Jim Raftery

Growth of lead chalcogenide thin films using single-source precursors

A series of lead dithiocarbamato complexes, [Pb(S2CNRR′)2] n (R = Me, Et; R′ n = n iPr, nBu) and dichalcogenoimidodiphoshanto complexes, [Pb((EPiPr2)2N)2] n (E = S, Se) have been synthesised and characterised. These compounds have been employed as single-source precursors for the growth of lead chalcogenide thin films by aerosol-assisted chemical vapour deposition (AACVD) and low-pressure metal–organic chemical vapour deposition (LP-MOCVD) on glass substrates. X-Ray powder diffraction (XRPD) studies show that the films are composed of cubic PbS/Se. The solid-state structures of the symmetrically substituted complexes, [Pb(S2CNR2)2] n (R = C6H10, C5H11), have been determined by single-crystal X-ray crystallography.

The deposition of thin films of CuME2 by CVD techniques (M = In, Ga and E = S, Se)

Thin film(s) of chalcopyrite CuME2 n(where M = In or Ga; E = S or Se) have been grown by low-pressure metal-organic chemical vapour deposition (LP-MOCVD) or aerosol-assisted chemical vapour deposition (AACVD) using the precursors M(E2CNMenHex)3 and Cu(E2CNMenHex)2. Films were grown on various substrates between 350–500 °C and characterized by X-ray diffraction, XPS, optical spectroscopy (UV/Vis), EDAX and scanning electron microscopy.

On the prebiotic synthesis of ribonucleotides: photoanomerisation of cytosine nucleosides and nucleotides revisited.

Recent work has emphasised the importance of D‐ribose aminooxazoline 1 in the synthesis of cytidine ribonucleosides under potentially prebiotic conditions. Upon treatment with cyanoacetylene, 1 is transformed into α‐D‐cytidine (α‐2), and if an efficient means of anomerising this nucleoside or a derivative thereof were to be found, then the synthesis of one of the key β‐D‐nucleosides required to make RNA would be realised. Photoanomerisation of α‐2 has previously been described, but the yield was extremely low. Therefore, the present study was initiated to determine whether this low yield was the result of a low conversion or competing reaction pathways.

The search for a potentially prebiotic synthesis of nucleotides via arabinose-3-phosphate and its cyanamide derivative

For the RNA world hypothesis to be accepted, the constitutional self-assembly of RNA will have to be demonstrated. Conceptually, the simplest route to RNA involves nucleotide polymerisation. Activated pyrimidine nucleotides can be derived from arabinose-3-phosphate under potentially prebiotic conditions, but the prebiotic synthesis of this sugar phosphate has not hitherto been investigated. The results of synthetic approaches involving phosphorylation, phosphate migration and 2,3-C--C bond construction are described herein.

The N-alkyldithiocarbamato complexes [M(S2CNHR)2] (M = Cd(II) Zn(II); R = C2H5, C4H9, C6H13, C12H25); their synthesis, thermal decomposition and use to prepare of nanoparticles and nanorods of CdS

A series of N-alkyldithiocarbamato complexes [M(S2CNHR)2] (M=Cd(II), Zn(II); R=C2H5, C4H9, C6H13, C12H25) have been synthesised and characterized. The decomposition of these complexes to sulfates has been investigated, and a mechanism proposed. The structures of [Zn(S2CNHHex)2], [Cd(SO4)2(NC5H5)4)]n and [Cd(SO4)2(NC5H5)2(H2O)2)]n have been determined by X-ray single crystal method. The cadmium complex [Cd(S2CNHC12H25)2] and zinc complex [Zn(S2CNHC6H13)2] were used as single-source precursors to synthesize CdS and ZnS nanoparticles, respectively. The synthesis of CdS nanoparticles was carried under various thermolysis conditions and changes in the shape of derived nanoparticles were studied by transmission electron microscope (TEM).

Co(II) and Cu(II) complexes of 2,4-diamino-5-(3,4,5-trimethoxybenzyl)pyrimidine

The Co(II) and Cu(II) complexes of 2,4-diamino-5-(3,4,5-trimethoxybenzyl)pyrimidine (trimethoprim) were synthesized and characterized by elemental analysis, UV-Vis and IR spectroscopy, magnetic susceptibility measurements, EPR (Cu complexes) and single crystal X-ray studies. The molecular structures of the compounds consist of dimeric metal ions in distorted octahedral environments, bridged with four acetate ions and each metal ion coordinated to one trimethoprim through the pyrimidinyl nitrogen atom.

Bis(acetyl­acetonato-κ2O,O′)[copper(II)nickel(II)(0.31/0.69)]: a mixed-metal complex

The title complex, [Cu0.31Ni0.69(C5H7O2)2], was isolated from the reaction of bis(N,N-dimethyaminoethanol)copper(II) with bis(acetylacetonato)nickel(II), which yielded crystals with mixed sites at the central metal position; the refined copper–nickel occupancy ratio is 0.31u2005(4):0.69u2005(4). Two acetylacetonate ligands, related by a centre of symmetry, are coordinated to the central metal atom in a square-planar configuration while the methyne C atoms of the acetylacetonate ligands, ca 3.02u2005Å away, are orthogonal to this plane at the metal site.

Synthesis and structural characterization of copper(II) complex of 2,2′-bipyridyl and L-lysine

The mixed ligand copper(II) complex of 2,2′-bipyridyl and L-lysine was synthesized from 2,2′-bipyrdine, lysine monohydrochloride and copper perchlorate. The resultant complex was characterized by elemental analysis, X-ray crystallography, IR and thermogravimetric analysis. X-ray studies showed that the title complex is a dimer. The geometry around copper atom is distorted square planar in which the Cu atom is bonded with N and O atoms from L-lysine and N, N atoms of 2,2′-bipyridyl ligand. The crystal structure is orthorhombic with unit cell parameters a = 10.5330(9) Å, b = 13.2169(12) Å, c = 32.618(3) Å; V = 4540.9(7) Å, Dx = 8, 1.705 Mg/m3, Mr = 582.83. IR spectral band has been studied and are agreed well with those obtained from the values of the expected CHN analyses and X-ray diffraction. Thermal decomposition of the complex has also been studied under an inert atmosphere.