The development and investigation of bimetallic systems that undergo proton-coupled intramolecular electron-transfer are reported. Initial studies involved the synthesis of a new family of synthetically versatile ruthenium complexes containing various $\beta$-diketonates (R$\sb2$mal) and 2,6-bis(N-pyrazolyl)pyridine and its methyl substituted derivatives (Me$\sb{\rm n}$bpp). These coordinatively saturated complexes are stable in water and exhibit low redox potentials which can be fine-tuned over a broad potential range. These complexes were used to prepare bimetallic systems in order to study optical electron transfer as a function of ligand substituent effects. In subsequent studies these (Me$\sb{\rm n}$bpp)(R$\sb2$mal)Ru- metal centers were linked to ruthenium centers containing a ligand with an ionizable proton. The general formula of these bimetallic complexes is (((Et$\sb2$N)$\sb2$bpy)$\sb2$Ru(pyz-LH)Ru(Me$\sb{\rm n}$bpp)(R$\sb2$mal)) $\sp{3+}$, where (Et$\sb2$N)$\sb2$bpy is 4,4$\sp\prime$-bis($N,N \sp\prime$-diethylamino)-2,2$\sp\prime$-pyridine and pyz-LH is 3-methyl-5-pyrazyl-pyrazole or 2-pyrazylbenzimidazole. These bimetallic complexes were specifically designed to investigate the relationships between the electrochemically measured proton-coupled electron-transfer process and the spectroscopically measured intervalence (IT) band in the mixed-valence complex. The reversible pH-dependent behavior of the IT-bands gives direct evidence of reversible pH-induced electron transfer between the metal centers. / Source: Dissertation Abstracts International, Volume: 54-12, Section: B, page: 6199. / Major Professor: Kenneth A. Goldsby. / Thesis (Ph.D.)--The Florida State University, 1993.

My work involved the synthesis, physical characterization, and studies into the chemical reactivity of various titanium, vanadium and chromium complexes of the macro-cyclic ligand (C(,22)H(,22)N(,4))('2-). These compounds were characterized using a variety of physical methods including ESR, NMR, IR Spectroscopy, cyclic voltammetry, and X-ray diffraction structure analysis, where appropriate. / The reaction of vanadyl acetate with the free ligand yields VO(C(,22)H(,22)N(,4)), which was structurally characterized. The vanadyl oxygen may subsequently be removed to give an extremely reactive (very water and oxygen sensitive) intermediate V((,22)H(,22)N(,4))Cl(,2)(.)HCl. The dihalovanadium (IV) complex reacts with a variety of small molecules including H(,2)S, NH(,3), and H(,2)O forming the sulfo, (mu)-nitrido dimer, and the starting vanadyl derivatives, respectively. / The analogous Ti(C(,22)H(,22)N(,4))Cl(,2) complex, prepared from TiCl(,4) and the free ligand, is less readily hydrolyzed than V(C(,22)H(,22)N(,4))Cl(,2)(.)HCl. An X-ray diffraction analysis of the structure revealed cis coordination of the two chloride ligands, leading to an approximate trigonal prismatic geometry of the inner coordination sphere. Several other complexes with cis geometry were prepared from a variety of ligands including catechol, 3,4dimercaptotoluene, oxalate, and 2,4pentanedione. A number of oxygen containing derivatives were isolated and characterized including the oxo compound TiO(C(,22)H(,22)N(,4)), the dimer O{Ti(C(,22)H(,22)N(,4))}(,2)X(,2), and a peroxo complex TiO(,2)(C(,22)H(,2)N(,4)). Two novel sulfur derivatives were prepared TiS(C(,22)H(,22)N(,4)) and TiS(,2)(C(,22)H(,22)N(,4)). The latter compound contains a coordinated persulfo ligand and is the only example of this type of coordination (that we are aware of) among the first row transition metals. Both TiS(,2)(C(,22)H(,22)N(,4)) and TiO(,2)(C(,22)H(,22)N(,4)) react with the atom transfer reagent P(C(,6)H(,5))(,3) to give S=P(C(,6)H(,5))(,3) and O=P(C(,6)H(,5))(,3), respectively. / Studies of chromium reaction chemistry in this ligand are currently being completed. The chromium chemistry is complicated by sensitivity to H(,2)O and O(,2), leading to irreversibly oxidized and decomposition products. The reaction of anhydrous CrCl(,3) with free ligand, in the presence of Zn, produces Cr(C(,22)H(,22)N(,4))(S)Cl where S is a coordinated solvent molecule, typically CH(,3)CN. Excess pyridine can be displaced both the solvent and the coordinated chloride. A bis-methoxy complex Cr(C(,22)H(,22)N(,4))(OMe)(,2) is prepared by the action of NaOMe or Cr(C(,22)H(,22)N(,4))(CH(,3)CN)Cl. A novel product in whichCH(,3)CN has added at the methine carbon atom of the pentanedionato / chelate ring to produce a pentadentate macrocyclic ligand can beisolated as the SCN('-) adduct,(' )Cr(C(,22)H(,22)N(,4))(-C=N)NCS. / (VBAR) / CH(,3) / Source: Dissertation Abstracts International, Volume: 43-08, Section: B, page: 2547. / Thesis (Ph.D.)--The Florida State University, 1982.

