Translate this page into:
Topological aspects of metal-organic structure with the help of underlying networks
⁎Corresponding author. imrandhab@gmail.com (Muhammad Imran)
-
Received: ,
Accepted: ,
This article was originally published by Elsevier and was migrated to Scientific Scholar after the change of Publisher.
Abstract
Metal–organic structures/Networks (MONs) are useful in modern chemistry. It is common to use as a storehouse for the storage of gases, it plays a role in the separation of gases and purification. The most important feature of MONs is that it acts as a predecessor for the development of a large number of nanostructures. Furthermore, MONs reflect very useful chemical-physical properties, changing organic ligands, exchanging of ions, etc. The method used to forecast the natural behaviors among the chemical-physical specifications of the chemical compounds in their primitive network is known as topological indices or TIs. This numerical quantity is used in the method of forecasting. TIs of MONs shows a key role in the environmental and theoretical pharmacology and chemistry. Line graphs also have powerful applications in chemistry and predicting the boiling point of cycloalkanes. In this paper, we study Randić, atom bound connectivity, geometric arithmetic, Zagreb, Multiplicative Zagreb, redefined Zagreb indices and Zagreb coindices for line graph of first organic network and second organic network .
Keywords
Metal–organic network
Chemical compounds
Topological indices
Line graph
1 Introduction
Graph theory plays a significant role in modern chemistry. In chemical graph theory, the atoms of molecules referred to as vertices, and chemical bonds between atoms referred to as edges. Graph theory provides the fundamentals tools to predict the properties of chemical networks. A topological index is a special tool that is used to describes the properties of chemical networks such as melting, flash and boiling points, temperature, tension, pressure, retention times, partition coefficient, the heat of formation, the heat of evaporation, and density (Matamala and Estrada, 2005; Rker and Rücker, 1999; Diaz et al., 2007; Gutman, 1994). Topological indices (TIs) are also associated with quantitative structure–activity relationship (QSAR) and quantitative structure–property relationship (QSPR) (Devillers et al., 1997; Gutman and Polansky, 1986). Degree-based and distance-based are the two major TIs. First time in 1957, Wiener used the distance-based TI to compute the boiling points of paraffin (Wiener, 1947).
There are many research work related to TIs most recent are following, on the edge dividing method implemented for a molecular structure (Gao and Farahani, 2015) discussed by Gao and Farahani, Gao et al. and Shao et al. discussed several atom bond analysis in Gao et al. (2016), Shao et al. (2018), topological indices on a network of honeycomb Hayat et al. (2015) studied by Hayat et al., reverse method of computing topological indices implemented in Gao et al. (2018), Nadeem et al. (2016), computed TIs of the line graphs of two-dimensional lattice, nanotorus and nanotube of with the operation of subdivision. Shabbir et al. (2020), worked on the two different nanotubes and computed the edge version of degree-based TIs. Baig et al. (2015), computed the TIs of poly-oxide, poly-silicate, DOX, and DSL networks. Nadeem et al. (2019), calculated the TIs of para-line graphs of V-phenylene nanostructures. Gutman and Estrada (1996) studied the TIs of the acyclic molecular graph and as well as on the line graph of the acyclic molecular graph and observed that the Wiener index (WI) of the molecular graph and the WI of the line graph differ by just a constant, some recent article on different topological indices and considering chemical structures we refer (Guirao et al., 2020; Cai et al., 2020; Jahanbani et al., 2020; Nadeem et al., 2019; Shabbir et al., 2020; Zheng et al., 2020).
In 2019, Wasson et al. (2019) proposed the idea of linker competition with a framework of metal–organic network for the topological perspectives. Furthermore, a fast hydrogen detecting device introduced by Tea et al. (2017) containing organic ligands and metal recognized as the metal–organic network (MON) which is able to identify the molecular hydrogen stages within seven seconds when it will be less than one percent.The MONs also show the physical and chemical properties such as changing organic ligands (Eddaoudi, 2002) and post-synthetic ligand (Min et al., 2012). The MONs are very useful devices for storage, the forerunner for the formation of many nano-structures (Min et al., 2017).
