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The ruthenium complexes containing 2-anilinopyridiante anionic bridging ligands substituted on the pyridyl site of the molecule are described. Reaction of the metal-metal bonded complex [Ru.sub.2]([[O.sub.2]CC[H.sub.3]).sub.4]Cl with 2-anilino-4-methylpyridine leads to the (3,1) isomer of the diruthenium (III,II) complex [Ru.sub.2][(ap-4-Me).sub.4]Cl, while the same reaction with 2-anilino-6-methylpyridine gives the monoruthenium(III) derivative, [Ru.sub.2][(ap-6-Me).sub.3].

Research has been conducted on nickel(II) porphyrins. The electrochemistry of these compounds has been investigated in the effort to understand the effect of structural and electronic factors on electron-transfer processes in porphyrins, and the details are reported.

Research has been conducted on the diruthenium and dirhodium complexes. The nature of the metal-axial ligand interaction has been investigated.

Two (C6H5CH2)4C60 isomers were characterized using spectral and electrochemical methods.

Research has been conducted on the sigma-bounded organo-iron and -cobalt porphyrins. The examination of these porphyrins as a compound oxidation state function had been carried out.

The electrochemistry and spectroelectrochemistry of (TPPBrx)Co dissolved in CH2Cl2 with weakly coordinating tetra-n-butylammonium hexafluorophosphate (TBA)PF6 has been studied. TPPBrx is the dianion of beta-brominated-pyrrole tetraphenylporphyrin and x is from O to 8. The reaction of CO with singly oxidized ((TPPBrx)Co)(super +) has also been investigated. The increasing nonplanarity of (TPPBrx)Co macrocycle with increasing Br groups was also looked into to find out if it would affect the binding of CO by in situ generated ((TPPBrx)Co)(super +).

Several iron porphyrins with sigma-bonded methyl, phenyl and substituted phenyl axial ligands were synthesized and characterized. Four new sigma-bonded aryl iron(III) porphycenes have been synthesized and characterized. They are represented as (EtioPc)Fe(R), with each compound characterized and compared to similar sigma-bonded aryl iron(III) complexes, having the octaethylporphyrin macrocycle. The reaction may or may not involve the metal center in the second reduction of the sigma-bonded porphyrins, and the second reduction of the sigma-bonded porphycenes only occurs at the macrocycle.

Cobalt(III) and cobalt(II) derivatives are the compounds most often characterized in metallocorrole synthesis. The electrochemical and spectroscopic properties of neutral and oxidized (OEC)M, with OEC the trianion of 2,3,7,8,12,13,17,18-octaethylcorrole, have been examined. The oxidation of (OEC)Co, (OEC)Ni and (OEC)Cu proceeds as a formation of dimeric species, contrasting with (OEC)Mn, which occurs only as a monomer in both neutral and oxidized forms.

Several reports have considered the properties of nonplanar porphyrins incorporating bulky components at the beta-pyrrole positions of the porphyrin macrocycle. A new study considers the spectral and electrochemical properties of zinc(II) tetraphenylporphyrins have 0-8 bromo substituents at the beta-pyrrole positions of the macrocycle. Such data provides important information on substituent effects and can be compared to theoretical results.

Four unsymmetrical covalently linked porphyrin dimers were synthesized and their electrochemical, spectroelectrochemical and/or photophysical characteristics were investigated. Computed energy transfer rate constants were observed to be consistent with the empirical data and indicated that the energy transfer mechanisms are best represented by a Foster process. Highly efficient and directional energy transfer processes were observed.

A systematic investigation of the redox properties of five sigma-bonded porphyrins in the OEP series under experimental conditions where a third oxidation might be observed at very positive potentials was conducted. The porphyrins were represented as (OEP)Fe(R), where R = C6H5, 3,4,5-C6F3H2,2,4,6-C6F3H2,C6F4H, or C6F5. Results demonstrate that neither the iron(III) spin state nor the ligand field strength of the sigma-bonded axial ligand are key factors in the occurrence of such reaction.

A study was conducted to investigate the electron transfer properties of organocobalt porphyrins. The migration of organic groups and cobalt-carbon bond energies in various oxidation states were also analyzed in the study. The formation constants for converting (TPP)-Co(R) to (TPP)Co(R)(L) were computed spectroscopically. Results indicated that the first-order rate constants supported a constant value and directly correlated with the TEMPO concentration.