The rate constants for thorium dissociation from humic acid, PMA (polymaleic acid) and PMVEMA (poly -methylvinylether/maleic acid ) were measured in the pH range of 4.20 to 5.94. The rate of thorium dissociation from these polyelectrolytes was determined by measuring the rate at which thorium was complexed with an exchange ligand. Arsenazo III was employed as the exchange ligand and its complexation of thorium was monitored by visible spectroscopy. / The dissociation of thorium from these polyelectrolytes occurred by several first order pathways. These pathways fit into two categories based on their dependence on pH, temperature and the amount of time thorium was in contact with the polyelectrolyte prior to dissociation. The first category was interpreted as dissociation of territorial bound thorium and thorium bound to specific sites on the surface of the polyelectrolyte. These types of bound thorium formed quickly and had large dissociation rate constants. Dissociation of territorial bound thorium as well as thorium bound to sites on the surface of the polyelectrolyte would be expected to have small activation energies and large negative activation entropies (from solvation of the charged group of the polyelectrolyte which releases thorium). Less than 6 (+OR-) 1 KJ/mole activation energy and between -250 (+OR-) 20 and -300 (+OR-) 20 joule/mole-(DEGREES)K of activation entropy was found for this category of thorium dissociation. / The second category of dissociation pathways was interpreted as dissociation of thorium from binding sites located within the coiled structure of the polyelectrolyte. This type of bound thorium formed very slowly and had small dissociation rate constants. The dissociation of internally site bound thorium should have large activation energies and activation entropies comparable to that for thorium bound to the surface of the polyelectrolyte. Between 20 (+OR-) 2 and 30 (+OR-) 2 KJ/mole activation energy and from -200 (+OR-) 20 to -250 (+OR-) 20 joule/mole-(DEGREES)K activation entropy was found for this category of thorium dissociation. / Source: Dissertation Abstracts International, Volume: 46-10, Section: B, page: 3433. / Thesis (Ph.D.)--The Florida State University, 1985.

The chemistry of early transition elements (Ti, V, Mo, W) with the macrocyclic ligands C(,22)H(,24)N(,4) and H(,2)TPP (tetraphenylporphyrin) has been demonstrated to be more versatile than the exhaustively studied macrocyclic complexes of transition metal from the right hand side of the periodic table. / New (mu)-oxo bridged heterobinuclear dimer complexes have been obtained from the reaction of titanyl and vanadyl species with other metal complexes. The V=O group of VO(C(,22)H(,22)N(,4)) reacts with highly oxophilic Lewis acids such as B(C(,6)H(,5))(,3) and -Si(CH(,3))(,3) yielding (mu)-oxo heterobinuclear compounds (C(,22)H(,22)N(,4))V=O-B(C(,6)H(,5))(,3) and C(,22)H(,22)N(,4)) V-O-Si(CH(,3))(,3) ('+). The Ti=O bond of Ti(O)(C(,22)H(,22)N(,4)) is much more reactive than the V=O group, it forms donor-acceptor complexes with a variety of metal complexes to give (mu)-oxo bridged heterobinuclear complexes of the type, (C(,22)H(,22)N(,4))Ti-O-M'L(M'=Fe('2+), Fe('3+), V('3+), Mn('2+), Cr('3+), Sn('4), MO(DEGREES), L = salen, TPP('2-), CO). The IR spectra and crystal structures indicate that Ti-O bond largely retains its double character. / Mo(CO)(,6) reacts with H(,2)TPP to yield a molybdenum-molybdenum quadruply bonded dimer complex. This discovery, in essence, corrects a fifteen year old literature report, which originally reported the synthesis of Mo(O)(OH)(TPP). The crystal structure shows the geometry of Mo(,2)N(,8) is nominally eclipsed with a twist angle of 18(DEGREES). The temperature dependent ('1)H NMR spectra show two distinguishable species at -95(DEGREES)C as result of minimum rotation of the Mo-Mo (delta) bonding. The activation barrier to rotation was estimated to be 6.3 kcal/mol from NMR line shape analysis. / W(V) porphyrin complexes react with H(,2)O(,2) yielding an unusual tungsten (VI) porphyrin complex having oxo and peroxo groups in cis coordination positions. Furthermore these groups are eclipsed with respect to the porphyrin nitrogen atoms. Two quite different W-N bond distances are observed. This non-equivalence of two types of trans bonding with respect to the nitrogen atoms leads to the most warped porphyrin skeleton known to data. W(O)(O(,2))(TPP) undergoes an intramolecular oxidative reaction at room temperature in which it appears that the coordinated peroxide oxygenates and breaks up the porphyrin ligand. / Ti(C(,22)H(,22)N(,4))Cl(,2) reacts with NaC(,5)H(,5) yielding a new type of sandwich complex Ti(C(,22)H(,22)N(,4))(C(,5)H(,5)). It consists of a minicycle (C(,5)H(,5)('1-)) and the tetraazo macrocyclic C(,22)H(,22)N(,4)('2-). / Source: Dissertation Abstracts International, Volume: 47-08, Section: B, page: 3352. / Thesis (Ph.D.)--The Florida State University, 1986.

