Alan H. Cowley

Bio: Alan H. Cowley is an academic researcher from University of Texas at Austin. The author has contributed to research in topics: Phosphorus & Crystal structure. The author has an hindex of 57, co-authored 677 publications receiving 14874 citations. Previous affiliations of Alan H. Cowley include University of Texas System & University College London.

Single‐Source III/V Precursors: A New Approach to Gallium Arsenide and Related Semiconductors

Abstract: Until recently, the production of gallium arsenide, indium phosphide, and related compound semiconductors has fallen in the domain of the materials scientist and the electrical engineer By clever use of classical chemistry, exemplified by the thermal reaction of Me3Ga and AsH3, it is possible to make semiconductors on a commercial scale However, there are some drawbacks associated with the existing methodology, including the environmental and health hazards of handling pyrophoric and toxic starting materials as well as stoichiometry control problems and undesirable side reactions Can the synthetic inorganic and organometallic chemist play a useful role in this important area by designing and developing new reagents for the production of semiconductor materials? We believe the answer is yes, and in this article we discuss a new approach to the preparation of GaAs and InP thin films based on single-source precursors These compounds feature strong σ-bonding between the group III and V elements, together with substituents that are capable of facile thermal elimination The III/V precursors are more stable toward air and moisture and considerably less toxic than either adducts or mixtures of group III and V compounds

Highly luminescent poly(methyl methacrylate)-incorporated europium complex supported by a carbazole-based fluorinated β-diketonate ligand and a 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene oxide co-ligand.

Abstract: A novel efficient antenna complex of Eu3+ [Eu(CPFHP)3(DDXPO)] supported by a highly fluorinated carbazole-substituted β-diketonate ligand, namely, 1-(9H-carbazol-2-yl)-4,4,5,5,5-pentafluoro-3-hydroxypent-2-en-1-one (CPFHP) and the 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene oxide (DDXPO) ancillary ligand, has been synthesized, structurally characterized, and its photoluminescent behavior examined. The single-crystal X-ray diffraction analysis of Eu(CPFHP)3(DDXPO) revealed that this complex is mononuclear, and that the central Eu3+ ion is surrounded by eight oxygen atoms, six of which are provided by the three bidentate β-diketonate ligands. The remaining two oxygen atoms are furnished by the chelating phosphine oxide ligand. The coordination polyhedron is best described as that of a distorted square antiprism. The photophysical properties of Eu(CPFHP)3(DDXPO) benefit from adequate protection of the metal by the ligands with respect to non-radiative deactivation as well as an efficient ligand-to-metal ...

Carbene-Pnictinidene Adducts

Abstract: The syntheses, characterizations, and X-ray crystallographic structure determinations are described for adducts of stable nucleophilic carbenes with pnictinidenes. The adducts between 1,3-dimesitylimidazol-2-ylidene and phenylphosphinidene, phenylarsinidene, (trifluoromethyl)phosphinidene, and (pentafluorophenyl)arsinidene are reported. These carbene-pnictinidene adducts are formed by the direct reaction of a stable nucleophilic carbene with the corresponding pnictinidene cyclic oligomers. The synthesis and structure of the adduct between 1,3-dimesitylimidazolin-2-ylidene and phenylphosphinidene from the reaction of 1,3-dimesitylimidazolin-2-ylidene with phenylphosphorus dichloride are also reported. These carbene-pnictinidene adducts possess strongly polarized pnictinidene-carbene bonds. The C-Pn-C angles are all typically small at 97-102 degrees, and there is only a 4% shortening of the nominal Pn=C double bond compared to the Pn-C single bond to the second substituent on the pnictogen. The (31)P NMR shifts of the phosphorus adducts suggest strongly shielded phosphorus centers in accord with the polarized structures.

Chemical Redox Agents for Organometallic Chemistry

Abstract: 1. Advantages of Chemical Redox Agents 878 2. Disadvantages of Chemical Redox Agents 879 C. Potentials in Nonaqueous Solvents 879 D. Reversible vs Irreversible ET Reagents 879 E. Categorization of Reagent Strength 881 II. Oxidants 881 A. Inorganic 881 1. Metal and Metal Complex Oxidants 881 2. Main Group Oxidants 887 B. Organic 891 1. Radical Cations 891 2. Carbocations 893 3. Cyanocarbons and Related Electron-Rich Compounds 894

Heterocyclic Carbenes: Synthesis and Coordination Chemistry

Abstract: The chemistry of heterocyclic carbenes has experienced a rapid development over the last years. In addition to the imidazolin-2-ylidenes, a large number of cyclic diaminocarbenes with different ring sizes have been described. Aside from diaminocarbenes, P-heterocyclic carbenes, and derivatives with only one, or even no heteroatom within the carbene ring are known. New methods for the synthesis of complexes with N-heterocyclic carbene ligands such as the oxidative addition or the metal atom template controlled cyclization of β-functionalized isocyanides have been developed recently. This review summarizes the new developments regarding the synthesis of N-heterocyclic carbenes and their metal complexes.

Lanthanide Luminescence for Biomedical Analyses and Imaging

Abstract: Keywords: Time-Resolved Fluorescence ; Resonance Energy-Transfer ; Near-Infrared Luminescence ; Double-Stranded Dna ; Prostate-Specific Antigen ; Photoinduced Electron-Transfer ; Europium-Tetracycline Complex ; Sybr-Green-I ; Terbium Complexes ; Optical Probes Reference EPFL-ARTICLE-149396doi:10.1021/cr900362eView record in Web of Science Record created on 2010-06-17, modified on 2017-05-12