The reaction between enantiopure amino acid amides and metal-coordinated isocyanides such as cis-[Cl2M(CNR)2] (M = Pd, Pt) and [ClAu(CNR)] affords chiral acyclic diaminocarbene complexes in 64 to 91% yields with full retention of configuration at stereogenic centers. Structural analysis of the representative Pdii complexes revealed isostructural enantiomeric pairs with slightly distorted square-planar geometry, featuring labile Pd-Cl bonds trans to the ADC ligand.

A series of ESIPT-capable IrIII-(acyclic diaminocarbene species) (ESIPT = Excited-state intramolecular proton transfer) exhibiting strong photoluminescence properties is described. The emission profile is strongly influenced by the nature of the azaheterocyclic fragment in the diaminocarbene ligand: pyrazine-derived species display phosphorescence bands red-shifted by approximately 100 nm compared to their pyridine analogues. This redshift is attributed to the luminescence of tautomerized species formed via an ESIPT process, wherein the iridium center enhances the basicity of the pyrazine ring, facilitating proton transfer from the Ccarbene-NH groups. This interpretation is supported by the solvatochromic emission behavior of complexes prepared and corroborated by density functional theory calculations. Prepared IrIII-(acyclic diaminocarbene species) complexes represent the first example of metal-organic luminophores in which the ESIPT mechanism involves direct participation of the metal center, resulting in orange emission.

A series of Pt(II) N^N^C pincer complexes bearing isocyanide-styrene ligand in the fourth position was synthesized and their photophysics was studied in detail. In solution the complexes exhibit phosphorescence from 3MLCT excited state, whereas in solid state due to crystal packing effects all but one complexes display 3MMLCT emission accompanied by a considerable red shift of emission band, which may be ascribed to formation of binary aggregates with short Pt–Pt contacts. The styrene function of the isocyanide ligand allows complexes copolymerizing with polyvinylpyrrolidone via RAFT chemistry to give amphiphilic block copolymers with the hydrophobic block consisting of a few “back-to-back” copolymerized platinum complexes. In organic solvent, the copolymers exist as isolated molecular entities showing a limited intramolecular aggregation of the platinum chromophores analogous to their behavior in the solid state. On the contrary, in aqueous media hydrophobicity of the platinum containing blocks provokes formation of micellar type nanospecies, demonstrating intermolecular aggregation of the platinum chromophores with tighter contacts of the platinum centers and multiple character of the aggregates. This behavior results in much stronger red shift of emission into NIR area that makes the copolymers promising for application in biological experiments as NIR emitting probes.

A novel and concise approach to rare 2,3,5-triamino-imidazole scaffolds via Ni-catalyzed coupling of alkylisocyanides and N,N'-diarylguanidines has been developed. This reaction is characterized by mild conditions (thermal or visible light activation), a wide substrate scope, and high efficiency. A plausible mechanism for the formation of the corresponding adducts is proposed. The testing of these compounds against pathogens of the ESKAPE panel showed a high activity with minimum inhibitory concentration up to 0.38 μg/mL.

A novel and concise approach to rare 2,3,5-triamino-imidazole scaffolds via Ni-catalyzed coupling of alkylisocyanides and N,N '-diarylguanidines has been developed. This reaction features include mild conditions (thermal or visible light activation), a wide substrate scope, and high efficiency. The coupling proceeds through a NiII/NiIV catalytic cycle, involving two-electron aerobic oxidation and the sequential insertion of two isocyanide units into Ni-N bonds.Testing these compounds against pathogens of the ESKAPE panel showed their high activity with a minimum inhibitory concentration down to 0.38 mu g/mL.

The arylation of isonitriles by diaryliodonium salts under photoredox conditions has been proposed for the first time. The suggested procedure allows preparing the broad range of N-substituted arylamides using both symmetric and unsymmetric diaryliodonium salts in mild conditions. The plausible mechanism for the reaction and the selectivity of aryl transfer in case of asymmetrical iodonium salts was studied.

The arylation of isonitriles by diaryliodonium salts under photoredox conditions has been proposed for the first time. The suggested procedure allows preparing a broad range of benzamides using both symmetric and unsymmetric diaryliodonium salts under mild conditions. A plausible mechanism for the reaction and the selectivity of aryl transfer (in case of unsymmetrical iodonium salts) were studied.

