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The preparations of multinuclear supramolecules assembled from ethynylferrocene(s) redox-active subunit end-capping with [(£b5-C5H5)(dppe)Ru] metal centers are described. Electrochemical measurements indicate that ferrocenyl-ethynyl spacers appear to be promising spacers which can ensure fast and quantitative transfer of information between two Ru2+ metal centers.

Over the last decade, the classic organic donor tetrathiafulvalene (TTF) has emerged as an important functionality in supramolecular systems and complex ligand chemistry. Due to synthetic advances, TTF is no longer a moiety strictly limited to the area of charge transfer salts in material science. In fact, many complex systems incorporating the electron rich donor system are known. More can be imagined. This doctoral dissertation describes the author's journey in designing, synthesizing, and studying various compounds in which the TTF moiety serves a practical purpose, oftentimes giving known molecules new functions. The reported findings have led to a greater understanding of anion binding effects on TTF-containing anion receptors, the use of transition metals to pre-organize [pi]-faces for through-space donor-acceptor interactions, and the introduction of actinide species to tetrathiafulvalene ligands. The first Chapter provides a brief introduction and a short history of TTF chemistry. It also provides an overview describing the fundamental properties of TTF compounds, including TTF dimeric behavior and redox properties. Chapter 2, as the major focus of this dissertation, details the use of a flexible TTF-modified macrocyclic ligand, which upon metallation can effectively preorganize two TTF units to interact when oxidized. Specifically, a new way to stabilize the through-space mixed-valence TTF dimer, in which a transition metal can affect the degree of interaction between the two TTF units, is described. The mixed-valence TTF species in question could see use as components in molecular machines and could play an important role as molecular organic conductors, and discussions along these lines are included in this chapter. These mixed valence complexes were investigated by spectroscopic (¹H-NMR, UV-Vis NIR titrations, and EPR analysis) and X-ray single crystallographic analyses involving both the neutral and oxidized products. Chapter 3 introduces the synthesis, characterization, and electrochemistry of the first TTF-ligand to form a complex with an actinide cation. Chapter 4 details the synthesis, binding studies and X-ray single crystallographic analyses of a TTF-based electrochemical sensor for dihydrogen phosphate anion detection. Experimental procedures and characterization data are reported in Chapter 5. / text

The hetero-bimetallic mixed valence metal polycyanides (Prussian Blue analogues (PBAs)) with formula AxMII[M’III(CN)6]y (where A= alkali-metal cation and M, M’= transition-metal cations respectively) are archetypal examples of molecule-based magnets, exhibiting a wealth of exotic electronic and magnetic behaviours. Similar intriguing electronic and magnetic properties are anticipated in nanoscale structures employing the PBA molecular building block. Herein investigations of multifunctional molecular magnets based on the PBA building block, with varying dimensionalities, are reported. Synthesis and characterisation of a novel family of mixed ferri-ferromagnets, RbNizMn(1-z)[Fe(CN)6] (0<z<1), illustrates how relatively minor changes in chemical composition can induce significant changes in the magnetic properties. Selected members of this series show photo-induced electronic transitions and pressureinduced magnetic pole inversions. The rare phenomenon of a double magnetic pole inversion is observed when FeII is introduced as a third MII ion. PBAs incorporating the Cu2+ ion are studied with the aim of establishing the influence of Jahn-Teller distortions on the photo-induced electron transfer which has been observed in a number of PBAs. X-ray powder diffraction and absorption measurements of CsCu[Fe(CN)6] under laser illumination reveal an unusual and unexpected behaviour, with photo-irradiation initiating a simultaneous reduction of both transition metal centres, which is proposed to occur via a chemical reaction. Superparamagnetic nanoparticles based on the CuII-NC-CrIII and Mn-NC-CrIII moieties are prepared by polymer protected synthesis, a method based upon spatial confinement. Control over the particle size, and consequently magnetic properties, of the isolated polymer-capped nanoparticles is achieved by altering the polymer concentration. The relaxation dynamics of the polymer-capped nanoparticles are studied using AC susceptibility.

