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Density functional theory using the B3LYP and BP86 functional is employed to study the divanadocene carbonyls [Cp.sub.2][V.sub.2][(CO).sub.n]. Results reveal extremely short vanadium distance predicted for the singlet structure of [Cp.sub.2][V.sub.2](CO).

We have investigated the microwave-absorbing properties for different shapes and aggregated states of carbonyl-iron particles dispersed in epoxy resin matrix at various volume concentrations. Here, we discuss the requirements of lower reflection coefficient for the microwave permittivity [[epsilon].sub.r] = [epsilon]' - j[epsilon]' and permeability [[micro].sub.r] = [micro]' - j[micro]'. Compared to the aggregated sphere-shaped particles (SS), the de-aggregated flake-shaped carbonyl iron particles (FS) have higher permeability, lower permittivity, better filling characteristics in epoxy resin, and better absorbing properties in the frequency range of 2-18 GHz. For the FS composite with volume fraction of 0.60 at single-layer thickness of 1 mm, the calculated reflection loss at 2 GHz reaches -4.04 dB and the minimum reflection loss is -12.2 dB at 4.4 GHz, which indicates that the FS composite can be applied as a thinner microwave absorber in the S-band than if SS particles are used. The results also show that different volume concentrations can have high absorption at different wave bands, a fact on which the design of absorbing material can be based. Index Terms--Carbonyl iron, complex permeability, complex permittivity, microwave absorber.

A study of the reaction of acyl phosph(on)ates, with serine [beta]-lactamases is demonstrated to show that these compounds could rapidly acylate the enzyme active site. Evidence obtained suggests that these compounds inhibited in the carbonyl form rather than by formation of tetrahedral adducts at the [beta]-lactamase active site.

We measured the effective complex magnetic permeability [[micro].sup.*.sub.eff] and dielectric permittivity [[epsilon].sup.*.sub.eff] spectra in rubber radar absorbing material (RAM) with various carbonyl iron volume fractions by using the transmission/reflection method with a vector network analyzer. We studied the effects of carbonyl iron content and rubber thickness on the microwave absorption properties in the frequency range of 2.6 to 18 GHz. Our mathematical analysis is based on electromagnetic theory. The results indicate that the effective complex magnetic permeability and dielectric permittivity values of the RAM increase as the carbonyl iron volume fraction increases. For sample thickness of 3.0 mm, an increase in carbonyl iron content reduces the minimum reflection loss from--1.3 to--23.9 dB and shifts the frequency of the minimum reflection loss from 15.5 to 3.5 GHz. For an equal volume fraction of carbonyl iron, the frequency of the minimum reflection loss decreases as the thickness is increased. However, the dip in the reflection loss plot (in decibels) initially decreases to a minimum value before it increases with a further increase in thickness. We determined the value of the reflection loss for the samples by the impedance matching degree (reflection coefficient), which depends on the thickness and composition of the RAM. Index Terms--Carbonyl iron, permeability, permittivity, radar absorbing material (RAM), reflection loss.

A broad array of phenyl substituents (X) and benzoyl substituents (Y) were measured for carbonyl carbon chemical shifts to study the substituent effects on the carbonyl unit. Electronic effects of the remote aromatic ring substituents modified sensitivity of the carbonyl carbon to the X or Y ring substituents.

Density functional theory (DFT) calculations were performed to understand the reaction pathways of methylenation of carbonyl compounds with bis(iodozincio)methane. The results indicated that the methylenation reaction with gem-dizinc reagent proceeds as a two-step reaction, methylene addition (RDS) and olefination.

The article explains the synthesis, characterization, as well as the properties of various ethoxycarbonyl-based organic electrodes used in lithium batteries. Organic components are shown to lead to significant enhancement of the performance of the batteries.

A combination of a vibrating sample magnetometer and the scanning electron microscopy technique is employed to explain the preparation and the properties of the surface modified carbonyl iron particles. The magnetorheology and the sedimentation behavior exhibited by these particles are also analyzed.

The cavity perturbation methodology is adopted to explain the dielectric, as well as the magnetic properties of the various carbonyl iron mixed Mn oxide-coated ferrite nanoparticles. An increase in the ratio of the nanoparticles in the compounds is shown to lead to a decrease in the saturation magnetization of the system.

The energetic contributions of unsatisfied hydrogen bonding groups by placing chemicallty modified substituents in select internal positions in RNA helices and conducting thermodynamic studies are evaluated. The studies have shown that unsatisfied hydrogen bonding groups are the key determinants in the folding energetics and specificity of many RNA and DNA molecules and are important in tertiary structure interactions.

