Acrylamide Complexes Research Articles

Reactivity of metal-containing monomers 66. Hydrogenation of nitrotoluene derivatives in the presence of polymer-immobilized Pd nanoparticles

A new approach to the synthesis of immobilized catalysts of the mixed type was developed: frontal polymerization of metal-containing monomers in the presence of a highly dispersed inorganic support. The synthesis of the acrylamide complex of PdII nitrate on the SiO2 surface followed by polymerization and reduction results in the formation of a polymer-inorganic composite with inclusions of Pd nanoparticles stabilized by the polymer matrix on the support surface. The study of the catalytic properties in the hydrogenation of nitrotoluene derivatives showed that the polymer-immobilized Pd nanoparticles on the inorganic support are efficient catalysts for the reduction of the nitrocompounds.

Intermatrix Synthesis of Magnetic Nanocrystals by Frontal Polymerization and Subsequent Pyrolysis of Iron Containing Monomer

Ferromagnetic composites, consisting of either Fe or Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> C nanocrystals stabilized in a carbon matrix, were prepared by the procedure including formation of an iron acrylamide complex, followed by frontal polymerization and pyrolysis of the polymer at various temperatures. The pyrolysis products were in a form of coarse powder particles having irregular shape and size. These particles contained, in their volume, randomly distributed nanocrystals having sizes from 10 to 80 of nm. The crystallite composition and size depended on the pyrolysis temperature. Ferromagnetic properties of the nanocomposites were confirmed by the magnetic measurements.

Enhancing the separation of phosphorylated proteins in gel electrophoresis with dinuclear bispyridylmethylamine–tyrosine–acrylamide complexes

Bispyridylmethylamine–tyrosine–acrylamide ligands were prepared from protected tyrosine and dipyridylmethylamine by a twofold Mannich reaction and converted into acryl amides. Their manganese complexes were used as gel additives to increase the specific phosphate affinity in SDS–PAGE protein separations. The modified gel showed a distinct mobility shift of phosphorylated α-casein in comparison to the dephosphorylated protein.

Ferromagnetic resonance of cobalt nanoparticles in the polymer shell

The magnetic properties of cobalt spherical nanoparticles (∼ 5–9 nm in size) in a polymer shell are investigated using ferromagnetic resonance (FMR) spectroscopy. The metal-polymer complex is prepared through the frontal polymerization of the cobalt acrylamide (CoAAm) complex, followed by the thermolysis at a temperature of 643 K. Analysis of the ferromagnetic resonance spectra demonstrates that the material has a high blocking temperature of ∼700 K. The anisotropy constant equal to 0.5 erg/cm3 is somewhat larger than the anisotropy constants characteristic of cobalt macrostructures. This difference is associated with the predominance of the surface anisotropy of nanoparticles. The surface anisotropy constant is calculated to be 0.17 erg/cm2, and the anisotropy field is determined to be ∼350 Oe. It is revealed that the polymer shell affects the magnetic properties of nanoparticles.

Formation of cobalt nanoparticles in inorganic matrix by frontal polymerisation and thermolysis of metal-containing monomers

Frontal polymerisation of cobalt acrylamide complex, followed by thermolysis at temperatures 673–1073 K was applied for the processing of ferromagnetic nanocomposites containing cobalt crystallites in an inorganic matrix. The cobalt nanocrystallites have mean size in the range 9–15 nm, depending on the thermolysis temperature. The particles are randomly distributed and their size and agglomeration can be controlled by the processing variables. The particles exhibit ferromagnetic properties. Higher annealing temperatures result in higher coercivity. Magnetic behaviour of the nanocomposites is dominated by interparticle dipolar interactions.

Coordination chemistry of acrylamide 3: Synthesis, crystal structure and IR spectroscopic properties of dichloro-tetrakis( O–acrylamide)copper(II), [Cu( O–OC(NH 2)CH [dbnd]CH 2) 4Cl 2

The molecular structure of copper(II) chloride complex with acrylamide (AAm CH 2 CHCONH 2), [Cu(AAm) 4Cl 2], was determined using X-ray diffraction analysis. The complex crystallizes in the cubic space group I- 43d with a = 17. 8310(2) Å, β = 90°, and V = 5669.27(11) Å 3 for Z = 12. The acrylamide molecules bind to the metal center via the carbonyl oxygen atom (Cu–O 1.996 Å). The coordination geometry of the metal center in the complex involves a tetragonally distorted octahedral structure with four O-donor atoms of acrylamide bonded in the equatorial positions and two chlorides in the apical positions. Comparison of crystal structure data of acrylamide and metal acrylamide complexes of those formed with divalent transition metal chlorides has been summarized.

