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Low-temperature hydrothermal techniques are used to investigate single crystals of Ag(sub 4)V(sub 2)O(sub 6)F(sub 2). The crystal structure determination reveals a compound with sheets of vanadium oxide fluoride chains separated by silver cations.

Coordination polymers and a macrocycle formed from the reactions between flexible bis(2-pyridyl) ligands and AgCF3SO3 are reported. The structural analyses of the polymeric compounds suggest that interactions between the aromatic rings play a significant role in stabilizing the polymeric structures.

The synthesis, comparative physicochemical properties and solid-state structures of five new oligothiophene classes differing in substituent nature and attachment are discussed. The report states that cyclic voltammetry data offer a reliable picture of frontier MO energies, which, in combination with DFT computations, provide key information on relationships between oligothiophene substituent affects and electronic response properties.

A series of six neutral, tetrametallic, molecular rectangles are synthesized that have the form ([Re(CO)3]2BiBzlm)2-Mu,Mu'-(LL)2, where BiBzlm is 2,2'-bisbenzimidazolate and LL is reducible, dipyridyl or diazine ligand. The X-ray crystallography and computational modeling shows that the observed differences largely reflect detailed geometric configurational differences that can either facilitate or frustrate productive direct orbital overlap.

The relationship between molecular structure and electronic properties of 18 N-arylbenzamides is investigated. The long-wavelength absorption maxima of the secondary amides are red-shifted, as the number of N-aryl groups increases, whereas the tertiary amides display are blue-shifted.

Research has been conducted on the transition metal oxide fluoride anions. The structures of these anions have been compared in investigating the role of the electronic effects and bond network interactions in the out-of-center distortions which involve d (super)0 transition metal cations and the details are reported.

Research has been conducted on the low-melting, volatile and fluorine-free lanthanide metal-organic chemical vapor deposition precursors. Results demonstrate the advantages of the precursors as a buffer layer for yttrium barium copper oxide films growth on these precursors.

Research has been conducted on the inorganic oxyfluoride chains. The hydrogen bonding occurring between these chains and the role of the racemic (inversion) twin formation have been investigated and the details are reported.

The reaction scope, metal and ancillary ligand effects, regio- and distereoselectivity, and kinetics and mechanism for several series of phosphinoalkenes and phosphinoalkynes are discussed. The similarities and differences in hydrophosphination vis-a-vis analogous organolanthanide-mediated hydroamination are specified.

Research has been conducted on the tosylate cluster. The preparation and characterization of the cluster have been performed via the use of IR and NMR spectroscopy, elemental analysis and X-ray crystal structure study and the results indicate that this cluster is a useful material for the pseudohalide cluster preparation.

The direct reaction of the salen ligand and Et(sub)2Zn serves as an alternative method for the preparation of zinc(II)salen-type complexes in high yield. Data indicate that the procedure is applicable to the preparation of bifunctional pyridine-modified zinc(II) bis(salicylidene) complexes as well.

The dichromate ion [Cr(sub 2)O(sub 7)](super 2-), which consists of two corner-shared tetrahedra, is an attractive building block for noncentrosymmetric materials. The combination of the dichromate and [M(py)(sub 4)](super 2+) (M = Cu, Zn) ions results in polar one-dimensional helical chains that are analogues to the TiO(sub 4/2)O(sub 2/2) chains in potassium titanyl phosphate (KTP).

The synthesis of the cluster prepared from the all-chloro cluster is discussed. Results indicate that it undergoes facile ligand substitution to yield clusters containing halides and pseudohalides.

Research has been conducted on the site-specific crystal chemistry governing structures and stoichometries formation. Results indicate that the formation of high-density structure is a composition function.

The polar (WO(sub 2)F(sub 4))(super 2-) anion is crystallized with two different cations in the solid state to order one of the two W=O bonds. Close examination of bond lengths and anisotropic thermal ellipsoids in disordered (WO(sub 2)F(sub 4))(super 2-) compounds elucidates the disorder mechanisms and suggests strategies for eliminating orientational disorder. The anion is inherently acentric and consists of polarizable W=O bonds.

