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The contents of this Thesis herein describe the catalytic asymmetric epoxidation of simple unfunctionalised alkenes. The first chapter, the introduction, describes some of the most successful procedures to date with respect to the asymmetric epoxidation of simple unfunctionalised alkenes. The second chapter, the results and discussion, describes previous work in the Page group in the area of asymmetric epoxidations and progresses to describe the current author's research in this area. This is focussed on the synthesis of several novel carbohydrate based dihydroisoquinolinium salt systems and their subsequent screening with respect to the asymmetric epoxidation of E-methylstilbene, triphenylethylene and 1-phenylcyclohexene. Most of the catalysts synthesised in this study were tested under both the aqueous and non-aqueous conditions developed within the Page group, where it was found that the non-aqueous conditions offered better catalytic activity for this family of catalysts. The best catalytic activities and enantioselectivities in the asymmetric epoxidation of the test substrates were obtained with some of the galactose-derived dihydroisoquinolinium salt systems. At best, enantioselectivities as high as 59% were obtained. Chapter three contains full experimental details for the synthetic studies carried out in chapter two. Finally, the appendix contains X-ray crystallographic data of two compounds synthesised in this study.

Enamine N-oxides have been reported only a very few times in the literature. Investigation into their reactivity has revealed that treatment with catecholborane can generate amines via an electrophilic iminium species, which provides evidence for a proposed reverse polarity reactivity, with respect to existing l,4-additions to nitro alkenes. Deprotonation at the a-carbon of enamine N-oxide double bonds has also been accomplished by 'BuLi, with deprotonation occurring fully after 5 min. Using methodology developed within the group, a novel enamine N-oxide has been synthesised in good yield, although attempts to form a cyclic enamine N-oxide were unsuccessful. The copper-catalysed asymmetric conjugate addition of trimethylaluminium to nitroalkenes was found to give moderate enantioselectivity (46 % ee) using Cu(OAc)2 and a phosphoramidite ligand in diethyl ether. Conjugate addition of dimethyl(alkynyl)aluminium reagents to cyclic and acyclic enones has been achieved in a racemic sense in good to excellent yields employing MTBE as the solvent with three equivalents of alkynylaluminium, although regioselectivity remains an issue depending on the enone substrate. Cross-coupling of dimethyl(alkynyl)aluminiums with aryl bromides, iodides and triflates catalysed by Pd2(dba)J'CHCh or Pd(dba)2 and DavePhos gave acetylene derivatives in good to excellent yields. These results are comparable with previously reported systems and in some cases gave improvements in yield. Using XPhos as ligand and adding DABCO, chlorobenzene was also coupled in moderate yield. Application to tetracene synthesis was not successful. Development of a novel method of alkyne hydroalumination usmg dichloroalane bis(tetrahydrofuran) adduct and catalytic Ti or Zr metallocene complexes gave high yields of vinyl aluminium reagents. Use of these reagents in Pd-catalysed cross-coupling with aryl halides gave good to excellent yields of (E)-alkenes, and is applicable to both aryl and alkyl terminal acetylenes. 1

Olefins (Ethylene and Propylene) are the most important products of the petrochemical industry, because of their wide range of applications. The global demand tor ethylene and propylene is expected to increase over tne next live years and production capacity must also increase to Keep up witti tins demand growth. There are several industrial processes for ethylene and propylene production; the most widely used process is the steam cracking process in which the hydrocarbon ieed is thermally-cracked to produce olefins. Coke is an undesirable by-product because it deposits on the internal walls of the reactor tubes, consequently reducing the heat transfer rate and increasing the pressure drop across the reactor. The reactor has to be shut down frequently for decoking. Several research studies have been conducted and new technologies developed to improve the performance of the steam cracking process.

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The research presented in this thesis aims to assess the capacity of metal organic frameworks with open metal sites for the separation of olefin mixtures. Chapter 1 provides a background to the field, including industrial separation techniques, metal organic frameworks and their applications and the current state-of-the- art for olefin separation. Chapter 3 describes the experimental techniques used in this research. Ethylene and propylene adsorption and desorption isotherms on Ni-CPO-27 and HKUST-1 at a range of temperatures are presented and compared in Chapter 4, and used to calculate isosteric heats of adsorption at varying coverages using the virial method. These pure component isotherms are used in Chapter 5 to predict selectivities for the separation of binary mixtures using ideal adsorbed solution theory. Temperature programmed desorption is used in Chapter 5 to calculate the enthalpy of desorption using Redhead's method and the heating rate variation method, and the two results are compared. The results presented in Chapters 4 and 5 conclude that propylene/ethylene separation is possible using adsorption onto metal organic frameworks with open metal sites. A new in situ environmental gas cell for single crystal X-ray diffraction is developed in Chapter 6, and the challenges encountered during this development process are discussed. The dehydration of one framework, Co-CPO-27, is studied in detail using the environmental gas cell. A dehydrated structure of HKUST-1, obtained using the gas cell, is presented for the first time. Crystal structures for the complete dehydration-adsorption-delivery cycle for biologically active NO on Co-CPO-27 are presented in Chapter 7, showing the utility of the in situ gas cell for prolonged experiments in multiple different gaseous environments. The crystal structure of NO-loaded Co-CPO-27 improves upon the models suggested in the literature, and the treatment of the dual occupancy of the open metal sites by water and NO is discussed in depth. A crystal structure of CO-loaded Co-CPO-27 is obtained for the first time, and crystal structures of Co-CPO-27 in ethylene and propylene environments are presented.

