- Diaryliodonium Tetrachloroplatinates(II): Recognition of a Trifurcated Metal-Involving μ3?I···(Cl,Cl,Pt) Halogen Bond // Cryst. Growth Des. 2021, https://doi.org/10.1021/acs.cgd.1c00654 (Q1/IF=4.076)
Synthesis and X-ray characterization of the four diaryliodonium tetrachloroplatinates(II) [Ar1Ar2I]2[PtCl4] (Ar1/Ar2 = Ph/Ph (1), 4-Cl-C6H4/2,4,6-(MeO)3C6H2 (2), 4-Me-C6H4/2,4,6-(MeO)3C6H2 (3), Ph/2,4,6-(MeO)3C6H2 (4)) allowed the deterimination of several types of unconventional halogen-bond (HaB) patterns. The first example of a metal-involved trifurcated four-center μ3-X···(X′,X′,M) HaB is represented by the metalinvolving I···Pt HaB (the structure of 4) with iodonium cations acting as HaB donors, which is supported by two weak I···Cl HaB contacts. The structures of 1−3 display bifurcated three-center μ2-I···(Cl,Cl) HaBs with iodonium cations. DFT calculations were used to estimate the energetic features of the two types of HaB contacts. Molecular electrostatic potential (MEP) surfaces and noncovalent interaction plot index (NCIPlot) computational tools were used to evaluate the σ-holes and characterize the HaBs, respectively, in all structures. - The Isocyanide Complexes cis-[MCl2(CNC6H4-4-X)2] (M = Pd, Pt; X = Cl, Br) as Tectons in Crystal Engineering Involving Halogen Bonds // Crystals 2021, 11, 799. https://doi.org/10.3390/cryst11070799 (Q2/ IF=2.589)
The isocyanide complexes cis-[MCl2(CNC6H4-4-X)2] (M = Pd; X = Cl, Br; M = Pt; X = Br) form isomorphous crystal structures exhibiting the Cl/Br and Pd/Pt exchanges featuring 1D chains upon crystallisation. Crystal packing is supported by the C–X___X–C halogen bonds (HaBs), C–H___X–C hydrogen bonds (HB), X___M semicoordination, and C___C contacts between the C atoms of aryl isocyanide ligands. The results of DFT calculations and topological analysis indicate that all the above contact types belong to attractive noncovalent interactions. A projection of the electron localization function (ELF) and an inspection of the electron density (ED) and the electrostatic potential (ESP) reveal the amphiphilic nature of X atoms playing the role of HaB donors, HaB and HB acceptors, and a nucleophilic partner in X___M semicoordination. - Copper-Catalyzed Selective N-Arylation of Oxadiazolones by Diaryliodonium Salts // Adv. Synth. Catal. 2021, 363, 1 –12 DOI: 10.1002/adsc.202100426 (Q1/ IF=5.837)
Here, we report the method for copper-catalyzed N-arylation of diverse oxadiazolones by diaryliodonium salts under mild conditions in high yields (up to 92%) using available CuI as a catalyst. The developed method allows utilizing both symmetric and unsymmetric diaryliodonium salts bearing auxiliary groups such as 2,4,6-trimethoxyphenyl (TMP). We found that the steric effects in aryl moieties determined the chemoselectivity of N- and O-arylation of the 1,2,4-oxadiazol-5(4H)-ones. Mesityl-substituted diaryliodonium salts demonstrated the high potential as a selective arylation reagent. The structural study suggests that steric accessibility of N-atom in 1,2,4-oxadiazol-5(4H)-ones impact to arylation with sterically hindered diaryliodonium salts. The synthetic application of proposed method was also demonstrated on selective arylation of 1,3,4-oxadiazol-2(3H)-ones and 1,2,4-oxadiazole-5-thiol. - Tetrabromoethane as s-Hole Donor toward Bromide Ligands: Halogen Bonding between C2H2Br4 and Bromide Dialkylcyanamide Platinum(II) Complexes // Crystals 2021, 11, 835. https://doi.org/10.3390/cryst11070835 (Q2/ IF=2.589)
