Abstract The reaction of the 2‐(trimethylsilyl)imidazolium triflate 9 with diarylboron halides (4‐R‐C 6 H 4 ) 2 BX (R=H, X=Br; R=CH 3 , X=Cl; R=CF X=Cl) afforded NHC‐stabilized borenium cations 10 a – c . Cyclic voltammetry revealed linear correlation between Hammett parameter σ p para substituent and half‐wave potential. Chemical reduction decamethylcobaltocene, [(C 5 Me Co], furnished corresponding radicals 11 ; their characterization by EPR spectroscopy confirmed paramagnetic character...

The reaction of 5,10,15-trimesitylcorrole (H3 cor) with tungsten hexachloride and hexacarbonyl resulted in the unexpected formation 3,17-dichloro-5,10,15-trimesitylcorrole radical (H2 cor*) as an air-stable product. X-ray crystallography proved planarization corrole structure, which was rationalized by reduced steric hindrance two versus three hydrogen atoms inside N4 cavity. Although aromaticity lost, no specific changes C-C or C-N bond distances could be observed. regioselectivity two-fold...

Thermoanalytical methods such as pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) are among the most promising techniques for quantification of microplastics (MP) in environmental samples. However, still lack harmonization and standardization. The use an internal standard (IS) can improve quality quantitative data robustness analytical method. Poly(styrene-d5) has frequently been used IS MP quantification, but suffers from H–D exchange during pyrolysis, which is catalyzed by...

A reliable analytical method has been developed to quantify poly(vinyl chloride) (PVC) in environmental samples. Quantification was conducted via combustion ion chromatography (C-IC). Hydrogen chloride (HCl) quantitatively released from PVC during thermal decomposition and trapped an absorption solution. Selectivity of the marker HCl complex samples ensured using cleanup pressurized liquid extraction (PLE) with methanol at 100 °C (discarded) tetrahydrofuran 185 (collected). Using this...

Abstract The reaction of 5,10,15‐trimesitylcorrole (H 3 cor) with tungsten hexachloride and hexacarbonyl resulted in the unexpected formation 3,17‐dichloro‐5,10,15‐trimesitylcorrole radical 2 cor*) as an air‐stable product. X‐ray crystallography proved planarization corrole structure, which was rationalized by reduced steric hindrance two versus three hydrogen atoms inside N 4 cavity. Although aromaticity lost, no specific changes CC or CN bond distances could be observed. regioselectivity...

The pyrrolyl-based iron pincer compounds [(tBuPNP)FeCl] (1), [(tBuPNP)FeN2] (2), and [(tBuPNP)Fe(CO)2] (3) were prepared structurally characterized. In addition, their electronic ground states probed by various techniques including solid-state magnetic susceptibility zero-field 57Fe Mössbauer X-band electron paramagnetic resonance spectroscopy. While the iron(II) starting material 1 adopts an intermediate-spin (S = 1) state, iron(I) reduction products 2 3 exhibit a low-spin 1/2) state....

Abstract Die Reaktion von 2‐(Trimethylsilyl)imidazoliumtriflat 9 mit Diarylborhalogeniden (4‐R‐C 6 H 4 ) 2 BX (R=H, X=Br; R=CH 3 , X=Cl; R=CF X=Cl) führte zu den NHC‐stabilisierten Boreniumkationen 10 a – c . Cyclovoltammetrische Untersuchungen offenbarten eine lineare Korrelation zwischen Hammett‐Parametern σ p der para‐Substituenten und Halbstufenpotentialen. chemische Reduktion mittels Decamethylcobaltocen, [(C 5 Me Co], lieferte die entsprechenden Radikale 11 ; ihre Charakterisierung...

Five metal complexes of 10,10‐dimethylisocorrole ligands with full β‐pyrrolic substitution is have been synthesized. The preparation nickel(II), palladium(II), and copper(II) was achieved by metal‐templated oxidative macrocyclization tetrapyrrolic 5,15‐biladiene precursors. reaction conditions for successful macrocycle formation in yields 18–32 % depended strongly on the type ion used. In case palladium, three different macrocyclic products were observed varying cyclization protocol....

Nickel, palladium, and copper complexes of the tripyrrolic ligand hexaethyltripyrrindione (H 3 Et 6 tpd, 1 ) have been prepared characterized by UV/Vis EPR spectroscopy, as well single‐crystal X‐ray structure determination. In all cases metal ion is coordinated in a distorted square‐planar geometry carrying water at fourth coordination site. The tpd acts radical dianion cases. solution, monomeric species are present which open‐shell character becomes apparent through spectroscopic...

