Synthesis of meso,ß-Fused Thiazinamine-Porphyrins via Oxidative C-N Fusion of Pyrimidinyl-Substituted Porphyrins.

5,15-Bis(pyrimidin-2-ylthio)porphyrins have been synthesized. Their electrochemical oxidation leads to the formation of mono- and bis-C-N-fused thiopyrimidinium intermediates depending on the applied charge and potential. These latter undergo nucleophilic attack with water during workup that drives the ring opening of the pyrimidinium moiety. When piperidine is added before or after workup, the neutral fused porphyrinthiazin-2-amines are generated, and they exhibit a significant bathochromic shift of their Soret and Q bands.

Analysis of Silver Nanoparticles in Ground Beef by Single Particle Inductively Coupled Plasma Mass Spectrometry (SP-ICP-MS).

The regulation and characterization of nanomaterials in foods are of great interest due to the potential risks associated with their exposure and the increasing number of applications where they are used within the food industry. One factor limiting the scientifically rigorous regulation of nanoparticles in foods is the lack of standardized procedures for the extraction of nanoparticles (NPs) from complex matrices without alteration of their physico-chemical properties. To this end, we tested and optimized two sample preparation approaches (enzymatic- and alkaline-based hydrolyses) in order to extract 40 nm of Ag NP, following their equilibration with a fatty ground beef matrix. NPs were characterized using single particle inductively coupled plasma mass spectrometry (SP-ICP-MS). Fast sample processing times (<20 min) were achieved using ultrasonication to accelerate the matrix degradation. NP losses during the sample preparation were minimized by optimizing the choice of enzymes/chemicals, the use of surfactants, and the product concentration and sonication. The alkaline approach using TMAH (tetramethylammonium hydroxide) was found to have the highest recoveries (over 90%); however, processed samples were found to be less stable than the samples processed using an enzymatic digestion based upon pork pancreatin and lipase (≈60 % recovery). Low method detection limits (MDLs) of 4.8 × 106 particles g-1 with a size detection limit (SDL) of 10.9 nm were achieved for the enzymatic extraction whereas an MDL of 5.7 × 107 particles g-1 and an SDL of 10.5 nm were obtained for the alkaline hydrolysis.

A new cobalt(ii) meso-porphyrin: synthesis, characterization, electric properties and application in the catalytic degradation of dyes.

In this work, a new porphyrin, 5,10,15,20-tetrakis{4-[((4-methoxyphenyl)acetyl)oxy]phenyl}porphyrin (H2TMAPP) (1), and its cobalt complex [CoII(TMAPP)] (2) were synthesized in good and quantitative yields, respectively. The chemical structures of these synthesized compounds were confirmed by FT-IR, 1H NMR, MS, UV-visible, and fluorescence spectroscopy. Their photophysical properties, namely their molar extinction coefficients (∑), fluorescence quantum yields (Φ f) and lifetimes (τ f), were determined and compared with those of meso-tetraphenylporphyrin. Furthermore, their electrochemical behaviours were examined using cyclic voltammetry (CV). Dielectric properties such as the conductivity (σ) and the real (M') and imaginary (M'') parts of the dielectric modulus were investigated as a function of temperature and frequency. The impedance analysis was carried out using Cole-Cole plots to elucidate the electrical conduction mechanism. The catalytic power and the adsorption properties of the prepared compounds were studied for methylene blue (MB) and crystal violet (CV) degradation. The results reveal that the studied compound [CoII(TMAPP)] can be used as a catalyst for the decolourisation of dyes in the presence of H2O2.

Crystal structure of (4-cyano-pyridine-κN){5,10,15,20-tetrakis[4-(benzoyloxy)phenyl]porphyrinato-κ(4) N}zinc-4-cyano-pyridine (1/1).

In the title compound, [Zn(C72H44N4O8)(C6H4N2)]·C6H4N2 or [Zn(TPBP)(4-CNpy]·(4-CNpy) [where TPBP and 4-CNpy are 5,10,15,20-(tetra-phenyl-benzoate)porphyrinate and 4-cyano-pyridine, respectively], the Zn(II) cation is chelated by four pyrrole-N atoms of the porphyrinate anion and coordinated by a pyridyl-N atom of the 4-CNpy axial ligand in a distorted square-pyramidal geometry. The average Zn-N(pyrrole) bond length is 2.060 (6) Šand the Zn-N(4-CNpy) bond length is 2.159 (2) Å. The zinc cation is displaced by 0.319 (1) Šfrom the N4C20 mean plane of the porphyrinate anion toward the 4-cyano-pyridine axial ligand. This porphyrinate macrocycle exhibits major saddle and moderate ruffling and doming deformations. In the crystal, the [Zn(TPBP)(4-CNpy)] complex mol-ecules are linked together via weak C-H⋯N, C-H⋯O and C-H⋯π inter-actions, forming supra-molecular channels parallel to the c axis. The non-coordinating 4-cyano-pyridine mol-ecules are located in the channels and linked with the complex mol-ecules, via weak C-H⋯N inter-actions and π-π stacking or via weak C-H⋯O and C-H⋯π inter-actions. The non-coordinating 4-cyano-pyridine mol-ecule is disordered over two positions with an occupancy ratio of 0.666 (4):0.334 (4).

Crystal structure of di-aqua-[5,10,15,20-tetra-kis-(4-bromo-phen-yl)porphyrinato-κ(4) N]magnesium.

The title compound, [Mg(C44H24Br4N4)(H2O)2] or [Mg(TBrPP)(H2O)2], where TBrPP is the 5,10,15,20-tetra-kis-(4-bromo-phen-yl)porphyrinato ligand, was obtained unintentionally as a by-product of the reaction of the [Mg(TBrPP)] complex with an excess of di-methyl-glyoxime in di-chloro-methane. The entire mol-ecule exhibits point group symmetry 4/m. In the asymmetric unit, except for two C atoms of the phenyl ring, all other atoms lie on special positions. The Mg(II) atom is situated at a site with symmetry 4/m, while the N and the C atoms of the porphyrin macrocycle, as well as two C atoms of the phenyl ring and the Br atom lie in the mirror plane containing the porphyrin core. The H atoms of the axially bonded water mol-ecule are incompatible with the fourfold rotation axis and are disordered over two sites. In the crystal, mol-ecules are packed in rows along [001]. Weak inter-molecular C-H⋯π and C-H⋯Br inter-actions, as well as O-H⋯Br hydrogen bonds, stabilize the crystal packing.

Di-µ-azido-bis-(µ-1,4,7,10,13,16-hexa-oxacyclo-octa-deca-ne)bis-(5,10,15,20-tetra-phenyl-porphyrinato)dicadmium-disodium.

The asymmetric unit of the title compound, [Cd2Na2(N3)2(C44H28N4)2(C12H24O6)2], consists of one half of the dimeric complex; the tetra-nuclear mol-ecule lies about an inversion centre. The Cd(II) atom is coordinated by the four pyrrole N atoms of the 5,10,15,20-tetra-phenyl-porphyrinate ligand and one N atom of the axial azide ligand in a square-pyramidal geometry. The azide group is also linked to the Na(I) atom, which is surrounded by one 18-crown-6 molecule and additionally bonded to a second 18-crown-6 molecule trans to the azide group. The porphyrin core exhibits a major doming distortion (∼40%) and the crystal structure is stabilized by weak C-H⋯π inter-actions. The mol-ecular structure features weak intra-molecular hydrogen bonds: two O-H⋯O inter-actions within the 18-crown-6 mol-ecule and one C-H(18-crown-6)⋯N(azido) contact.