Aromaticity tetramer clusters

In the recent past, our group has explored the possibility of aromaticity in several tetramer clusters comprising of homo- and heteroatomic elements [136-138]. The... 

It is known that the aromatic molecules possess cyclic and planar structures having high chemical and structural stability. From our previous calculations it is clear that all investigated tetramer clusters have very high IP and low EA, which can be regarded as an important parameter to understand their electronic stability. Other than this, the structural stability of these clusters can be verified from their interactions with any reactive species. Benzene, which is universally accepted as a leading... 

Nigam, S. Majumder, C. Kulshreshtha, S. K., Structure and bonding of tetramer clusters theoretical understanding of the aromaticity, J. Mol. Struct. (THEOCHEM) 2005, 755,187. 

Among the recently published works, the one which showed that the cyclic structures of water clusters open up to form a linear structure above a certain threshold electric field value a was a systematic ab initio study on the effect of electric field on structure, energetics, and transition states of trimer, tetramer, and pentamer water clusters (both cyclic and acyclic) [36], Considering c/.v-butadiene as a model system, the strength and the direction of a static electric field has been used to examine the delocalization energy, the probabilities of some local electronic structures, the behavior of electron pairs, and the electronic fluctuations [37]. Another recent work performed by Rai et al. focused on the studies using the DFT and its time-dependent counterpart of effects of uniform static electric field on aromatic and aliphatic hydrocarbons [38],... 

FIGURE 1.7 Comparison of molecular orbital energy levels for the free and hydrogenated tetramer aromatic clusters. Top seven occupied levels are considered for this purpose. For clear representation, we have chosen three typical examples one each from positive (Si ), negative (Al ), and neutral(Al2Si2> clusters. (From S. Nigam, C. Majumder, S. K. Kulshreshtha, J. Mol. Struct. (TheoChem) 755, 187, 2005. With permission.)... 

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