Atom-Precise Ligated Copper and Copper-Rich Nanoclusters with Mixed-Valent Cu(I)/Cu(0) Character: Structure-Electron Count Relationships.

Copper homometallic and copper-rich heterometallic nanoclusters with some Cu(0) character are reviewed. Their structure and stability are discussed in terms of their number of "free" electrons. In many aspects, this structural chemistry differs from that of their silver or copper homologs. Whereas the two-electron species are by far the most numerous, only one eight-electron species is known, but more electron-rich nanoclusters have also been reported. Owing to the relatively recent development of this chemistry, it is likely that more electron-rich species will be reported in the future.

Molecular structures, chemical descriptors, and pancreatic lipase (1LPB) inhibition by natural products: a DFT investigation and molecular docking prediction.

Density functional theory (DFT) calculations and molecular docking have been carried out on natural products containing eugenol, gingerol, ascorbic acid, oleurpoein, piperine, hesperidin, quercetin, Luteolin, and curcumin in order to predict their biological activities and to analyze their pancreatic lipase inhibition. The biological activity predictions are based on the global and local chemical descriptors, namely, HOMO-LUMO gaps, chemical hardness, chemical potential, electrophilicity, dipole moment, and Fukui functions. Our findings show that the studied compounds can be divided into two groups based on the chemical descriptors; the first group is composed of eugenol, gingerol, ascorbic acid, and oleuropein and the second one is composed of piperine, hesperidin, quercetin, Luteolin, and curcumin depending on the HOMO-LUMO gaps and electrophilicity values predicting best reactivity for the second group than the first one. The frontier orbitals offer a deeper insight concerning the electron donor and electron acceptor capabilities, whereas the local descriptors resulting from Fukui functions put emphasis on the active sites of different candidate ligands. The molecular docking was performed in order to compare and identify the inhibition activity of the natural candidate ligands against pancreatic lipase which were compared to that of synthesized ones. The molecular docking results revealed that the Luteolin compound has the best binding affinity of -8.56 kcal/mol due to their unique molecular structure and the position of -OH aromatic substituents. Supplementary Information: The online version contains supplementary material available at 10.1007/s11224-023-02176-2.

Carbonylmetallates as Versatile 2-, 4- or 6-Electron Donor Metalloligands in Transition-Metal Complexes and Clusters: A Global Approach.

Carbonylmetallates [m]- , such as [MoCp(CO)3 ]- , [Mn(CO)5 ]- , [Co(CO)4 ]- , have long been successfully used in the preparation of hundreds of metal-metal bonded carbonyl complexes and clusters, in particular of the heterometallic type. We focus here on situations where [m]- can be viewed as a terminal, doubly or even triply bridging metalloligand, developing metal-metal interactions with one, two or three metal centers M, respectively. With metals M from the Groups 10-12, it is not straightforward or even impossible to rationalize the structure of the resulting clusters by applying the well-known Wade-Mingos rules. A very simple but global approach is presented to rationalize structures not obeying usual electron-counting rules by considering the anionic building blocks [m]- as metalloligands behaving formally as potential 2-, 4- or 6-electron donors, similarly to what is typically encountered with for example halido ligands. Qualitative and theoretical arguments by using DFT calculations highlight similarities between seemingly unrelated metal complexes and clusters and also entail a predicting power with high synthetic potential.

How the ascorbic acid and hesperidin do improve the biological activities of the cinnamon: theoretical investigation.

DFT/B3LYP calculations have been performed on series of molecules of natural products containing cinnamon and citrus, namely, cinnamic aldehyd, ascorbic acid and hesperidin. This theoretical investigation predicts the biological activities of mixtures between cinnamon and ascorbic acid and between cinnamon and hesperidin based on already proven values for these molecules. The strength of the intermolecular interactions is evaluated in term of energy decomposition of the total interaction energy ΔE int between molecules, which are mainly governed by electrostatic interactions. The HOMO-LUMO gaps explain that the possible charge transfer interactions that take place within the molecules are responsible for the molecular reactivity of the studied molecules. The chemical hardness, the chemical potential and the electrophilicity indexes are good indicators for biological activities showing their improvement to that of cinnamon itself. The mixture of hesperidin and cinnamon could be an excellent blood thinner with the regard to its polarity's enhancement.

Synthesis, X-ray structure, in silico calculation, and carbonic anhydrase inhibitory properties of benzylimidazole metal complexes.

Three coordination compounds of formula {M(bmim)2Cl2} were synthetised (M = Co, Zn, and Hg) and fully characterised. Each complex incorporates 1-benzyl-2-methylimidazole (bmim) as ligand. The coordination polyhedron around the metal center for all complexes has a quasi-regular tetragonal geometry. Density functional theory calculations were carried out on the title compounds and as well on hypothetical complexes (Cu, Ni), in order to elucidate their electronic and molecular structure. The calculations reproduced the Co, Zn, and Hg experimental structures and could predict stable complexes in the case of Ni(II) and Cu(II) ions. The carbonic anhydrase (CA, EC 4.2.1.1) inhibitory effects of the three complexes were investigated. Only compound {Hg(bmim)2Cl2} (3) exhibited a modest inhibitory effect against hCA I, probably due to the affinity of Hg(II) for His residues at the entrance of the active site cavity.

