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Single-crystal determinations of the structures of anhydrous rubidium and cesium formates are presented. The structures reported differ from the previously reported structures and remove the main anomalies observed in that of cesium formate.

Research has been conducted on the polyammonium monocycle and corollary bicycle. The nitrate and sulfate binding with these macrocycle and bicycle has been studied and the results demonstrate negligible binding for the polyammonium monocycle and nitrate and high affinity for the sulfate.

Research has been conducted on the bicyclic pentadentate ligand that demonstrates a high degree of preorganization with respect to metal complexation. The synthesis of the ligand has been described.

Research has been conducted on the N,N'-diphenylformamidines and their deprotonated silver(I) complexes. The synthesis of these complexes is described.

Structural analysis of the two new cross-bridged tetraazamacrocyclic complexes reveals that the ligand skeletons within them are identical. Data further show that the complexes have kinetic stability under harsh conditions.

Research was conducted to tune the steric protection yielded by substituents on the triamidoamine ligands such that the actinide complexes would have symmetric structures but also be reactive enough to be utilized in the exploration of the chemistry of the elements of this form. Using the tert-butyldimethylsilyl ligand obtains this objective. A convenient approach to the system via the preparation of monomeric, tetravalent actinide chlorides, bromides, iodides and amides is described.

A series of novel tridentate Schiff base ligands that can be used in octahedral molecular templates was synthesized. The crystal structures of the free ligand, 2,6-pyridinedicarboxaldhydebis(p-hydroxyphenylimine), its zinc(II) and nickel(II) complexes and the product of methylation of the nickel(II) complex, were also described. Results showed that two molecules of the ligand exhibit equatorial coordination to six-coordinate octahedral metal ions to produce orthogonally oriented molecular turns around the anchoring metal ion.

Mannich condensation is used to prepare amine-substituted dicompartmental ligands containing picolyl pendant arms on their amine substituent from salicylaldehydes, formaldehyde and substituted diaminoethane. A number of derivatives are also synthesized and characterized. Metal-containing complexes were generated using these dicompartmental ligands. X-ray diffraction studies were undertaken to elucidate the crystal structures of these ligands and complexes.

A novel type of isomerism in the cyclidene chemistry was charcterized based on the cis or trans orientation of the two bridge terminals. In unsubstituted cyclidene dioxygen carriers, the absence of methyl substituents from the parent macrocycle caused significant change in the molecular conformation of the novel cis-trans isomerism. These alterations in the structure of the cylcidene dioxygen carriers profoundly affected their chemical and physical properties.

Dicopper(II) complexes were synthesized using an asymmetric Robson-type ligand, consisting of a Schiff base and oxime compartments to demonstrate the applicability of a novel strategy of constructing metal chains using two bimetallic units linked together by a fifth metal ion. The (CuCl4)(super 2-) and ClO4- complexes showed a strong tendency to form coordination dimers and tetramers while the binuclear cation is almost planar, with the copper ions slightly displaced to opposite sides of the donor atoms. The Cu(II)/Cu(I) complex was found to be thermodynamically stable toward disproportionation.

The synthesis and characterization of the platinum(II) complexes M3 Pt(SnX3) (M = Bu4N+, PhCH2PPh3+; X = Cl, Br), cis-M2 PtX2(SnX3)2 (M = Bu4N+, PhCH2PPh3+, CH3PPh3+, Pr4N+; X = Cl, Br) and (PhCH2PPh3)2(PtBr3 SnBr3 ), are described. The complexes were characterized by 195Pt NMR, far-infrared, and electronic absorption and emission spectroscopies. The results showed that SnBr3- is a poorer sigma-donor and pi-acceptor than SnCl3-.

The 'lacuna' in transition metal complexes is a cavity or void that can accommodate dioxygen or other small ligands, resulting in the formation of a superstructure binding the ligand with metal ion. A lacunar structure prevents the simultaneous binding of O(sub 2) to two metal ions. Dioxygen carriers undergo autoxidation in solution but reduction processes restore their ability to bind to O(sub 2). The negativity of the M(III, II) redox couple is directly proportional to the couple's affinity for autoxidation.

An analysis of the factors controlling reversible dioxygen binding in lacunar Co(II) cyclidene complexes reveal that steric and electronic methods control dioxygen affinity. The Co-O-O bond angle is sensitive to the atmosphere and reveals complex variations that depend upon ligand substituents. ESR and simulation methods characterize the dioxygen complexes.

An analysis of the thermal dimerization reaction of 1-substituted-3,4-dimethylphosphole platinum(II) complexes reveals that the reaction mechanism involves branching and yields oxomethylene analogues as end products. The 1,4-butanedyl biradical is the common intermediate that causes the branching. The precursor complex has to have cis geometry for reaction initiation as the trans geometry prevents intramolecular C-C bonding. The halide characteristic affects the complex geometry only.

The synthesis and characterization of cobalt(II) cyclidene complexes with long polymethylene bridges and their reactions with dioxygen were described. The crystal structure of the bis(isothiocyanate) undecamethylene-bridged cobalt(III) complex has been solved, and the effects of coordination of a small molecule within the cavity on the conformation of the ligand were examined. Moreover, the dioxygen affinities and autoxidation reactions of the long-bridged cobalt(II) complexes are compared with those of the shorter bridged cobalt(II) cyclidene complexes.