Let be a simple, without loop and connected molecular graph with vertex set and edge set . Let the order of molecular graph is and size is . The degree of a vertex a is a total number of vertices adjacent to a. A line graph of graph is a graph that having order m and two vertices having common neighborhood in iff their corresponding edges are adjacent in .
2 Methodology of computing topological indices
The concept of a line graph is not very new in chemical graph theory and the applications of line graph can be found in chemistry such as quantitative structure–activity relationship (QSAR) and quantitative structure–property relationship (QSPR) could be developed on the basis of TIs of line graph (Gutman and Tomovic, 2000), predict the boiling points of Cyclone-alkalies (Gutman and Tomovic, 2001), and predicting the surface tension of alkanes (Gutman et al., 1997). Following are some of the formulas of topological indices which are discussed in this work along with their citations.
The Randić index
(Randić, 1975) for a graph
defined as:
3 Results of the Topological Indices of line graph of organic network
In this section, we will discuss about line graph of first metal–organic network
. The first metal organic network discussed in Hong et al. (2020) and line graph of first organic network
is shown in Fig. 1. In this paper, we represents the line graph of metal organic network
as
. The order of
is
and size of
is
. There are seven different types of edges in
on the bases of different degree of end vertices. We have
Let be a line graph of first metal–organic compound network with . Then general Randić indices are
Using formula from Eqs. (1), (19) and (20), the general Randić indices are computed as bleow, for , □
Let be a line graph of first metal–organic compound network with . Then the atom bond connectivity and geometric arithmetic indices are;
Using formulae from Eqs. (2), (3), (19) and (20), the atom bond connectivity and geometric arithmetic indices computed as below, □
Let be a line graph of first metal–organic compound network with . Then the first, second Zagreb and hyper-Zagreb indices are,
Using formulae from Eqs. (4), (5), (6), (19), and (20) for the first, second Zagreb and hyper-Zagreb indices respectively. □
Let be a line graph of first metal–organic compound network with . Then the first and second Zagreb coindices are,
Using formula from either Eqs. (7), (8) or (9), (10) with Eqs. (19) and (20), the first and second Zagreb coindex is computed as below, □
Let be a line graph of first metal–organic compound network with . The first and second multiplicative Zagreb indices are
Using formula from Eqs. (11), (12) with Eqs. (19), and (20) the first and second multiplicative Zagreb index is computed as: □
Let be a line graph of first metal–organic compound network with . Then the forgotten, augmented Zagreb and Balaban indices are,
Putting Eqs. (19), (20) in the formula from Eqs. (13)–(15), the results computed as: □
Let be a line graph of first metal–organic compound network with . Then the first, second and third redefine Zagreb indices are,
Using concept in Eq. (19), value in Eq. (20) and formula from Eqs. (16)–(18), the results of first, second and third redefine Zagreb indices are computed as: □

- Line grapph of metal–organic network
.
