INFORME FINAL"Alguns importants descobriments de la ciència són accidentals. Això fou, certament, el cas del ful·lerè C60. Quan ara fa quatre anys, l'any 2000, vaig iniciar el treball d'investigació sobre els metal·loful·lerens m'havien arribat veus de la importància mediàtica d'aquestes noves estructures però no de la intensa història del seu descobriment. Aquesta m'ha fascinat. Sobretot quan l'any 2003 vaig tenir la possibilitat de fer una estada al grup del professor Kroto de la universitat de Sussex (Gran Bretanya). Llavors els textos, sorprenents però inerts, que havia llegit sobre la història del descobriment dels ful·lerens prenien forma en espais coneguts i personatges propers". Aquest és el prefaci de la meva tesi. Segurament aquesta estada a Sussex al grup d'un dels descobridors dels ful·lerens ha estat el moment més entranyable en aquesta carrera científica per l'estudi dels metal·loful·lerens.A partir de la síntesi de la molècula de C60 en quantitats apreciables la química dels ful·lerens en general, i en particular amb metalls de transició, ha experimentat un increment espectacular. L'objectiu d'aquesta tesi és l'estudi de l'estructura i la reactivitat de diferents derivats organometàl·lics de ful·lerens o metal·loful·lerens. El treball d'investigació usa les eines de la química computacional (Teoria del funcional de la densitat, DFT) per tal de modelar els metal·loful·lerens més interessants apareguts entre el 1999 i el 2005. Tot i que els metal·loful·lerens presenten una varietat d'estructures formidable, podem classificar-los en tres grans famílies des del punt de vista estructural: un primer grup són els metal·loful·lerens exoèdrics on els metalls es situen fora de la caixa, en un segon grup tenim els metal·loful·lerens heteroèdrics o heteroful·lerens on les caixes de carbonis han estat dopades (certes posicions han estat substituïdes) amb altres elements com ara: N, B, Si, Fe i altres metalls i finalment l'últim grup són els metal·loful·lerens endoèdrics on la derivatització metàl·lica es dóna a l'interior de la caixa. Així l'estudi teòric dels compostos més novedosos i novells de cadascuna de les tres famílies de metal·loful·lerens és el puntal de la present tesi doctoral. Per cadascuna de les famílies hem desgranat l'estructura electrònica i geomètrica, hem descrit el tipus d'enllaç metall-ful·lerè, hem avaluat els factors que intervenen en l'estabilitat relativa dels possibles isòmers, hem també predit la reactivitat davant de reaccions d'addició i finalment els hem caracteritzat des d'un punt de vista físic (càlcul del potencial d'ionització i afinitat electrònica). L'estructura electrònica ens ha permès seleccionar quins metal·loful·lerens endoèdrics seran estables avançant-nos als experimentalistes en la seva cerca de nous complexos. La diversitat de tipologies d'enllaç ha sigut tant gran com famílies de metal·loful·lerens. Hem descrit un enllaç iònic pels metal·loful·lerens endoèdrics, un enllaç covalent en el cas dels metal·loful·lerens heteroèdrics i un enllaç coordinatiu pels metal·loful·lerens exoèdrics. Hem aplicat noves metodologies per l'estudi de l'isomerisme. Les tècniques d'anàlisi multivariant de dades ens han permès esbrinar quins factors són importants per l'estabilitat relativa dels isòmers i a la vegada construir models de predicció per altres isòmers. Així doncs, l'acoblament de la química teòrica i la quimiometria ha estat sens dubte l'aportació més rellevant del present treball d'investigació.Tarragona, 28 de novembre de 2004Josep Maria Campanera AlsinaFINAL REPORT The characterisation of the most novel metallofullerenes up to 2004 has been theoretically and systematically discussed in this study. From the structural point of view, metallofullerenes can be divided into three main groups, all of which have been discussed in this study: endohedral, heterohedral and exohedral metallofullerenes. The main families of compounds studied are Sc3-nMnN@Ck (n = 0-3, M = Y, La; k = 68, 78, 80) (endohedral), CxMn (x = 56, 57, 58, 59; M = Pt, Ir, Os; n = 1, 2) (heterohedral) and (-Ck){M(PH3)2}n (k = 60, 70, 84; M = Pt, Pd, Ni; n = 1, 2, 4, 6) (exohedral). The present study is a step forward in our knowledge of each of these families of compounds, and in particular, in our understanding of the metal-carbon bond, isomerism and reactivity. The DFT method proved to be an excellent computational tool for providing good geometries, for solving the intricacies of the different metal-carbon bonds, for producing experimental data (ionization potentials and electron affinities) and also for making predictions about isomerism stability and reactivity. The principal conclusions drawn about the species studied here are: Different types of structures, different types of metal-carbon bonds. The metal units in each family of compounds are located differently in relation to the fullerene carbon framework: inside the cage, within the carbon framework and outside the cage. The encapsulation of a trimetallic nitride template unit (TNT, Sc3-nMnN; n = 0-3; M = Y, La) inside the carbon cage to produce TNT endohedral metallofullerenes is explained by an ionic pair (cage-metal) model in which the TNT unit formally transfers six electrons to the cage. On the other hand, in heterohedral metallofullerenes, metals establish a covalent metal-carbon bond without causing oxidation to the metal. Finally, the (MPH3)2 metal units situated exohedrally to the fullerene are only coordinated in a  mode to the CC bond. Chemometric tools applied to isomerism studies. The regioisomers of heterohedral metallofullerenes are numerous: for example, the stoichiometry C57Pt2 has 47 distinct regioisomers. Thus, chemometric techniques which can manage considerable amounts of data must be used if we want to understand regioisomerism in heterohedral metallofullerenes. These tools have also been very useful for drawing conclusions from the considerable quantities of data provided by the factors which affect the stability of regioisomers. These tools have been used not only for analysing data but also for predicting the stability of other heterofullerenes.TNT encapsulation stabilizes fullerene isomers that are not available as free fullerenes. TNT endohedral metallofullerenes are formed by the encapsulation of a metallic nitride template inside the following cages: D3-C68:6140, D3h'-C78:5, D5h-C80:6 and Ih-C80:7. Any of these cages have never been detected experimentally.So, endohedral metallofullerenes can make non-classical fullerene isomers available for study. Furthermore, on the basis of the electronic structure we predicted that no other IPR fullerenes between C60 and C84 will be capable of encapsulating a TNT unit, apart from the fullerene isomers that are already known.Stability of the carbon skeleton is the principal factor that determines the regioisomer stability of the heterofullerenes. Metal atoms occupy neighbouring positions in the most stable structures of C57Pt2 and C56Pt2. Metal substitution deforms the carbon framework and partially destroys the fullerene aromaticity. This is the key factor in determining the stability of these disubstituted clusters. Indeed, it is much easier to make a big hole that permits the incorporation of two Pt atoms in the carbon cage than two smaller holes in two opposite sites of the fullerene. Prediction of the exohedral reactivity taking into account the full characterization of the different CC bond types. We first performed a full characterization of all CC bond types of the fullerenes Ih-C60:1, D3-C68:6140, D5h-C70:1, D3h'-C78:5, Ih-C80:7, D2-C84:22 and D2d-C84:23. Each CC bond type is characterized by its topology, length, pyramidalization angle and Mayer bond order. This systematization enabled us to identify which sites were most reactive to a nucleophilic addition to free fullerenes or a [4 + 2] cycloaddition to TNT endohedral metallofullerenes.Tarragona, 8th Novembre 2004Josep Maria Campanera Alsina