The complexes trans-[PtBr2(NCNR2)2] (R2 = Me2 1, (CH2)5 2) were cocrystallized with 1,1,2,2-tetrabromoethane (tbe) in CH2Cl2 forming solvates 1_tbe and 2_tbe, respectively. In both solvates, tbe involved halogen bonding, viz. the C–Br___Br–Pt interactions, were detected by singlecrystal X-ray diffractions experiments. Appropriate density functional theory calculations (M06/def2-TZVP) performed for isolated molecules and complex-tbe clusters, where the existence of the interactions and their noncovalent nature were confirmed by electrostatic potential surfaces (r = 0.001 a.u.) for isolated molecules, topology analysis of electron density, electron localization function and HOMO-LUMO overlap projections for clusters. - Alkylverdazyls as a Source of Alkyl Radicals for Light-Triggered Cancer Cell Death // Molecular Pharmaceutics 2021, №XX, XXX. https://doi.org/10.1021/acs.molpharmaceut.1c00780 (Q1/IF=4.939)
Two alkylated verdazyl radicals (AlkVZs) were investigated as active compounds for photoinitiated controlled MCF-7 cell death. Observed results unambiguously showed that AlkVZ could be a potential structural moiety for the design of a novel family of photodynamic therapy agents. The main advantage of the proposed substances is an oxygen-independent generation of active radicals, which play a pivotal role in the treatment of oxygen-deficient tumors. - Diaryliodonium Tetracyanidometallates Self-Assemble into Halogen-Bonded Square-Like Arrays // Crystal Growth & Design. 2022. https://doi.org/10.1021/acs.cgd.2c00175 (Q1/IF: 4.076)
Two diphenyliodonium tetracyanidometallates, [Ph2I]2[M(CN)4] (M = Ni and Pd), were prepared through anion metathesis. Their X-ray structural analyses show that the structure-defining contact for both crystals is the charge-assisted I···N halogen bond (HaB) formed between the I atom of the iodonium cations and the N atoms of the CN– ligands. These HaBs assemble the bidentate and 90°-orienting HaB donor Ph2I+ and the tetradentate, square planar, and 90/180°-orienting HaB acceptors [M(CN)4]2– into supramolecular rectangles, which further assemble into infinite chains by sharing the vertexes occupied by the [M(CN)4]2– anions. The noncovalent nature of these contacts was confirmed by density functional theory calculations (M06/def2-TZVP) followed by combined topological analysis of the electron density distribution in the quantum theory of the atoms-in-molecules approach and noncovalent interaction analysis. The philicities of the HaB partners were further verified by the analysis of electron localization function projections, electron density/electrostatic potential profiles along the I···N bond paths, natural bond orbital analysis, and the natural population analysis or atoms-in-molecules charge sums in model systems. - Zwitterionic iodonium species afford halogen bond-based porous organic frameworks // Chemical Science.2022. https://doi.org/10.1039/D2SC00892K (Q1/IF:9.969)
Porous architectures characterized by parallel channels arranged in honeycomb or rectangular patterns are identified in two polymorphic crystals of a zwitterionic 4-(aryliodonio)-benzenesulfonate. The channels are filled with disordered water molecules which can be reversibly removed on heating. Consistent with the remarkable strength and directionality of the halogen bonds (XBs) driving the crystal packing formation, the porous structure is stable and fully preserved on almost quantitative removal and readsorption of water. The porous systems described here are the first reported cases of one-component 3D organic frameworks whose assembly is driven by XB only (XOFs). These systems are a proof of concept for the ability of zwitterionic aryliodonium tectons in affording robust one-component 3D XOFs. The high directionality and strength of the XBs formed by these zwitterions and the geometrical constraints resulting from the tendency of their hypervalent iodine atoms to act as bidentate XB donors might be key factors in determining this ability. - Antifouling surface for biomedical devices: Modification of COC surface by quaternary ammonium moieties via diazonium chemistry // Applied Surface Science. 2022. https://doi.org/10.1016/j.apsusc.2022.154415 (Q1/ IF : 6.707)
