Adsorption and Premicellar Aggregation of CTAB Molecules and Fabrication of Nanosized Platinum Lattice on the Glass Surface

Premicellar aggregation processes were investigated in a wide range of concentrations and temperatures of cetyltrimethylammonium bromide (CTAB) aqueous solutions. Two independent techniques were involved to study adsorption and aggregation of CTAB molecules at the glass/solution interface. Electronic spin resonance (ESR) was used to estimate microviscosity properties through the reorientation correlation time τ_<i>c</i> of (2,2,6,6-tetramethylpiperidin-1-oxyl), while atomic force microscopy (AFM) was involved to evaluate the CTAB molecule morphology at the glass/solution interface. In the dependence of τ_<i>c</i> vs the CTAB concentration three discontinuities were revealed within 0.2–0.5, 0.5–1.02, and 1.02–1.1 mM narrow concentration ranges, which are probably connected with the formation of bilayer and hemispherical, hemicylindrical, cylindrical, and spherical admicelles. The images of some of them at the glass surface have been independently obtained by AFM. One-dimensional thin layer (2 nm) of Pt parallel strips on a glass surface have been synthesized by chemical vapor deposition of the Pt on the surface micellar CTAB linear templates followed by washing of the latter

The Salts of Copper Octafluoro- and Hexadecafluorophthalocyanines Containing [Cu^II(F₈Pc)^4–]^2– Dianions and [CuF₁₆Pc]⁻ Monoanions

Crystalline anionic salts with copper octafluoro- and hexadecafluorophthalocyanines, (Bu₄N⁺)₂[Cu^II(F₈Pc)^4–]^2–·2C₆H₄Cl₂ (<b>1</b>) and (PPN⁺)₃[CuF₁₆Pc]₃^3–·2C₆H₅CN (<b>2</b>), where PPN⁺ is bis­(triphenylphosphoranylidene)­ammonium and Pc is phthalocyanine, have been obtained. The absence of noticeable absorption in the NIR range and DFT calculations for <b>1</b> indicate that both negative charges are mainly localized on the Pc ligand, and that the [Cu^II(F₈Pc)^4–]^2– dianions are formed without reduction of Cu^II. The magnetic moment of 1.60 μ_B corresponds to the contribution of one <i>S</i> = 1/2 spin per dianion. The spin is localized on the Cu^II atom, which shows an EPR signal characteristic of Cu^II. Dianions are isolated in <b>1</b>, providing only weak magnetic coupling of spins with a Weiss temperature of −4 K. Salt <b>2</b> contains closely packed π–π stacks built of [CuF₁₆Pc]⁻ anions of types I and II, and the interplanar distances are 3.187 and 3.275 Å. According to the DFT calculations, the [CuF₁₆Pc]⁻ anions of types I and II can have different charge distributions, with localization of an extra electron on the copper atoms to form diamagnetic [Cu^I(F₁₆Pc)^2–]⁻ monoanions or delocalization of an extra electron on the F₁₆Pc ligand to form [Cu^II(F₁₆Pc)^•3–]^•– having an <i>S</i> = 1/2 (Cu^II) + 1/2 (F₁₆Pc^•3–) spin state. In fact, at 300 K, the magnetic moment of <b>2</b> of 3.25 μ_B per formula unit is rather close to the contribution from two [Cu^II(F₁₆Pc)^•3–]^•– (calculated μ_eff is 3.46 μ_B). The Weiss temperature of −21.5 K indicates antiferromagnetic coupling of spins, which can be modeled by stronger intermolecular coupling between (F₁₆Pc)^•3– with <i>J</i>₁/<i>k</i>_B = −23.5 K and weaker intramolecular coupling between Cu^II and (F₁₆Pc)^•3– with <i>J</i>₂/<i>k</i>_B = −8.1 K. This interaction is realized in the {[Cu^II(F₁₆Pc)^•3–]^•–}₂ dimers separated by diamagnetic [Cu^I(F₁₆Pc)^2–]⁻ species. In spite of the stacking arrangement of phthalocyanine macrocycles in <b>2</b>, the inhomogeneous charge distribution and nonuniform distances between the macrocycles should suppress electrical conductivity

The Salts of Copper Octafluoro- and Hexadecafluorophthalocyanines Containing [Cu^II(F₈Pc)^4–]^2– Dianions and [CuF₁₆Pc]⁻ Monoanions

