The stability and reactivity of neutral and charged aluminium doped carbon clusters (Al1,2C2-70,±)

Abstract

The stability and reactivity of Al-doped linear and quasi-linear carbon chains (Al1,2C2-70,±) were computationally investigated using various reaction and binding energy parameters. The dissociation of the clusters was studied via the elimination of Al, C from the neutral species, Al0,+, C0,+ the cationic species, and Al0,-, C0,- from the anionic species. The stability was further examined based on electron elimination reactions, such as electron detachment from Al1,2C2-7- and ionization of Al1,2C2-7. The study proceeded by formulating a novel relative energy parameter, which was generated from the binding energy values. The lowest energy dissociation channels of Al1,2C1-70,± were the Al and Al+ elimination from the neutral/anionic and cationic clusters, respectively. Under the dissociation conditions, the even-carbon species (m = 2,4,6) AlCm (doublet), AlCm+ (triplet), AlCm- (singlet), Al2Cm (singlet), Al2Cm+ (doublet) were found to be more stable than that of the odd-carbon clusters (m = 3,5,7), irrespective of the spin states. In the case of Al2Cm-, the odd carbon clusters were found to be more stable. The stability orders based on the widely used highly endothermic C-elimination reaction were found to be significantly different. We have systematically addressed the above disparities and have commented on how to accurately predict the abundance of the species under extreme experimental conditions. The reactivity of Al1,2-doped clusters was found to be higher than the bare carbon chains. Based on the bond-strength parameters calculated using AIM analysis, the Al1,2-doping led to an activated Al-C bond rather than the carbon chains, eventually resulting in reactive meal-carbon clusters. The Al-C bonding was discussed using electron density at the Al-C bond critical points (ρAl-C), the vibrational frequency of the Al-C bond (νAl-C), bond length (rAl-C), the NBO charge on the Al atoms (qAl) and with the molecular orbital diagrams. The results of the current investigations can be highly relevant to astrochemistry, spectroscopy, material, and organometallic chemistry communities.