We report the synthesis and photospectroscopic characterisation of intrinsically fluorescent triazole-appended cytidines. Fluorescence was found to be highly dependent on solvent conditions. X-Ray crystallographic data show the proton of the exocyclic amine of the nucleobase and the triazole N(3) engaged in a H-bond.

A novel ligand-exchange route for the synthesis of amidinate-containing compounds of aluminum is explored. Syntheses of three new compounds, MeC(NiPr)2AlEt2 (4), EtC(NiPr)2AlMe2 (5), and (Me2NC(NiPr)2)2AlH (6), are presented. These mixed-ligand compounds are difficult to make in high yields by the more traditional routes of carbodiimide insertion or salt metathesis. The thermal reactivities of these compounds and their parent homoleptic compounds [MeC(NiPr)2]3Al (1), [Me2NC(NiPr)2](3)Al (2), and [EtC(NiPr)2]3Al (3) are explored in detail and analyzed with respect to their utility as potential atomic-layer-deposition precursors for aluminum-containing films. The major mechanism of thermal decomposition is found to be carbodiimide deinsertion to form aluminum alkyls or amides. Because of their thermal characteristics, both compounds 3 and 5 hold promise for use as precursors.

Unsaturated N-heterocyclic phosphenium cations (uNHP) stabilize the [Pd 0 (PR3)2X] -anion proposed over the past decade to be the crucial but elusive intermediate in palladium-catalyzed cross-coupling reactions (X = halide). Insertion of metal into the PBr bond of the precursor mesityl-substituted bromophosphine gives the structurally characterized Pd(0)-phosphenium complex (uNHPMes)Pd(PPh3)2Br, which features a long Pd-Br bond (2.7240(9)Å) and the shortest known Pd-P bond (2.1166(17)Å). The reaction is proposed to proceed by an associative pathway involving a Pdbromophosphine complex that undergoes P-to-Pd bromide transfer.

A bis(imino)acenaphthene (BIAN) ligand containing a pendant Lewis base has been used as a new framework to support a N-heterocyclic phosphenium cation (NHP). Reactivity studies demonstrate the ability of the ligand to act as a Lewis base, while the phosphorus centre provides a Lewis acidic site, giving new opportunities in NHP chemistry.

A bulky guanidinate ligand has been utilized in supporting a dichloroarsine, which is an excellent precursor to an arsenium cation and a 2,2'-bipyridine base stabilised arsetidinium dication.

The reported chemistry and reactivity of guanidinate supported group 15 elements in the +3 oxidation state, particularly phosphorus, is limited when compared to their ubiquity in supporting metallic elements across the periodic table. We have synthesized a series of chlorophosphines utilizing homo-and heteroleptic (dianionic)guanidinates and have completed a comprehensive study of their reactivity. Most notable is the reluctancy of these four-membered rings to form the corresponding Nheterocyclic phosphenium cations, the tendency to chemically and thermally eliminate carbodiimide and the scarcely observed ring expansion by insertion of a chloro(imino)phosphine into a P-N bond of the P-N-C-N framework.Computational analysis has provided corroborating evidence for the unwillingness of the halide abstraction reaction by demonstrating the exceptional electron acceptor properties of the target phosphenium cations and the underscoring strength of the P-X bond.

The ligand exchange of guanidinate ligands between metal centres can play an important role in guanidinate chemistry, and ligand exchange between aluminium centres will form a dimeric intermediate. The synthesis and characterization of the dimer [Me(2)NC(N(i)Pr)(2)](2)Al(2)Cl(4) is reported here: compound crystallizes with a twisted boat conformation of its dimer ring. This compound decomposes to monomers at room temperature over four days, or within 18 hours at 90 degrees C. We undertook a detailed computational characterization of the reaction pathway, which supported the dimer structure and subsequent monomer formation. The ligand exchange route was also exploited for the synthesis of [MeC(N(i)Pr)(2)](2)AlCl, [EtC(N(i)Pr)(2)](2)AlCl, [MeC(N(i)Pr)(2)](2)GaCl, and [Me(2)NC(N(i)Pr)(2)](2)GaCl.

The growth mechanisms of thiolate-capped lead sulfide nanocrystals have been elucidated using stoppedflow UV-visible absorption spectroscopy. Spectra were recorded over the range of 0-45 °C at 48 ms intervals during the first 144 s of reaction between Pb(NO 3 ) 2 and Na 2 S in an aqueous solution containing thioglycerol and dithioglycerol capping ligands at pH 11. The spectra were deconvoluted by fitting to three Gaussian curves; the lowest-energy of these corresponded to the first excitonic transition and was used to approximate the average particle radius using a linear relationship between the band gap and the particle diameter for spherical PbS clusters. Kinetic models for oriented attachment (OA) and Ostwald ripening (OR) growth mechanisms were used to interpret the evolution of particle radius with time. Least-squares fitting analysis revealed that OR was the single dominant mechanism of growth in the low temperature range (0-25 °C), while at higher temperatures (30-45 °C) the mechanism was time dependent: within the first 20 s, growth was predominantly by OR; OA was favored thereafter. Parametric optimization showed that OR was controlled by the dissolution kinetics at the particle-matrix interface. The enthalpy (∆H ‡ ) and entropy (∆S ‡ ) of activation for the OA process were determined by Eyring treatment to be 12 ( 3 and -160 ( 10 J K -1 mol -1 , respectively; the resulting Gibbs free energy of activation (∆G ‡ ) was 62 ( 6 kJ mol -1 . The very early stages of nanocrystal growth (<0.5 s) were dominated by nucleation processes, and the kinetic data could be fit to neither OR nor OA models.