99 research outputs found

    [(1R,4S)-(+)-3-Benzoyl-1,7,7-trimethyl­bicyclo­[2.2.1]heptan-2-olato-κ2 O 2,O 3](η4-norbornadiene)rhodium(I)

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    In the title complex mol­ecule, [Rh(C17H19O2)(C7H8)], the rhodium(I) metal centre is coordinated by the O atoms of a benzoyl­camphorate anion and the C=C bonds of the norbornadiene mol­ecule into a slightly distorted square-planar coordination geometry. The six-membered chelate ring is essentially planar (r.m.s. deviation = 0.0378 Å) and forms a dihedral angle of 31.67 (11)° with the phenyl ring

    Catalytic β-Bromohydroxylation of Natural Terpenes: Useful Intermediates for the Synthesis of Terpenic Epoxides

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    In a one-step procedure, various ß-bromoalcohols were synthesized from natural terpenes in good to excellent yields. Using different catalysts, the reaction was carried out at room temperature, with H 2 O as nucleophile and N-bromosuccinimide as a bromine source under mild reaction conditions. The synthesized ß-bromoalcohols were subsequently converted in situ to the corresponding epoxides in good yields. © 2019 Saadia Oubaassine et al

    [(1R)-3-Benzoyl-1,7,7-trimethyl­bicyclo­[2.2.1]heptan-2-onato-κ2 O,O′]chlorido(η6-p-cymene)ruthenium(II)

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    The asymmetric unit of the title compound, [RuCl(C10H14)(C17H19O2)], contains two diastereomers. In both, the RuII ion has a tetra­hedral coordination, formed by two O atoms of the camphor-derived ligand and the p-cymene and Cl ligands. In the crystal structure, weak inter­molecular C—H⋯Cl inter­actions link the mol­ecules into columns propagated along [010]

    Natural Hydroxyapatite Ca5(PO4)3OH: An Efficient Catalyst for the Chemo- and Regioselective Enamination of the β-Ketoesters

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    Hydroxylapatite or hydroxyapatite Ca5(PO4)3OH (Hap), a natural mineral species of the family of phosphate, efficiently catalyzed the condensation of 1,3-ketoesters with primary amines under solvent-free conditions. The reaction was complete in 10 min, to afford β-enamino esters in a high yield and good selectivity. Moreover, the catalyst can be re-used for four times with good activities

    Formation of one-dimensional self-assembled silicon nanoribbons on Au(110)-(2x1)

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    We report results on the self-assembly of silicon nanoribbons on the (2x1) reconstructed Au(110) surface under ultra-high vacuum conditions. Upon adsorption of 0.2 monolayer (ML) of silicon the (2x1) reconstruction of Au(110) is replaced by an ordered surface alloy. Above this coverage a new superstructure is revealed by low electron energy diffraction (LEED) which becomes sharper at 0.3 Si ML. This superstructure corresponds to Si nanoribbons all oriented along the [-110] direction as revealed by LEED and scanning tunneling microscopy (STM). STM and high-resolution photoemission spectroscopy indicate that the nanoribbons are flat and predominantly 1.6 nm wide. In addition the silicon atoms show signatures of two chemical environments corresponding to the edge and center of the ribbons.Comment: Under publication in Applied Physics Letter

    One-Pot Transformation of Olefins into -Aminoalcohols Via Vic- Bromohydrins Catalyzed by Silica

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    Commercially available silica (SiO2) was found to be highly effective catalyst for one-pot synthesis of a-aminoalcohols from olefins via bromohydrins using morpholine as nitrogen fragment donor. Furthermore, silica in the presence of easily accessible N-bromosuccimide (NBS) catalyzes a rapid and quantitative room temperature bromohydroxylation of simple olefins. Various olefins are easily converted to the corresponding vic-bromohydrins and in “one pot†to a-aminoalcohols in excellent yields and high selectivity. The reaction offers a simple and efficient method for the preparation of vic-bromohydrins and a-aminoalcohools

    The effect of Tecamin Brix-V2 in tomato (Solanum lycopersicum L.) fruit under salt stress

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    The goal of the present experiment was to evaluate the effect of some biostimulants applications (Tecamin Brix version 2) on the organoleptic quality and production yield parameters of tomato Solanum lycopersicum L. grown under salt stress in the Nador region, Morocco. Climate change is becoming increasingly constraining for plant growth and development, especially in arid and semi-arid areas. These ecosystems are characterized by highly irregular rainfall associated with significant evaporation, which favours the accumulation of salts in the soil. Salt stress is considered in the semi-arid region as a limiting factor affecting crop production and quality. Biostimulants are substances that have the ability to modify plant physiological processes in such a way as to provide potential benefits to growth, development, or stress response. For this purpose, foliar fertilization with Tecamin Brix Version 2 ®, compensates for nutrient deficiency in the roots due to salt stress. The water-soluble fertilizer or a Tecamin brix® Version 2 substance was applied to the foliage to determine the effects on yield and fruit quality parameters of tomato, especially in the Mediterranean region with a high range of salinity
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