A series of dimolybdenum compounds having a Mo2 4+ core coordinated by various ligands, including formamidinate (e.g. DAniF = N, NN-di-p-ansisylformamidinate ), acetate and/or acetonitrile molecules, have been synthesized as building blocks for the construction of Mo2-containing supramolecular arrays. Compound Mo2(DAniF)3(O2CCH3) was specifically designed for the preparation of dimolybdenum pairs, whereas the others meet the needs of Mo2 4+ units for different geometry settings. Compounds described by a general formula [Mo2]L[Mo2], where [Mo2] = [Mo2(DAniF)3]+, have two dimetal units electronically coupled by the central unit L , which consequently engender significant impact on the redox property and electronic structure of the molecule. It is found that in the weakly coupled complex system, [Mo2]M(OCH3)4[Mo2] (M = Zn and Co), the mixed-valence complexes present asymmetric molecular structures with two distinct [Mo2] units corresponding to be a bond order 4.0 (F2B4*2) and 3.5 (F2B4*1), respectively. EPR and magnetic susceptibility measurements for the doubly oxidized species show that there is no significant antifferromagnetic spin coupling. Electron delocalization occurs in the complex system where a N, N'-dimethyloxamidate binds two [Mo2] units within two fused six-membered rings. In this case, the mixed-valence complex has a symmetric molecular structure, implying that the odd electron is fully delocalized over two [Mo2]units. Strong metal-metal interaction is also evidenced by intervalence charge transfer of the mixed-valence species and the diamanetism of the doubly oxidized complex. Remarkably, two isomers varying in linkage conformation, namely, alpha and beta, have been isolated as diaryloxamidate ligands are used as the linker. Studies on the neutral and the oxidized compounds of the two isomers by employing various techniques consistently show that in the alpha form intramolecular electron transfer is blocked , while in the beta form, the electrons are delocalized over the two [Mo2] units. Thus, the mixed-valence complexes of the two isomers are appropriately described by alpha-[Mo2]0(oxamidate)[Mo2]1+ and beta- [Mo2]0.5+(oxamidate)[Mo2]0.5+ respectively.

A series of conformationally constrained 2,6-bisferrocenylphenyl thioethers were synthesized via Suzuki-Miyaura cross coupling reactions. Structural information was obtained using X-ray crystallography and dynamic ¹H NMR spectroscopic studies, showing highly constrained m-terphenyl systems. Interaction of the ferrocene moieties through space mediated by the sulfur were studied by ultra-violet photoelectron spectroscopy (UPS), cyclic voltammetry, differential pulse voltammetry, UV-Vis-NIR spectroscopy and DFT computations. Electrochemical results show two, fully reversible 1e⁻ redox processes for the ferrocenes where the separation of peaks is affected by both solvent and supporting electrolyte, suggesting significant electrostatic interaction which is further confirmed in the gas phase by UPS studies. To determine if these interactions could be observed at greater distances, extended m-terphenyl complexes were shown in which 2-sulfur and 3-aromatic moieties were synthesized using a developed selective Suzuki-Miyaura monocoupling procedure in good yields. In these systems, interaction was not observed by electrochemistry or UPS. This suggests the distance between redox centers (~16 Å) is too great for electrostatic interaction, even though there is enhanced interactions observed in the truncated systems. Two new bisferrocenylphenylsulfoxides were also synthesized and studied to determine the effect of the polar sulfoxide bond on through space interaction between the ferrocene moieties. The electronic and redox properties of these compounds were studied by ultra-violet photoelectron spectroscopy, cyclic voltammetry, differential pulse voltammetry, and DFT computations. Electrochemical results for 2,6-bis(ferrocenyl) thioanisole S-oxide show two, fully reversible one electron redox processes. The initial oxidation shows a 62 mV negative shift compared to the sulfide analog 2,6-bis(ferrocenyl)thioanisole, and an increased peak separation for the oxidations of 160 mV. No peak separation is observed in the extended sulfoxide system. No intervalence charge transfer band was observed in the truncated sulfoxide complex by monitoring the UV-Vis/NIR spectroscopy of the mixed valence complex, ruling out electronic communication. Thus, the through space electrostatic interactions of the sulfoxide causes the non-equivalent ferrocenes in the truncated system to have different oxidation potentials. Synthesis was developed towards the synthesis of 1,8-bisferrocenyl-9-(alkylthio) anthracene complexes. It was observed that due to steric congestion at the C9 position of the anthracene scaffold, standard thionation reactions did not proceed as expected. Instead, the reaction of 1,8-dibromo-9-anthrone with Lawesson reagent afforded the intramolecular nucleophilic aromatic substitution cyclization product in quantitative yields. The reaction of the same anthrone under studied dithioketal formation conditions led to sulfur-rearrangement, giving the undesired 1,8-bisferrocenyl-10-(ethylthio)anthracene derivative, as confirmed by X-ray crystallography. Attempted Newman-Kwart rearrangement of 1, 8-dibromoanthracen-9-yl) dimethylcarbamothioate afforded no significant observed product formation, and decomposition of starting materials when heated for extended times. 1,8-bisferrocenyl-9-(methoxy)anthracene was synthesized and structurally characterized by dynamic X-ray crystallography to confirm connectivity. Electrochemical experiments show 2 reversible redox processes separated by 115 mV. Chemical oxidation experiments show unexpected, strong electronic coupling in the mixed valence complex. This coupling was characterized by near-IR absorption at 941 nm, indicating intervalence charge transfer (IVCT). Single electron reduction of 1,8-bisferrocenyl-9-(methoxy)anthracene, followed by quenching with various electrophiles afforded an inseparable mixture of products, one of which was identified by mass spectrometry as the desired 1,8-bisferrocenyl-9-(methylthio)anthracene product. However, this complex was not separable from the mixture and further characterization was not possible. All other routes attempted to incorporate sulfur into the system afforded no conversion of starting materials or decomposition of the reaction mixture.