Five-coordinate (P)Co(NO) complexes were produced by the reaction of four-coordinate (P)Co compounds with nitric oxide at room temperature. The solid-state (P)Co(NO) complexes are stable in air and undergo decomposition in 2-3 weeks. The compounds are diamagnetic with a metalloporphyrin core. The NO ligands of the complexes are composed of a 24-atom porphyrin ring that displaces the Co atom. The cobalt nitrosyl porphyrin, (TPP)Co(NO), also exhibits a bent Co-N-O linkage while (P)Fe(NO) compounds display Fe-N-O bonds angles that ranges from 131-151 degrees.

The electrochemical and spectroscopic characteristics of three iron corroles were examined. Benzonitrile, dichloromethane and pyridine containing 0.1M tetra-n-butylammoniun perchlorate or tetra-n-ethylammonium hexafluorophosphate were used as supporting electrolyte. An iron(IV) tetrapyrrole pi cation radical has been isolated and characterized as a perchlorate. The strong antiferromagnetic coupling between the iron(IV) center and the singly oxidized corrole macrocycle has been confirmed by Mossbauer, X-ray crystallographic and magnetic susceptibility studies.

Spectroelectrochemical and electrochemical methods reduced flurophenyl sigma-bonded iron(III) porphyrins, resulting in OH- and RH. The porphyrins involved in the process are (P)Fe(C6F4H) and (P)Fe(C6F5). The unreduced (P)Fe(R) has an axial flurophenyl ligand that is displaced by OH-, inducing a chain reaction that enables total conversion of the sigma-bonded porphyrin to monomeric (P)FeOH. Substoichiometric quantities of OCH3- or F-, when added to (P)Fe(R), yields identical Fe(III) prophyrin products.

Electrochemical and spectroelectrochemical studies showed that (5,10,15,20-tetrakis 1-methyl-4-pyridyl porphinato)-manganese(III) chloride in N, N-dimethylformamide underwent a three-step electroreduction process that involved the transfer of five electrons. The process began with a metal-centered one-electron transfer followed by a two-electron transfer towards the conjugated porphyrin structure and finally, a two-electron electroreduction at the 1-methyl-4-pyridyl moieties of the TMpyP macrocycle. Moreover, these processes occurred concomitantly with chloride dissociation equilibria.

The reaction of (3,1) isomer of Ru2(F5ap)4Cl5 with THF followed by distillation in sodium and benzophenone yields Ru2(F4Oap)(F5ap)3Cl, where F4Oap = 2-(3,4,5,6-tetrafluoro-2-oxoanilino)pyridinate dianion and F5ap = 2-(2,3,4,5,6-pentafluoroanilino)pyridinate. The resulting Ru(II) complex represents the first diruthenium derivative containing tridentae ligand attached to two metal centers. The complex is characterized by X-ray single crystal diffraction, electrochemistry and mass spectrometry. Each Ru atom contains a distorted octahedral coordinated with four nitrogens to form an equatorial plane.

The structural, electrochemical and spectroscopic properties of [Ru.sub.2][(ap).sub.4][(C[triple bond]C[C.sub.5][H.sub.4]N).sub.2] (ap = anilinopyridinate anion) and (4,0) [Ru.sub.2][([F.sub.3]ap).sub.4]Cl ([F.sub.3]ap = 2-(2,4,6-trifluoranilino)pyridinate anion) are examined. The (4,0) [Ru.sub.2][([F.sub.3]ap).sub.4]Cl can be formed as the sole product isolated from the major (3,1) isomer, thus removing the need for costly process to obtain the (4,0) isomer.

The ligand addition and rearrangement products formed in the reaction between CN(super -) and four different diruthenium complexes of the type Ru(sub 2)(L)(sub 4)Cl, is reported. The structural and electrochemical properties of each synthesized compound were examined.

Research has been conducted on diruthenium(III,II) complexes possessing unsymmetrical bridging ligands. The authors describe the investigation of the factors affecting the spectroelectrochemical and electrochemical properties of these ligands.

An unusually stable metallofullerene, La C83 anion, is described.

A nonaqueous medium is used to reveal three reversible one-electron oxidations which influence a Ni(II) porphyrin or porphyrene to form (P)Ni and (OEPc) Ni. A Pi cation radical and dication are produced in a systematic method to coordinate with the primary two oxidations. A Ni(II/III) interaction is observed at half-wave potentials during the third oxidation. The Fe(II) and CO(II) complexes show metal-centered oxidations with TPP, OEPc or ORTPP macrocycles, with half-wave potentials that are compared to the Ni(II) porphyrins.