The synthesis of nickel(II) and cobalt(II) complexes with 14-cyclidene was reported. The crystal structure of (Ni(MeNMeC12(14)cyclidene))(PF6)2 consisted of a flat 14-membered macrocyclic ring with the ring methyl groups occupying the trans positions. Cyclic voltammograms of Co MeNMeC12(14)cyclidene in acetonitrile showed two oxidative peaks for the metal- and ligand-centered reaction with the (16)cyclidene complexes. The dioxygen binding ability and autoxidation of the cobalt complexes were also studied.

The complex (Fe DPC Cl)PF6 derived from the reaction of iron(II) chloride with 4,7-bis(2-picolyl)-4,7-diaza-1-oxacyclononane (DPC) was studied using X-ray crystallography. DPC was synthesized from the interaction between (9)-aneON2 and 2-picolyl chloride hydrochloride in water. Results showed that the newly formed complex contained a macrocyclic ring with a chloride atom attached trans to a nitrogen atom of DPC. Additional reactivity studies involving Fe(TPC)2+ were conducted to further characterize the compound's structure.

Ruthenatetraborane, (RuH(B3H8)(CO)(PPh3)2), is synthesized from the reaction of (Nme4)(B3H8) with (RuH(CO)(NCMe)2(PPh3)2)ClO4 and (RuClH(CO)(PPh3)3). Structural analysis indicates that the complex forms monoclinic crystals of space group P2(sub 1)/c, with a distorted octahedral environment on the metal center. The conversion reactions to stable halometallatetraboranes, (RuX(B3H8)(CO)(PPh3)2) where X = Cl, Br, I, are also described.

Two new Pd(II) compounds of the general formula PdLCl2 where L is a variant of the tetraazamacrocycle-glyoxal condensation products, derived from cyclam and cyclen, were synthesized and their crystal structure determined. These complexes represent the first examples of transition metal ions complexed to a well-known type of tetracyclic tetraamine formed from the condensation of glyoxal and tetraazamacrocycles. These ligands generate unusual structures that demonstrate their potential usefulness in applications which require rigid bidentate ligands.

H2TAAB salts were prepared via direct reduction of o-nitrobenzaldehyde using a wide array of reducing agents. The method used featured a reducing agent that typically transforms nitro- into amino-group functionality and does not alter the aldehyde groups. It also employed a highly acidic medium which can expedite the conversion of o-aminobenzaldehyde to H2TAAB salts. The results demonstrated that {FeCl4} and {SnCl3} anions do not have an effect on the reactions of the H2TAAB salts.

Novel methods of synthesizing 20-membered {1 + 1} Schiff base macrocycle and 40-membered {2 + 2} Schff base macrocycle was developed. The design featured the utilization of copper(II) and nickel (II) ions as templates, respectively. Copper(II) and nickel(II) were proven to be effective template ions for the synthesis of the large, polyether Schiff base macrocyclic ligands in the complexes CuL(super 4)Cl(H(sub 2)O)(PF(sub 6)) and NiL(super 5)(PF(sub 6))(sub 2). These complexes revealed that large metal ion templates were not indispensable for production of large macrocycles.

The ruthenatetraborane Ru(B3H8)(PPh3)(k3-HB pz 3) is synthesized by the reaction of RuCl(PPh3)2(k3-HB pz 3) with NMe4(B3H8) or (super n)Bu4N(B3H8). This complex is air stable in the solid phase and is slowly decomposed by air in halocarbon solution. RuCl(PPh3)2(k3-HB pz 3) is formed from the reaction of RuCl2(PPh3)3 with K(HB pz 3) (Pz = pyrazol-1-yl). The compound crystallizes in the monoclinic space group P2(sub 1)/a, with unit cell dimensions of a = 19.75(1) Angstrom (A), b = 22.48(1) A, c = 20.283(7) A, beta = 112.94(3) degrees and Z = 8.

Research has been conducted on copper(II) complexes. The synthesis of these complexes which contain metal bond to the tetracyclic bisaminal formed from glyoxal and tetraazamacrocycle condensation is described.

The synthesis, characterization, and reactivity of the Mn(super 3+) and Fe(super 3+) complexes of ethylene cross-bridged tetraazamacrocycles derived from cyclam and cyclen is reported, prepared by the chemical oxidation of the divalent analogues. Dimethoxy and bis-azido complexes of Mn(super 3+) with this ligand have been prepared.

A hexaprotonated anion receptor crystallizes the mixture of dihydrogen phosphate and phosphoric acid. The crystal structure provides a snapshot of the situation, occurring at relatively low pH, in which both H2PO (sub 4)(super -) and H3PO4 are present.

The synthesis and structure of the trilithium salt triamidoamines, [Li3(NN'3)(THF)3], were evaluated. The complex subsequently transformed into the solvent free compound, [Li3(NN'3)]. The method used for the preparation of the compound was the one-pot synthesis conducted at low temperature. The complex solution was then cooled at -30 degrees centigrade which resulted to the elimination of a single THF ligand and the formation of [{Li3(NN'3)(THF)2}2] colorless crystals. The one-pot method was considered as a convenient method in preparing the lithiated triamidoamine.