π–π Stacking‐Interlinked Molecular Squares with Hepta‐Coordinated Cadmium(II) Corners, [Cd(DMAP)3(NO2)2]·0.5H2O

The single crystal X‐ray analysis data of the new hepta‐coordinate cadmium(II) complex of N,N‐dimethyl‐N‐(4‐pyridyl)amine (DMPA), [Cd(DMPA)₃(NO₂)₂]·0.5H₂O, shows that the coordination environment around the Cd^II is pentagonal bipyramidal. Furthermore, self‐assembly of this complex as molecular squares that interlink via π–π stacking interactions is observed. This network contains voids that are filled by water molecules.     

Solvent Effects on the Chemoselectivity of Stable Phosphorus Ylides Involving a Sulfonamide

Hydrazine sulfonamide derivatives undergo a smooth reaction with dialkyl acetylenedicarboxylates in the presence of triphenylphosphine in varieties of solvent for generation of phosphorus ylides in a chemoselective manner.     

Manganese Biosorption from Aqueous Solution by Penicillium camemberti Biomass in the Batch and Fix Bed Reactors: A Kinetic Study

Biosorption of manganese(II) using suspended and immobilized cells of fungal Penicillium camemberti (biomass) and nano-P. camemberti (nano-biomass) was studied by evaluating the physicochemical parameters of the solution such as initial manganese ion concentration, pH, temperature, dosage, and contact time in both batch system and fixed bed column. The maximum biosorption obtained from the batch process was 91.54 and 71.08 % for nano-biomass and biomass in initial concentration of 5 ppm, respectively. The Langmuir, Freundlich, Temkin, and BET isotherms isotherm models were used in the equilibrium modeling. The correlation coefficient of more than 0.90 turned out that the adsorption process of Mn(II) on biomass and nano-biomass were in accordance with both Langmuir and Freundlich isotherms. The sorption process followed a second-order rate kinetics indicating the process to be diffusion controlled. The results also demonstrate that an intra-particle diffusion mechanism plays a significant role in the sorption process. The structure of P. camemberti was characterized by FT-IR spectrums.     

Reaction of Alkyl and Aryl Isocyanides with Floren‐9‐ones in the Presence of Acetylenic Esters: Preparation of γ‐Spiroiminolactones

The reactive 1∶1 intermediate generated by the addition of alkyl and aryl isocyanides to dialkyl acetylenedicarboxylate was trapped by 2,7‐dinitrofloren‐9‐one and floren‐9‐one to yield iminolactones in good yields.     

Microwave-Induced Stereoselective Conversion of Dialkyl 2-(Imido-N-yl)-3-(triphenylphosphoranylidene) butanedioates to Electron-Poor ( Z )- N -Vinylimides in the Presence of Potassium Dihydrogen Phosphate and Sodium Dihydrogen Phosphate in Solvent-Free Conditions

Abstract

Potassium dihydrogen phosphate powder and sodium dihydrogen phosphate powder were found to catalyze stereoselective conversion of dialkyl 2-(imido-N-yl)- 3-(triphenylphosphoranylidene)butanedioates to electron-poor (Z)-N-vinylimides in solvent-free conditions under microwave irradiation in 5-6 minutes in high conversions.     

A facile synthesis of oxazolo[3,2-a][1,10]phenanthrolines via a new multicomponent reaction

The synthesis of N-cyclohexyl-10-(2-fluorophenyl)-8aH-oxazolo[3,2-a][1,10]phenanthroline and N-(2,6-dimethylphenyl)-10-(2-fluorophenyl)-8aH-oxazolo[3,2-a][1,10]phenanthroline by reaction of 2-fluorobenzaldehyde, phenanthroline and cyclohexyl or 2,6-dimethylphenyl isocyanide is reported.     

Subtle Interplay of Weak Intermolecular Interactions. Crystal Structures of Lead(II) Complexes with 4,4′‐Dimethyl‐2,2′‐bipyridine

Three adducts of the N,N′‐bidentate aromatic base 4,4′‐dimethyl‐2,2′‐bipyridine (dmbpy) of lead(II) salts, [Pb(dmbpy)₂(NO₃)₂] ( 1 ), [Pb(dmbpy)₂(ClO₄)₂] ( 2 ) and [Pb(dmbpy)(NCS)₂]_n ( 3 ) have been synthesized and characterized by elemental analysis, IR, ¹H‐NMR and ¹³C‐NMR spectroscopy and studied by thermal analysis as well as X‐ray crystallography. The single‐crystal structures of these complexes show that the 6s electrons of lead(II) constitute a stereochemically active lone pair (SALP). The coordination numbers of the Pb^II ions are eight and seven, respectively. The supramolecular features in these complexes are guided/controlled by weak directional intermolecular interactions.     

Five‐cycle pulses near λ = 3 μm produced in a subharmonic optical parametric oscillator via fine dispersion management

Five‐cycle (50 fs) mid‐IR pulses at 80‐MHz repetition rate are produced using a degenerate (subharmonic) optical parametric oscillator (OPO), synchronously pumped by an ultrafast 1560‐nm fiber laser. The effects of cavity dispersion and the length of a periodically poled lithium niobate (PPLN) gain element on the output spectrum and pulse duration are investigated by taking advantage of a very broad (∼ 1000 cm⁻¹) gain bandwidth near the 3.1‐μm OPO degeneracy point. A new method of assessing the total OPO group delay dispersion across its entire spectrum is proposed, based on measuring spectral signatures of trace amounts of molecular gases injected into the OPO cavity.     

Radiation-induced reduction of mixed copper and aluminum ionic aqueous solution

Colloidal Cu–Al nanoparticles were prepared in an aqueous polyvinyl alcohol solution containing copper chloride and aluminum chloride as precursors, isopropanol as a scavenger of hydroxyl radicals, and distilled water as a solvent. The gamma irradiations were carried out in a ⁶⁰Co gamma source chamber with different doses up to 120 kGy. The formation of Cu–Al nanoparticles has been observed initially by the change in color of the colloidal samples from colorless to brown. The nanoparticles properties were characterized by transmission electron microscopy, energy dispersive X-ray spectrometry, and UV–Vis spectrophotometer. At a constant Cu/Al molar ratio, size of the nanoparticles can be well controlled by varying the precursors concentration and radiation dose. The average particle diameter increases with increase of precursors concentration and decreases with increase of dose. This is owing to the competition between nucleation process, aggregation process, and ions association in the formation of nanoparticles during irradiation.     

Syntheses and Crystal Structures of Two 3D Lead(II) Coordination Polymers with Isonicotinic Acid N‐Oxide and Pseudohalides

Two novel 3D lead(II)‐azido and ‐thiocyanato coordination polymers with isonicotinate acid N‐oxide (INO) as the coligand were synthesized and characterized by elemental analysis, IR, and ¹H NMR spectroscopy and were also studied using X‐ray crystallography technique. These complexes have the formulas [Pb(INO)(NCS)]_n ( 1 ) and [Pb(INO)(N₃)(H₂O)]_n ( 2 ).