Theoretical Study On The Structure And Physical And Chemical Properties Of Binary Carbon Groups Containing Group ⅢA Elements

Heteroatom-doped carbon clusters have attracted much attention both experimentally and theoretically since these species have been discovered in the interstellar medium and in the atmosphere of some planets. Some of them have been synthesized in the laboratory and they are mostly stable under normal conditions. A deep investigation of the properties of the doped carbon clusters is necessary because the hetero-atoms are expected to play a special role in their physical and chemical property. In addition, studies on heteroatom-doped carbon clusters can also help us to understand their stabilities, reveal their formation mechanism, guide their interesting application and elaborate new types of materials.A theoretical study of a series Heteroatom -doped carbon clusters CnX/CntX+/CnX(X =Ga,In,T1; n=1-10) has been systematic studied with density functional theory (DFT) met hod at the B3LYP/6-311+G* and LANL2DZ level. The computed properties include e quilibrium geometries, electronic energies, vibrational frequencies, dipole moments, relat ive stabilities, binding energies, adiabatic ionization potential, adiabatic electronic affinit y, fragmentation energies, magnetic properties and polarization rate for individual spe cies. The main results are as follows:(1) According to structural optimization and frequency calculations, shows, except for smaller C2X/C2X+/C2X-(X=Ga,T1), the open-chain linear or quasi-linear isomers with the heteroatom atom bound to the end of the carbon chain are the most stable geometry in all cases. The electronic ground state is found to be a doublet state for all neutral clusters, with the only exception of the smallest XC, and the stability of the different states are in the order of doublet> quartet> sextuplet for the linear clusters. For the cationic clusters, the electronic ground state of n-even members is a triplet state, and n-odd members is a singlet state. Anionic clusters situation is just the opposite with cation’s. In the lowest-energy linear structures, the X-C bond is longer, while all our corresponding C-C bonds are shorter, It can be assimilated to moderately strong double bonds, we also observed a clear alternation in C-C distances, Codd-Ceven distances being shorter than Ceven-Codd ones. Clusters of metastable or third stable structure type must be a cyclic or fan structure, and with the increase of clusters size of this structure tability performance is more and more obvious.(2) The incremental binding energy and the second difference in energy diagram shows a strong even-odd alternation in the cluster stability for these linear structure of the neutral and anionic clusters, with their n-even members being much more stable than the adjacent odd-numbered ones, while the cationic clusters situation is just the opposite. Through the series of clusters of adiabatic ionization potential and adiabatic electronic affinity insulation further confirmed the stability about the rule of even-odd alternation. In addition, by comparing with the fragmentation energies accompanying various channels, the most favorable dissociation channels are acquired.(3) The dipole moment increases regularly with n for the ground state of all the case reported in this paper; Magnetic moment/atom of the neutral clusters has been trending down with the increase of size, the cationic and anionic clusters with the increase of the mass of family size parity obviously shocks. The cationic clusters is odd weak even stronger, " magnetic quenching" phenomenon occurred in n-even members of clusters. While the anionic clusters is just the opposite," magnetic quenching " phenomenon occurred in n-odd members of clusters. Three types of clusters of polarizability tensor average and per average polarizability of the atom show the same basic rule which Its is increas with the size.