Enantioselective transfer hydrogenation of carbonate in the presence of aromatic, allylic, or aliphatic alcohols using a cyclometalated iridium C,O-benzoate derived from allyl acetate, 4-cyano-3-nitrobenzoic acid and (S)-SEGPHOS has delivered products of (hdroxymethyl)allylation in good anti-diastereoselectivities and enantiocontrol. The studies have represented the first general method for enantioselective carbonyl hydroxymethyl)allylation, a process has does not have any highly stereoselective counterpart in conventional allylmetal chemistry.

The reaction of [[[Co.sub.6]C[(CO).sub.15]].sup.2-] with 2 equiv of Pt[Cl.sub.2][([Et.sub.2]S).sub.2] has produced the new heterobimetallic [[[Co.sub.8][Pt.sub.4][C.sub.2][(CO).sub.24]].sup.2-], carbonyl cluster, which has undergone reversible chemical and electrochemical oxidation and reduction processes disclosing a complete series of [[[Co.sub.8][Pt.sub.4][C.sub.2][(CO).sub.24]].sup.n-] (n = 1-4) clusters. The studies have shown that even-electron transition metal carbonyl clusters (TMCC) can be magnetic.

FePt nanocrystals are prepared by simultaneous reduction of platinum acetylacetonate and thermal decomposition of iron pentacarbonyl in solvents/surfactants and the shape control is realized by varying synthesis parameters. The as-synthesized FePt nanocrystals are transformed to the chemically ordered [L1.sub.0] structure upon heat treatment, which has displayed hard magnetic properties with coercivity as high as 25 kOe.

A cavity perturbation resonance method is used for determining the complex permittivity and permeability of iron-based composite absorbers prepared by mixing various weight percentages of carbonyl iron powder with epoxy as the matrix. The complex permittivity and permeability are measured around X-band by the cavity perturbation resonance method and the differences in them have increased with increasing weight percentage of carbonyl iron.

The self-assembly, X-ray structure and the optical properties of two different semiconducting tellurium-iron-copper carbonyl polymers are explained. These polymers are shown to exhibit extremely surprising superconducting properties with small band gaps.

The dCD) and vapor pressure osomometry (VPO) studies were performed for monomeric to pentameric (P)-ethylnylhelicene oligomers possessing perfluorooctyl side chains to demonstrate the formation of stable homo-double-helix in trifluoromethylbenzene. The ability of perfluorooctyl (P)-pentamer to form a hetero-helix dimer with decyloxycarbonyl (M)-pentamer revealed the higher stability of the hetero-helix dimer over the homo-helix dimers.

A combination of photoelectron spectroscopy (PES) and synchrotron radiation in the valence region were employed to study the small penta-atomic molecules like FC(O)SCl and ClC(O)SCl. The results provided insight into electronic properties and the ionization channels of both species.

Ultrafast two-dimensional infrared (2D IR) and visible pump-infrared probe (Vis-IR) spectroscopy are used for examining the dynamics of photoinduced charge separation and the motion of the resulting electrons in an organic photovoltaic material. The results have shown that organic solar cells with higher mobility and the efficiency are obtained by controlling the morphology of the polymer and fullerene materials.

The synthesis, spectroscopic characteristics, and electrochemistry of 2,3,9,10,16,17,24,25-octakis(octyloxycarbonyl)phthalocyanine compounds are discussed. Both electrochemical and theoretical calculation results reveal the electron-withdrawing nature of the octyloxycarbonyl groups attached onto the peripheral positions of phthalocyanine ring.

The tandem cross metathesis intramolecular Aza-Michael reaction, which is completely microwave-assisted, is described. The microwave irradiation is found to highly accelerate the tandem process, which then leads to an inversion of the selectivity with [alpha]-substituted amines being used as the starting materials.

The mechanism of the hydrogen abstraction by [alpha]-diketones in the presence of phenols is studied by using laser flash photolysis (LFP), atoms in molecules (AIM) and density functional theory (DFT) calculations. The results have indicated that hydrogen abstraction for [alpha]-diketones is facilitated by the electrophilicity of the ketone, instead of neighboring group participation by the second carbonyl group.

The description of a novel anionic hybrid carbonyl-telluride cobalt cluster belonging to the rare type of pentagonal-prismatic [M.sub.10] polyhedral geometry is presented. It is observed that the interactions of the CO-bridging half-shell with [[Cp*].sub.2]Nb[(CO).sub.2].sup.+] cations gives rise to the formation of supramolecular networks containing ribbons of anions and cations.

Density functional theory (DFT) is used to study the manganese carbonyl nitrosyls Mn(NO)[(CO).sub.4], [Mn.sub.2][(NO).sub.2][(CO).sub.n] (n =7, 6, 5, 4) and [Mn.sub.3][(NO).sub.3][(CO).sub.9] and compare their predicted structures with those of isoelectronic iron carbonyl derivatives. DFT predicts a trigonal bypyramidal structure for Mn(NO)(CO)4 with an equitorial NO group very close to the experimental structure.