Crystalline anionic salts with copper octafluoro- and hexadecafluorophthalocyanines, (Bu₄N⁺)₂[Cu^II(F₈Pc)^4–]^2–·2C₆H₄Cl₂ (<b>1</b>) and (PPN⁺)₃[CuF₁₆Pc]₃^3–·2C₆H₅CN (<b>2</b>), where PPN⁺ is bis­(triphenylphosphoranylidene)­ammonium and Pc is phthalocyanine, have been obtained. The absence of noticeable absorption in the NIR range and DFT calculations for <b>1</b> indicate that both negative charges are mainly localized on the Pc ligand, and that the [Cu^II(F₈Pc)^4–]^2– dianions are formed without reduction of Cu^II. The magnetic moment of 1.60 μ_B corresponds to the contribution of one <i>S</i> = 1/2 spin per dianion. The spin is localized on the Cu^II atom, which shows an EPR signal characteristic of Cu^II. Dianions are isolated in <b>1</b>, providing only weak magnetic coupling of spins with a Weiss temperature of −4 K. Salt <b>2</b> contains closely packed π–π stacks built of [CuF₁₆Pc]⁻ anions of types I and II, and the interplanar distances are 3.187 and 3.275 Å. According to the DFT calculations, the [CuF₁₆Pc]⁻ anions of types I and II can have different charge distributions, with localization of an extra electron on the copper atoms to form diamagnetic [Cu^I(F₁₆Pc)^2–]⁻ monoanions or delocalization of an extra electron on the F₁₆Pc ligand to form [Cu^II(F₁₆Pc)^•3–]^•– having an <i>S</i> = 1/2 (Cu^II) + 1/2 (F₁₆Pc^•3–) spin state. In fact, at 300 K, the magnetic moment of <b>2</b> of 3.25 μ_B per formula unit is rather close to the contribution from two [Cu^II(F₁₆Pc)^•3–]^•– (calculated μ_eff is 3.46 μ_B). The Weiss temperature of −21.5 K indicates antiferromagnetic coupling of spins, which can be modeled by stronger intermolecular coupling between (F₁₆Pc)^•3– with <i>J</i>₁/<i>k</i>_B = −23.5 K and weaker intramolecular coupling between Cu^II and (F₁₆Pc)^•3– with <i>J</i>₂/<i>k</i>_B = −8.1 K. This interaction is realized in the {[Cu^II(F₁₆Pc)^•3–]^•–}₂ dimers separated by diamagnetic [Cu^I(F₁₆Pc)^2–]⁻ species. In spite of the stacking arrangement of phthalocyanine macrocycles in <b>2</b>, the inhomogeneous charge distribution and nonuniform distances between the macrocycles should suppress electrical conductivity

The Salts of Copper Octafluoro- and Hexadecafluorophthalocyanines Containing [Cu^II(F₈Pc)^4–]^2– Dianions and [CuF₁₆Pc]⁻ Monoanions

Crystalline anionic salts with copper octafluoro- and hexadecafluorophthalocyanines, (Bu₄N⁺)₂[Cu^II(F₈Pc)^4–]^2–·2C₆H₄Cl₂ (<b>1</b>) and (PPN⁺)₃[CuF₁₆Pc]₃^3–·2C₆H₅CN (<b>2</b>), where PPN⁺ is bis­(triphenylphosphoranylidene)­ammonium and Pc is phthalocyanine, have been obtained. The absence of noticeable absorption in the NIR range and DFT calculations for <b>1</b> indicate that both negative charges are mainly localized on the Pc ligand, and that the [Cu^II(F₈Pc)^4–]^2– dianions are formed without reduction of Cu^II. The magnetic moment of 1.60 μ_B corresponds to the contribution of one <i>S</i> = 1/2 spin per dianion. The spin is localized on the Cu^II atom, which shows an EPR signal characteristic of Cu^II. Dianions are isolated in <b>1</b>, providing only weak magnetic coupling of spins with a Weiss temperature of −4 K. Salt <b>2</b> contains closely packed π–π stacks built of [CuF₁₆Pc]⁻ anions of types I and II, and the interplanar distances are 3.187 and 3.275 Å. According to the DFT calculations, the [CuF₁₆Pc]⁻ anions of types I and II can have different charge distributions, with localization of an extra electron on the copper atoms to form diamagnetic [Cu^I(F₁₆Pc)^2–]⁻ monoanions or delocalization of an extra electron on the F₁₆Pc ligand to form [Cu^II(F₁₆Pc)^•3–]^•– having an <i>S</i> = 1/2 (Cu^II) + 1/2 (F₁₆Pc^•3–) spin state. In fact, at 300 K, the magnetic moment of <b>2</b> of 3.25 μ_B per formula unit is rather close to the contribution from two [Cu^II(F₁₆Pc)^•3–]^•– (calculated μ_eff is 3.46 μ_B). The Weiss temperature of −21.5 K indicates antiferromagnetic coupling of spins, which can be modeled by stronger intermolecular coupling between (F₁₆Pc)^•3– with <i>J</i>₁/<i>k</i>_B = −23.5 K and weaker intramolecular coupling between Cu^II and (F₁₆Pc)^•3– with <i>J</i>₂/<i>k</i>_B = −8.1 K. This interaction is realized in the {[Cu^II(F₁₆Pc)^•3–]^•–}₂ dimers separated by diamagnetic [Cu^I(F₁₆Pc)^2–]⁻ species. In spite of the stacking arrangement of phthalocyanine macrocycles in <b>2</b>, the inhomogeneous charge distribution and nonuniform distances between the macrocycles should suppress electrical conductivity