A series of cyclometalated platinum(II) complexes bearing neutral isocyanide or acyclic diaminocarbene ancillary ligands were designed and developed. Their photophysical properties were systematically studied in different polymer systems: poly(methyl methacrylate), polystyrene, poly(isobornyl acrylate), and copolymers based on them. The dependence of luminescent characteristics on the concentration of the doped complex (0.5-10 wt %), composition, and properties of the polymer material was investigated as key factors for the measurement of quantum yields, excited-state lifetimes, and spectral profiles in routine studies.

Halogen bonding (HaB) traditionally occurs between electrophilic halogen donors and nucleophilic acceptors, yet this study reveals a phenomenon wherein anionic iodide ligands demonstrate an electrophilic behavior in platinum(IV) complexes, directly contradicting their inherent nucleophilic nature. Crystallographic analysis of trans-[PtI4(CNCy)2], [PtI4(phen)]·I2, and trans-[PtI4(SMe2)2], combined with molecular electrostatic potential (ESP), quantum theory of atoms in molecules (QTAIM), natural bond orbital (NBO), and electron localization function (ELF) analyses, demonstrates that platinum(II) oxidation to platinum(IV) transforms coordinated iodides from HaB acceptors to HaB donors. This transformation occurs through positive σ-hole development at iodide ligands, with ESP values shifting from negative (-9.6 kcal/mol) in platinum(II) to positive (+1.9 kcal/mol) in platinum(IV) complexes. Energy decomposition analysis reveals that dispersion forces dominate these interactions rather than electrostatics, contrasting with classical σ-hole donors where electrostatic contributions typically prevail. Cambridge Structural Database analysis identifies 32 additional platinum(IV) structures exhibiting similar PtIV-I···Nu HaBs, demonstrating this phenomenon's widespread nature. This study reveals new opportunities for controlling noncovalent interactions through metal oxidation state manipulation.

The clinical efficacy of first-line oxaliplatin-based treatments in metastatic colorectal cancer (CRC) is universally limited by acquired resistance, a process driven by metabolic plasticity that allows tumors to dynamically reprogram their energy metabolism for survival. To exploit this vulnerability, we developed a novel organometallic scaffold based on palladium(II) complexes bearing acyclic diaminocarbene ligands. The complexes exhibit potent, low-micromolar antiproliferative activity against glycolytic CRC models and, crucially, display undiminished efficacy against oxaliplatin-resistant cells. We establish that their antiproliferative action hinges on the formation of stable H-bonded lipophilic cations under physiological conditions, which selectively target mitochondria of metabolically dysregulated cancer cells. This triggers a critical surge in mitochondrial lipid peroxidation, culminating in a regulated cell death that adapts to the cellular context, manifesting as either apoptosis or non-apoptotic death depending on the metabolic and redox status of the tumor cell.

Halogen bonding (HaB) serves as a directional noncovalent interaction between electrophilic halogen donors and nucleophilic acceptors. This study demonstrates the unique role of thiocyanate nitrogen as a HaB acceptor in the supramolecular assembly of transition metal complexes. Pt(ii)-thiocyanate complexes featuring halogen-substituted aryl isocyanides [Pt(ppy)(SCN)(CNAr)] (ppy = 2-phenylpyridinato-C2,N; Ar = C6H3-2-I-4-Br 4, C6H3-2,4-I25, C6H3-2,4-Br26) were synthesized and fully characterized (HR ESIMS, IR, NMR, UV-vis, luminescence). Solution studies revealed a dynamic S/N-thiocyanate isomer equilibrium, while crystallization yielded exclusively S-coordinated solvates (4SCHCl3, 5SCHCl3, 6SMeNO2). X-ray diffraction confirmed isomorphic structures stabilized by directional C-X & ctdot;NCS (X = Br, I) HaBs, with the thiocyanate nitrogen acting as the preferred acceptor despite its coordination to platinum. Theoretical analyses (DFT, QTAIM, NCIplot, ELF, NBO) validated the sigma-hole-driven interactions, revealing binding energies of 1.61-4.07 kcal mol-1. A Cambridge Structural Database survey underscores the rarity of such N & ctdot;X contacts in metal-thiocyanate systems compared to prevalent S & ctdot;X interactions. These findings establish thiocyanate nitrogen as an underutilized supramolecular synthon for crystal engineering of metal-organic materials.