Organic coatings can guarantee long-term protection of steel structures due to causing a physical barrier against water and oxygen. Because their mechanical properties resistances heat chemicals, epoxy resin-based are widely used for corrosion protection. Despite the aromatic backbone resulting susceptibility UV degradation, resins frequently as binding agent in top layers anti-corrosion coating systems. Consequently, these organic polymers directly exposed sunlight thus radiation. The...

Abstract Zinc and cadmium complexes of meso ‐arylisoporphyrins carrying a pyrrolyl or dipyrrinyl substituent at the sp 3 carbon atom were obtained through simple one‐pot variation Alder–Longo porphyrin synthesis. Key to formation stabilization isoporphyrins is presence metal acetates during oxidative macrocyclization step. The characteristic Q‐bands are found in NIR region between 750 nm 880 nm. All isolated pyrrolyl‐ dipyrrinyl‐appended stable under typical laboratory conditions allow...

The broad use of plastics and the persistence material results in plastic residues being found practically everywhere environment. If remain (aquatic) environment, natural weathering leads to degradation processes compounds may leach from into To investigate impact process on toxicity leachates, different types UV irradiation (UV-C, UV-A/B) were used simulate containing virgin as well recyclate biodegradable polymers. leached substances investigated toxicologically using in-vitro bioassays....

A novel synthesis for dialkyl cobalt compounds [(tmeda)CoR2] is presented. In these complexes tmeda readily replaced by an NHC or a bidentate phosphine ligand to form 3- and 4-coordinate compounds, respectively. [(ItBu)Co(CH2SiMe3)2] (ItBu = 1,3-di-tert-butylimidazolin-2-ylidene) serves as efficient, homogeneous olefin hydrogenation pre-catalyst allows the preparation of bis(alkyne) complex [(ItBu)Co(η2-PhCCPh)2].

To explore the possibility of tuning oxidation state a coordinated metal ion in an adsorbed tetrapyrrole complex by minor modification ligand structure, multilayers and monolayers 3H-hexaethyl-dimethyl-corrole (3H-HEDMC) on Ag(111) were situ metalated under ultrahigh vacuum (UHV) conditions subsequently analyzed with spectroscopic microscopic methods. The metalation reaction leads to formation Fe(III)-hexaethyl-dimethyl-corrole (Fe-HEDMC). results compared those for Fe-octaethyl-porphyrin...

The heme synthase AhbD catalyzes the oxidative decarboxylation of two propionate side chains iron-coproporphyrin III to corresponding vinyl groups during alternative biosynthesis pathway occurring in sulfate-reducing bacteria and archaea. belongs family Radical SAM enzymes contains [4Fe-4S] clusters. Whereas one these clusters is required for substrate radical formation, role second iron-sulfur cluster not known. In this study, function auxiliary catalysis was investigated. Two single...

Sterically encumbered ferrocenium salts with four, five, or six tert ‐butyl substituents and a variety of counteranions ([BF 4 ] – , [SbF 6 [PF ) were prepared. The electronic structures these materials investigated by various physical techniques including electron paramagnetic resonance (EPR) Mössbauer spectroscopy solid‐state magnetic susceptibility measurements. Spin–orbit coupling low‐symmetry distortions split the ground states ( 2 E 2g in compounds into two Kramers doublet (Ψ Ψ b );...

Abstract Chemically inert oxidometal(V) corrols of molybdenum and rhenium undergo clean ligand‐exchange reactions upon the action SiCl 4 . The resulting dichlorido complexes show trigonal prismatic coordination metal ion with chlorine atoms residing in a cis configuration, were studied by optical resonance spectroscopy as well DFT calculations. In situ reactivity studies carbon nucleophiles indicate high for replacement. Treatment sodium cyclopentadienide paves way to robust corrolocene...

Homoleptic iron complexes of six bis(pyridylimino)isoindoline (bpi) ligands with different substituents (H, Me, Et, tBu, OMe, NMe2) at the 4-positions pyridine moieties have been prepared and studied regard to temperature-dependent spin redox states by a combination (57)Fe Mössbauer spectroscopy, SQUID magnetometry, single-crystal X-ray diffraction analysis, X-band EPR, (1)H NMR spectroscopy. While H-, methyl-, ethyl-substituted remain in pure high-spin state irrespective temperature,...