Volume 46, Issue 1

Two new Zn( ii ) coordination complexes [Zn(L)(dna)(H 2 O)] ( 1 ) and [Zn(L)(glu)] 2 ·H 2 O ( 2 ) (L = 2-(4-fluorophenyl)-1 H -imidazo[4,5- f ][1,10]phenanthroline, H 2 dna = 3,5-dinitrosalicylic acid, H 2 glu = glutaric acid) have been hydrothermally synthesized and characterized by single crystal X-ray diffraction, elemental analysis, fluorescence spectrum, and infrared spectroscopy. For complex 1 , the dna 2− anion adopts μ 1 -η 1 :η 1 chelating bidentate mode to coordinate with one Zn( ii ) atom and π–π stacking interactions are formed between the L ligands. For complex 2 , glu 2− anions connect Zn( ii ) atoms to form a wavy two-dimensional layer, and the L ligands are attached on two sides of the two-dimensional layer.

In order to probe the role of Li⋯F interactions toward the stabilisation of low-coordinate lithium complexes, the four fluoroarylsilylamides [LiN(SiMe 3 )(2-C 6 H 4 F)] ( 1-Li ), [LiN(SiMe 3 )(2,6-C 6 H 3 F 2 )] ( 2-Li ), [LiN(SiMe 3 )(C 6 F 5 )] ( 3-Li ), and [LiN(SiMe 2 H)(2-C 6 H 4 F)] ( 4-Li ) have been synthesised in high yields by deprotonation of the parent amines with n BuLi. They have been comprehensively characterised by multinuclear NMR spectroscopy, and complete assignments were achieved with the help of 2D NMR data. The molecular solid-state structures of [( 2-Li ) 2 ] ∞ , [ 3-Li · Et 2 O ] 2 , and [ 4-Li ] 8 were determined by single-crystal X-ray diffraction. They feature unusual coordination patterns, notably for the formation of the polymeric [( 2-Li ) 2 ] ∞ and a unique octagonal, crown-like [ 4-Li ] 8 . In both structures, the role of Li⋯F non-covalent interactions was the key toward the building of the final architecture. It is shown that Li–F and C–F interatomic distances, along with | 1 J C,F | coupling constants, can be used as qualitative tools for the evaluation of the presence and relative strength of Li⋯F contacts.

The permeable materials known as metal–organic frameworks (MOFs) have a large porosity volume, excellent chemical stability, and a unique structure that results from the potent interactions between metal ions and organic ligands. Work on the synthesis, architectures, and properties of various MOFs reveals their utility in a variety of applications, including energy storage devices with suitable electrode materials, gas storage, heterogeneous catalysis, and chemical assessment. A topological index, which is a numerical invariant, predicts the physicochemical properties of chemical entities based on the underlying molecular graph or framework. In this article, we consider two different zinc-based MOFs, namely zinc oxide and zinc silicate MOFs. We compute 14 neighbourhood degree sum-based topological indices for these frameworks, and the numerical and graphical representations of all the aforementioned 14 indices are made.

Two lead( ii ) coordination complexes with 2-(4-fluoro-phenyl)-1 H -imidazo[4,5- f ][1,10]phenanthroline formulated as [Pb(L) 2 (tlba) 2 )] ( 1 ) and [Pb(L)(dpea)] 2 ( 2 ) (HTLBA = 2,3,4,5-tetrachlorobenzoic acid, H 2 dpea = diphenic acid) were synthesized under hydrothermal conditions. In 1 , the neighboring [Pb(L) 2 (tlba) 2 )] molecules formed into a two-dimensional (2D) layer structure with C–Cl⋯π interactions and N–H⋯O hydrogen bond interactions. For 2, Pb1 and Pb1 i ions are connected by four carboxylate groups from two dpea anions to yield a binuclear unit. Two L ligands are situated in two flanks of the dimer. The L ligands from dimers in the vicinity pile up by two π–π interactions to form a 2D supramolecular structure. Moreover, PXRD of 2 was also studied.

Transamination reactions of two different aminosilanes (trimethyl( tert -butylamino)silane and dimethyl(diamino)silane) with amines (diethylamine, pyrrolidine, tert -butylamine, iso -propylamine, and n -propylamine) are studied. For trimethyl(organoamino)silanes, the reaction of trimethyl( iso -propylamino)- or trimethyl(diethylamino)silane as aminosilanes and aniline or pyrrolidine are good starting materials to produce trimethyl(anilino)- and trimethyl(pyrrolidino)silane. The investigated equilibrium constants of the reactions of monoaminosilanes show a good correlation with quantum chemically calculated values. The reaction of two different diaminosilanes Me 2 Si(NR 1 R 2 ) 2 and Me 2 Si(NR 3 R 4 ) 2 containing different amino moieties leads to the formation of mixed diaminosilanes Me 2 Si(NR 1 R 2 )(NR 3 R 4 ) in most cases.