Τα αυτό -οργανούμενα μονοστρωματικά συστήματα (self-assembled monolayers, SAMs) παρουσιάζουν μεγάλο τεχνολογικό και βιομηχανικό ενδιαφέρον καθώς προσφέρουν μοναδική ευκαιρία για την κατανόηση των διεπιφανειακών φαινομένων και των διεργασιών που σχετίζονται με αυτά. Ο έλεγχος των ιδιοτήτων διαβροχής και λίπανσης της επιφάνειας , η επιλεκτική ρόφηση διαφόρων ειδών μορίων (π .χ ., μεγάλων βιολογικών μορίων) για το σχηματισμό επιπρόσθετου μονοστρώματος προς μία προεπιλεγμένη δομή (π.χ ., με συγκεκριμένο μοριακό προσανατολισμό), ο σχεδιασμός βιοαισθητήρων αλλά και άλλα παραδείγματα αποτελούν μερικές μόνο από τις πιο διαδεδομένες εφαρμογές των SAMs. Στην παρούσα εργασία εστιάσαμε στο πιο διαδεδομένο σύστημα SAM, αυτό που δημιουργείται κατά τη ρόφηση μορίων αλκανοθειολών σε επιφάνεια χρυσού (R-SH/ Au(111)). Πιο συγκεκριμένα διερευνήσαμε τις δομικές ιδιότητες καθώς και τις ιδιότητες διαμόρφωσης του σχηματιζόμενου μονοστρώματος με τη βοήθεια ενός καινούργιου αλγορίθμου Monte Carlo (MC) που σχεδιάσαμε στο εργαστήριο, βασισμένου σ’ ένα ιδιαίτερα αποδοτικό μίγμα τόσο απλών όσο και πιο σύνθετων (συχνά μη φυσικών) κινήσεων για τη δειγματοληψία απεικονίσεων του συστήματος. Η καινοτομία του αλγόριθμου MC συνίσταται στο ότι, ανεξάρτητα από την αρχική απεικόνιση του συστήματος, έχει την ικανότητα να οδηγεί αποτελεσματικά όλα τα μόρια της αλκανοθειόλης επάνω στο υπόστρωμα του χρυσού με αποτέλεσμα στο τέλος της προσομοίωσης αυτό να χαρακτηρίζεται από 100% επιφανειακή κάλυψη. Κατά τον τρόπο αυτό παρακάμπτεται ένας σημαντικός περιορισμός των προηγούμενων μεθόδων , οι οποίες ουσιαστικά προ-υπέθεταν την αρχική απεικόνιση του συστήματος (στη βάση πειραματικών δεδομένων). Επιπλέον, λαμβάνοντας υπόψη ένα εκτεταμένο σύνολο αντιγράφων του συστήματος καθένα από τα οποία προσομοιώνεται σε μία διαφορετική τιμή της διαμέτρου van der Waals των ατόμων θείου, σss, και επιχειρώντας ανταλλαγές απεικονίσεων μεταξύ συστημάτων με παρακείμενες τιμές σss, ο νέος αλγόριθμος μας επέτρεψε να προσομοιώσουμε αποτελεσματικά πρότυπα συστήματα R-SH/Au(111) για ένα φάσμα τιμών της παραμέτρου σss από 4.25 Å που αντιστοιχεί στο μοριακό μοντέλο των Hautman-Klein [J. Chem. Phys., 1988; 1989] έως 4.97 Å που αντιστοιχεί στο μοριακό μοντέλο των Siepmann-McDonald [Langmuir, 1993]. Η εφαρμογή του αλγορίθμου MC επεκτάθηκε ακολούθως σε συστήματα αλκανοθειολών ροφημένων σε διαφορετικά μεταλλικά υποστρώματα, με σκοπό τη μελέτη της επίδρασης του είδους της μεταλλικής επιφάνειας στις δομικές ιδιότητες των συστημάτων SAMs. Προς την κατεύθυνση αυτή, αρχικά εκτελέστηκαν κβαντομηχανικοί υπολογισμοί ( ab initio calculations) για ένα μόριο μεθανοθειόλης ροφημένου σε επιφάνεια χρυσού, αργύρου ή πλατίνας και τα αποτελέσματα χρησιμοποιήθηκαν για την εξαγωγή ενός κλασσικού δυναμικού για την περιγραφή των αλληλεπιδράσεων μεταξύ θείου -μετάλλου. Με το δυναμικό αυτό διεξήχθησαν στη συνέχεια ατομιστικές προσομοιώσεις MC για διάφορα μοριακά μήκη συστημάτων SAMs R-SH και στη συνέχεια έγινε ανάλυση των δεδομένων, με έμφαση στην εξάρτηση των δομικών ιδιοτήτων του σχηματιζόμενου φιλμ (μοριακός προσανατολισμός, διαμόρφωση αλυσίδων και στατιστική των ατελειών gauche) από τη φύση του μεταλλικού υποστρώματος. Στο τελευταίο στάδιο της διατριβής εστιάσαμε στη μελέτη της θερμοκρασίας υαλώδους μετάπτωσης Tg ισότροπων συστημάτων αλλά και λεπτών υμενίων πολυαιθυλενίου (PE) με τις αλυσίδες εμφυτευμένες σε σκληρή, ενθαλπικά ουδέτερη επιφάνεια και σχετικά μεγάλη πυκνότητα εμφύτευσης. Για το λόγο αυτό επεκτάθηκε η μεθοδολογία προσομοίωσης MC σε χαμηλές θερμοκρασίες (κοντά στο ή ακόμα και χαμηλότερα από το σημείο Tg) χρησιμοποιώντας την πολύ δραστική κίνηση MC αναγεφύρωσης άκρων (end-bridging, EB). Τα δεδομένα της προσομοίωσης για την εξάρτηση της πυκνότητας και της ενθαλπίας από την θερμοκρασία χρησιμοποιήθηκαν για τον υπολογισμό της θερμοκρασίας υαλώδους μετάπτωσης, με το αποτέλεσμα να συμφωνεί σχεδόν επακριβώς με την αντίστοιχη πειραματική τιμή για ημικρυσταλλικό πολυαιθυλένιο στο όριο μηδενικού