Coordination Chemistry of Acrylamide 4. Crystal Structures and IR Spectroscopic Properties of Acrylamide Complexes with CoII, NiII, and ZnII nitrates

AbstractAcrylamide complexes of metal nitrates: [M(O‐OC(NH2)CHCH2)n(H2O)m][NO3]2 (M = Co(1), Ni(2) (n = 6 and m = 0) and Zn(3) (n = 4 and m = 2)) have been determined by using single crystal X‐ray diffraction analysis. All complexes crystallize in the triclinic space group ${\rm P}{\bar 1}$. The structures of 1 and 2 represent octahedral species [M(AAm)6]2+ (AAm = O‐OC(NH2)CHCH2 and M = Co or Ni) and uncoordinated nitrate ions. The structure of 3 involves the octahedral cation [Zn(AAm)4(H2O)2]2+ in which the Zn2+ environment includes oxygen atoms of four acrylamide and two water molecules that are stabilized using ionic nitrate ions. The observations of the solid‐state IR spectroscopic vibrational frequencies of these acrylamide complexes are in agreement with the crystal structures.

Thermomechanical properties of polymeric composites based on 2-hydroxyethylmethacrylate and fumed silicas

Thermomechanical properties have been investigated for the composites synthesized by the thermal polymerization of 2-hydroxyethylmethacrylate or its polymerization initiated with acrylamide complex of cobalt nitrate in the presence of the fumed silica or silicon hydride-containing silicas. The effect of the filler surface nature on temperature dependencies of deformability of the polymeric composites has been studied.

Hydride-containing silicas in hydrosilylation of olefin monomers

The kinetics of catalytic hydrosilylation of divinyltetramethyldisiloxane and 2-hydroxyethyl methacrylate with SiH groups fixed on the silica surface was studied. The influence exerted by the nature of the silica surface (initial and hydride-containing) on thermal and initiated [with a cobalt(II) acrylamide complex] polymerization of 2-hydroxyethyl methacrylate was examined.

Proton-Coupled Electron Transfer in DNA−Acrylamide Complexes

A theoretical study of proton-coupled electron transfer (PCET) in the radical anionic thymine−acrylamide complex is presented. This study is based on a multistate continuum theory, in which the solute is represented by a multistate valence bond model, the solvent is described by a dielectric continuum, and the transferring hydrogen nucleus is represented by a quantum mechanical wave function. In this application, the ground and excited electronic states are calculated with the complete active space self-consistent-field (CASSCF) method, the electronic coupling for the electron transfer reaction is calculated with the generalized Mulliken−Hush method, and the solvation properties are calculated with the frequency-resolved cavity model. The influence of neighboring DNA base pairs is determined by studying solvated DNA−acrylamide models in addition to the solvated thymine−acrylamide complex. The calculations indicate that the final product corresponds to single electron transfer (ET) for the solvated thymine...

Frontal Polymerization of Metal-Containing Monomers: A Topical Review

The peculiarities of the frontal polymerization of metal-containing monomers containing acrylamide (AAm) complexes of transition metal nitrates, M(AAm) x (H2O) y (NO3)2 (M=Co, Ni, Fe, Cu, Zn, Cd, Ba), that are thermally initiated at 353–433 K are considered. It was found that nitrogen oxides (e.g., NO2, NO, N2O), which were formed by partial oxidation of the nitrate groups, were able to initiate the polymerization reaction. The reaction front and a self-sustained thermal wave were determined by structural-chemical and energy factors. The application of a self-propagating frontal polymerization to synthesize metal-containing copolymers was demonstrated. The constants of reactivity of the monomers (r1=0.63, r2=0.70) confirmed the statistical character of the copolymers obtained. Frontal polymerization of the AAm complexes that were filled by silica or glass powder was studied. Adding fillers stabilized the front and resulted in spatially uniform products. By following the controlled thermolysis of the metallopolymer or the controlled change of frontal polymerization into the burning regime lead to the formation of metallopolymer nanocomposites. The products were metal (or metal oxides) nano-scale particles that were stabilized by the polymer matrix that is formed.

Proton-Assisted Electron Transfer in Irradiated DNA−Acrylamide Complexes: Modeled by Theory

Theoretical calculations at the density functional theory (DFT) level are employed to elucidate a proton-assisted electron transfer (PA-ET) reaction within a DNA base (thymine)−acrylamide hydrogen-bonded complex, a process suggested from previous experimental results. Calculations with a 6-31+G* basis set are performed with full geometry optimizations and with vibrational analysis. Theory predicts the initial unpaired spin is delocalized over both thymine and acrylamide, and proton transfer then serves to fully localize the spin to the acrylamide. The PA-ET reaction is found to be exergonic by 1.6 kcal/mol. The final step of the reaction, i.e., an intramolecular proton transfer from the oxygen to the terminal carbon on acrylamide, results in the experimentally observed radical, i.e., CH3CH(•)CONH2, and is also predicted to be highly exergonic (18 kcal/mol).