Palladium-based complexes with the ligand N-heterocyclic carbene have long received attention as active catalysts for many catalytic reactions. Recently, the biological activities of these air- and moisture-stable complexes have also been investigated. In our work, bis(benzimidazol-2-ylidene)palladium complexes 3a–d were synthesized by reacting benzimidazolium salts 2a–d with PdCl 2 under reflux in tetrahydrofuran for 24 h and analyzed by spectroscopy (FT-IR [Fourier transform infrared], 1 H NMR [proton nuclear magnetic resonance]) characterization, 13 C NMR [carbon-13 (C13) nuclear magnetic resonance]), and elemental analysis. The in vitro antibacterial and antifungal activities of these complexes were studied against Gram-positive and Gram-negative microorganisms, and two different fungi showed their remarkable biological potential. In addition, the analysis of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals using spectrophotometry showed that they are an antioxidant. The potent antibacterial and antioxidant activities of the synthetic complexes suggest that they are more effective antibacterial agents. Our study extends the biological relevance of palladium bis(benzimidazol-2-ylidene) complexes with antibacterial and antioxidant activities. Furthermore, the main goal of the docking simulation is to provide a detailed analysis of the interaction between the complex and the protein of interest.

A series of ruthenium( ii ) complexes with N-heterocyclic carbene (NHC) ligands of the general type (arene)(NHC)Ru( ii )X 2 (where X = halide) ( 3a–3d ) were synthesized and characterized in order to compare their antibacterial activities with benzimidazolium salts 2 . Our comparison revealed that ruthenium( ii ) NHC complexes 3 were more active than benzimidazolium salts 2 . Furthermore, the two complexes 3b and 3d had a potent inhibitory effect against acetylcholinesterase with an IC 50 of 4.52 and 4.04 g·mL −1 and against tyrosinase with an IC 50 of 20.77 and 25.84 g·mL −1 , respectively. In addition, screening of benzimidazolium salts ( 2a–2d ) and their ruthenium( ii ) complexes ( 3a–3d ) against colon carcinoma cell lines (HCT-116) and hepatocellular carcinoma cell lines (HepG-2) were studied. The obtained results revealed that complex 3a is the most active against vinblastines.

A family of chemical compounds known as metal–organic networks (MONs) is composed mainly of clusters of metal ions with organic ligands. It can increase volatility or make substances soluble in organic solvents. By using these salient features, organic compounds generate applications in material sciences for sol–gel processing. A graph’s entropy is utilized as a complexity indicator and is interpreted as the structural information content of the graph. Investigating the entropies of relationship systems is a common occurrence in discrete mathematics, computer science, information theory, statistics, chemistry, and biology. In this article, we investigated the degree-based entropies: geometric arithmetic entropy, atom bond connectivity entropy, general Randic′ entropy, and general sum connectivity entropy for MONs. Furthermore, we created tables for all expressions by using 1–10 values for the s s parameter of these entropies.

Triethylammonium dichloro[ N -[(2-oxyphenyl)methylidene]valinato]-phenyl-tin( iv ) was prepared and characterized by spectroscopic methods and single crystal X-ray crystallography. The compound consists of a triethylammonium cation and a tin complex as anion. The tin complex is composed of a tridentate O,N,O -Schiff base ligand coordinated to a SnCl 2 Ph unit. The tin atom is in distorted octahedral coordination geometry. NMR spectroscopic studies have shown that the unusual hexa-coordinated tin complex was formed as a kinetically controlled product. Storage of the solid product for several years led to a transformation into a thermodynamically stable penta-coordinated tin complex.

In this study, we characterize the structure and some topological indices of a class of random spider trees (RSTs) such as degree-based Gini index, degree-based Hoover index, generalized Zagreb index, and other indices associated with these. We obtain the exact and asymptotic distributions of the number of leaves via probabilistic methods. Moreover, we relate this model to the class of RSTs that evolves in a preferential attachment manner.

The various topological indices are helpful in predicting the bioactivity of molecular compounds in quantitative structure–activity relationship/quantitative structure–property relationship study. The Balaban index and Harary index are the distance-based indices. The sum-Balaban index is another variant of Balaban index. Harary index can be used to indicate the decay of interaction between any two atoms of molecules. Whereas, the Balaban and sum-Balaban indices can be linked with some physico-chemical properties of octanes and lower benzenoids. In this work, the closed expression of Balaban index, sum-Balaban index, and Harary index of some regular dendrimers in the form of parameter m {\rm{m}} are computed using the action of automorphism group of these dendrimers.