Search

Cyclopentadienyl dialuminum with a half sandwich structure is prepared in a pulsed laser ablation cluster beam source and identified with a time of flight photoionization mass spectrometer. The high resolution electron spectrum of this complex is obtained using pulsed field ionization zero electron kinetic energy photoelectron spectroscopy.

The matrix-isolation infrared spectroscopy is employed to study the reactions taking place between the laser-ablated lathe lanthanide atoms and the dilute carbon monoxide in solid argon. The analysis of the [Ln.sub.2][[[eta.sup.2]([mu.sub.2]-C, O)].sub.x] (Ln = Tb, Dy, Ho, Er, Lu; x = 1, 2) molecules demonstrate the activation of the C-O bonds.

A simple method to prepare the microstructure of the Zn/ZnO core/shell nanoparticles controlled by laser ablation in liquid medium is demonstrated. The synthesis provides insight into physical origins of the blue emission in nanostructured ZnO as well as its use in optical and electronic applications.

Matrix-isolation infrared spectroscopy is used to investigate the reactions of laser-ablated Cu atoms with CO and NO mixtures in solid argon and neon. The results have indicated that it is difficult for copper, silver and gold to form metal carbonyl nitrosyl complexes, while metal carbonyls and metal nitrosyls are readily formed from the reactions of metal atoms with CO/NO mixtures.

An analysis of the formation of various titanium-based nanoparticles by laser ablation of a titanium rod in liquid environments comprised of water, ethanol, 2-propanol, and n-hexane is presented. It is found that the nanoparticles created in their respective liquid environments are very stable, maintain their character over time, and remain in solution for months after creation.

The influence of polymer molecular weight ([M.sub.W]) on the chemical modifications of poly(methyl methacrylate) (PMMA) and polystyrene (PS) films doped with iodonaphthalene (NaPI) and iodophenanthrene (PhenI) is investigated. The results obtained for femtosecond laser ablation enables the successful processing of a wide range of substrates as those found in restoration of artwork or for biological applications since their success is related to highly restricted and selective chemistry.

Zeolite LTA nanoparticles are prepared by laser-induced fragmentation of zeolite LTA microparticles using a pulsed laser and its formation is attributed to absorption of the laser at impurities or defects within the zeolite microcrystal generating thermoelectic stress. It is experimentally found that nanoparticles have a wide size and morphology distribution.

High-resolution spectra of the B(super 2)A1-X(super 2)A1 transitions of CaCH3 and SrCH3 are recorded in a molecular jet/laser ablation source using laser excitation spectroscopy. Rotational and fine structure parameters are determined for the B(super 2)A1 states of each molecule and structures are estimated for the B(super 2)A1 states of CaCh3 and SrCh3.

The recombination of O atoms on an anodized Al surface in oxygen plasma is studied using a new spinning wall technique and a multisite adsorption model is developed. The model reproduces the observed shapes of the O2 desorption decay curves and the lack of detectable desorption of O and predicts a high O-atom recombination coefficient on anodized aluminum with several adjustable parameters.

A transition metal carbonyl species, Cr(CO)4dpp, is successfully attached to bare silver nanoparticles prepared by laser ablation of a metal foil in ethanol. A large binding energy of about 122 kJ/mol is also computed between silver and nitrogen atoms thus lending support to Cr(CO)4dpp being chemisorbed onto the silver surface.

A coarse-grained model is developed for molecular dynamics simulations of the interaction of light with polymeric materials. The model adopts physically and experimentally known quantities such as enthalpies and probabilities of reactions.

Twenty-one adsorption isotherms for argon on single-walled carbon nanotubes are produced by laser ablation. The coverage dependence of the isosteric heat of adsorption for argon on single carbon nanotubes (SWNT) prepared by laser ablation is determined.

The C-H insertion reaction of laser-ablated Hf atoms with ethylene in excess argon is carried out during codeposition at 7 K, and the reaction products are investigated by means of infrared spectroscopy. The mono- and dihydrido C-H insertion complexes are reaction intermediates of hydrogen elimination from ethylene by second-row transition-metal atoms.

The modifications induced in haloaromatic, ArX (Ar, Nap, Phen, and An; X = Br and I), dopants dispersed within poly(methyl methacrylate) (PMMA) upon UV irradiation are examined. The results are well accounted for within a thermal model of the laser interaction with PMMA and the factors that controls the reactivity in the UV ablation of polymer substrates are illustrated.

A series of pulsed-laser-induced reshaping experiments on SiO2-Au metallodielectric core-shell nanoparticles, known as nanoshells, are reported. It is shown that the use of femtosecond pulse leads to an efficient and controllable heating regime compared to the use of nanosecond pulses.

The novel AuH2 molecule is formed in solid hydrogen by reactions of excited gold atoms from laser ablation and thermal evaporation. The computed bending potential energy surfaces of three electronic states of AuH2 using CASSCF/MRSDCI methods show that there is a barrier for decomposition of the X(super 2)B(sub 2) ground state to Au((super 2)S) + H2.

The quantitative photophysical description of matrix-assisted laser desorption ionization (MALDI) is explored by using a wide range of optical pumping rates. The longer laser pulse can sequentially desorb and ionize analyte molecules due to the extended interaction of the laser pulse and the MALDI plume.

Uranium was laser-ablated in the presence of N2/Ar mixtures, and the reaction products were studied using matrix isolation infrared spectroscopy. It was observed that at low N2 concentrations in Ar, the reaction product was the insertion product UN2, and its complexes with molecular N2.

The ablation characteristics of various polymers were studied at low and high fluences. The amount of detected gaseous products follows the same trend as the ablation activity suggesting a combined mechanism of photochemical decomposition and associated volume increase of the designed polymers.

Efforts to enhance the corrosion resistance, hardness, and wear resistance of materials such as aluminum, which is widely used in various industrial applications, have been a constant interest of manufacturers [...]