the first geometric-arithmetic index was introduced in the chemical theory as the summationof 2 du dv /(du  dv ) overall edges of the graph, where du stand for the degree of the vertexu. in this paper we give the expressions for computing the first geometric-arithmetic index ofhexagonal systems and phenylenes and present new method for describing hexagonal systemby corresponding a simple graph...

In this study, an effort has been made to analyze the aromaticity of oligomers phenylenes and thiophenes, with presence absence linkers using Nucleus-Independent Chemical Shift (NICS) as a descriptor. The relation between HOMO–LUMO gaps, reorganization excitation energies respective NICS values employed develop structure-aromaticity-conjugation spectroscopy relationship (SACSR). Results show th...

We present the first helicene carbon nanoohop that integrates a [6]helicene into [7]cycloparaphenylene. The endows nanohoop with chiroptical properties and configurational stability typical for higher helicenes, while radially conjugated seven para-phenylenes largely determine optoelectronic properties. structure of was unambiguously characterized by NMR, MS X-ray analysis revealed it possesses...

The asymmetric synthesis of a chiral, nonracemic π-conjugated system with D2 point group of symmetry, dodecaphenylene 4 is described. In the key step, (−)-sparteineand Cu(II)-mediated oxidation of 2,2′-dilithio-1,1′-biaryls in ether gives the corresponding dimers, tetra-o-phenylenes, in 80% isolated yields and 50–60% ee’s. X-Ray crystallography confi rms the structure of rac-4 and its molecular...

The first geometric-arithmetic index was introduced in the chemical theory as the summation of 2 du dv /(du  dv ) overall edges of the graph, where du stand for the degree of the vertex u. In this paper we give the expressions for computing the first geometric-arithmetic index of hexagonal systems and phenylenes and present new method for describing hexagonal system by corresponding a simple g...

Let $$G =(V_{G}, E_{G})$$ be a simple connected graph with its vertex set $$V_{G}$$ and edge $$E_{G}$$ . The Mostar index Mo(G) was defined as $$Mo(G)=\sum \limits _{e=uv\in E(G)}|n_{u}-n_{v}|$$ , where $$n_{u}$$ (resp., $$n_{v}$$ ) is the number of vertices whose distance to u v) smaller than v u). In this study, we determine first three minimum indices tree-like phenylenes characterize all at...