Invited for the cover of this issue are Tatiyana Serebryanskaya, Mikhail Kinzhalov and co-workers at St. Petersburg State University, the Research Institute for Physical Chemical Problems, Belarusian State University, Togliatti State University and Blokhin National Medical Research Center of Oncology. The image depicts the shield of Pallas Athena with the structure of a palladium carbene complex that protects against triple-negative breast cancer. Read the full text of the article at 10.1002/chem.202400101.

A series of gold(I) monoisocyanide [AuCl(C6H4–4-X)] (X = Cl (IIa), Br (IIb), I (IIc) and bis-isocyanide [Au(C6H4–4-X)2](PF6) (X = Cl (IIIa), Br (IIIb), I (IIIc) complexes were prepared by the reaction of [AuCl(Tht)] (Tht = tetrahydrothiophene) with the specified isocyanide. The molecular structure of IIa – IIc was established by X-ray diffraction (CCDC no. 2253450 (IIa), 2253447 (IIb), 2253448 (IIc)). The crystals of IIb and IIc are isostructural; they were found to have several types of intermolecular interactions, particularly, C–X⋯Cl – Au halogen bonds, π-hole (CCNR) ⋯ (Au) interactions, and Au⋯Au aurophilic contacts, which form together a two-layer 2D supramolecular polymer. The crystals of IIb, IIc and IIIa, IIIb exhibit phosphorescence at room temperature; compounds IIa and IIIc do not possess luminescent properties; and mechanical grinding of IIa – IIc and IIIa – IIIc powders does not change the photophysical properties.

Metal-mediated self-assembly of isocyanides and methyl 4-aminopyrimidine-5-carboxylate leads to luminescent PdII and PtII complexes featuring C,N-cyclometalated acyclic diaminocarbene (ADC) ligands. The solid-state luminescent properties of these diaminocarbene derivatives are attributed to their triplet-state metal/metal-to-ligand charge-transfer (3MMLCT) nature, which is driven by attractive intermolecular M···M interactions further reinforced by the intramolecular π-π interactions even in the structure of the Pd compound, which is the first Pd-ADC phosphor reported.

Platinum(II) metalla-N-heterocyclic carbene complexes featuring pyridyl heterocyclic moiety demonstrate remarkable catalytic efficiency in alkyne hydrosilylation under green light irradiation. The photocatalytic properties of complexes are rationalised by the photo-induced charge transfer occurring in extended condensed system identified with the help of various experimental (UV/vis and emission spectroscopy, cyclic voltammetry) and theoretical methods (DFT/TD-DFT, IFCT analysis).

The article provides a review of the scientific research of Academician V.Yu. Kukushkin and his students on the reactivity of coordination compounds, metal complex catalysis, supramolecular chemistry, as well as in other areas. The recognition of the scientific contribution of Academician V.Yu. Kukushkin and his school in Russia and all over the world is highlighted. The article is dedicated to the 300th anniversary of the founding of St. Petersburg University.

In X-ray structures of the isomorphic mer-[IrX3(THT)(CNXyl)2] (X = Cl 1, Br 2; THT = tetrahydrothiophene; Xyl = 2,6-Me2C6H3-) complexes, we revealed short intermolecular contacts between the C-atom of an isocyanide methyl group and halide ligands of another molecule. Geometrical consideration of the X-ray data and analysis of appropriate DFT studies allowed the attribution of these contacts to CMe···X–IrIII (X = Cl, Br) tetrel bond. Specifically, through the application of DFT calculations and various theoretical models, the presence of tetrel bonding interactions was validated, and the contribution of the CMe···X–IrIII interaction was assessed. Furthermore, the reinforcement of the tetrel bond upon the isocyanide coordination to iridium(III) is substantiated by molecular electrostatic potential (MEP) surface calculations. This work provides the first example of metal-induced enhancement of a tetrel bond.

Cyclometallated platinum(II) complexes with the general formula [Pt(Рpy)(CNR)2]X (HРpy = 2‑phenylpyridine; R = iPr, tBu, Cy; X = BF4, OTf, PF6) containing various alkylisocyanide ligands and counterions are synthesized. The compounds are studied by elemental analysis, ESI HRMS, IR spectroscopy, and 1H, 13C1H, and 195Pt1H NMR spectroscopy. The structures of [Pt(Рpy)(CNiPr)2]BF4 and [Pt(Рpy)(CNtBu)2]BF4 are determined by XRD (CIF files CCDC nos. 2325595 and 2325527, respectively). The photophysical properties in the solution and in the solid state of the synthesized compounds are studied.