Prefilled biomedical devices (PFD) are growing in the pharmaceutical market due to the ease of delivering a precise dose of protein drugs. As an appealing alternative to the fragile glass, cyclic olefin copolymer (COC) was suggested. However, in the case of COC, the stability of the drug may be negatively impacted by protein aggregation. To potentially improve the surface properties of COC for PFDs, we performed functionalization of COC with quaternary ammonium moieties (QAS) using the advantages of diazonium surface chemistry. The successful functionalization of COC using QAS-diazonium salts (QAS-DS) with different alkyl chain lengths (C4, C8, C9, C10, C12) was confirmed by Raman spectroscopy and XPS measurements. Optical and fluorescence measurements revealed the optimal length of the alkyl chain-COC-C4 for improved antibiofouling performance towards bovine serum albumin (BSA). Moreover, in contrast to glass, polypropylene (PP), and pristine COC, COC-C4 allows storing the insulin for at least 2 weeks without the changes in protein structure according to dynamic light scattering and TEM images. Additionally, diazonium functionalization allows for conserving the high permeability resistance, transparency, and mechanical stiffness. The improved stability of insulin in a COC-C4 container is explained by the formation of an additional hydration layer serving as a barrier to undesired interaction with biomolecules. - Halogen Bonding Involving Gold Nucleophiles in Different Oxidation States // Inorganic Chemistry. 2022. https://doi.org/10.1021/acs.inorgchem.2c01858 (Q1/ IF: 4.97)
A single-crystal X-ray diffraction (XRD) study of diaryliodonium tetrachloroaurates (or, in the recent terminology, tetrachloridoaurates), [(p-XC6H4)2I][AuCl4] (X = Cl, 1; Br, 2), was performed for 1 (the structure is denoted as 1a to show similarity with the isomorphic structure 2a) and two polymorphs-2a (obtained from MeOH) and 2b (from 1,2-C2H4Cl2). Examination of the XRD data for these three structures revealed 2-center C–X···AuIII (X = Cl and Br) and 3-center bifurcated C–Br···(Cl–Au) halogen bonding (abbreviated as XB) between the p-Cl or p-Br atoms of the diaryliodonium cations and the gold(III) atom of [AuCl4]?. The noncovalent nature of AuIII-involving interactions, the nucleophilicity of the gold(III) atoms, and the electrophilic role of p-X atoms of the diaryliodonium cations in the XBs were studied by a set of complementary computational methods. Combined experimental and theoretical studies allowed the recognition of the d-nucleophilicity of the [d8AuIII] atom which, regardless of its rather substantial formal 3+ charge, can function as a d-nucleophilic partner of XB. This conclusion was also supported by theoretical calculations performed for the structures’ refcodes BINXOM and ICSD 62511; the obtained data verified the nucleophilicity of AuIII toward a K+ ions or a ?-(Cl)-hole, respectively. All our results, together with consideration of relevant literature, indicate that gold atoms in the three oxidation states (0, I, and even III) exhibit nucleophilicity in XBs. - Polymorph-Dependent Phosphorescence of Cyclometalated Platinum(II) Complexes and Its Relation to Non-covalent Interactions // ACS Omega. 2022. https://doi.org/10.1021/acsomega.2c04110 (Q1/IF: 4.132)
Cyclometalated platinum(II) complexes [Pt(ppy)Cl(CNAr)] (ppy = 2-phenylpyridinato-C2,N; Ar = C6H4-2-I 1, C6H4-4-I 2, C6H3-2-F-4-I 3, and C6H3-2,4-I24) bearing ancillary isocyanide ligands were obtained by the bridge-splitting reaction between the dimer [Pt(ppy)(?