A Comparative of Quantum Mechanical Calculations on Adsorption of CClO 2 by Carbon-Carbon and Aluminum-Nitride Nanotubes

In this paper, is calculated structural optimization and interactions on surface nanotubes (AlN,CNT) and phosgene. Based on the optimized ground state geometries using B3LYP/6-31G* method, the NBO analysis of donor-acceptor (bondanti bond) interactions revealed that the stabilizationenergies associated with the electronic delocalization.

analog carbon nanotubes (CNTs).They are isoelectronic with CNTs and have been synthesized successfully by different research groups [5][6][7] .Because of their high temperaturestability, large energy gap, thermal conductivity and low thermal expansion 8 , AlNNTs and aluminum nitride nano materials are widely used in technological applications, mainly in micro and optoelectronics such as laser diodes and solar-blindltraviolet photo detectors and semiconductors 8 .Unlike CNTs, AlNNTs exhibit electronic properties and semiconductor behavior independent oflength, tubular diameter and chirality.Tuning the electronicstructures of the semiconducting AlNNTs for specific applications important in building specific electronic and mechanical devices.Phosgene is a major component of natural gas and its adsorption behavior in pores has been extensively studied.In this study, B3LYP studies of the absorption behavior of phosgene gas on nanotube were performed in terms of adsorption energy.

Computational details
In our current study, extensive quantum mechanical calculations of structure of Aluminum -Nitride nanotube [zigzag (8,0)] have been performed on a Pentium-4 based system using Gaussian 03 program 17 .At first, we have modeled and the nanotube with Nanotube Modeler package and then optimized at the B3LYP level of theory with 6-31G*basisset.After fully optimization of nanotube, we have calculated adsorption of phosgene at the level of 6-31G* theory on the outside (external) of carbon nanotube and have been reported in Table 1, and finally we calculate Natural Bond Orbital (NBO) parameters for this structure, Table 2.The BE (Binding Energy) of CCl2O on the optimized nanotubes model is calculated as follows: Where E CCl2O -AlNNTs was obtained from optimization of the adsorption CCl2O on surfaces AlN models, AlNNTs is the energy of the optimized AlNNTs structure and CNTs energy of the optimized CNT s structure and E CCl2O the energy [13] of the optimized phosgene gas.

RESULTS AND DISCUSSION
In this paper B3LYP method with 6-31G*basis set were employed to investigate the structure optimization, energy minimization of AIN, carbon nanotubes and phosgene (Fig 1 and Table 1).
To study absorption behavior of phosgene gas on AlN nanotube, we performed absorption for two sites in nanotube (outside (external) of carbon nanotube) the after a full optimization (Table 1), we found two structures of this absorption (Fig 2, 3) In the NBO analysis, in order to compute the span of the valencespace, each valence bonding NBO (AB), must in turn, be paired with a corresponding valence anticoding NBO (*AB) Namely, the Lewis -type (donor) NBO are  The anti-bonds represent unused valenceshell capacity and spanning portions of the atomic valence space that are formally unsaturated by covalent bond formation.Weak occupancies of the valence ant bonds signal irreducible departures from  These interactions (or energetics stabilizations) are referred to as 'delocalization' corrections to the zeroth-order natural Lewis structure.The most important interaction between "filled" (donor) Lewis-type NBO and "empty" (acceptor) non-Lewis isreported in Table (2,3) in Fig 3. We observed interactions between the bonding orbital () C20-C50 and H49-C29 but do not this bonding orbital for phosgene.

CONCLUSION
we have modeled the nanotube with Nanotube Modeler program and then optimized at the B3LYP level of theorywith 6-31G*basis set.After fully optimization of nanotube, we have calculated adsorption of phosgene at the levelof 6-31G*theory on outside (external) of Aluminum -Nitride nanotube.
The most important interaction between "filled" (donor) Lewis-type NBO and "empty" (acceptor) non-Lewis, weobserved between the bonding orbital () C20-C50 and H49-C29 but don't see this bonding orbital for nano tube and internal phosgene.