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In this work, the fabrication of a metal deposit atop a cyanide adlayer on a Pt(111) surface in a M-CN-Pt(111) sandwich design is attempted. The methodology also known as electroless deposition comprises electrochemically reducing pre-adsorbed metal cations (Cu2+, Ag+ and Pd2+) on a cyanide modified Pt(111) in the absence of Mz+ in the electrolyte. The cyanide adlayer on Pt(111) forms a robust and stable monolayer with an ordered adlattice on Pt(111) presenting a unique adlayer for metallization. The successful immobilization of Ag+, Cu2+ and Pd2+ cations on the cyanide adlayer prior to electrochemical reduction is evidenced through cyclic voltammetry (CV) and scanning tunnelling microscopy (STM). Particularly in the case of Cu2+ and Ag+ the observation of a honeycomb pattern that corresponds to cation coordination to the cyanide adlayer is observed. Electrochemical reduction of pre-adsorbed Cu2+ results in the observation of reversible copper nanoislands that grow via an Otswald's ripening process on the cyanide selfassembled monolayer (SAM). In the case of pre-adsorbed Ag+ on the cyanide adlayer on Pt(111), the electrochemical reduction results in the formation of a AgPt surface alloy upon consecutive potential cycling. Electrochemical reduction of pre-adsorbed Pd2+ on the cyanide adlayer on Pt results in a direct deposit of Pd on the Pt substrate. The observed Pd island deposits increase in size up to a maximum of ca. 500 atoms with sequential potential cycling. These results clearly show that electrochemical reduction of the immobilized Mz+ cations (Cu2+, Pd2+ and Ag+) on a cyanide modified Pt(111) yields different results that in turn suggest the sensitivity of deposited metal/cation interaction to the SAM and more importantly the role of the nature of the cyanide SAM (Self assembled monolayer) in determining the outcome in synthesizing M-SAM-M structures.

The synthesis, characterisation and anion binding properties of a series of mono- and bifunctional Lewis acidic borylferrocene compounds are described within this thesis. The original parent compound FcBMes₂ (3.1), revealed a versatile route for the synthesis of such borylferrocenes and subsequently the analogous compound Fc*BMes₂ (3.2) was synthesised. The anion binding properties of (3.1) and (3.2) were investigated and both were shown to bind one equivalent of cyanide. The binding event was signalled by an electrochemical shift (ca. -560 mV) and a quenching of bands at 510 or 542 nm respectively in the UV/Vis spectrum, while the mode of anion binding in the solid state was established by X-ray crystallography for [nBu₄N]⁺[(3.1)·CN]⁻. Incorporation of a suitable redox active dye (i.e. tetrazolium violet for 3.2) allowed conversion of the electrochemical response to a colorimetric change on cyanide binding. However, a competing response for fluoride is also seen for (3.1) and (3.2). Thus a two component system is reported involving (3.2) and the boronic ester FcB(OR)₂ (3.4), [where (OR)₂ = OCH(Ph)CH(Ph)O], which from previous research is known to selectively bind fluoride, and allows for selective colorimetric cyanide sensing by simple Boolean AND/NOT logic. 1,4-C₆H₄(BMes₂)[B(OR)₂] (3.5), 4,4-C12H₈(BMes₂)[B(OR)₂] (3.6) and 1,1′-fc(BMes2)(B(OR)2) (3.7) were synthesised as possible single molecules for discrimination between cyanide and fluoride. (3.5) and (3.6) proved only capable of binding one equivalent of either anion, (3.7) showed some ability to bind two equivalents of fluoride however based on ESI-MS studies although only in the presence of a large excess of anion. Systematic variation of the para-boryl substituent was investigated by synthesis of compounds FcB(XylF)₂ (4.1), FcB(Xyl)₂ (4.2) and FcB(XylOMe)₂ (4.3). Anion binding studies reveal a linear increase in fluoride binding affinity consistent with that expected based on the para,/em>-Hammett parameters, however with only minor differences, while no pattern is observed with respect to their cyanide binding capabilities. The addition of neutral and cationic peripheral substituents has been investigated through synthesis of [1,2-fc(CH₂NMe₂)BMes₂] (4.6) and [1,2-fc(CH₂NMe₃)BMes₂]⁺ (4.7). Subsequent binding studies revealed (4.6) to be moisture sensitive, however reaction of (4.7) with fluoride and cyanide led to formation of the adducts [(4.7)·F]⁻ and [(4.7)·CN]⁻. The anion affinity of (4.7) exhibits a substantial increase when compared to the parent compound (3.1). Even when compared to the isomeric 1,1′ system an increase of approximately three orders of magnitude is seen attributed to the closer nature of the cationic charge and in the fluoride adduct the presence of a cooperative intramolecular hydrogen bond. The 1,1′-bifunctional analogues of the mono-substituted systems were synthesised [e.g. 1,2-fc(BMes₂)₂ (5.1)] and shown to complex two equivalents of fluoride or cyanide in acetonitrile. The 1:1 cyanide adduct of (5.1) was isolated in chloroform however, no evidence for chelation was observed. The analogous systems 1,2-fc(BMes₂)₂ (5.5), 1,2-fc(BXyl₂)2 (5.7), and 1,2-fc(BMes₂)(BXyl₂) (5.8) were also investigated. Reaction of (5.5) with fluoride and cyanide revealed it to bind only one equivalent of either anion, neither however was bound in a chelating fashion although X-ray crystallography revealed cyanide binds exo whilst fluoride binds endo to the B···B cavity. Finally the kinetics of fluoride binding were studied by UV/Vis spectroscopy and showed a systematic increase in rate constant upon reduction of steric bulk.

Part I . Mechanistic intermediates were discovered in the Henry condensations of partially and non-protected pyranoses with a free anomeric hemiacetal function with nitromethane in various solvents for the syntheses of C-glycopyranosides in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)/molecular sieves catalyst system. Part II . Syntheses of glycosyl cyanides were optimized with a new catalyst system. Mechanism of cyanation with trimethylsilyl cyanide (TMS-CN) in the presence of the mild and recyclable Lewis acid HgBr 2 in nitromethane were proposed for the syntheses of 1,2-trans per- O -acetylated C-glycopyranosyl cyanides. Part III . Tri-O-acetyl-β-L-fucopyranosyl cyanide and Pd-H 2 , in presence of BOC-anhydride, gave N-BOC-mono- and -di-(2,3,4-tri-O-acetyl-β-L-fucopyranosylmethyl)-amines, which allow for the syntheses of small cluster oligosaccharide mimetics of fucopyranosylomethyl-substituted ureas. From di-(2,3,4-tri-O-acetyl-β-L-fucopyranosylmethyl) amine was also prepared a carbamoyl chloride as potentially useful synthon for preparation of more complex C-glycosidic conjugates.

Carbohydrate research remains one of the most exciting endeavors in the field of organic chemistry. The importance of carbohydrates needs little elaboration. Quite literally, without glucose, cellulose, and starch, the necessities of life such as food, clothing, and shelter would be missing. In our laboratory, we have for some time been interested in one particular class of carbohydrate derivatives - the aldohexopyranosyl cyanides.