Triiodide-Based Chair-Like Copper Complex Assembled by Halogen Bonding

Cocrystallization of the dimeric [Cu2(μ-I)2(CNXyl)4] (Xyl = 2,6-Me2C6H3, 1) and polymeric catena-[Cu(μ-I)(CNC6H3-2-Cl-6-Me)2] (2) complexes with I2 at different molar ratios between the reactants resulted in a series of (RNC)2CuI-based crystal polyiodides formed along with gradual accumulation of iodine, namely the cocrystals [1·I2]·[Cu(μ1,1-I3)(CNXyl)2]2 followed by the generation of [Cu(μ1,3-I3)(CNXyl)2]2·2I2 (5·2I2) or [Cu(μ1,1-I3)(CNC6H3-2-Cl-6-Me)2]2 and then [Cu(μ1,3-I3)(CNC6H3-2-Cl-6-Me)2]n·n/2I2. The polyiodide 5·2I2 exhibits a novel supramolecular motif─a purely inorganic halogen-bonded Cu2(μ1,3-I3)2 core in the chair conformation. The X-ray structure of 5·2I2 featuring I···I contacts was analyzed by a set of theoretical methods and attributed to moderately strong halogen bonding (from -3.2 to -3.9 kcal/mol); these interactions determine the supramolecular architecture of 5·2I2.

Sterically Hindered Tellurium(IV) Catecholate as a Lewis Acid

Sterically hindered tellurium catecholate Te(Cat³⁶)₂ (Cat³⁶ = 3,6-di-tert-butyl-catecholate) was synthesized with the reaction of amorphous Te with 3,6-di-tert-butyl-o-benzoquinone. Adducts of Te(Cat³⁶)₂ with various O- and N-donors were isolated and characterized by means of single-crystal X-ray diffraction along with IR, UV-vis, and NMR (¹H, ¹³C, and ¹²⁵Te) spectroscopies. In the crystal structure of the adduct with 2,2'-bipyridine (bipy), the unprecedented μ-κ²N,N':κ²N,N'-bridging coordination mode of bipy was observed. Various intermolecular interactions Te...O, Te...N, and Te...C in adducts were analyzed using density functional theory calculations and quantum theory of atoms in molecules analysis. The estimated strength for appropriate short contacts varies from 0.9 to 5.3 kcal/mol, and they are attractive and purely non-covalent.

Multi-Phase In Silico Discovery of Potential SARS-CoV-2 RNA-Dependent RNA Polymerase Inhibitors among 3009 Clinical and FDA-Approved Related Drugs

Proceeding our prior studies of SARS-CoV-2, the inhibitory potential against SARS-CoV-2 RNA-dependent RNA polymerase (RdRp) has been investigated for a collection of 3009 clinical and FDA-approved drugs. A multi-phase in silico approach has been employed in this study. Initially, a molecular fingerprint experiment of Remdesivir (RTP), the co-crystallized ligand of the examined protein, revealed the most similar 150 compounds. Among them, 30 compounds were selected after a structure similarity experiment. Subsequently, the most similar 30 compounds were docked against SARS-CoV-2 RNA-dependent RNA polymerase (PDB ID: 7BV2). Aloin 359, Baicalin 456, Cefadroxil 1273, Sophoricoside 1459, Hyperoside 2109, and Vitexin 2286 exhibited the most precise binding modes, as well as the best binding energies. To confirm the obtained results, MD simulations experiments have been conducted for Hyperoside 2109, the natural flavonoid glycoside that exhibited the best docking scores, against RdRp (PDB ID: 7BV2) for 100 ns. The achieved results authenticated the correct binding of 2109, showing low energy and optimum dynamics. Our team presents these outcomes for scientists all over the world to advance in vitro and in vivo examinations against COVID-19 for the promising compounds.

Chameleonic Metal-bound Isocyanides: π-Donating CuI-center Imparts a Nucleophilicity to the Isocyanide Carbon toward Halogen Bonding

In the structures of the isostructural cocrystals [CuI3(CNXyl)3]·CHX3 (X = Br, I), two adjacent CuI-bound isocyanide groups, whose carbon lone pairs are blocked by the ligation, exhibit nucleophilic properties induced...