A study demonstrates that the reaction of isocyanates with [super i][Bu.sub.2]Al[Te.sup.n]Bu affords aluminum azaenolates of carbamotelluroates, while the tellurium-lithium exchange reaction of carbamotellurates and subsequent trapping with electrophiles gives the corresponding amide derivatives. These results indicate that carbamoyllithium synthons having an aryl group and/or a hydrogen on the nitrogen are generated efficiently from isocyanates by one-pot operation.

The electronic properties and the thermodynamic preferences for O2 addition to various tetrathiatriarylmethyl (TAM)-type triarylmethyl (trityl) radicals were theoretically investigated. Results show that H substitution on the aromatic ring affects the trityl radical's stability and might lead to substitution reactions in cellular systems.

The mechanism of the enantioselective 1,4-addition of Grignard reagents to alpha,beta-unsaturated carbonyl compounds promoted by copper complexes of chiral ferrocenyl diphosphines is studied using kinetic, spectroscopic and electrochemical analysis. The mechanistic studies are used to identify catalytically active species and a possible catalytic cycle is proposed that is consistent with the results observed in enantioselective conjugate addition (CA).

The experimental charge densities in the binary carbonyls Cr(CO)6, Fe(CO)5 and Ni(CO)4 are investigated on the basis of high-resolution X-ray diffraction data collected at 100 K. The experimental atomic graphs for the metal atoms in Fe(CO)5 and Ni(CO)4 are found to be dependent on the multipole model used for that atom.

Time-resolved infrared absorption spectroscopy is used to monitor the events during the first ~100 mu s following 308-nm photolysis of trans-RhCl(CO)(PMe3)2 in a C6D6 or Decalin solution. Upon photolysis, the intensity of the carbonyl stretching absorption of trans-RhCl(CO)(PMe3)2 decreases and a new C-O stretching absorption appears at 2006 cm(super -1) in C6D6 (2013 cm(super -1) in Decalin).

The elaboration of a physically reliable model of an anionic unsaturated bilayer of 1,2-dioleoyl-sn-glycero 3-phosphoserine (DOPS) for long-term molecular dynamics (MD) simulation is discussed. Water molecules are able to penetrate deeply inside the 1,2-dioleoyl-sn-glycero 3-phosphocholine (DOPC) bilayer for strong interaction with carbonyls of lipids as the water-lipid interface of the DOPC bilayer is looser than that for DOPS.

Equilibria between the Z (T1= 0 degree) and E (Ti= 180 degree) conformers of p-substituted phenyl acetates and trifluoroacetates were studied by ab initio calculations at the HF/6-31G* and MP2/6-31G* levels of theory. An appropriate isodesmic reaction is used to show that electron-withdrawing substituents decrease the stability of both conformers, but the effect is higher with the E conformer.

The GaCl3 -catalyzed [4+1] cycloaddition reactions of alpha,beta- unsaturated ketones with isocyanides leading to lactone derivatives are described. The reactions are significantly affected by the structure of both the isocyanides and the alpha, beta-unstructured ketones.

The isolation and X-ray characterization of the novel anions [Co(sub 9)P(CO)(sub 21)](super 2-) and [Co(sub 10)P(CO)(sub 22)](super 3-), exhibiting capped square antiprismatic metal cluster geometries are reported. The electrochemistry shows that [Co(sub 9)P(CO)(sub 21)](super 2-) and [Co(sub 10)P(CO)(sub 22)](super 3-) in acetonitrile solution undergo either a one-electron oxidation or a two-electron reduction, thus testifying that no stable redox exist for these phosphide clusters.

Direct electrophilic trifluoromethylation has been scarcely studied and few reagents have been developed for this use. For a long time, bioactive trifluoromethylated compounds have been prepared from trifluoromethylated 'building blocks' through iterative modifications.

Phase modulated dynamic Fourier transform infared spectroscopy (FT-IR) experiments are performed to study the response of the materials to sinusoidal mechanism perturbations. The cyano band is used to follow mesogen movements and the urethane carbonyl is used to track the hard segment for the polyurethane under study.

The new carbonyl-functionalized quaterhiophenes are prepared and characterized. The materials possess low-lying LUMOs that allow and facilitate electron injection and transport as well as HOMO energies compatible with respectable hole transport and organic field-effect transistors (OFETs) fabricated by conventional methods exhibit the largest oligothiophene thin-film mu(sub e) found to date and approach the performance of pentacene/SiO(sub 2) OFETs.