Research Front Essay: Forensic Chemistry
James Robertson
pp. 1-2
The author discusses the benefits for forensic science from greater engagement with basic and other applied areas of chemistry and gives examples of how his organization, the Australian Federal Police, have partnered with academia and others to promote the use of chemistry in areas of trace evidence, illicit drugs, fingerprint detection, and explosives.
Recent Advances in the Application of Stable Isotope Ratio Analysis in Forensic Chemistry
Niamh Nic Daeid, Hilary A. S. Buchanan, Kathleen A. Savage, James G. Fraser and Sarah L. Cresswell
pp. 3-7
The application of a wide range of chemical techniques and methods to issues relating to judicial matters is not a new phenomena. However with increasing sensitivity of instrumentation and the use of robust mathematical systems in the interpretation of results, attention should be refocused onto the interpretation of those results within a specific case context and emphasizes the urgent need for clear communication between scientist, police and lawyer. This paper explores some of the emerging applications of techniques such as isotope ratio mass spectrometry (IRMS) within a forensic science context and the issues this raises.
This review paper updates the previous literature in relation to the continued and developing use of Stable Isotope Ratio analysis in samples which are relevant to forensic science. Recent advances in the analysis of drug samples, explosive materials and samples derived from human and animal samples are discussed. The paper also aims to put the use of IRMS into a forensic context and discuss its evidential potential.
A Study of the Metabolome of Ricinus communis for Forensic Applications
Simon P. B. Ovenden, Benjamin R. Gordon, Christina K. Bagas, Bob Muir, Simone Rochfort and David J. Bourne
pp. 8-21
The plant Ricinus communis (castor bean plant) contains the toxic protein ricin, a chemical warfare agent. The ability to determine specimen and provenance of R. communis extracts would aid forensic and law enforcement agencies. The metabolome of R. communis has been subjected to chemical and multivariate statistical analysis, which allowed some specimen determinations to be made.
Significant Determinants of Isotope Composition During HI/Pred Synthesis of Methamphetamine
Gabrielle E. David, D. Brynn Hibbert, Russell D. Frew and Alan R. Hayman
pp. 22-29
The HI/Pred synthesis of methamphetamine from ephedrine is one of the most prevalent methods used for the illicit manufacture of methamphetamine in Australasia. The synthetic determinants of the products isotopic composition have been evaluated by isotope ratio mass spectrometry and 2H NMR spectroscopy.
Detection of Impurities in Organic Peroxide Explosives from Precursor Chemicals
Andrew Partridge, Stewart Walker and David Armitt
pp. 30-37
Gas chromatography-mass spectrometry analysis of the organic peroxide explosives triacetone triperoxide and hexamethylene triperoxide diamine (HMTD), prepared from domestically available off-the-shelf precursors, showed that compounds originating from such precursors could be detected. Furthermore, some compounds could also be detected in the residues of samples that had been subjected to thermal initiation.
An Improved and Rapid Radiochemical Method for the Determination of Polonium-210 in Urine
Elizabeth Manickam, Sandra Sdraulig and Richard O'Brien
pp. 38-46
Assessment of the impact of radiological emergencies requires rapid, robust methods of measurement and analysis. This paper describes the development and validation of a method to estimate the excretion rate of 210Po in urine. This allows the determination of the 210Po intake, which is required to estimate the resulting radiation dose.
Oxazoles XXII. The Cobalt(II) Coordination Chemistry of 2-(ortho-Anilinyl)-4,4-dimethyl-2-oxazoline: Syntheses, Properties, and Solid-State Structural Characterization
Felix J. Baerlocher, Robert Bucur, Andreas Decken, Charles R. Eisnor, Robert A. Gossage, Sarah M. Jackson, Leslie Jolly, Susan L. Wheaton and R. Stephen Wylie
pp. 47-55
The title ligand, 2-(o-anilinyl)-4,4-dimethyl-2-oxazoline (l), represents a relatively unexplored metal-binding framework. The treatment of cobalt(II) metal salts with l leads to the isolation and characterization of five novel (κ2-N,N′-bonded) complexes having either distorted tetrahedral or octahedral bonding motifs around the metal centre. This work represents the first systematic investigation of the binding properties of l with a first-row metal in formally the 2+ oxidation state.