-Cl)]2 and 2 equiv any one of the corresponding CNAr. Complex 2 was crystallized in two polymorphic forms, namely, 2I and 2II, exhibiting green (emission quantum yield of 0.5%) and orange (emission quantum yield of 12%) phosphorescence, respectively. Structure-directing non-covalent contacts in these polymorphs were verified by a combination of experimental (X-ray diffraction) and theoretical methods (NCIplot analysis, combined electron localization function (ELF), and Bader quantum theory of atoms in molecules (QTAIM analysis)). A noticeable difference in the spectrum of non-covalent interactions of 2I and 2II is seen in the Pt···Pt interactions in 2II and absence of these metallophilic contacts in 2I. The other solid luminophores, namely, 1, 3I–II, 4, and 4·CHCl3, exhibit green luminescence; their structures include intermolecular C–I···Cl–Pt halogen bonds as the structure-directing interactions. Crystals of 1, 2I, 3I, 3II, 4, and 4·CHCl3 demonstrated a reversible mechanochromic color change achieved by mechanical grinding (green to orange) and solvent adsorption (orange to green). - Stacking Interactions: a Supramolecular Approach to Upgrade Weak Halogen Bond Donors // Chemistry A European Journal, 2022. https://doi.org/10.1002/chem.202201869 (Q1/IF: 5.020)
The co-crystallization of tetracyanobenzene (TCB) with haloarenes ArX provided six new co-crystals TCB•ArX (ArX = PhCl, PhBr, 4-MeC 6 H 4 Cl, 4-MeC 6 H 4 Br, 4-MeOC 6 H 4 Cl, 1,2-Br 2 C 6 H 4 ) which were studied by X-ray diffraction. In these systems, the strong collective effect of ??? stacking interactions and lone pair-(X)??-hole-(C) bondings between TCB and ArX promote the strength of X?N cyano halogen bonding (HaB). Theoretical studies showed that the stacking interactions affect the ?-hole depth of the haloarenes, thus significantly boosting their ability to function as HaB donors. According to the molecular electrostatic potential calculations, the ?- hole-(Cl) value (1.5 kcal/mol) in the haloarene 4-MeOC 6 H 4 Cl (featuring an electron-rich arene moiety and exhibiting very poor ?-hole-(Cl) ability) increases significantly in the stacked trimer (TCB) 2 •4-MeOC 6 H 4 Cl (12.5 kcal/mol). Theoretical DFT calculations demonstrate the dramatic increase of X?N cyano HaB strength for stacked trimers in comparison with parent unstacked haloarenes. - Controlled Halogen-Bond-Involving Assembly of Double-σ-Hole-Donating Diaryliodonium Cations and Ditopic Arene Sulfonates // Crystal Growth & Design. 2022. https://doi.org/10.1021/acs.cgd.2c01090 (Q1/IF: 4.076)
The supramolecular dimensionality of halogen bonded architectures formed in the solid state by diaryliodonium salts is greater when the anion is a disulfonate rather than a monosulfonate. Specifically, diaryliodonium cations conventionally function as double-σ-hole halogen bond (XB) donors and form 0D-heterotetrameric motifs when paired with monosulfonate anions. Here it is reported that when 1,5- and 2,6-naphthalenedisulfonate anions are used as ditopic XB acceptors, their assemblies with diaryliodonium cations provide architectures of higher dimensionality. 1,5-Naphthalenedisulfonate leads to the occurrence of 1D chains, while the longer and less sterically encumbered 2,6-naphthalenedisulfonate produces either 1D chains or 2D layers. The two-center I···OSO supramolecular synthon is observed most frequently, and the three-center I···OSO linkage was identified in some assemblies based on 2,6-naphthalenedisulfonate. - Waste PET Upcycling to Conductive Carbon-Based Composite through Laser-Assisted Carbonization of UiO-66 // J. Mater. Chem. A, 2023. https://doi.org/10.1039/D2TA08127J (Q1/IF: 14.511 )
The upcycling of waste polymers into novel materials with high added value is a vital task for modern chemical engineering. Here, we propose diversifying waste polyethylene terephthalate (PET) upcycling to materials with enhanced photothermal properties by laser-assisted carbonization of surface-grown UiO-66. The UiO-66 homogenous layer has been formed using a solvothermal procedure on the surface of recycled PET sheets. The treatment by a 405 nm laser system allowed the formation of a carbonaceous layer with enhanced electrical conductivity and photothermal properties due to the presence of zirconium carbide and graphene. The developed approach opens new perspectives in the application of upcycled PET-based materials.
