Water-soluble platinum and palladium porphyrins with peripheral ethyl phosphonic acid substituents: synthesis, aggregation in solution, and photocatalytic properties.

Water-soluble porphyrins have garnered significant attention due to their broad range of applications in biomedicine, catalysis, and material chemistry. In this work, water-soluble platinum(II) and palladium(II) complexes with porphyrins bearing ethyl phosphonate substituents, namely, Pt/Pd 10-(ethoxyhydroxyphosphoryl)-5,15-di(-carboxyphenyl)porphyrins (M3m, M = Pt(II), Pd(II)) and Pt/Pd 5,10-bis(ethoxyhydroxyphosphoryl)-10,20-diarylporphyrins (M1d-M3d; aryl = -tolyl (1), mesityl (2), -carboxyphenyl (3)), were synthesized by alkaline hydrolysis of the corresponding diethyl phosphonates M6m and M4d-M6d. NMR, UV-vis, and fluorescence spectroscopy revealed that the mono-phosphonates M3m tend to form aggregates in aqueous media, while the bis-phosphonates M3d exist predominantly as monomeric species across a wide range of concentrations (10-10 M), ionic strengths (0-0.

Synergism of primary and secondary interactions in a crystalline hydrogen peroxide complex with tin.

Despite the significance of HO-metal adducts in catalysis, materials science and biotechnology, the nature of the interactions between HO and metal cations remains elusive and debatable. This is primarily due to the extremely weak coordinating ability of HO, which poses challenges in characterizing and understanding the specific nature of these interactions. Herein, we present an approach to obtain HO-metal complexes that employs neat HO as both solvent and ligand.

Magnetic Anisotropy of Homo- and Heteronuclear Terbium(III) and Dysprosium(III) Trisphthalocyaninates Derived from Paramagnetic H-NMR Investigation.

H-NMR spectroscopy of lanthanide complexes is a powerful tool for deriving spectral-structural correlations, which provide a clear link between the symmetry of the coordination environment of paramagnetic metal centers and their magnetic properties. In this work, we have first synthesized a series of homo- (M = M* = Dy) and heteronuclear (M ≠ M* = Dy/Y and Dy/Tb) triple-decker complexes , where BuO- and 15C5- are, respectively, butoxy and 15-crown-5 substituents on phthalocyanine (Pc) ligands. We provide an algorithmic approach to assigning the H-NMR spectra of these complexes and extracting the axial component of the magnetic susceptibility tensor, χax.

The Domain and Structural Characteristics of Ferroelectric Copolymers Based on Vinylidene Fluoride Copolymer with Tetrafluoroethylene Composition (94/6).

This paper presents data on the macroscopic polarization of copolymer films of vinylidene fluoride with tetrafluoroethylene obtained with a modified apparatus assembled according to the Sawyer-Tower Circuit. The kinetics of the polarization process were analyzed taking into consideration the contributions of both bound and quasi-free (impurity) charges. It was shown that an "abnormal" decrease in conductivity was observed in fields near the coercive fields.

Gold nanoparticles activate hydrogenase synthesis and improve heterotrophic growth of Ralstonia eutropha H16.

Ralstonia eutropha is a facultative chemolithoautotrophic aerobic bacterium that grows using organic substrates or H2 and CO2. Hydrogenases (Hyds) are synthesized under lithoautotrophic, or energy-limited heterotrophic conditions and are used in enzyme fuel cells (EFC) as anodic catalysts. The effects of chemically synthesized gold nanoparticles (Au-NPs) on R.

Effect of Composition and Surface Microstructure in Self-Polarized Ferroelectric Polymer Films on the Magnitude of the Surface Potential.

The values of the surface potentials of two sides of films of polyvinylidene fluoride, and its copolymers with tetrafluoroethylene and hexafluoropropylene, were measured by the Kelvin probe method. The microstructures of the chains in the surfaces on these sides were evaluated by ATR IR spectroscopy. It was found that the observed surface potentials differed in the studied films.

Solvation-Induced Conformational Switching of Trisphthalocyanates for Control of Their Magnetic Properties.