This dissertation seeks to determine the differences in the lanthanides and later actinides in non-aqueous media. Research in the f-elements is significantly understudied compared to the other metals of the periodic table. Even more so are the later actinides which were largely unstudied for an extended period as it was believed later actinides were identical to lanthanides. A review by Neidig et al, "The Covalency in f-element Complexes" has ignited significant interest in the bonding of the actinides.1 A tremendous amount of research in the f-elements, particularly the actinides, has been performed in aqueous conditions at high temperatures and pressures. Chemistry under these conditions limit the research possible for lower oxidation states. Additionally, non-aqueous techniques allow for the investigation of these elements in more organic environments. The goal of this work is to pave a greater understanding of knowledge for lanthanides and actinides by examining their redox and coordination chemistries in these environments that could lead to applications other than nuclear energy and weapons. The first portion of this dissertation examines the chemistry that is already heavily acknowledged about f-elements: coordination chemistry. When modeling later actinides, a common notion is to utilize the isoelectronic lanthanide as the surrogate. Although for electronic comparisons this is useful, it is often not the case for examining isostructural compounds. The isoelectronic lanthanide is often smaller in ionic radius, which is a factor that dominates the chemistry of the lanthanides. Despite this, isolation of isostructural coordination compounds was obtained for the isoelectronic and size analogs of americium; europium and neodymium. This seemingly mundane study showed that americium portrays a small amount of covalency in its bonds which is not observed in the lanthanides. These small differences lead to profound changes in chemical properties as observed later in this work. The second portion of this work focuses on analyzing the divalent oxidation state of f-elements with crown ethers. The divalent oxidation state has been obtained for all lanthanides using potassium and 2.2.2-cryptand. The next step was to determine the extent to which crown ethers and solvents have on the redox properties of f-elements. Because all the lanthanides had been obtained in the divalent oxidation state in a similar matter, it was expected that the redox chemistries would behave identically. To surprise, ytterbium behaves differently and shows greater reversibility than the most stable divalent lanthanide, europium. Additionally, it was found that californium also behaves like ytterbium electrochemically, even though it would be expected to behave like samarium. It was proposed that this may be attributed to the 5f orbitals. The last of this work involves obtaining californium in the divalent oxidation state as a molecular system. This was done by modeling with samarium which is the most similar to californium in its redox and coordination properties. Quick and simple routes to synthesizing divalent samarium structures were obtained in ordinary glovebox conditions for attempts with californium. Under identical reaction conditions, isolation of Cf(II) crystals in the solid state were unsuccessful. However, interesting spectroscopic properties where observed that portrayed divalent californium as having tunable luminescence similar to divalent europium compounds. To our surprise, even though samarium resembles californium, the chemistry between the two elements are very different, further broadening the gap between the 4f and 5f elements. / A Dissertation submitted to the Department of Chemistry and Biochemistry in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Fall Semester 2018. / September 28, 2018. / Actinides, Californium and Americium, Coordination Chemistry, Divalent Samarium, Lanthanides, Redox Chemistry / Includes bibliographical references. / Thomas E. Albrecht-Schmitt, Professor Directing Dissertation; Samuel L. Tabor, University Representative; Kenneth G. Hanson, Committee Member; Yan-Yan Hu, Committee Member.