Experimental and theoretical investigation of cyclometallated platinum(ii) complex containing adamantanemethylcyanamide and 1,4-naphthoquinone derivative as ligands: synthesis, characterization, interacting with guanine and cytotoxic activity.

A new cyclometallated platinum(ii) complex with 1-adamantanemethylcyanamide (1-ADpcydH) and 2-[amino(2-phenylpyridine)]-1,4-naphthoquinone (1,4-NQ) ligands with the formula cis-Pt(1,4-NQ)(1-ADpcyd)(H2O) was synthesized and fully characterized. Cellular uptake, DNA platination, and cytotoxicity against human MCF-7 breast, HepG-2 liver hepatocellular carcinoma, and HT-29 colon cancer cell lines were evaluated. The interaction of guanine (G) with cis-Pt(1,4-NQ)(1-ADpcyd)(H2O) was studied by 195Pt NMR and mass spectroscopy. Furthermore, DFT calculations were performed on the complexes cis-Pt(1,4-NQ)(1-ADpcyd)(H2O) 1 and cis-Pt(1,4-NQ)(1-ADpcyd)(G) 2 using the BP86-D and B3LYP functionals, in order to gain deeper insights into the molecular and electronic structures. Decomposition energy analysis gave a clear understanding of the bonding within both complexes, showing that the interactions were governed by two-third ionic and one-third covalent characters, which were stronger between the guanine and the Pt(ii) center than those between water and the Pt(ii).

DFT and TD-DFT insights, photolysis and photocatalysis investigation of three dyes with similar structure under UV irradiation with and without TiO2 as a catalyst: Effect of adsorption, pH and light intensity.

TiO2-mediated photocatalytic degradation of three triphenylmethane dyes (basic fuchsin, acid fuchsin and Gentian violet), was investigated in aqueous suspensions in the presence and the absence of titanium dioxide P25 Degussa as photocatalyst. The photodegradation process was investigated using UV-A (365nm) and UV-C (254nm) light alone and UV-A in the presence of TiO2·The effects of various operational parameters were investigated such as: the effect of adsorption in the dark, the influence of pH, the influence of irradiation wavelength and the effect of light intensity. The study of the effect of various parameters reveals that the photolysis of dyes increases with the increase of light intensity, the degradation rate under UV-C (254nm) was found better than under UV-A 365nm. The photocatalytic degradation was found to follow the same order of adsorption. The decolorization and the degradation kinetics were found to follow the pseudo-first-order kinetics. The mineralization of dye was found to follow the same order of disappearance as the photocatalytic degradation and depended directly to its functional groups and its number of carbons. Additionally, density functional theory (DFT) was applied for calculations of both electronic structure and spectroscopic properties of the studied compounds, where the obtained results of the three dyes show that the theoretical electronic spectra and the experimental UV-visible ones are similar in shapes, positions and intensities.

Alkynyl ruthenium colorimetric sensors: optimizing the selectivity toward fluoride anion.

We report on the synthesis of alkynyl ruthenium colorimetric sensors whose receptors are constituted by thiazolidinedione, rhodanine, or barbituric heads as recognition centers for anions. As modifications in the charge density at these recognition centers affect the whole molecule, through the alkynyl ligand acting as a communicating wire, the effects of hydrogen-bonding interactions with the anions were observed with the naked eye and monitored by UV-vis absorption spectrometry. The selectivity of the sensors was improved through electronic modifications of the alkynyl ruthenium subunit: the higher the electron density at the receptor head, the higher the selectivity is. TD-DFT calculations rationalize the long-range electronic communication as a main characteristic of the alkynyl ruthenium species and as a key to improve the selectivity of alkynyl ruthenium-based sensors toward anions.

Electron-sponge behavior and electronic structures in cobalt-centered pentagonal prismatic Co11Te7(CO)10 and Co11Te5(CO)15 cluster anions.

The novel cluster anion [Co(11)Te(5)(CO)15]- ([3]-) has been isolated and structurally characterized as part of the salt [Cp*(2)Nb(CO)2][3] (Cp* = C(5)Me(5)). The cobalt-centered Co10 pentagonal prism is surrounded by a shell of two mu5-Te, three mu4-Te ligands, and 15 CO groups in terminal, symmetrical, and sigma-semibridging bonding modes. The hybrid carbonyl-telluride character of the ligand shell is reflected in the solid state by a one-dimensional assembly of polyhedral prisms along a backbone of [Cp*(2)Nb(CO)2]+ cations. Electrochemical studies reveal the presence of four redox couples of [3]n (n = -1 to -5). The electronic structures of various metal-centered and empty pentagonal-prismatic (PP) M10 clusters (M = Co, Ni) are calculated and compared to those of pentagonal-antiprismatic (PA) M10 structures. Closed-shells of 152 and 156 metal valence electrons, respectively, are found to determine the electronic structures and chemical properties of these geometries. From these considerations, magnetic properties have been predicted. They have been verified for the [Co(11)Te(7)(CO)10]- cluster anion, which exhibits a singlet-triplet gap of 0.318 kcal/mol.