Thin-film forms of molecular materials composed of selected tetrarhenium square assemblies were prepared and identified. It was believed that the films were intensely attached and characterized by few pinhole defects. Results of the electrochemical transport experiments revealed that the materials were porous in terms of small solution-phase permeants although hindering larger permeants. Also, a single isomer crystal structure was discovered in one of the square assemblies.

The structures of the iron tetrapolyvanadate, Fe2V4O13, and the iron polyvanadomolybdate, Fe2V3.16Mo0.84O13.42, were compared and analyzed. Single crystals of Fe2V4O13 and Fe2V3.16Mo0.84O13.42 were grown from Fe2O3/V2O5 and Fe2O3/V2O5/MoO3 melts, respectively. Experimental results showed that the two structures are closely related and contain isolated Fe2O10 octahedral dimers with the same orientations. The unique U-shaped clusters in Fe2V4O13 were in order while those in Fe2V3.16Mo0.84O13.42 were not.

The phase stability of mixed transition metal oxide fluorides synthesized via hydrothermal reaction of the metal oxides in (HF)(sub x)*pyridine/H2O/pyridine solution was investigated using composition space diagrams. As in ternary phase diagrams, the products in composition space diagrams are directly related to initial reactant mole fractions. The negative charge distribution on the anions is apparently the most important factor governing the relative stability of the crystalline products in mixed transition metal oxide fluorides.

The new ligand tetraazaporphyrin has been found to coordinate PdCl2 and PtCl2 in its synthesis wherein it was substituted at the periphery with a single bidentate dimethylamino chelating group. Dithiolato ligands substituted for chlorine ligands and the first stable heteroleptic bis(amine)dithiolene palladium(II) complex was synthesized and structurally characterized. The peripheral heteroleptic core was found to be electroactive for electron-rich dithiolene ligands, but not for the comparably electron-poor dithiolene, maleonitriledithiolate.

Substitution and redox reactions of [Bu4N]2[Ta6Cl12(OSO2CF3)6] with ligands that are potential reductants are described. Results showed that the reactions form substituted clusters with the general formula [TaCl12X6]3-/4-. Differences between the electrochemical properties of the anionic ligand and the charge of the substituted products are also observed. The core of {Ta6Cl12}4+ was reduced by anions such as Cl- and Br- as a result of the positive reduction potentials of [Bu4N2][Ta6-Cl12(OSO2CF3)6].

Isolable and x-ray crystallographically characterizable catalysts for studying the molecular basis of polymerization catalysis are of interest. It has been impossible to isolate characterizable metallocene active species using the MAO activator, and complex, intractable species are the product of MAO-activated reactions. A focus on anion engineering incorporates efforts to better define the cation-anion interaction and effects on polymerization, using two complementary cocatalysts.

FeVMoO7 and CrVMoO7 were shown by single-crystal X-ray diffraction to be isostructural with V(super 5+) and Mo(super 6+) ions crystallographically distinct. They were also found to contain Mo-oxo double bonds, a highly unusual occurrence in solid-state oxides. Infrared and Raman spectroscopy were also used to examine these extremely rare structural features. These results confirm the assignment of the Mo=O stretching frequencies from Raman studies at about 980 cm(super -1).

A synthetic, molecular structure, thermochemical and ab initio study of bonding and bonding energetics in the group 6 metallocene oxo series Cp2Mo/(MeCp)2MO is presented. Among findings are the efficient and high-yield syntheses of the pairs Cp2MH2/(MeCp)2MH2, Cp2MCl2/(MeCp)2MCl2 and Cp2MO/(MeCp)2MO and a 'bent sandwich' geometry in the molecular structure of (MeCp)2WO. These findings lead to increased understanding of the electronic structure, molecular geometry, bond strengths and chemical reaction patterns of metallocene oxo complexes.