In the 2018 Nuclear Posture Review, it has been emphasized that the continued production of nuclear materials is and will continue to be an essential part of American interest and policy. Necessarily, the cleanup and environmental management of excess nuclear waste, especially from the Cold War era, also continues to be an ongoing effort. For example, just the disposition of legacy plutonium, amounting to 34 MT, is not scheduled to be complete for several decades. The electrochemistry of lanthanide and actinide ligand complexes has been studied to various degrees. In some cases, this area has been very understudied. Most of the known coordination complexes are unstudied. Plutonium as an element perhaps presents some of the most interesting redox phenomena, exhibiting up to four oxidation states simultaneously in solution. Later actinides berkelium and californium have very scarce published literature, especially non-aqueous based electrochemistry. Other physical data such as log β and diffusion coefficients are also hard to find for many actinides. The beginning chapters focus on a well-studied ligand, 2,6-pyridinedicarboxylic acid (H2DPA) that has been well-characterized in solid-state methods for the lanthanides and actinides. This ligand has almost exclusively been studied under aqueous conditions, yet for reductive efforts with elements such as Sm, developing a non-aqueous approach was preferred. Detailed solubility investigations are provided, as well as detailed studies with cerium and plutonium, and finally studies with europium and samarium. The next set of chapters deals with later actinide investigations. For reductive electrochemistry with californium, detailed studies with cryptand were developed with the lanthanides. A preferred method was developed that was ultimately used to obtain novel data for californium. In the case of Bk, a pyridyl nitroxide ligand (pyNO) was used to collect the first non-aqueous cyclic voltammogram for this element. Lastly, the final chapter covers a few others systems that were given some efforts. Many of these systems have very interesting electrochemistry, but they were beyond the scope of just one dissertation to complete. These include Schiff bases and DOPO chemistry. The Schiff base data adds insightful data along with the tetravalent chemistry studied in earlier chapters, while the DOPO chemistry covers non-innocent redox phenomena affected by Pu. / A Dissertation submitted to the Department of Chemistry and Biochemistry in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Fall Semester 2018. / September 27, 2018. / Actinides, Berkelium, Californium, Cyclic Voltammetry, Electrochemistry, Lanthanides / Includes bibliographical references. / Thomas E. Albrecht-Schmitt, Professor Directing Dissertation; Todd Adams, University Representative; Yan-Yan Hu, Committee Member; Michael Shatruk, Committee Member.

Source: Dissertation Abstracts International, Volume: 31-09, Section: B, page: 5245. / Thesis (Ph.D.)--The Florida State University, 1970.

The nickel (II) complex of the macrocyclic ligand 7,16-dihydro-6,8,15,17-tetramethyldibenzo{b,i}{1,4,8,11}-tetraazacyclotetradecinato (abbreviated Ni TMTAA) undergoes an oxidative dimerization reaction at the 7,16-positions. The complexes of cobalt (III) and other early transition metals are stable to this reaction. In order to study the factors that govern the course of this reaction the characteristics of the oxidized species were investigated. To stabilize the ligand to the coupling reaction to allow spectroscopic observation of the oxidized complexes, the 7 and 16 positions were encumbered by attachment of benzoyl groups. The nickel (II) and cobalt (III) complexes of the disubstituted ligand were electrochemically oxidized and studied via ESR and visible spectroscopy. The oxidized nickel complex is characterized as a distinctive 6-coordinate Ni(III) species in strongly coordinating media. In weakly to moderately coordinating solvents the oxidized compound is 4 or 5 coordinate and is intermediate between a metal-based and a ligand-based radical. The oxidized cobalt compound is predominately a ligand-based radical with a ('59)Co hyperfine of only 13 G. A mechanism for the dimerizaton based on the inhibitory effects of axial ligands is offered to account for the large stability differences between the oxidized nickel and cobalt complexes of the unsubstituted ligand. / In a related study, the sensitivity of anodic redox processes of Ni TMTAA to substitution on the macrocyclic ligand was investigated. A number of complexes derived from three patterns of substitution were prepared. Nine previously unreported compounds have been synthesized. The E(, 1/2) values of the first oxidation wave were measured by cyclic voltammetry. The substitution sensitivities of this process were quantitated by the Hammett equation and expressed in terms of (rho) values. The (rho) values obtained are discussed and compared to similar studies with other tetraaza macrocyclic complexes including metalloporphyrins. / The synthetic methodology developed for the substituted Ni TMTAA complexes was exploited for the preparation of a "capped" macrocyclic ligand. The iron(II) complexes of such a ligand have potential applications to reversible oxygenation studies. The synthesis and prelimary characterization of the nickel(II) complex is reported. There are some indications that the isolated compound may be in fact a cofacial dimeric species rather than a monomer. / Source: Dissertation Abstracts International, Volume: 43-07, Section: B, page: 2204. / Thesis (Ph.D.)--The Florida State University, 1982.

Source: Dissertation Abstracts International, Volume: 40-09, Section: B, page: 4291. / Thesis (Ph.D.)--The Florida State University, 1979.

Source: Dissertation Abstracts International, Volume: 40-09, Section: B, page: 4293. / Thesis (Ph.D.)--The Florida State University, 1979.