of phosgene molecule onto pristine as well as Al- and Ga-doped B12N12 and B16N16 nanoclusters is investigated using density functional theory calculations. It is found that in contrary to the pristine clusters, Al- and Ga- doped clusters effectively interact with the phosgene molecule with considerable electronic response. The HOMO-LUMO gaps of the Al-doped clusters decrease about 50% by the adsorption of phosgene molecule. Since the adsorption of phosgene onto pristine clusters is physiorption in nature, dispersion forces play important role in these interactionsand they should be considered in calculations. The obtained results for both clusters are nearly the same, which imply to this fact that the adsorption process is independent of cluster size. The obtained results introduce Al- and Ga- doped cluster as promising chemical sensors for phosgene monitoring.