Stabilization of different conformers of sandwich phthalocyaninates by changing the solvation environment has been demonstrated with the examples of new heteroleptic yttrium(III) and terbium(III) triple-decker complexes (where M = Y or Tb, [(BuO)Pc] = octa--butoxyphthalocyaninato ligand, and [(15C5)Pc] = tetra-15-crown-5-phthalocyaninato ligand). To this end, we have performed a comprehensive crystallographic characterization of two solvates formed by the Y(III) complex with either toluene or dichloromethane. In the solvate with toluene, both pairs of Pc ligands are in staggered conformations, providing both metal cations with a square-antiprismatic environment.

Site-Selective Solvation-Induced Conformational Switching of Heteroleptic Heteronuclear Tb(III) and Y(III) Trisphthalocyaninates for the Control of Their Magnetic Anisotropy.

In the present work, we report the synthesis of isomeric heteronuclear terbium(III) and yttrium(III) triple-decker phthalocyaninates (M = Tb, M* = Y or M = Y, M* = Tb, [(BuO)Pc]-octa--butoxyphthalocyaninato-ligand, [(15C5)Pc]-tetra-15-crown-5-phthalocyaninato-ligand). We show that these complexes undergo solvation-induced switching: the conformers in which both metal centers are in square-antiprismatic environments are stabilized in toluene, whereas in dichloromethane, the metal centers M and M* are in distorted prismatic and antiprismatic environments, respectively. This conclusion follows from the detailed analysis of lanthanide-induced shifts in H NMR spectra, which makes it possible to extract the axial component of the magnetic susceptibility tensor χaxTb and to show that this term is particularly sensitive to conformational switching when terbium(III) ion is placed in the switchable "M" site.

Supramolecular hybrids based on Ru(II) porphyrin and octahedral Mo(II) iodide cluster.

The coordination-driven design and synthesis of new stable supramolecular cluster-porphyrin (CP) hybrids based on an A-type ruthenium porphyrin 5,15-bis[(-tolyl)porphyrinato(2-)]ruthenium(carbonyl)(aqua) [RuDTolP(CO)H2O] and an octahedral molybdenum(II) iodide cluster with six terminal isonicotinate ligands (BuN)[{MoI}(OOC-CHN)] (PyMoC) are reported. The stepwise supramolecular assembly of the PyMoC "superoctahedron" with RuDTolP(CO)H2O has been studied by H NMR and 2D H-H COSY, H-N HMBC and DOSY techniques, as well as by UV-vis spectroscopy and HR-ESI mass spectrometry. The formation of discrete cluster-porphyrin CPn adducts with different numbers of coordinated porphyrins ( = 1-6), including the geometrical isomers of CP2, CP3 and CP4, has been observed.

Optical and Electrophysical Properties of Vinylidene Fluoride/Hexafluoropropylene Ferroelectric Copolymer Films: Effect of Doping with Porphyrin Derivatives.

Polymer films doped by different porphyrins, obtained by crystallization from the acetone solutions, differ in absorption and fluorescence spectra, which we attribute to the differences in the structuring and composition of the rotational isomers in the polymer chains. According to the infrared spectroscopy data, the crystallization of the films doped with tetraphenylporphyrin (TPP) proceeds in a mixture of α- and γ-phases with TGTG and TGTG conformations, respectively. Three bonds in the planar zigzag conformation ensures the contact of such segments with the active groups of the porphyrin macrocycle, significantly changing its electronic state.

Oxidative stress and histopathological changes in several organs of mice injected with biogenic silver nanoparticles.

The widespread use of silver nanoparticles (AgNPs) requires a study of their safety. The aim of the present study was to assess the levels of oxidative stress markers and histopathological changes in the experimental model of sarcoma S-180 of outbred mice caused by biogenic AgNPs. AgNPs were synthesized using 50% ethanol extract of leaves that was standardized for rosmarinic acid content.

Structure Determination of Binuclear Triple-Decker Phthalocyaninato Complexes by NMR via Paramagnetic Shifts Analysis Using Symmetry Peculiarities.

