Synthesis of Novel Pyrrolo-[3,2-c]quinolines via Iron-Catalyzed Cross-Coupling Reaction of Grignard Reagents

Cross-coupling reaction of alkyl and aryl magnesium halides with 4-chloro-pyrrolo-[3,2-c]quinoline in the presence of a catalytic amount of iron salt is described. The reactions are completed in 30 min, resulting in moderate to excellent yields of 52–94% in a tetrahydrofuran (THF)–N-methylpyrrolidinone (NMP) solvent mixture.     

On symmetric algebras which are Cohen Macaulay

We give some necessary and sufficient conditions for S_A(m) being Cohen-Macaulay, where S_A(m) is the Symmetric algebra of the maximal ideal of an homomorphic image A of a regular local ring.This paper was supported by C.N.R. (Consiglio Nazionale delle Ricerche)     

Copper‐Mediated Reversible Deactivation Radical Polymerization in Aqueous Media

Key advances within the past 10 years have transformed copper‐mediated radical polymerization from a technique which was not very tolerant of protic media into a range of closely related processes capable of controlling the polymerization of a wide range of monomers in pure water at ppm catalyst loadings. This approach has afforded water‐soluble macromolecules of desired molecular weight, architecture, and chemical functionality, with applications ranging from drug delivery to oil processing. In this Review we highlight and critically evaluate the synthetic methods that have been developed to control radical polymerization in water by using copper complexes as well as identify future areas of interest and challenges still to be overcome.     

Characterization of two new zinc(II) complexes with saccharinate and imidazole or benzimidazole as ligands

The crystal structure of the complexes [Zn(sac)₂(im)₂] (1) and [Zn(sac)₂(bzim)₂]₂2Et-OHH₂O (2) (sac = saccharinate anion; im = imidazole; bzim = benzimidazole; EtOH = ethanol) was determined by single crystal X-ray diffractometry. Complex 1 crystallizes in the monoclinic P2 ₁/n space group with a = 9.1585(5), b = 16.4409(6), c = 15.0249(5) Å, = 94.079(1)°, and Z = 4, whereas complex 2 belongs to the triclinic space group P1 with a = 10.8500(2), b = 12.4860(2), c = 13.5640(3) Å, = 115,696(1), = 100.086(1), = 102.169(1)°, and Z = 1. In both complexes, the Zn(II) cations are in a slightly distorted tetrahedral ZnN₄ environment, coordinated to two saccharinate anions and to two imidazole (1) and to two benzimidazole (2) molecules. The complexes were also characterized by means of infrared spectroscopy and their thermal behavior investigated by means of thermogravimetric and differential thermal analytical techniques.     

Characterization of Two New Copper(II) Complexes with Saccharinate and Benzimidazole as Ligands

The crystal structure of the complexes [Cu(sac)₂(bzim)₂(H₂O)] ( 1 ) and [Cu(sac)₂(bzim)(H₂O)(EtOH)] · 2 EtOH ( 2 ) (sac = saccharinate anion; bzim = benzimidazole; EtOH = ethanol) was determined by single crystal X‐ray diffractometry. Complex 1 crystallizes in the monoclinic C2/c space group with Z = 8 whereas complex 2 belongs to the triclinic P1 space group with Z = 2. Room temperature magnetic susceptibilities as well as electronic and IR spectra of both complexes were discussed. Their thermal behaviour was investigated by means of TG and DTA methods.     

Neutralization of Li ions scattered by the Cu (1 0 0) and (1 1 1) surfaces: A localized picture of the atom-surface interaction

Large and face dependent neutral fractions have been found recently in the scattering of Li⁺ by Cu(1 0 0) and Cu(1 1 1) surfaces. These results for high work function surfaces are unexpected within the ‘traditional’ picture of a Li⁺ ion departing from a jellium surface model. In the present work the Li⁺/Cu(1 0 0) and Li⁺/Cu(1 1 1) interacting systems are described by a previously developed bond-pair model based on the localized interactions between the projectile ion and the atoms of the surface, and on the extended features of the electronic band structure through the surface local density of states. By only including the resonant neutralization to the Li atom ground state we explained the face and energy dependences of the measured neutral fractions for large outgoing energy values. We found that the downward shift of the Li ionization level below the Fermi level caused by the short range chemical interactions, is the main responsible of a high neutralization by the resonant mechanism. The remaining differences between theory and experiment values can be explained in terms of the energy gaps and image potential states appearing in these surfaces. The calculated distance behaviours of the energy levels corresponding to the first excited (Li-1s²2p) and the negative (Li-1s²2s²) atomic configurations indicate that they can also participate in the ion-surface charge exchange process.     

Spektroskopische Eigenschaften von Bis(imidazol)kupfer(II)diacetat

Summary Electronic and vibrational spectra of bis(imidazol)copper(II)diacetate were investigated in order to obtain a wider insight into the structural properties of this interesting complex compound, which presents high cytotoxic activity. Electronic transitions were investigated by reflectance measurements of the solid and by absorption, using aqueous and methanolic solutions. IR spectra could be interpreted on the basis of the characteristic ligand vibrations. Some information could also be obtained for the Cu-N and Cu-O vibrations. For comparative purposes, the IR spectrum of Cu(imidazol)₄I₂ was also recorded and analyzed.

     

Exploiting catalytic chain transfer polymerization for the synthesis of carboxylated latexes via sulfur‐free RAFT

We present a systematic study of incorporating carboxyl groups into latex particles to enhance colloidal stability and the physical properties of the latex. Statistical copolymers of methacrylic acid and methyl methacrylate) were synthesized via catalytic chain transfer polymerization (CCTP) in emulsion. The vinyl‐terminated oligomers were in turn successfully utilized as chain transfer agents for the formation of diblock and pseudo triblock copolymers via sulfur‐free reversible addition–fragmentation chain transfer polymerization (SF‐RAFT). These copolymers were characterized using ¹H NMR, size exclusion chromatography (SEC), dynamic light scattering (DLS), dynamic mechanical analysis (DMA), contact angle measurements and matrix‐assisted laser desorption/ionization time of flight mass spectroscopy (MALDI‐TOF‐MS) techniques. © 2019 The Authors. Journal of Polymer Science Part A: Polymer Chemistry published by Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, E1–E9     

Navier–Stokes equations and forward–backward SDEs on the group of diffeomorphisms of a torus

We establish a connection between the strong solution to the spatially periodic Navier–Stokes equations and a solution to a system of forward–backward stochastic differential equations (FBSDEs) on the group of volume-preserving diffeomorphisms of a flat torus. We construct representations of the strong solution to the Navier–Stokes equations in terms of diffusion processes.     

A New Green Thermoplastic Polymer with Improved Hydrophobic Character

Summary: A green thermoplastic polymer based on wheat flour was modified by the addition of a natural crosslinker genipin. Films of the polymer modified with different composition of genipin were prepared by extrusion. Free surface energy using contact angle method, moisture absorption test and hardness test were used to characterize the products. From moisture absorption and contact angle measurements, it was seen that for genipin amounts higher than 0.2% w/w, a hydrophobic character is achieved. Results obtained indicate enhancement in hydrophobic properties of the films.