Chemical Modifications on 4-Arylpiperazine-Ethyl Carboxamide Derivatives Differentially Modulate Affinity for 5-HT1A, D4.2, and α2A Receptors: Synthesis and In Vitro Radioligand Binding Studies
Amaury Graulich, Marc Léonard, Mélissa Résimont, Xi-Ping Huang, Bryan L. Roth and Jean-François Liégeois
pp. 56-67
Different chemical modifications, such as the bioisosteric replacement of the naphthalene moiety by nitrogen-containing aromatic heterocycles is carried out in a series of 4-arylpiperazine-ethyl-naphthalene carboxamides. Although the presence of a quinoxaline or quinoline moiety leads to reduced lipophilicity, the affinity and/or selectivity for 5-HT1A receptors is conserved or increased. A 4-phenyl-1,2,3,6-tetrahydropyridine in place of the corresponding 4-phenyl-piperazine side chain is also favourable.
Counterion Effects and Dynamics of Parathion in Anionic Lyomesophases
Victor Bahamonde, Hernán Ahumada, Ramiro Araya-Maturana and Boris E. Weiss-López
pp. 68-74
Parathion, an organophosphorous pesticide, is always associated to hydrophobic bilayers. It is located near the interface, and oriented with the nitro group pointing toward the charged headgroups and the ethoxy chains to the hydrophobic core.
Synthesis and Electrochemical Studies of Nickel β-Diketonate Complexes Incorporating Asymmetric Diimine Ligands
Phimphaka Harding, David J. Harding, Nitisastr Soponrat, Kittiya Tinpun, Sirirat Samuadnuan and Harry Adams
pp. 75-82
The octahedral complexes, [Ni(β-diketonate)2(ppaX)], have been synthesized. The electrochemical behaviour of the complexes reveals quasi-reversible or irreversible one-electron oxidation to Ni(III) depending on the type of β-diketonate ligand present.
Adsorption of Ink-Jet Inks and Anionic Dyes onto Mg-Al-NO3 Layered Double Hydroxides of Variable Mg:Al Molar Ratio
Anthony R. Auxilio, Philip C. Andrews, Peter C. Junk and Leone Spiccia
pp. 83-91
Mesoporous layered materials consisting of positively charged metal hydroxide layers with nitrate as counterions show promise as adsorbing media for ink-jet printing. We have prepared materials with varying Mg:Al molar ratios and examined their dye adsorption properties. The adsorption of common ink-jet printing dyes was found to correlate with the Mg:Al molar ratio and textural properties of these materials.
The Condensation of (Chlorocarbonyl)phenyl Ketene with Bisnucleophiles. Synthesis of 4-Hydroxy-5-phenylpyro-[2,3-c]pyrazol-6-ones and Formation of Pyrazolo[1,2-a]pyrazole-triones by Hydrogen Exchange in Unstable Mesoionic Compounds
Mehdi Abaszadeh, Hassan Sheibani and Kazem Saidi
pp. 92-95
The addition of (chlorocarbonyl)phenyl ketene (2) to 5-alkylpyrazol-3(4H)-ones 1 led to the formation of hydroxypyrazolo[1,2-a ]pyrazole-dione/pyrazolo[1,2-a ]pyrazole-trione derivatives 3. This is ascribed to hydrogen exchange in initially formed unstable, mesoionic pyrazolo[1,2-a]pyrazol-4-ium-5-olates. In contrast, condensation of the same ketene with 3-alkyl-1-phenyl-2-pyrazolin-5-ones 4 afforded 4-hydroxy-3-alkyl-1,5-diphenylpyrano[2,3-c]pyrazol-6-one derivatives 5. The latter reaction provides a new and rapid route to 4-hydroxy-2-pyrones fused to pyrazole rings, in good to excellent yields.
Transition Metal-Substituted Double Dawson-Type Polyoxotungstates and Their Supramolecular Structures
Shuang Yao, Zhiming Zhang, Yangguang Li and Enbo Wang
pp. 96-102
Reactions of hexavacant polyoxotungstate [H2P2W12O48]12– with various transition metal cations lead to the isolation of three double Dawson-type polyoxotungstates. All the compounds are further connected into supramolecular structures via H-bonding interactions. The {P2W12} building block undergo structural transformation from {P2W12} to {P2W17} or {P2W14} in the synthesis of these three compounds.