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Thesis (Ph. D.)--University of Wisconsin--Madison, 1968. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliography.

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Thesis (PhD)--Stellenbosch University, 1975. / ENGLISH ABSTRACT: Some problems of applied mathematics, for instance in the fields of aerodynamics or electron optics, involve certain singular integrals which do not exist classically. The problems can, however, be solved pLovided that such integrals are interpreted as finite-part integrals. Although the concept of a finite-part integral has existed for about fifty years, it was possible to define it rigorously only by means of distribution theory, developed about twenty-five years ago. But, to the best of our knowledge, no quadrature formula for the numerical eva= luation of finite-part integrals ha~ been given in the literature. The main concern of this thesis is the study and discussion of.two kinds of quadrature formulae for evaluating finite-part integrals in= volving an algebraic singularity. Apart from a historical introduction, the first chapter contains some physical examples of finite-part integrals and their definition based on distribution theory. The second chapter treats the most im= portant properties of finite-part integrals; in particular we study their behaviour under the most common rules for ordinary integrals. In chapters three and four we derive a quadrature formula for equispaced stations and one which is optimal in the sense of the Gauss-type quadra= ture. In connection with the latter formula, we also study a new class of orthogonal polynomials. In the fifth and.last chapter we give a derivative-free error bound for the equispaced quadrature formula. The error quantities which are independent of the integrand were computed for the equispaced quadrature formula and are also given. In the case of some examples, we compare the computed error bounds with the actual errors. ~esides this theoretical investigation df finite-part integrals, we also computed - for several orders of the algebraic singularity the coefficients for both of the aforesaid quadrature formulae, in which the number of stations ranges from three up to twenty. In the case of the equispaced quadrature fortnu1a,we give the weights and - for int~ger order of the singularity - the coefficients for a numerical derivative of the integrand function. For the Gauss-type quadrature, we give the stations, the corresponding weights and the coefficients of the orthogonal polynomials. These data are being published in a separate report [18] which also contains detailed instructions on the use of the tables.

<p>In April 2007 we contacted Lennart Augustsson at Designpartners AB in Västerås. He came up with the idea to investigate and evaluate their construction of a interaction beam, CSB-beam. CSB is short for Connector Interaction beam. The beam is based on a horizontal C-profile of high-tensile steel and in the bottom of the profile are vertical flat bar welded so called block connectors. These block anchorsare also made of hightensilesteel. Their task is to create collaboration between the steel and the concrete.</p><p>The dimensioning of the block connectors is done according to the Swedish standard SSENV199411.The purpose of this study is to evaluate and control the formula used for the dimensioning which is found in SS-ENV 1994-1-1.There has been two main parts of this exam work. Part 1: Theoretical preliminary investigations,consisting of calculations and literature studies of block anchors. Part 2: Practical testloads of four prefabricatedCSB-beams.The results of the two parts were thencompared to see if theory corresponded to reality.</p><p>The result shows that the comparison of the formula in Swedish standard, SS-ENV 1994-1-1 can be used for dimensioning of block connectors in interaction beams.</p>