scholarly journals Molassembler: Molecular Graph Construction, Modification, and Conformer Generation for Inorganic and Organic Molecules

2020 ◽  
Vol 60 (8) ◽  
pp. 3884-3900 ◽  
Author(s):  
Jan-Grimo Sobez ◽  
Markus Reiher
2007 ◽  
Vol 72 (12) ◽  
pp. 1321-1327 ◽  
Author(s):  
Ivan Gutman ◽  
Slavko Radenkovic ◽  
Boris Furtula ◽  
Toufik Mansour ◽  
Matthias Schork

The Estrada index EE is a recently proposed molecular structure-descriptor, used in the modeling of certain features of the 3D structure of organic molecules, in particular of the degree of folding of proteins and other long-chain biopolymers. The Estrada index is computed from the spectrum of the molecular graph. Therefore, finding its relation with the spectral radius r (= the greatest graph eigenvalue) is of interest, especially because the structure-dependency of r is relatively well understood. In this work, the basic characteristics of the relation between EE and r, which turned out to be much more complicated than initially anticipated, was determined.


2021 ◽  
Author(s):  
Juris Burlakovs ◽  
◽  
Ruta Ozola-Davidane ◽  
Maris Klavins

The study reveals the development of appropriate innovative sorbents based on clay material for arsenic and p-nitrophenol sorption using iron oxy-hydroxide and surfactant modification. Natural and manufactured clay were chosen for comparison of modification efficiency to obtain the best sorption results for As (V) and p-nitrophenol. Obtained results indicate that modification of clay with iron compounds and various surfactants significantly improve the sorption capacity of newly developed materials used for sorption of inorganic and organic compounds from aqueous solutions in landfill leachates.Natural clay minerals have received a lot of attention as potential sorbents, because of their abundance, cost-effectiveness, high sorption and ion-exchange properties [1]. Clay minerals can be modified using different approaches to obtain innovative materials for application as sorbents in the removal of inorganic and organic pollutants from leachates, wastewater, groundwater and soil [2, 3]. Modification with surfactants improves hydrophobization needed if interaction with low polarity organic molecules is necessary, but chemical modification with inorganic species, e.g., hydrated iron supports the physical improvement of sorption and ion exchange process in order to benefit the treatment of media from inorganic pollutants [4]. Materials achieved better properties for specific remedial applications regarding heavy metals and metalloids, prepared organoclays from hydrophilic montmorillonite by intercalating cationic or nonionic surfactants can interact with organic molecules of differing polarity and serve as immobilizers for organic molecules and toxicants, e.g., phenols and NOCs. Further studies will reveal improved properties to benefit landfill leachate treatment, wastewater engineering and environmental remediation industries.


2016 ◽  
Vol 45 (28) ◽  
pp. 11471-11495 ◽  
Author(s):  
Yan-Xia Zhao ◽  
Qing-Yu Liu ◽  
Mei-Qi Zhang ◽  
Sheng-Gui He

Progress on the activation and transformation of important inorganic and organic molecules by negatively charged bare metal clusters as well as ligated systems with oxygen, carbon, and nitrogen, among others.


2013 ◽  
Vol 354-355 ◽  
pp. 105-112 ◽  
Author(s):  
Zhen Yuan ◽  
Yan-Xia Zhao ◽  
Xiao-Na Li ◽  
Sheng-Gui He

2001 ◽  
Vol 66 (9) ◽  
pp. 605-611 ◽  
Author(s):  
Ivan Gutman ◽  
Mirko Lepovic

Let ?v denote the degree of the vertex v of a molecular graph G. Then the connectivity index of G is defined as C (?) = G (?,C) = ? (?u?v)?, where the summation goes over all pairs of adjacent vertices. The exponent ? is usually chosen to be equal to -1/2, but other options were considered as well, especially ?=-1. We show that whereas C(-1/2) is a suitable measure of branching of the carbon-atom skeleton of organic molecules, and thus applicable as a topological index for modeling physico-chemical properties of the respective compounds, this is not the case with C(-1). The value of ? is established, beyond which C(?) fails to correctly reflect molecular branching.


ChemInform ◽  
2016 ◽  
Vol 47 (44) ◽  
Author(s):  
Yan-Xia Zhao ◽  
Qing-Yu Liu ◽  
Mei-Qi Zhang ◽  
Sheng-Gui He

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