The detailed knowledge about the structure of multinuclear paramagnetic lanthanide complexes for the targeted design of these compounds with special magnetic, sensory, optical and electronic properties is a very important task. At the same time, establishing the structure of such multinuclear paramagnetic lanthanide complexes in solution, using NMR is a difficult task, since several paramagnetic centers act simultaneously on the resulting chemical shift of a particular nucleus. In this paper, we have demonstrated the possibility of molecular structure determination in solution on the example of binuclear triple-decker lanthanide(III) complexes with tetra-15-crown-5-phthalocyanine Ln[(15C5)Pc] {where Ln = Tb () and Dy ()} by quantitative analysis of the pseudo-contact lanthanide-induced shifts (LIS).

The Contribution of Phospholipase A and Metalloproteinases to the Synergistic Action of Viper Venom on the Bioenergetic Profile of Vero Cells.

Increasing concern about the use of animal models has stimulated the development of in vitro cell culture models for analysis of the biological effects of snake venoms. However, the complexity of animal venoms and the extreme synergy of the venom components during envenomation calls for critical review and analysis. The epithelium is a primary target for injected viper venom's toxic substances, and therefore, is a focus in modern toxinology.

Relationship between Respiratory Morbidity and Environmental Exposure to Organochlorine Pesticides in Armenia.

Background: Many studies have investigated the effects of organochlorine pesticides (OCPs) on adverse health outcomes. However, studies addressing the link between respiratory health and OCPs are limited. Organochlorine pesticides are stable compounds and belong to the class of endocrine disrupting chemicals that represent a threat to global health.

A molecular dynamics study of protein denaturation induced by sulfonate-based surfactants.

Microsecond timescale explicit-solvent atomistic simulations were carried out to investigate how anionic surfactants modulate protein structure and dynamics. We found that lysozyme undergoes near-complete denaturation at the high concentration (> 0.1 M) of sodium pentadecyl sulfonate (SPDS), while only partial denaturation occurs at the concentration slightly below 0.

Switchable Aromaticity of Phthalocyanine via Reversible Nucleophilic Aromatic Addition to an Electron-Deficient Phosphorus(V) Complex.

Reversible nucleophilic addition to a phthalocyanine core was observed for the first time for the electron-deficient cationic phosphorus(V) complex [PcP(OMe)], whose reaction with KOH afforded a highly distorted nonaromatic adduct bearing an OH group at one of the α-pyrrolic carbon atoms. This adduct was characterized by single-crystal X-ray diffraction, ESI HRMS, and NMR, and UV-vis spectroscopy, together with quantum-chemical modeling. The acidic treatment of this adduct restored aromaticity and recovered the starting cationic complex.

A 70-Year-Old Mystery in Technetium Chemistry Explained by the New Technetium Polyoxometalate [H O ] [Tc O ] ⋅ 4H O.

[H O ] [Tc O ] ⋅ 4H O [1] was prepared from an aqueous Tc O solution concentrated over anhydrous H SO . [Tc O ] is the first polyanionic species to be reported for Tc. The unit cell contains one centrosymmetric [Tc O ] polyanion as well as hydronium ions and water molecules.

Heteroleptic Crown-Substituted Tris(phthalocyaninates) as Dynamic Supramolecular Scaffolds with Switchable Rotational States and Tunable Magnetic Properties.

Herein we report single-crystal X-ray diffraction characterization and complementary solution studies of supramolecular interaction between potassium salts and heteroleptic homo- and heteronuclear triple-decker crown phthalocyaninates [(15C5)Pc]M*[(15C5)Pc]M(Pc) or , where M* and M = Y and/or Tb. Our results evidence that, in contrast to the previously studied crown-substituted phthalocyanines, the interaction of K cations with does not induce their intermolecular aggregation. Instead, the cations reversibly intercalate between the crown-substituted phthalocyanine ligands, resulting in switching of the coordination polyhedron of the metal center M* from square-antiprismatic to square-prismatic.

Comparison of the effects of dendrimer, micelle and silver nanoparticles on phospholipase A2 structure.

The interaction of nanoparticles (NP) with proteins (the so-called 'protein corona') is a huge challenge in attempting to apply them in personalized nanomedicine. We have analyzed the interaction between A) two 'soft' NPs (a cationic phosphorus dendrimer of generation 3; a cationic phosphorus amphiphilic dendron of generation 2), and B) one 'hard' nanoparticle (silver NP covered with cationic carbosilane dendritic moieties); and membrane-bound protein phospholipase A2 from bovine pancreas. The hard and soft NPs have differences in the nature of their interactions with phospholipase A2.

