MeCp Research Articles

Influence of Growth Parameters on the Structural, Morphological and optical Properties of Mg x Zn 1-x O Prepared by Metal Organic Chemical Vapor Deposition

The influence of growth parameters on the structural, morphological and optical properties of MgxZn1-xO grown on sapphire substrate by metal organic chemical vapor deposition is studied. Pure oxygen gas is used as oxidant, bis-methyl-cyclopentadienyl magnesium ((MeCp)2Mg) and diethyl zinc are used as Mg and Zn source, respectively. The growth temperature between and 320°C and 620°C, the VI/II (O/Mg, Zn) ratio ranging from 60 to 960 and the growth rate from 0.5 to 3.3 m/h, are systematically varied to determine their effects upon the above mentioned physical properties. Structural, morphological and optical properties of the thin films are characterized by means of X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM) and Photoluminescence (PL). Experimental results indicate that the growth conditions are essential for engineering the growth of MgxZn1-xO. The optimum substrate temperature is found to be 420°C for the growth of MgxZn1-xO with a solid composition x below 30%, composition above which a phase segregation has been previously observed. With increasing temperature, strong parasitic reaction between (MeCp)2Mg and oxygen is found to occur before they rich the substrate.

Response to Varying Dietary Energy and Protein With or Without Enzyme Supplementation on Growth and Performance of Leghorns: Growing Period

Bovans White Leghorn pullets were utilized to evaluate the use of an enzyme cocktail from 0 to 126 d of age. Dietary treatments varied in CP, ME, and enzyme (EZ) supplementation. Feed intake, BW gain, and feed conversion ratio data were gathered in addition to determining nutrient retention and digestibility during the trial. Cumulatively, feed consumption was decreased by EZ supplementation when added to a required ME diet. Body weight gains were similar across dietary treatments; however, cumulative feed conversion ratio was significantly improved with EZ supplementation. Interactions regarding nutrient retention and digestibility were numerous. Similar responses were noted for energy and protein retention values during the trial with changes in response to dietary treatments as the pullets aged. Compared with feeding an industry applicable diet (required ME/CP without EZ − $0.27/lb gain), all dietary treatments reduced production costs with significant reductions when reducing CP. Lowest feed cost ($)/lb gain and percent excreta N was feeding pullets a diet with reduced ME and CP supplemented with EZ ($0.262/lb gain; 5.19% N). Possible further reductions in ME or dietary CP, or both, with EZ supplementation may prove to be even more economical and environmentally friendly.

Polymerization of methyl methacrylate with iron-ytterbium dinuclear metallocene catalyst

A novel iron-ytterbium dinuclear catalyst, FcB(MeCp) Yb (MeCp) Cl (Fc: ferrocenyl, B: diethylene ether), was synthesized for the polymerization of methyl methacrylate (MMA). Synergistic effects between the ferrocenyl group and the lanthanocene part were investigated regarding their catalytic behaviors. UV, IR, GPC and NMR were used to characterize the structures of the catalyst and polymer. Kinetic study showed that polymerization is first order in monomer concentration and fractional order (0.78) in the catalyst. The bimetallic complex is a good catalyst for the polymerization of MMA, giving high molecular weight PMMA with 78% syndiotactivity.

Synthetic studies on the cyclopentadienylruthenium-triphenylphosphine-diselenium system: redox interconversions of Ru2(Se2)2 cores

The reaction of NaSeH and CpRu(PPh 3 ) 2 Cl gave CpRu(PPh 3 ) 2 SeH, while the synthesis of (MeCp)Ru(PPh 3 ) 2 SeH required the use of NMe 4 SeH. The corresponding H 2 Se complexes could not be prepared, as CpRu(PPh 3 ) 2 OTf failed to add H 2 Se and protonation of (MeCp)Ru(PPh 3 ) 2 SeH gave (MeCp)Ru(PPh 3 ) 2 H 2 +

Zur Kenntnis der Chemie der Metallcarbonyle und der Cyano-Komplexe in flüssigem ammoniak : XL. Über die Reaktion kationischer Cyclopentadienyl-carbonyl-nitrosyl-Komplexe des Mangans und Rheniums mit flüssigem Ammoniak

The reactions of the cationic complexes [CpMn(CO) 2NO] +, [MeCpMn(CO) 2NO] + (Cp = η 5-C 5H 5, MeCp = η 5-C 5H 4CH 3), [CpRe(CO) 2NO] +, [CpMn(CO)(L)NO] + (L = PPh 3, PEt 2Ph, AsPh 3, CNMe, CNEt), {[CpMn(CO)NO] 2Me 2PC 2H 4PMe 2} 2+ and {CpMn(CO)NO] 2Ph 2PC 2H 4PPh 2} 2+ with liquid NH 3 yield the neutral carbamoyl complexes CpMn(CO)(NO)CONH 2, MeCpMn(CO)(NO)CONH 2, CpRe(CO)(NO)CONH 2, CpMn(L)(NO)CONH 2 (L = PPh 3, PEt 2Ph, AsPh 3, CNMe, CNEt), [CpMn(NO)CONH 2] 2Me 2PC 2H 4PMe 2 and [CpMn(NO)CONH 2] 2Ph 2PC 2H 4PPh 2. Properties and reactions of these new compounds are described.