SILVA, Maria Aparecida Santiago da. Síntese e Caracterização do Composto Heterobimetálico trans-[(SO3)(cyclam)Co-NCS-Ru(NH3)4(NCS)](BF4). 2009. 101 f. Dissertação (Mestrado em química)- Universidade Federal do Ceará, Fortaleza-CE, 2009. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-06-02T19:19:53Z No. of bitstreams: 1 2009_dis_massilva.pdf: 2887733 bytes, checksum: 595bebd5e087742ed6f88b835417ecf7 (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-07-20T19:55:07Z (GMT) No. of bitstreams: 1 2009_dis_massilva.pdf: 2887733 bytes, checksum: 595bebd5e087742ed6f88b835417ecf7 (MD5) / Made available in DSpace on 2016-07-20T19:55:07Z (GMT). No. of bitstreams: 1 2009_dis_massilva.pdf: 2887733 bytes, checksum: 595bebd5e087742ed6f88b835417ecf7 (MD5) Previous issue date: 2009 / Trans-[Co(cyclam)(SO3)(NCS)]·4H2O, trans-[Ru(NH3)4(NCS)(SO4)], and trans-[(SO3)(cyclam)Co−NCS−Ru(NH3)4(NCS)](BF4) complexes, where cyclam = 1,4,8,11-tetraazacyclotetradecane, were synthesized and characterized by X-ray difraction, vibrational and electronic (ultraviolet, visible and near infrared) spectroscopies, and electrochemical techniques. The electronic communication between Co and Ru metal centers of the binuclear complex was evaluated by electrochemistry and electronic spectrocopy in the near infrared region. Crystals suitable for X-ray studies were only isolated for the trans-[Co(cyclam)(SO3)(NCS)]·4H2O complex. The obtained results indicate a monoclic structure with cyclam ligand at the equatorial plane and SO32− and NCS− moieties occupying the axial positions being coordinated through, respectively, sulfur and nitrogen atoms. This result is reinforced by the observation, in the vibrational spectrum, of bands typically assigned to the cyclam ligand in a trans configuration. The cyclic voltammograms obtained for this compound indicate as Electrochemical-Chemical-Electrochemical mechanism. In fact, the spectroelectrochemical experiments obtained at -0.80 V vs Ag/AgCl show that this compound, upon reduction, suffers a substitution reaction in which the SO32− and NCS− moieties are replaced by solvent molecules (L) thus forming [Co(cyclam)(L)2]2+ type complexes. The observation in the vibrational spectrum of the trans-[Ru(NH3)4(NCS)(SO4)] complex of the 2132, 887 e 478 cm-1 bands assigned, respectively, to the νCN, νCS e δ(NCS) vibrational modes of the NCS− ligand indicates that this moiety is coordinated through the nitrogen atom. Electrochemical and spectroscopic studies of this compound in aqueous medium indicate that the reduction of the metal center induces the replacement of SO42− ligand by a water molecule. The synthesis of the binuclear compound, therefore, was made under reductive conditions aiming to produce the aquo-complex and, then, replace the water molecule by a coordination site of the trans-[Co(cyclam)(SO3)(NCS)]·4H2O complex. The results obtained for the isolated material hints that the binuclear complex is formed with the NCS− fragment as the bridge ligand. The acquired cyclic voltammogram presents two redox process with the half-wave formal potentials (E1/2) observed at −0.27 and 0.13 V vs Ag|AgCl and being assigned to the Co and Ru metal centers, respectively. In comparison to the monomers, the positive potential shift reflects the stabilization of the reduced state of the ruthenium metal atom (RuII) and the destabilization of the cobalt metal center (CoIII). This result is assigned to the coordination to an oxidated metal center, CoIII, whose effective nuclear charge increased the electronic delocalization increasing the withdrawing character of the NCS− bridge ligand. The comproportionation constant, Kc = 5.78 x 106, was calculated from the difference between the E1/2 values. The Kc value indicates a strong electronic communication between the metal atoms and classifies this binuclear complex as a mixed valence system of class II. / Os compostos trans-[Co(cyclam)(SO3)(NCS)]·4H2O, trans-[Ru(NH3)4(NCS)(SO4)] e trans-[(SO3)(cyclam)Co−NCS−Ru(NH3)4(NCS)](BF4), onde cyclam = 1,4,8,11-tetraazaciclotetradecano, foram sintetizados e caracterizados por difrações de raios-X, espectroscopias vibracional na região do infravermelho e eletrônica nas regiões do ultravioleta e visível (UV-Vis) e por técnicas eletroquímicas. O grau de comunicação eletrônica entre os átomos de Co e Ru do complexo binuclear foi avaliado por eletroquímica e espectroscopia eletrônica na região do infravermelho próximo. Apenas para o complexo trans-[Co(cyclam)(SO3)(NCS)]·4H2O foi possível a obtenção de cristais que permitiram a determinação estrutural. Os dados obtidos indicam estrutura monoclínica com o ligante cyclam no plano equatorial e os ligantes SO32− e NCS− ocupando posições trans e coordenados ao átomo de Co através, respectivamente, dos átomos de S e N. Este resultado é reforçado através da observação, no espectro vibracional, de bandas tipicamente atribuídas ao ligante cyclam quando este se encontra em uma geometria trans. Os resultados de voltametria cíclica deste composto indicam um mecanismo eletroquímico-químico-eletroquímico. De fato, os experimentos de espectroeletroquímica (potencial controlado em -0,80 V vs Ag/AgCl) indicam que este composto experimenta, após redução, reação de substituição das moléculas SO32− e NCS− por moléculas do solvente (L), formando compostos do tipo [Co(cyclam)(L)2]2+. A observação, no espectro vibracional do complexo trans-[Ru(NH3)4(NCS)(SO4)], das bandas em 2132, 887 e 478 cm-1, atribuídas aos modos de νCN, νCS e δ(NCS), respectivamente, do ligante NCS−, indica a coordenação deste grupo através do átomo de nitrogênio. Estudos eletroquímicos e de espectroscopia eletrônica deste composto em meio aquoso indicam que a redução do centro metálico induz a reação de substituição do ligante SO42− por uma molécula de H2O. A reação para formação do composto binuclear, portanto, foi realizada em condições redutoras a fim de induzir a formação do aquo-complexo de rutênio e, em seguida, a reação de substituição da molécula de H2O por um sítio de coordenação do monômero trans- [Co(cyclam)(SO3)(NCS)]·4H2O. Os resultados obtidos para o material isolado indicam que há a formação do complexo binuclear com o ligante NCS− ocupando a posição ponte. A curva voltamétrica obtida para este composto apresenta dois pares de ondas redox com potenciais formais de meia-onda (E1/2) em −0,27 e 0,13 V vs Ag|AgCl atribuídos, respectivamente, aos centros metálicos de Co e Ru. Comparativamente aos monômeros, há a observação de um deslocamento positivo de potencial o que reflete a estabilização do estado reduzido para o átomo de rutênio, RuII, e desestabilização do estado oxidado para o átomo de cobalto, CoIII. Este resultado é atribuído a coordenação a um centro oxidado, CoIII, cuja carga nuclear efetiva aumenta a deslocalização de densidade eletrônica aumentando o caráter retirador do ligante ponte NCS−. O valor da constante de comproporcionamento, Kc = 5,78 x 106, calculada a partir da diferença entre os valores de E1/2, indica um forte grau de comunicação entre os centros metálicos e classifica este complexo como um sistema de valência mista de classe II.

Title: Electron properties of the substituted cerium compounds Author: Milan Klicpera Department: Department of Condensed Matter Physics Supervisor: doc. Mgr. Pavel Javorský Dr. Abstract: The subject of this work is the study of vibron states in tetragonal CeCuAl3 and CePd2Al2 compounds and their development with the substitution of constituent elements. After the preparation of single crystals and polycrystalline samples, the careful chemical and structural characterization was done. The structural, magnetic and superconducting phase transitions in samples were observed and thoroughly investigated. The crucial experiments were performed using the elastic and inelastic neutron scattering techniques leading to the refinement of magnetic structures in CeCuAl3, CePd2Al2 and CePd2Ga2. The energy spectra of substituted Ce(Cu,Al)4 and CePd2(Al,Ga)2 compounds were studied as well allowing to determine the crystal field excitations and their interaction with phonons (vibron states) in these materials. Keywords: cerium internetallic compounds, vibron states, electronic properties, neutron scattering

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第21073号 / 工博第4437号 / 新制||工||1690(附属図書館) / 京都大学大学院工学研究科分子工学専攻 / (主査)教授 佐藤 啓文, 教授 関 修平, 准教授 伊藤 彰浩, 教授 梶 弘典 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM