Siloxymethylamines as Aminomethylation Reagents for Amines Leading to Labile Diaminomethanes That can be Trapped as Their [Mo(CO)4] Complexes

Compound Et₃SiOCH₂NMe₂ transfers Me₂NCH₂ to R₂NH (R₂=Et₂, PhMe, [Cr(η⁶‐C₆H₅)(CO)₃]Me, PhH) to form previously unknown diaminomethanes, Me₂NCH₂NR₂ and, in the case of R₂=PhH, the triamine Me₂NCH₂N(Ph)CH₂NMe₂. The diaminomethanes exhibit an unreported disproportionation to a mixture of (R₂N)₂CH₂, (Me₂N)₂CH₂, and Me₂NCH₂NR₂, which can be trapped as their [Mo(CO)₄(diamine)] complexes. Whereas PhMeNCH₂NMe₂ is a labile material, the metal‐substituted ([(η⁶‐C₆H₅)Cr(CO)₃]MeNCH₂NMe₂ is a stable material. The triamine Me₂NCH₂N(Ph)CH₂NMe₂ is unstable with respect to transformation to 1,3,5‐triphenyltriazine, but is readily trapped as the bidentate‐triamineMo(CO)₄. All metal complexes were characterized by single‐crystal X‐ray diffraction.     

Characterizing elemental, equivalent black, and refractory black carbon aerosol particles: a review of techniques, their limitations and uncertainties

Elemental-, equivalent black- and refractory black-carbon are terms that have been defined in order to dissect the more general term, black carbon, into its component parts related to its specific chemical and optical properties and its impact on climate and health. Recent publications have attempted to clarify the meaning of these terms with respect to their environmental impact, particularly on climate. Here, we focus on the measurement aspects, reviewing the most commonly implemented techniques for the direct and indirect derivation of black carbon properties, their strengths, limitations, and uncertainties, and provide a non-exhaustive bibliography where the reader can find more detailed information. This review paper is designed as a guide for those wishing to learn about the current state of black carbon measurement instrumentation, how calibration is carried out, when one instrument may have the advantage over another, and where new techniques are needed to fill important knowledge gaps.     

Regioselective Intramolecular Carbon-Hydrogen Insertion in Copper-Catalyzed Carbenoid Decompositions of cis-1-Methyl-3-Arylcyclohexane-1-Diazomethyl Ketones : Some Synthetic Applications

Recently, we have developed¹ a new route for the stereo-specific introduction of an angular carboxyl or functionalized methyl groups² in a rigid hydrophenanthrene moiety. The key step in this approach is a regioselective intramolecular α-keto carbenoid insertion across the benzylic C-H bond (at C-4a) in CuSO₄-catalyzed thermal decomposition of the diazoketones and to the corresponding tetracyclic ketones and in moderate to good yields. A modified procedure³ of carbenoid decomposition of these diazoketones, in the presence of Cu₂O under irradiation with tungsten filament lamp, improves the yields of the desired C-H insertion products. Thus, the ketones and have been prepared now in consistently higher yields (53-55%) from the pure diazoketones , m.p. 125-127°, and , m.p.     

Mild Deprotection of tert‐Butyl Carbamates of NH‐Heteroarenes under Basic Conditions

Aqueous methanolic potassium carbonate under reflux has been demonstrated to be a highly effective deprotective agent for the tert‐butyl carbamates of indoles, indazoles, carbazole, thiazoloindole, and pyrrole. The method is a mild one and is particularly expeditious for NH‐heteroarenes bearing electron‐withdrawing groups.     

Structural, thermal and spectroscopic properties of supramolecular coordination solids

Molecules in metal isonicotinate tetrahydrates, M(NC₅H₄-p-CO₂)₂.4H₂O with M = Mn, Fe, Co, Ni, Cu, Zn, consisting of the hexacoordinate complexestrans-[M(NC₅H₄-p-CO₂)(OH₂)₄], participate in exhaustive hydrogen-bond formation among themselves to lead to a robust 3D supramolecular network in the solid state. Solid-state diffuse reflectance UV-Vis-NIR spectra of the complexes have been assigned to ligand field and charge transfer transitions. Sharp weight loss due to dehydration, as shown by TGA of Cu(NC₅H₄-p-CO₂)₂.4H₂O, suggests the suitability of this complex for the gravimetric estimation of copper.     

Synthesis,characterization, and applications with the manifestation of antifungal activity and seed germination properties of nickel doped zinc oxide nano platform by biochemical contrivance

In the recent era, nanotechnology, a rapidly emerging field, has been explored as the most studied field worldwide. The goal of this study is to use neem leaves extract as an effective ‘reducing agent’ and ‘stabilizing agent’ in the green synthesis of bio-medically important Zn_1-XNi_XO (X = 0.00, 0.04, 0.08, 0.12) nanoparticles. The molar concentrations of nickel nitrate and zinc nitrate are varied to produce nickel-doped ZnO nanoparticles. Color change is the first indicator of nanoparticle formation during this biosynthesis. The hexagonal wurtzite structure with good crystallinity is confirmed by X-ray diffraction. FTIR analysis reveals the fact that the Zn–O stretching vibration shifts with the introduction of impurities into the ZnO matrix. UV–Vis spectra show the typical surface plasma resonance around 370 nm and the hydrodynamic diameter is larger than the size calculated from the XRD value, according to DLS. The main finding of this study is that Ni_0.12Zn_0.88O has a strong antifungal activity against and a significant growth rate after treating wheat seeds with biologically synthesized Ni_0.12Zn_0.88O nanoparticles.