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A computational study of the crystal chemistry of [beta]-SnW[O.sub.4], PbW[O.sub.4], and both polymorphs of BiV[O.sub.4] was carried out to better understand the bonding interactions that drive stereoactive lone pair and distortions and periodic trends that dictate their crystal chemistry. In compounds containing P[b.sup.2+] and B[i.sup.3+] the relativistic contraction of the 6s orbital reduces its interaction with oxygen, effectively diminishing its role in shaping the crystal chemical preferences of these ions while in PbW[O.sub.4] this leads to a stabilization of the symmetric scheelite structure.

Studies were conducted to determine the crystal structure and magnetic properties of P[b.sub.2]C[u.sub.3][B.sub.4][O.sub.11] which is built up from infinite zigzag chains of [[C[u.sub.3][O.sub.8]].sup.10-] units. The analysis of magnetic susceptibility and heat capacity showed that P[b.sub.2]C[u.sub.3][B.sub.4][O.sub.11] has spin-gap and Curie-Weiss behavior.

The synthesis, spectroscopic, electrochemical, as well as p[b.sup.2+]-binding properties of a series of different tetarthiafulvalence (TTF) acetylene derivatives, exhibiting a strong donor-acceptor interaction are studied. The analysis clearly demonstrates that the extent of the intermolecular charge transfer interactions through the [pi]-conjugated triple bond is smaller than that through the double bond.

The short-circuit photocurrent (SC-PHC) in the 200-800 nm wavelength domain was used to investigate the photovoltaic properties of the metal-ferroelectric-metal structures having SrRu[O.sub.3] metal oxide electrodes and Pb(Zr, Ti)[O.sub.3] (PZT) as ferroelectric layer. The band-gap energies evaluated from the PHC spectral distribution for different PZT compositions range between 3.9 to 4.4 eV and it is constantly higher than the reported experimental values on polycrystalline films but agree well with theoretical values.

The effect of Ta substitution on the structural, microstructural, molecular and dielectric characteristics of Pb[Sc(sub)0.5Nb(sub)0.5]O(sub)3 (PSNT), synthesized by mechano-synthesis and conventional mixed oxide methods is studied. It is found that the ceramics show the formation of the materials in a single phase in the rhombohedral structure with the existence of nanodomain.

The preparation of PbZrTiO(sub)3 [PZT] and PbZrO(sub)3 [PZ] superlattices on (100) SrTiO(sub)3 [STO] substrates with and without SrRuO(sub)3 [SRO] bottom electrodes by pulsed laser deposition (PLD) and their structural and ferroelectric properties were studied. It is found that the PZT and PZ layers in the superlattices turn to an a-axis orientation from the c-axis of the first PZT layer and have smooth morphology and sharp interfaces, while the orthorhombic and antiferroelectric phases are absent, possibly due to strain hindering the phase transition.

Various x-ray diffraction experiments are employed to study the microscopic-scale structures of 0.72Pb([Mg.sub.1/3][Nb.sub.2/3])[O.sub.3]-0.28PbTi[O.sub.3] relaxor ferroelectrics in a high external dc field during phase transition. The results clearly prove that a change in the temperature also leads to a major change in the dominating cluster's orientation, as well as their interaction direction.

Electrospray ionization mass spectrometry experiments (ESIMS) are performed on the pyrimidine nucleobases (B) uracil and thymine complexed with lead(II). The intermolecular proton transfers in uracil-[H.sub.2]O, uracil-O[H.sup.-] or uracil-uracil complexes have explained the experimentally detected [[Pb(U)-H].sup.+] ions.

The preparation of several series of chimeric compounds based on the cocrystal structures of natural product inhibitors of 90 kDa heat shock protein (Hsp90), geldanamycin, and radicicol is described. Upon preparation of these compounds, antiproliferative assays and protein degradation assays supported the initial hypothesis that chimeric compounds represent good lead compounds for the development of Hsp90 inhibitors.

Relaxor-type ferroelectric (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PT) films, 2-3 mum in thickness, with a PbTiO3 content (x) ranging from 0 to 1 were grown on [(100).sub.c]SrRuO3 ll (100)SrTiO3 substrates at 650 degree Celsius by metal-organic chemical vapor deposition. The constituent phase changed from a rhombohedral (pseudocubic) single phase, a mixture phase of rhombohedral (pseudocubic) and tetragonal phases, and a tetragonal single phase, with increasing x.