Cation-Induced Dimerization of Heteroleptic Crown-Substituted Trisphthalocyaninates as Revealed by X-ray Diffraction and NMR Spectroscopy.

We report comprehensive X-ray diffraction and NMR studies of potassium-induced dimerization of heteroleptic triple-decker crown-phthalocyaninates [(15C5)Pc]M(Pc)M(Pc) (, M = Y and Tb). Characterization of the crystalline dimer gave the first structural evidence of the formation of a six-decker structure with four rare earth metal ions perfectly aligned near the symmetry axis. NMR studies of soluble supramolecular dimers provided a spectral-structural model that allowed us to assign the NMR spectra of related complexes with paramagnetic lanthanides and to further evaluate their structure and long-range interaction between the Ln(III) centers in multinuclear tetrapyrrolic complexes.

Tetrakis(1,2,5-thiadiazolo)porphyrazines. 9. Synthesis and spectral and theoretical studies of the lithium(i) complex and its unusual behaviour in aprotic solvents in the presence of acids.

The template cyclotetramerization of 1,2,5-thiadiazolo-3,4-dicarbonitrile in the presence of lithium n-butoxide in n-butanol leads to the Li(i) complex of tetrakis(1,2,5-thiadiazolo)porphyrazine. Various possible structures of dilithium and monolithium complexes have been considered by DFT/B3LYP molecular modelling using the cc-pvtz basis set, and their theoretical IR and UV-VIS spectra have been calculated. The experimental Li NMR, IR and UV-VIS spectra measurements show that the complex contains two inequivalent lithium atoms - one is coordinated to the macrocyclic dianion to form the anionic lithate complex [TTDPaLi], while the other forms the solvated countercation [Li(Solv)].

Electrochemical, Spectroelectrochemical, and Structural Studies of Mono- and Diphosphorylated Zinc Porphyrins and Their Self-Assemblies.

Three series of porphyrins containing a Zn(II) central metal ion and zero, one, or two phosphoryl groups at the meso-positions of the macrocycle were characterized as to their electrochemical, spectroscopic, and structural properties in nonaqueous media. The investigated compounds are represented as 5,15-bis(4'-R-phenyl)porphyrinatozinc, 10-(diethoxyphosphoryl)-5,15-bis(4'-R-phenyl)porphyrinatozinc, and 5,15-bis(diethoxyphosphoryl)-10,20-bis(4'-R-phenyl)porphyrinatozinc, where R = OMe, Me, H, or CN. Linear-free energy relationships are observed between the measured redox potentials at room temperature and the electronic nature of the substituents at the 5 and 15 meso-phenyl groups of the macrocycle.

Hybrid organic-inorganic supramolecular systems based on a pyridine end-decorated molybdenum(ii) halide cluster and zinc(ii) porphyrinate.

Herein, first examples of supramolecular hybrid organic-inorganic cluster-porphyrin [CP (n = 2, 6)] systems constructed via metal-ligand coordination have been reported. The pyridine end-decorated Mo(ii) halide cluster ((BuN)[{MoI}(OOC-CHN)]), possessing remarkable photophysical properties, was chosen as the inorganic part and A-type zinc porphyrin 5,15-bis[(p-tolyl)porphyrinato(2-)]zinc was selected as the organic part. The crystal structures of CP and CP hybrids have been characterised by single crystal X-ray diffraction.

Finding a receptor design for selective recognition of perrhenate and pertechnetate: hydrogen vs. halogen bonding.

Receptors bearing hydrogen and halogen bond donors for recognition of perrhenate and pertechnetate were designed and studied. Acyclic hosts with N-H and C-H binding sites showed the best selectivity for TcO4- and ReO4- over spherical and more basic tetrahedral anions.

Tc NMR determination of the oxygen isotope content in O-enriched water.

Tc NMR has been suggested as an original method of evaluating the content of oxygen isotopes in oxygen-18-enriched water, a precursor for the production of radioisotope fluorine-18 used in positron emission tomography. To this end, solutions of NH TcO or NaTcO (up to 0.28 mol/L) with natural abundance of oxygen isotopes in virgin or recycled O-enriched water have been studied by Tc NMR.