βαθμού κρυσταλλικότητας (προβλεπόμενη τιμή Tg μεταξύ 220 και 240 Κ). / Self-assembled monolayers (SAMs) find numerous applications in a variety of fields: in the production of thin films from organic materials, in optics and electronics, as means for controlling the hydrophobic or hydrophilic behavior of a surface, as coatings for the protection of surfaces from corrosion, in molecular recognition, and more recently even as biosensors. In an effort to understand the mechanisms and interactions controlling chain organization and packing in these systems and how these affect their macroscopic properties, the present thesis has focused on the development of a Monte Carlo (MC) algorithm, built around a set of simpler but also more complex (sometimes non-physical) moves, for the atomistic simulation of the SAM structures formed by the adsorption of short alkanethiol molecules on a Au(111) surface. The innovation of the MC algorithm is that it is capable of efficiently driving all alkanethiol molecules to the Au(111), thereby leading to full surface coverage, irrespective of the initial setup of the system. This circumvents a significant limitation of previous methods in which the simulation typically starts from optimally packed structures on the substrate that are close to thermal equilibrium. Further, by considering an extended ensemble of configurations each one of which corresponds to a different value of the sulphur-sulphur repulsive core potential, σ ss , and by allowing for configurations to swap between different σ ss values, the new algorithm can adequately simulate model R-SH/ Au(111) systems for values of σ ss ranging from 4.25 Å corresponding to the Hautman-Klein molecular model [J. Chem. Phys., 1988; 1989] to 4.97 Å corresponding to the Siepmann-McDonald model [Langmuir, 1993]. A thorough investigation of the variation of molecular organization and ordering on the Au(111)substrate with chain length is presented. In a parallel study, the MC method was extended to alkanethiol SAM systems on different metal surfaces. This has allowed us to perform a detailed investigation of the substrate’s effect on the structure and conformation of the above systems through atomistic MC simulations based on a first-principles density functional modeling of the sulphur-metal interaction. Ab initio calculations on a methanethiol molecule adsorbed on gold, silver and platinum surfaces were conducted and the data obtained were used to develop an accurate classical force field which served as an input to the new MC algorithm. Emphasis was given primarily to the study of the effect of the substrate on the structural properties of the simulated R-SH SAM systems, like molecular orientation, molecular conformation, and statistics of gauche defects. In the last part of this thesis, and in an attempt to investigate the phenomenon of glass transition ( Tg ), the MC algorithm was employed in simulations with a less complex, than the SAM structures, system, that of amorphous polyethylene (PE). Two sets of simulations were executed: one with a bulk, isotropic sample, and the other with a thin film in which all PE chains were grafted on a hard surface on the one side and exposed to vacuum on the other. In all cases, the simulations were carried out for very long times in order for the autocorrelation function of the chain end-to-end vector to drop practically to zero. For both systems, the value of the glass transition temperature Tg was extracted using volumetric and enhtalpic simulation data and it was found to be between 220 and 240K, i.e., in remarkable agreement with measured data for semicrystalline PE in the limit of zero crystallinity. Additional results about the temperature dependence of the conformational (e.g., the equilibrium mean-square chain end-to-end distance) and structural (e.g., the intermolecular pair distribution function) properties in the two PE systems were also obtained and discussed in detail.