Relaxor-type ferroelectric (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PT) films, 2-3 mum in thickness, with a PbTiO3 content (x) ranging from 0 to 1 were grown on [(100).sub.c]SrRuO3 ll (100)SrTiO3 substrates at 650 degree Celsius by metal-organic chemical vapor deposition. The constituent phase changed from a rhombohedral (pseudocubic) single phase, a mixture phase of rhombohedral (pseudocubic) and tetragonal phases, and a tetragonal single phase, with increasing x.

The crystal structure and physical properties of Fe(sub 1.5)Pb(sub 5.5)In(sub 10)S(sub 22) are reported. This compound behaves like a semiconductor and the dominant magnetic interaction is found be antiferromagnetic, but magnetic orderings are not observed down to 2 K.

The o-phenylenediamine-derived disulfonamide ligands N,N'-Diphenyl-1,2-benzenedisulfonamide (1)and N,N'-Di-(4-tert-butylbenzene)-1,2-benzenedisulfonamide (2) complex and efficiently extract Pb(II) from water into 1,2-dichloroethane via ion-exchange, in combination with 2,2'-bipyridine. The corresponding Pb(II)-sulfonamido binary complexes of ligands 1 and 2 and ternary complexes with 2,2'-bipyridine are isolated and characterized.

A combination of potentiometric and absorption spectroscopic data allowed to characterize the formation and the dissociation mechanism of octacoordinated lead complexes of primary and tertiary tetrakiscarbamoylmethyl cyclam derivatives. In solution, the Pb(super 2+) cation is entrapped in a molecular cage constituted by the four macrocyclic nitrogen and the four amidic oxygen atoms.

The reaction of elemental In, Pb, or K, or Rb within welded Ta containers at 900 degree Celcius followed by subsequent annealing at 35 degree Celcius gives the new phases A(sub5)InPb(sub)8 (A = K, Rb). Wades rules for counting bonding electron states in a given class of clusters indicate that the charge assigned to an ideal deltahedral tetral cluster is independent of its nuclearity.

The structures of lead sulfide neutral clusters (PbS)(sub 1-9) were investigated by the use of density functional theory at the B3LYP level. It is showed that, the HOMO-LUMO gaps and binding energies oscillate with increasing cluster size, and remarkably small clusters already begin to take on the characteristic rock-salt structure of galena.

The dependence of the domain structure on poling for (001)-oriented Pb(Mg1/3Nb2/3)O3-x%PbTiO3 crystals is discussed by scanning force microscopy in the piezoresponse mode and by polarized optical microscopy. The results demonstrate a domain hierarchy on various length scales, ranging from nanometers to millimeters, which is notably dependent upon the electrical history of the specimen.

A study is carried out on the crystal structure and dielectric properties of (1-x)Pb(Yb1/2Nb1/2)O3-Pb(Sc1/2Nb1/2)O3 (PYN(1-x)PSNx) (O less than or equal to x less than or equal to 0.60) solid solution. Details of its pseudobinary phase diagram are determined.

It has been proved that doubly charged lead monohydrate can be synthesized may be in low yields, from ligand exchange resulting in energized collisions, between three hydrated ions. These ions are stable against any dissociative charge transfer.

An optical microscopy study on the domain structures of 0.955Pb(Zn(sub 1/3)Nb(sub 2/3))O3-0.045PbTiO3 rhombohedral phase single crystals poled along [001] of the cubic coordinates is reported. The study showed that the domain patterns in the domain engineered PZN-4.5%PT single crystals are predominantly twins containing only two of the four possible domains after being poled in [001].

The synthesis and structure of the mixed-metal lead rare-earth oxyhalides of [Pb.sub.6]La[O.sub.7]X (X = Cl, Br) is described. These compounds are the first for which the presence of mixed O[Pb.sub.n][Ln.sub.4-n] tetrahedral is recognized.

The fabrication and properties of the porous lead zirconate titanate ceramics with one dimensional ordered pore structure are analyzed. The piezoelectric and dielectric properties of the ceramics are shown to get reduced because of the special structure.

Lead zirconate titanate (Pb[Zr.sub.0.52][Ti.sub.0.48][O.sub.3]-PZT) thin films with different thicknesses are deposited on Pt(111)/Ti/Si[O.sub.2]/Si substrates by using sol-gel method. The scanning force microscopy is used for studying the effect of thickness on the microscopic piezoresponse and the differences between the macroscopic and microscopic electrical properties of the films are assigned to changes in the nonswitching film-electrode layer and domain structure.

The article presents a complete analysis of the technology used for the fabrication of the two-dimensional photonic crystal (PhC) band edge lasers that are found to be operating at the terahertz frequencies. The photonic band structure of the system is shown to be the main determinant of its lasing properties.