A study was conducted on a new methodology for the selective synthesis of regiochemically defined porphyrazines of the form M[pz(A2;B2)] where A and B are peripheral functionalization attached to the Beta-positions of the pyrroles. The findings indicate that the technique is mild enough to tolerate a wide rage of functionality and heteroatoms. Moreover, these trans-porphyrazines exhibit split Q-bands.

The synthesis of the family of compounds (pyH)2(Cu(py)4(MX(sub 6))2) was achieved by crystallizing the complex anions with two different cations, tetrakis(pyridine)copper(II) and pyridinium. The combination of these two different and strongly binding cations causes the anions to adopt regular and ordered orientations. Orientational disorder was avoided as each cation binds to a specific site on the anion, allowing accurate determination of bond lengths and angles by single-crystal X-ray diffraction.

Reaction of Os3(CO)12 with thionylaniline in refluxing methylcyclohexane results in Os3(CO)9(mu3-NPh)(mu3-S) (1) in good yield. Compound 1 and Os3(CO)9(mu3-eta2-(PhN)2SO)(mu3-S) (2) are produced when Os3(CO)10(NCMe)2 is treated with thionylaniline. Compound 1 reacts with trimethylamine oxide in the presence of acetonitrile to produce Os3(CO)8(NCMe)(mu3-NPh)(mu3-S) (3). Compounds 1-3 were characterized by mass, IR and NMR spectroscopies and their structures were determined by single-crystal X-ray diffraction.

The hydrogenation of acyclic imines by Cp'2 Ln/Me2SiCp''2Ln catalyst was analyzed to determine the mechanics of the organolanthanide-catalyzed synthetic process which led to the formation of amines. The organolanthanide-mediated imine hydrogenation led to the formation of organolanthanide byproducts which were produced by sequences of insertions of unsaturated species into metal-ligand sigma-bonds. The reaction was also characterized by exothermic, catalyst-deactivating C=N insertions and sigma-bond metathetical C-H activation.

Nuclear magnetic resonance spectroscopy, X-ray crystallography, voltammetry and extended Huckel studies were done to define the electrochemical and structural properties of a series of synthetic mononuclear rhodium(II) bis(phosphine), eta-6-arene complexes. The complexes, collectively called piano-stool compounds, were found to acquire their stability based on the following factors: the arene substituents, the presence or absence of ligand chelation, the type of ligand chelation and the structural changes which may occur on oxidation of the metal center.

The crystal structures of a family of six secondary arenedicarboxamides were investigated. Four rodlike arenedicarboxamides pack in one-dimensional tapes in which the hydrogen scaffold contains adjacent arenes with fixed spaces of 5 angstroms. The dihedral angles between the planes of adjacent arenes vary from 0 to 68 degrees. Two naphthalenedicarboxamides pack in two-dimensional sheets. The 2,6-naphthalenedicarboxamide packs in a higly puckered single-layer sheet with no arene-arene close contacts.

The two novel copper niobium oxyfluorides, pyH+ (sub 2) CuNb2(py)4O2F10 (super 2-) and CuNb(py)(sub 4)OF5 were synthesized from (HF)(sub x) pyridine/pyridine/water solution with the aid of CuO and Nb2O5 reagents. The structure of the first compound revealed aggregates of CuNb2(py)4O2F10 (sub 2-) anions connected by the N-H+...F hydrogen bond to the pyH+ cations while the second compound has a unidimensional structure of alternating Cu(py)4(O/F)2/2 (super 0.5+) and NbF4(O/F)2/2 (super 0.5-) octahedral chains which were perpendicular to the c axis.

The chiral C1-symmetric group 4 metallocenes catalyze the stereoregular polymerization of alpha-olefins. The reaction between zirconocene and hafnocene tetrachloride and Li2Me2Si(Me4C5)(C5H3R*) where R* denotes (1R,2S,5R)-trans-5-methyl-cis-2-(2-propyl)cyclohexyl leads to the dichlorides of Zr and Hf complexes. The treatment of metallocene dichlorides with MeLi.LiBr yields the respective dimethyl complexes. The nature and concentrations of the cocatalyst influence the polymerization activities, stereoregularities and molecular weights of the polymers.