Product graphs have been gainfully used in literature to generate mathematical models of complex networks which inherit properties of real networks. Realizing the duplication phenomena imbibed in the definition of corona product of two graphs, we define Corona graphs. Given a small simple connected graph which we call seed graph, Corona graphs are defined by taking corona product of a seed graph iteratively. We show that the cumulative degree distribution of Corona graphs decay exponentially when the seed graph is regular and cumulative betweenness distribution follows power law when seed graph is a clique. We determine explicit formulae of eigenvalues, Laplacian eigenvalues and signless Laplacian eigenvalues of Corona graphs when the seed graph is regular. Computable expressions of eigenvalues and signless Laplacian eigenvalues of Corona graphs are also obtained when the seed graph is a star graph.

RSnCl3 (R = 2-phenylazophenyl) on reaction with Na2S·9H2O in a 1:1 mixture of acetone and methanol afforded a tetranuclear monoorganotin sulfide cage [(RSnIV)4(μ-S)6]·2CHCl3·4H2O (R = 2-phenylazophenyl) (1). Complex 1 crystallizes in the monoclinic space group P2/n. The molecular structure of 1 contains five-coordinate tin centers in distorted trigonal bipyramidal geometry. Complex 1 is monoorganotin sulfide derivative having a tetranuclear double-decker cage-like structure. In 1, four tin centers are bridged by a μ2-S unit affording a ubiquitous Sn–S–Sn motif among monoorganotin sulfide compounds. In addition, each tin also has intramolecular coordination to a nitrogen atom of a 2-phenylazophenyl substituent (N → Sn). The DFT calculation suggests that the complex 1 involves mainly ligand based transitions. The complex 1 based device was studied for its electrical behavior and was found to show stable, reproducible memristive behavior with an on–off ratio of 103, which suggests that the complex 1 is a promising material for memory device applications.

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