Redox Chemistry of Pt(II) Complex with Non-Innocent NHC Bis(Phenolate) Pincer Ligand: Electrochemical, Spectroscopic, and Computational Aspects

A Pt(II) complex bearing chelating tridentate bis-aryloxide tetrahydropyrimidinium-based N-heterocyclic carbene (NHC) was synthesized and characterized by using different techniques. Both cyclic voltammetry and differential pulse voltammetry were used to study the electrochemical properties of the complex, revealing two reversible one-electron oxidation processes. The chemical generation and isolation of one-electron-oxidized species were performed oxidizing the initial complex by means of AgBF4. A combination of spectroscopic (UV-Vis/NIR- and EPR-) and theoretical (density functional theory (DFT)) studies suggests the formation of a Pt(II)-phenoxyl radical complex. The latter open-shell derivative was structurally characterized by means of X-ray diffraction analysis. Finally, the neutral platinum complex was tested as a mediator in the process of electrocatalytic oxidation of 2-(methylamino)ethanol (MEA)

ROS-producing nanomaterial engineered from Cu(I) complexes with P2N2-ligands for cancer cells treating

Abstract The work presents core–shell nanoparticles (NPs) built from the novel Cu(I) complexes with cyclic P2N2-ligands (1,5-diaza-3,7-diphosphacyclooctanes) that can visualize their entry into cancer and normal cells using a luminescent signal and treat cells by self-enhancing generation of reactive oxygen species (ROS). Variation of P- and N-substituents in the series of P2N2-ligands allows structure optimization of the Cu(I) complexes for the formation of the luminescent NPs with high chemical stability. The non-covalent modification of the NPs with triblock copolymer F-127 provides their high colloidal stability, followed by efficient cell internalization of the NPs visualized by their blue (⁓450 nm) luminescence. The cytotoxic effects of the NPs toward the normal and some of cancer cells are significantly lower than those of the corresponding molecular complexes, which correlates with the chemical stability of the NPs in the solutions. The ability of the NPs to self-enhanced and H2O2-induced ROS generation is demonstrated in solutions and intracellular space by means of the standard electron spin resonance (ESR) and fluorescence techniques correspondingly. The anticancer specificity of the NPs toward HuTu 80 cancer cells and the apoptotic cell death pathway correlate with the intracellular level of ROS, which agrees well with the self-enhancing ROS generation of the NPs. The enhanced level of ROS revealed in HuTu 80 cells incubated with the NPs can be associated with the significant level of their mitochondrial localization

A new Time-of-flight detector for the R 3 B setup

© 2022, The Author(s).We present the design, prototype developments and test results of the new time-of-flight detector (ToFD) which is part of the R3B experimental setup at GSI and FAIR, Darmstadt, Germany. The ToFD detector is able to detect heavy-ion residues of all charges at relativistic energies with a relative energy precision σΔE/ ΔE of up to 1% and a time precision of up to 14 ps (sigma). Together with an elaborate particle-tracking system, the full identification of relativistic ions from hydrogen up to uranium in mass and nuclear charge is possible.11Nsciescopu