The preparation and reactivity of metal-containing monomers. 54. Thermolysis of the acrylamide monomer [Co(CH2=CHCONH2)4(H2O)2](NO3)2

The kinetics and pathways of thermolysis of the Co(II) complex with acrylamide, [Co(CH2=CHCONH2)4(H2O)2](NO3)2 (1) were studied. The rate of gas evolution is satisfactorily approximated by a first-order equation of autocatalysis. The composition of gaseous and solid products of thermolysis of 1 was studied by IR spectroscopy, mass spectrometry, and electronic microscopy. Thermal transformations of acrylamide complex 1 include three macro stages: dehydration, polymerization of the dehydrated monomer, and thermooxidative destruction of the resulting polymer.

Mass spectrometric and computational study of complex formation of nucleic acid bases with acrylamide as a surrogate for asparagine and glutamine residues

In the context of the problem of nucleic acid–protein interactions, thermodynamic and geometrical parameters of complexes of methylated nucleic acid bases with acrylamide (as a model of the side chains of asparagine and glutamine) were investigated. Enthalpies of formation of nucleic acid base–acrylamide complexes, determined experimentally by means of temperature-dependent field ionization mass spectrometry, were in reasonable agreement with the interaction energies calculated theoretically using atom–atom potential functions. A stability order for base–acrylamide complexes was determined: m9Gua ≥ m21,4 Cyt ≥ m1 Cyt > m9 Ade > m31,4,4 Cyt > m1 Ura > m21,3 Thy.The geometries of the most energetically favourable complexes are determined and discussed. © 1998 John Wiley & Sons, Ltd.

The transition of spontaneous polymerization of acrylamide to “explosive” regime

Experimental results related to the transition of spontaneous polymerization of acrylamide complexes with metal nitrates to the “explosive” regime at room temperature are presented. It is suggested that the “explosion” has a thermal nature.

Phase transitions in the product of spontaneous polymerization of the acrylamide complex of calcium nitrate

Phase transitions in the spontaneously polymerized acrylamide-calcium nitrate system have been studied by X-ray diffraction analysis. The polymerization occursvia the stage of formation of crystalline particles, which exist in a homogeneous solution and are identical to crystallites in chemical composition. At the stage of particle formation, the degree of crystallinity is 60 %, the particle size is 65 nm, and paracrystallinity is 0.0208. An amorphous metal-containing polymer is the final structural state of the system.

Preparation and reactivity of metal containing monomers

The preparation of HTSC ceramics based on ym and Bi III was studied. The polymers were obtained by two methods: by the reaction of preliminarily synthesized polyacrylic acid (PAA) or polyacrylamide (PAAm) with ym, Ba H, and Cu II nitrates or by copolymerization of metal containing monomers (metal (y11, Bali, and Cu I1) acrylates or acrylamide complexes of metal (Bi Ill, Ca lI, Sr If, Pb u, and CuII) nitrates). The copolymerization was carried out in solution, in the solid phase, or using spontaneous polymerization, which has been previously discovered by the authors. The properties of the HTSC ceramics obtained are improved when the products of copolymerization of metal containing monomers are used.

Thermal polymerization of acrylamide during the formation of the structures of acrylamide complexes with metal nitrates

The effects of the composition of MnII, CoII or NiII nitrate hydrate — acrylamide (AAM) mixtures and of the duration of their aging at ambient temperature on the structurization of acrylamide complexes and on the character of their thermal polymerization have been studied by scanning and isothermic differential calorimetry. Structurization is a rather prolonged step in the synthesis of acrylamide complexes. The peculiarities and rate of this step are determined by the composition of the mixture and by the nature of the complexforming compound; it yields several structural modifications of the AAM complexes. The thermal polymerization of those structural forms of acrylamide complexes that polymerize at low temperatures may be formally described as polymerization in an acrylamide-nitrate-water mixture. The effective activation energy of the polymerization of acrylamide mixed with MnII nitrate hydrate is 45 kJ mol−1.

Thermally initiated frontal polymerization of transition metal nitrate acrylamide complexes

AbstractThe effect of the thermally initiated frontal polymerization of acrylamide complexes of transition metal nitrates such as those of Mn(II), Co(II), Ni(II), and Zn(II) was disclosed. The rate of the polymerization front propagation was found to be 2−9 × 10−2cm/c, depending appreciably on sample diameter and density, as well as the presence of radical inhibitor additives. The rate was found to decrease in the series: Co(II) &gt; Ni(II) &gt; Mn(II) &gt; Zn(II). Polymerization was shown to occur directly in the melting region of a complex at 80–100°C to give three‐dimensional polymers. A mechanism of the polymerization being initiated with the products of the partial nitrate group decomposition was proposed. © 1994 John Wiley &amp; Sons, Inc.

Model investigation of the polymerization of acrylamide complexes with metal nitrates by ESR

Modelling experiments have shown that the interaction between NO2 and acrylamide (AA) and the AA complex with calcium nitrate leads to the formation of radical centers. Analogous paramagnetic centers are detected directly in AA complexes with calcium nitrate. The ESR spectrum differs from that of γ-irradiated AA and is caused by nitroxyl radicals appearing in the course of the consecutive transformations in the system. The data obtained support the earlier suggested mechanism of NO2-initiated polymerization of acrylamide complexes with metal nitrates.