4 Results of the Topological Indices of line graph of organic network
In this section, we will discuss about line graph of second metal organic network
. The second metal organic network has also discussed in Hong et al. (2020) and line graph of second organic network
as shown in Fig. 2. In this paper, we represents the line graph of second metal organic network
as
. The order and size of
and
respectively. There are seven different types of edges in
on the bases of different degree of end vertices. We have
Let be a line graph of second metal–organic compound network with . The general Randić indices are
Using formula from Eqs. (1), (21) and (22), the general Randić indices are computed as below, when , □
Let be a line graph of second metal–organic compound network with . Then the atom bond connectivity and geometric arithmetic indices are
Using formula from Eqs. (2) and (3) along (21) and (22), the results are computed as: □
Let be a line graph of second metal–organic compound network with . Then the first, second Zagreb and hyper-Zagreb indices are
Putting Eqs. (21) and (22) in the formula from Eqs. (4), (5) and (6), the results computed as following: □
Let be a line graph of second metal–organic compound network with . Then the first and second Zagreb coindices are
Putting Eqs. (21) and (22) in the formula from either Eqs. (7), (8) or Eqs. (9), (10), the results computed as following: □
Let be a line graph of second metal–organic compound network with . Then first and second multiplicative Zagreb indices are
Using formulae from Eqs. (11) and (12) along Eqs. (21) and (22), the first and second multiplicative Zagreb indices are computed as: □
Let be a line graph of second metal–organic compound network with . Then the forgotten, augmented Zagreb and Balaban indices are
Using formula from Eqs. (13), (14), (15), (21), and (22), the results computed as: □
Let be a line graph of second metal–organic compound network with . The first, second and third redefine Zagreb indices are
Using formula from Eqs. (16), (17), (18), (22), ands (21), the results computed as: □

- Line grapph of metal–organic network
.
5 Conclusion
In this paper, we discussed some physical properties of the line graph of the first and second metal–organic network in terms of topological indices, for this we computed different TIs such as Randić, atom bound connectivity, geometric arithmetic, Zagreb, Multiplicative Zagreb, and redefined Zagreb indices for line graph of first organic network and second organic network . We also computed the first and second Zagreb co-indices for the same networks. This computational work will help the researchers to understand the chosen structure more easily and will motivate the others to focus on the organic network. The computational method considered here are useful to analyse the physico-chemical properties of stated networks, and are cost effective and time efficient.
Author Contributions
All authors contributed equally for the preparation of this article.
Data Availability Statement
All data sets presented in this study are included in the article/ Supplementary Material.
Funding
This research is supported by the UPAR Grant of United Arab Emirates University (UAEU), Al Ain, UAE via Grant No G00003271.
Declaration of Competing Interest
The authors declare no conflict of interest.
References
- On topological indices of poly oxide, poly silicate, DOX, and DSL networks. Can. J. Chem.. 2015;93(7):730-739.
- [Google Scholar]
- Highly discriminating distance-based topological index. Chem. Phys. Lett.. 1982;89:399-404.
- [Google Scholar]
- The smallest graphs, trees, and 4-trees with degenerate topological index. J. Mathe. Chem.. 1983;14:213-233.
- [Google Scholar]
- On Ve-degree and Ev-degree based topological properties of silicon carbide II[p, q] Polycyclic Aromat. Compd. 2020
- [Google Scholar]
- Prediction of partition coefficients using autocorrelation descriptors. SAR and QSAR in environmental research. Environ. Resp.. 1997;7:151-172.
- [Google Scholar]
- Medicinal chemistry and Bioinformatics Current trends in drugs discovery with networks topological indices. Current Top. Med. Chem.. 2007;7(10):1015-1029.
- [Google Scholar]
- Vertex-weighted Wiener polynomials for composite graphs. Ars Mathe. Contemporary. 2008;1:66-80.
- [Google Scholar]
- Systematic design of pore size and functionality in isoreticular MOFs and their application in methane storage. Science. 2002;5554(295):469-472.
- [Google Scholar]
- An atom-bond connectivity index, modeling the enthalpy of formation of alkanes. Indian J. Chem.. 1998;37:849-855.
- [Google Scholar]
- Degree-based indices computation for special chemical molecular structures using edge dividing method. Appl. Mathe. Nonlinear Sci.. 2015;1(1):94-117.
- [Google Scholar]
- Generalized atom-bond connectivity analysis of several chemical molecular graphs. Bul. Chem. Commun.. 2016;48(3):543-549.
- [Google Scholar]
- Some reverse degree-based topological indices and polynomials of dendrimers. Mathematics. 2018;6(214):1-20.
- [Google Scholar]
- On valency-based molecular topological descriptors of subdivision vertex-edge join of three graphs. Symmetry. 2020;12(6):1026.