The magnetoelectric (ME) response and magnetic-field sensitivities of engineered laminate sensors comprised of magnetostrictive and piezoelectric phases are compared. The studies have resulted in the enhancement in the magnetic-field sensitivity for the structures with single crystals and the noise floors are lower for composites with Pb([Mn.sub.1/3][Nb.sub.2/3])[O.sub.3]-PbTi[O.sub.3] (PMN-PT) or Pb([Zn.sub.1/3][Nb.sub.2/3])[O.sub.3]-PbTi[O.sub.3] (PZN-PT) fibers than those with Pb(Zr,Ti)[O.sub.3] (PZT).

Lead zirconate titanate (PZT) stacks that have an interdigital internal electrode configuration are tested and significant reductions in piezoelectric and dielectric responses are observed during the cycling depending on the measuring condition. The results have shown the feasibility of using a semibipolar mode to drive a PZT stack under a mechanical preload and also display the potential fatigue and damages of the stack in service.

The synthesis of compositePbSe/CdS nanocrystals with two distinct geometries, core/shell/shell structures and tetrapods, is described. The ultralong carrier lifetimes and controlled geometry have made the nanocrystals attractive for a variety of applications from lasing to photocatalysis and photovoltaics.

The possible mechanisms of phonon scattering by nanostructures and defects in PbTe-X (X = 2%Sb, Bi, or Pb) thermoelectric materials systems are examined. The particle-induced local elastic perturbations have interfered with the phonon propagation pathway, thereby contributing to the reduction in lattice thermal conductivity and increasing the overall thermoelectric figure of merit.

The stability of various crystallographic phases of (1-x)BiFe[O.sub.3]-xPbTi[O.sub.3] is studied as a function of composition and temperature. The comparison between the bon lengths between oxygen and other cations has shown that the very high c/a ratio in the tetragonal phase of the system is linked with the covalency effects for bonding between both A and B site cations with oxygen.

The generation of charge in thin piezoelectric structures is measured and modeled under sinusoidal hydrostatic pressure and has also shown the domination of the subsequent thermally induced pyroelectric effect on the response in the smallest samples. The analysis of the piezoelectric and pyroelectric charge response has major impact on the design and functional behavior of small-scale piezoelectric devices.

Monodisperse, high-quality, single-crystal PbSe nanorods are prepared in a catalyst-free, one-pot reaction by using a new phosphine selenide precursor. The growth of nanorods is monitored, indicating that oriented attachment is involved to provide anisotropic PbSe nanostructures and the absorption and emission spectra along with the lifetime measurements have shown the differences between nanoscale PbSe spheres and rods.

The treatment of oxazolidinone carboxylic acid with potassium carbonate has produced olefin by a double decarboxylation reaction. 15,16-Normaltrexone derivative prepared from double decarboxylation product has displayed strong affinity for the [mu] opioid receptor, showing it to be a new opioid lead compound.

The size-dependent twinning and changes taking place in the morphology of the different nanocrsytal supperlattices are discussed. The analysis also helps in the development of a new set of materials, which are capable of exhibiting multiple twinning with high flexibility.

The formation of various isostructural inorganic-organic hybrid ferroelectric compounds from the aggregation of the [[Pb[I.sub.3]].sub.delta] chains directed organic cations to Kagome-shaped tubular architecture is discussed. The large spontaneous polarizations exhibited by these compounds are also explained.

Nanocrystals (NCs) with synthetic protocols for high shape and size monodispersity is used as templates to independently control the NC composition through successive cation exchange reactions. The studies have shown that CdS/PbS heterostructure nanorods are obtained by precise control over ion insertion and removal, where the spatial arrangement of materials is controlled via an intermediate exchange reaction.

The mechanisms involved in the managanese(III) acetate-mediated radical reaction of [60]fullerene with carboxylic acids in the presence of 4-(dimethylamino)pyridine are discussed. The reactions are shown to be extremely beneficial for the synthesis of a large number of fullerene products.

The temperature dependence of the visible fluorescence lines of large Pb[F.sub.2] nanocrystals codoped with [Er.sup.3+] and [Yb.sup.3+] ions is studied. The studies have shown that the fluorescence is affected both by the near-field optical distribution and by temperature variations.

The various mechanisms involved in the intramolecular aziridination of cyclopent-3-enyl-methylamines to 1-azatricyclo[2.2.1.[0.sup.2,6]]heptanes with lead tetraacetate are discussed. The presence of one or two methyl groups is shown to lead to an increase in the rate of the discussed aziridination reaction.

The article presents a new methodology that can be employed for the controlled synthesis of the PbS nanostructures with zero-, one- and two-dimensional structures. The degree of confinement of these nanostructures is shown to be highly dependent on the spatial dimensionality, hence making it useful for polarization-sensitive devices.