Current Organic Chemistry - Volume 19, Issue 3, 2015

In the present study, valence-topological charge-transfer indices are used to calculate the isoelectric point (pI). Dipoles are computed by vector semisums µvec and valence vector semisums µvec V comparing with isoelectronic series (cyclopentadiene, benzene, styrene). The valence vector semisum results intermediate between the vector semisum and experimental dipole. The steric effect stays constant and the dominatin Read More

The edge-Wiener index We (G) of a simple connected graph G is defined as the sum of distances between all pairs of edges of G. The main goal of this survey is to collect all the hitherto obtained results on the edge-Wiener index.

The Timisoara-eccentricity (TM-EC) index of a molecular graph is defined as the sum of δiεiζi over all atoms i in Γ, where ζi, εi and ζi are the degree, eccentricity and the number of atoms at distance εi from atom i. The topological efficiency index of ζ is defined as ρ = 2W / Nw , where W denotes the Wiener index, w is the minimal vertex contribution and N is the number of carbon atoms. This paper is devoted to the study Read More

This work presents chemical applications of topological methods in various sectors, from small molecule to biological systems, in studying for example enzyme-catalyzed reaction, protein folding kinetics, DNA sequence characterization. Topological descriptors participate to QSAR/QSPR models and, furthermore, are able to individuate the regions which are stabilized (or, vice versa, made reactive) by certain topological i Read More

We consider generalization of the terminal matrix of Zaretsky, in which only distances are listed between terminal vertices of acyclic graphs, to a condensed matrix for cyclic and polycyclic systems. Some 50 years ago Zaretsky has proved that the distance matrix between terminal vertices of acyclic graphs allows full reconstruction of the graph. We consider the question: Is there a subset of vertices in cyclic and polycyclic grap Read More

Herein, poly(ethylene glycol) and azobenzene are used as thermo- and photo-sensitive unit, respectively; and azobenzene, heptamethylene, and adamantyl are utilized as photo-responsive recognition group, second recognition group, and stopper for α-cyclodextrin to construct a novel dually thermo- and photo-responsive supramolecular system whose phase transition can be regulated by the photo-controlled selective molec Read More