The study of macrocyclic ligands for complexation of alkali metals (macrobicyclic polyether cryptands) and transition metals (tetraaza macrocycles) is reported. The synthesis of a new bis(phosphotriester) macrobicyclic polyether cryptand, O = P (O(CH$\sb2)\sb2\rm O(CH\sb2)\sb2O(CH\sb2)\sb2O\rbrack\sb3$ P = O, 1, called phosphocrypt, and its acyclic tripodal precursor O = P (O(CH$\sb2)\sb2\rm O(CH\sb2)\sb2O(CH\sb2)\sb2OH\rbrack\sb3$, 2, is described. Aqueous stability constants (K$\sb{\rm s}$) measured with a cation selective electrode with potassium and rubidium are 10$\sp{3.7}$ and 10$\sp{3.6}$ for 1, and are 10$\sp{3.6}$ and 10$\sp{3.0}$ for 2, respectively. The K$\sb{\rm s}$ values for phosphocrypt are 1000 fold greater than comparably sized nitrogen bridgehead cryptands. $\sp1$H and $\sp{13}$C NMR indicate 1 is flexible at 20$\sp\circ$C. Molecular mechanics calculations confirm the flexibility of 1. Also reported are the synthesis and characterization of (1) a new mixed-valence bimetallic ruthenium complex, Ru$\sb2\rm (C\sb{20}H\sb{36}N\sb8)Cl\sb{4}\sp{+}$, 3, that contains a cross-conjugated bridge that links two tetraaza macrocycles; and (2) the formation, physical properties, and reduction chemistry of a new iron $\beta$-diimine keto macrocyclic complex, Fe(C$\rm \sb{10}H\sb{18}N\sb{4}O)(CH\sb3CN)\sb{2}\sp{2+},$ 4. The ruthenium dimer 3 was formed by oxidative dehydrogenation of Ru(C$\rm\sb{10}H\sb{24}N\sb4)(Cl\sb2)\sp+$ and its mass was determined by positive ion fast atom bombardment mass spectrometry. The binuclear species 3 is assigned as a Robin and Day strongly coupled class III mixed-valence species based on cyclic voltammetry, electronic spectroscopy, and X-ray photoelectron spectroscopy (XPS). The XPS photopeaks of 3 for the binding energies from the Ru 3p$\sb{1/2}$ and Ru 3p$\sb{3/2}$ regions show only a single peak, indicating the unpaired electron is delocalized on the short (10$\sp{-17}$ s) timescale of the XPS experiment. The keto complex 4 was formed in high yields ($>$90%) from the reaction of Fe$\rm\sb2(C\sb{20}H\sb{36}N\sb8)(CH\sb3CN)\sb{4}\sp{4+}$, 5, (the diiron analog of 3) with molecular oxygen. Its mass was determined by electrospray mass spectrometry and its structure by NMR spectroscopy ($\sp1$H, $\sp{13}$C, COSY, NOE DIFF). The complex is rigid at room temperature in CD$\sb3$CN and this allows the assignment of the ten distinct protons. Reduction of the keto group in 4 under anaerobic conditions, followed by aerobic oxidation, leads to the reformation of 5.

<p> A phosphotriester synthesis for short deoxy oligomers was developed based on the RNA synthesis developed in Neilson's laboratory. This synthesis parallels that of Catlin and Cramer (1973) but differs significantly in a number of procedures and reagents used and represents an overall improvement in every aspect of the previous method. This synthetic procedure allows the synthesis of sufficient quantities of DNA for 1H-NMR analysis. The following sequences were successfully synthesized using this procedure: d(GCA) d(AGCT) d(ACGT) d(ACGTp) d (ACGTACGTp).</p> <p> It was found by variable temperature 1H-NMR that the trimer and the tetramer duplexes had a very low Tm (0-10°C) as compared to their RNA counter-parts which had Tms between 29-34°C. This demonstrates quantitatively that the short DNA duplex is significantly less stable than the short RNA duplex. Consequently, sequences of at least five or six bases in length will be required for model studies of DNA duplex stabilities using variable temperature NMR methods.</p> <p> A CD study of d(ACGTACGTp) in conditions of low salt (1M NaCl) and high salt (5M NaCl) demonstrated that a high salt B to Z-helix transition did not occur. Instead, the duplex remained in the right handed B form in both low and high salt.</p> / Thesis / Master of Science (MSc)