Medicinal Chemistry of Isocyanides

In eons of evolution, isocyanides carved out a niche in the ecological systems probably thanks to their metal coordinating properties. In 1859 the first isocyanide was synthesized by humans and in 1950 the first natural isocyanide was discovered. Now, at the beginning of XXI century, hundreds of isocyanides have been isolated both in prokaryotes and eukaryotes and thousands have been synthesized in the laboratory. For some of them their ecological role is known, and their potent biological activity as antibacterial, antifungal, antimalarial, antifouling, and antitumoral compounds has been described. Notwithstanding, the isocyanides have not gained a good reputation among medicinal chemists who have erroneously considered them either too reactive or metabolically unstable, and this has restricted their main use to technical applications as ligands in coordination chemistry. The aim of this review is therefore to show the richness in biological activity of the isocyanide-containing molecules, to support the idea of using the isocyanide functional group as an unconventional pharmacophore especially useful as a metal coordinating warhead. The unhidden hope is to convince the skeptical medicinal chemists of the isocyanide potential in many areas of drug discovery and considering them in the design of future drugs.

PdII- and PtII-mediated coupling of aryl isocyanides with N-heterocyclic thiones

A Pd^II- and Pt^II-mediated reaction of aryl isocyanides with N-heterocyclic thiones results in a previously undescribed type of regioselectivity for ambident nucleophile addition to coordinated isocyanides.

Interactions of aromatic rings in the crystal structures of hybrid polyoxometalates and Ru clusters

Computational analysis for π–π interaction energies of {(arene)Ru}2+ containing complexes and relative group 5 hybrid polyoxometalates reveals different frameworks. Some perspectives on πOF materials processing and crystal engineering were discussed.

Non-Covalent Interactions in Coordination and Organometallic Chemistry

The problem of non-covalent interactions in coordination and organometallic compounds is a hot topic in modern chemistry, material science, crystal engineering and related fields of knowledge. Researchers in various fields of chemistry and other disciplines (physics, crystallography, computer science, etc.) are welcome to submit their works on this topic for our Special Issue “Non-Covalent Interactions in Coordination and Organometallic Chemistry”. The aim of this Special Issue is to highlight and overview modern trends and draw the attention of the scientific community to various types of non-covalent interactions in coordination and organometallic compounds. In this editorial, I would like to briefly highlight the main successes of our research group in the field of the fundamental study of non-covalent interactions in coordination and organometallic compounds over the past 5 years.

The halogen bond with isocyano carbon reduces isocyanide odor

Predominantly, carbon atoms of various species function as acceptors of noncovalent interactions when they are part of a π-system. Here, we report on the discovery of a halogen bond involving the isocyano carbon lone pair. The co-crystallization or mechanochemical liquid-assisted grinding of model mesityl isocyanide with four iodoperfluorobenezenes leads to a series of halogen-bonded adducts with isocyanides. The obtained adducts were characterized by single-crystal and powder X-ray diffraction, solid-state IR and ¹³C NMR spectroscopies, and also by thermogravimetric analysis. The formation of the halogen bond with the isocyano group leads to a strong reduction of the isocyanide odor (3- to 46-fold gas phase concentration decrease). This manipulation makes isocyanides more suitable for laboratory storage and usage while preserving their reactivity, which is found to be similar between the adducts and the parent isocyanide in some common transformations, such as ligation to metal centers and the multi-component Ugi reaction.

Carbon atoms of various species typically function as acceptors of noncovalent interactions when they are part of a π-system. Here, the authors report their discovery of a noncovalent halogen bond involving the isocyano carbon lone pair, which results in adducts with strongly reduced isocyanide odor.

Non-covalent sulfoxide⋯(nitrosyl group) interactions involving coordinated nitrosyl in a Ru(ii) nitrosyl complex with an α-diimine ligand: structural and computational studies

Inspection of the X-ray structure of the newly prepared Ru–nitrosyl complex bearing an α-diimine ligand revealed for the first time the π-hole interaction involving the coordinated nitrosyl group with DMSO.