- [Google Scholar]
- Selected properties of the schultz molecular topological index. J. Chem. Informat. Model.. 1994;34(5):1087-1089.
- [Google Scholar]
- The first Zagreb index 30 years after. Match Community Mathe. Comput. Chem.. 2004;50:83-92.
- [Google Scholar]
- Topological indices based on the line graph of the molecular graph. J. Chem. Informat. Comput. Sci.. 1996;36:31-33.
- [Google Scholar]
- Mathematical Concepts in Organic Chemistry. New York, USA: Springer-Verlag; 1986.
- On the application of line graphs in quantitative structure property studies. J. Serbian Chem. Soc.. 2000;65(8):577-580.
- [Google Scholar]
- Modeling boiling points of cyclo-alkanes by means of iterated line graph sequences. J. Chem. Informat. Comput. Sci.. 2001;41:1041-1045.
- [Google Scholar]
- Graph theory and molecular orbitals., Total -electron energy of alternant hydrocarbons. Chem. Phys. Lett.. 1972;17:535-538.
- [Google Scholar]
- Application of line graphs in physical chemistry. Predicting surface tension of alkanes. J. Serbian Chem. Soc.. 1997;62
- [Google Scholar]
- Computing topological indices of honeycomb derived networks. Romanian J. Informat. Sci. Technol.. 2015;18:144-165.
- [Google Scholar]
- Degree-based topological invariants of metal-organic networks. IEEE Access. 2020;8:68288-68300.
- [Google Scholar]
- Generalised topological indices: Optimisation methodology and physico-chemical interpretation. Chem. Phys. Lett.. 2005;410(4–6):343-347.
- [Google Scholar]
- Post synthetic Ligand and Cation Exchange in Robust Metal-Organic Frameworks. J. Am. Chem. Soc.. 2012;134:18082-18088.
- [Google Scholar]
- Study suggests choice between green energy or economic growth. Green Energy Environ.. 2017;2(8):218-245.
- [Google Scholar]
- On topological properties of the line graphs of subdivision graphs of certain nanostructures. Appl. Mathe. Comput.. 2016;273:125-130.
- [Google Scholar]
- Topological indices of para-line graphs of V-phenylenic nanostructures. Open Mathe.. 2019;17(1):260-266.
- [Google Scholar]
- Relation between phenylene and hexagonal squeez using harmonic index. Int. J. Graph Theory. 2013;1:116-121.
- [Google Scholar]
- On topological indices, boiling points, and cycloalkanes. J. Chem. Informat. Comput. Sci.. 1999;39(5):788-802.
- [Google Scholar]
- On edge version of some degree-based topological indices of [p, q] and [p, q] nanotubes. Polycyclic Aromatic Comp. 2020
- [Google Scholar]
- On the maximum ABC index of graphs with prescribed size and without pendent vertices. IEEE Access. 2018;6:27604-27616.
- [Google Scholar]
- The hyper-Zagreb index of graph operations. Iranian J. Mathe. Chem.. 2013;4(2):213-220.
- [Google Scholar]
- Composite nanowires for fast responding and transparent hydrogen sensors. Am. Chem. Soc. Appl. Matter Interf.. 2017;9(45):39464-39474.
- [Google Scholar]
- Topological index based on the ratios of geometrical and arithmetical means of end-vertex degrees of edges. J. Math. Chem.. 2009;46:1369-1376.
- [Google Scholar]
- Linker competition within a metal-organic framework for topological insights. Inorg. Chem.. 2019;58(2):1513-1517.
- [Google Scholar]
- Structural determination of paraffin boiling points. J. Am. Chem. Soc.. 1947;69(1):17-20.
- [Google Scholar]
- Polypyrrole hollow microspheres with boosted hydrophilic properties for enhanced hydrogen evolution water dissociation kinetics. ACS Appl. Mater. Interf.. 2020;12(51):57093-57101.
- [CrossRef] [Google Scholar]