Organometallic Gold(I) Acetylide/Polyoxometalate Hybrid Langmuir-Blodgett Films: Preparation, Characterization, and Photoelectric Properties
Li Liu, Qian Liu, Ming Chen, Ming-Jian Li, Li-Ping Xu, Shi-Zhong Liu, Zu-Liang Du and Wai-Yeung Wong
pp. 103-108
A new class of luminescent organometallic/inorganic nanohybrid LB films based on a π-conjugated digold(I) bis(acetylide) complex and inorganic polyoxometalates (POMs) were prepared and characterized by π–isotherms, AFM, STM and SPS. These hybrid LB composites display strong photovoltaic effect with the performance dependent of the nature of POMs.
2-(1H-2-Benzimidazolyl)-6-(1-(arylimino)ethyl)pyridylnickel Complexes: Synthesis, Characterization, and Ethylene Oligomerization
Liwei Xiao, Min Zhang, Rong Gao, Xiaoping Cao and Wen-Hua Sun
pp. 109-115
A series of nickel complexes bearing 2-(1H-2-benzimidazolyl)-6-(1-(arylimino)ethyl)pyridines was synthesized and characterized. Upon activation with Et2AlCl, good catalytic activities up to 106 g mol–1 (Ni) h–1 for ethylene oligomerization with major dimerization were exhibited. These complexes with a N–H group on the benzimidazole exhibit a higher activity than their analogues containing alkylated benzimidazoles.
The Synthesis and Preliminary Pharmacological Evaluation of a Series of Substituted 4'-Phenoxypropyl Analogues of the Atypical Antipsychotic Clozapine
Ben Capuano, Ian T. Crosby, Fiona M. McRobb, Anna Podloucka, David A. Taylor, Amelia Vom and Elizabeth Yuriev
pp. 116-124
This paper describes the synthesis and pharmacological evaluation of a series of novel substituted 4′-phenoxypropyl analogues of clozapine, for the potential treatment of schizophrenia. The synthesized compounds exhibited a favourable receptor binding affinity profile compared with clozapine for the target receptors of interest. From the ensuing behavioural evaluation, two analogues have emerged as potential lead compounds for further evaluation as prospective antipsychotic agents.
Optical and Electronic Properties of Doubly Ortho-linked cis-4,4'-Bis(diarylamino)stilbene/Fluorene Hybrids
Yan-Ling Liu, Xue-Qin Ran, Ji-Kang Feng, Ai-Min Ren and Lu-Yi Zou
pp. 125-130
Doubly ortho-linked cis-4,4′-bis(diarylamino)stilbene/fluorene hybrids have potential application in organic light emitting diodes (OLEDs). Here we study the structural, electronic, and optical properties of these molecules. The results presented in this work suggest that these doubly ortho-linked cis-4,4′-bis(diarylamino)stilbene/fluorene hybrids show great potential as efficient hole transport, sky-blue fluorescent OLED materials.
Granulated Carbon Nanotubes as the Catalyst Support for Pt for the Hydrogenation of Nitrobenzene
Shao Jin, Weizhong Qian, Yi Liu, Fei Wei, Dezeng Wang and Jinchang Zhang
pp. 131-134
The feasibility of granulated Pt/carbon nanotubes (CNTs) for further industrial application was tested in a hydrogenation process. They exhibited a better catalytic performance than Pt/activated carbon. We evinced that larger dominant pores of Pt/CNT catalyst allow the easy mass transfer of H2 to convert nitrobenzene and intermediates into aniline quickly.
Cerium Triflate: An Efficient and Recyclable Catalyst for Chemoselective Thioacetalization of Carbonyl Compounds under Solvent-Free Conditions
Anil Kumar, M. Sudershan Rao and V. Kameshwara Rao
pp. 135-140
A simple and efficient chemoselective thioacetalization of carbonyl compounds has been achieved using Ce(OTf)3 (10 mol-%) as a catalyst under solvent-free conditions. Advantages of the methodology include short reaction times, excellent yields, catalytic use of a water tolerant Lewis acid, and recovery and reuse of the catalyst.
Conjoint Analysis of Kinetic and Equilibrium Data for Mechanistic Elucidation in Polynuclear Complexation Reactions, Exemplified by Metal(II) Helicate Complex Formation
Sarah E. Clifford, Geoffrey A. Lawrance, Yorck-Michael Neuhold and Marcel Maeder
pp. 141-144
Supramolecular structures are of considerable complexity, with several ligand and metal ions forming a unit that is often helical. Very little is known about the mechanism of their formation from the building blocks. Using combined kinetic and equilibrium investigations, we have determined two pathways for Cu(II) (blue) and Ni(II) (green) as indicated in the graph.