The formation of mixed germanium–cobalt carbonyl clusters: an electrospray mass spectrometric study, and the structure of a high-nuclearity [Ge₂Co₁₀(CO)₂₄]²⁻ anion

The reaction of [µ₄-Ge{Co₂(CO)₇}₂] with [Co(CO)₄]⁻ has been monitored by electrospray mass spectrometry to detect the cluster anions generated. Conditions giving known mixed Ge–Co carbonyl clusters were established, and a new high nuclearity cluster anion, [Ge₂Co₁₀(CO)₂₄]²⁻ was detected. Conditions for its formation were optimised and it was subsequently isolated as its [Et₄N]⁺ salt and characterised by single-crystal X-ray crystallography. The Ge₂Co₁₀ cluster core has a novel geometry with the two germanium atoms in semi-encapsulated positions, forming seven formal Ge–Co bonds. There are also eighteen formal Co–Co bonds. Corresponding reactions of [µ₄-Si{Co₂(CO)₇}₂] with [Co(CO)₄]⁻ were also investigated

The Crescent Student Newspaper, April 20, 1990

Student newspaper of Pacific College (later George Fox University). 4 pages, color.https://digitalcommons.georgefox.edu/the_crescent/2057/thumbnail.jp

Synthesis of enantiomeric polyhydroxyalkylpyrrolidines from 1,3-dipolar cycloadducts. Evaluation as inhibitors of a β-galactofuranosidase

Enantiomeric 2,3,4-tris(hydroxyalkyl)-5-phenylpyrrolidines have been synthesized from the major cycloadducts obtained by the 1,3-dipolar cycloaddition of sugar enones with azomethine ylides derived from natural amino acids. Reduction of the ketone carbonyl group of the cycloadducts, which possess a basic structure of bicyclic 6-(menthyloxy)hexahydropyrano[4,3-c]pyrrol-7(6H)one, afforded a number of pyrrolidine-based bicyclic systems. A sequence of reactions, which involved hydrolysis of the menthyloxy substituent, reduction, N-protection, and degradative oxidation, afforded varied pyrrolidine structures having diverse configurations and patterns of substitution; in particular, polyhydroxylated derivatives have been obtained. The unprotected products were isolated as pyrrolidinium trifluoroacetates. Because of the furanose-like nature of the target trihydroxyalkyl pyrrolidines, these molecules have been evaluated as inhibitors of the β-galactofuranosidase from Penicillium fellutanum. The compounds showed practically no inhibitory activity for concentration of pyrrolidines in the range of 0.1–1.6 mM.Fil: Oliveira Udry, Guillermo Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; ArgentinaFil: Repetto, Evangelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; ArgentinaFil: Vega, Daniel Roberto. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes. Gerencia de Investigación y Aplicaciones; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Varela, Oscar Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; Argentin

Numerical studies of collapsing interstellar clouds

Numerical simulation of the structure and evolution of interstellar clouds was conducted. Steps were taken toward an integrated treatment of the dynamical, thermal, and chemical processes entering model calculations, and a detailed study was made of radiative transfer in molecular lines to allow model predictions to be tested against empirical data. It is shown that the shapes of molecular lines are sensitive to details of the cloud structure and evolutionary state and are thus useful in inferring the cloud density, temperature, chemical composition, age, and initial conditions. The calculations have successfully reproduced and explained several observed cloud properties, including abundances of complex molecular species and the apparent depletion of CO in dense cores

Investigations of 2-Thiazoline-2-thiol as a Ligand: Synthesis and X-ray Structures of [Mn\u3csub\u3e2\u3c/sub\u3e(CO)\u3csub\u3e7\u3c/sub\u3e(\u3cem\u3eμ\u3c/em\u3e-NS\u3csub\u3e2\u3c/sub\u3eC\u3csub\u3e3\u3c/sub\u3eH\u3csub\u3e4\u3c/sub\u3e)\u3csub\u3e2\u3c/sub\u3e] and [Mn(CO)\u3csub\u3e3\u3c/sub\u3e(PPh\u3csub\u3e3\u3c/sub\u3e)(\u3cem\u3eκ\u3c/em\u3e\u3csup\u3e2\u3c/sup\u3e-NS\u3csub\u3e2\u3c/sub\u3eC\u3csub\u3e3\u3c/sub\u3eH\u3csub\u3e4\u3c/sub\u3e)]

Treatment of Mn2(CO)10 with 2-thiazoline-2-thiol in the presence of Me3NO at room temperature afforded the dimanganese complexes [Mn2(CO)7(μ-NS2C3H4)2] (1) and [Mn2(CO)6(μ-NS2C3H4)2] (2) in 51 and 34% yields, respectively. Compound 1 was quantitatively converted into 2 when reacted with one equiv of Me3NO. Reaction of 1 with triphenylphosphine at room temperature furnished the mononuclear complex [Mn(CO)3(PPh3)(κ 2-NS2C3H4)] (3) in 66% yield. All three new complexes have been characterized by elemental analyzes and spectroscopic data together with single crystal X-ray diffraction studies for 1 and 3. Compound 1 crystallizes in the orthorhombic space group Pbca with a = 12.4147(2), b = 16.2416(3), c = 19.0841(4) Å, β = 90°, Z = 8 and V = 3848.01(12) Å3 and 3 crystallizes in the monoclinic space group P 21/n with a = 10.41730(10), b = 14.7710(2), c = 14.9209(2) Å, β = 91.1760(10)°, Z = 4 and V = 2295.45(5) Å3

A Method to Extract Potentials from the Temperature Dependence of Langmuir Constants for Clathrate-Hydrates

It is shown that the temperature dependence of Langmuir constants contains all the information needed to determine spherically averaged intermolecular potentials. An analytical ``inversion'' method based on the standard statistical model of van der Waals and Platteeuw is presented which extracts cell potentials directly from experimental data. The method is applied to ethane and cyclopropane clathrate-hydrates, and the resulting potentials are much simpler and more meaningful than those obtained by the usual method of numerical fitting with Kihara potentials.Comment: 33 pages, 7 figures, to appear in Physica