Shared posts

15 Dec 00:00

Spatial control of functional properties via octahedral modulations in complex oxide superlattices

by E. J. Moon

Article

Structural properties have been a key factor that controls the electronic and magnetic behaviour at the interface of two oxide materials. Here the authors achieve a spatial control over these functional properties in oxides through the formation of octahedral superstructures in manganite superlattices.

Nature Communications doi: 10.1038/ncomms6710

Authors: E. J. Moon, R. Colby, Q. Wang, E. Karapetrova, C. M. Schlepütz, M. R. Fitzsimmons, S. J. May

03 Nov 20:30

Hierarchically Organized Silica–Titania Monoliths Prepared under Purely Aqueous Conditions

by Sylvia Flaig, Johanna Akbarzadeh, Paolo Dolcet, Silvia Gross, Herwig Peterlik, Nicola Hüsing

Abstract

Hierarchically organized silica–titania monoliths were synthesized under purely aqueous conditions by applying a new ethylene glycol-modified single-source precursor, such as 3-[3-{tris(2-hydroxyethoxy)silyl}propyl]acetylacetone coordinated to a titanium center. The influence of the silicon- and titanium-containing single-source precursor, the novel glycolated organofunctional silane, and the addition of tetrakis(2-hydroxyethyl)orthosilicate on the formation of the final porous network was investigated by SEM, TEM, nitrogen sorption, and SAXS/WAXS. In situ SAXS measurements were performed to obtain insight into the development of the mesoporous network during sol–gel transition. IR-ATR, UV/Vis, XPS, and XAFS measurements showed that up to a Si/Ti ratio of 35:1, well-dispersed titanium centers in a macro-/mesoporous SiO2 network with a specific surface area of up to 582 m2 g−1 were obtained. An increase in Ti content resulted in a decrease in specific surface area and a loss of the cellular character of the macroporous network. With a 1:1 Si/Ti ratio, silica–titania powders with circa 100 m2 g−1 and anatase domains within the SiO2 matrix were obtained.

Thumbnail image of graphical abstract

Hierarchically organized SiO2/TiO2 monoliths were synthesized in purely aqueous conditions by applying an ethylene glycol modified single-source precursor (SSP), such as 3-[3-{tris(2-hydroxyethoxy)silyl}propyl]acetylacetonate coordinated to a titanium center. The influence of the SSP on the formation of the final porous network was investigated. The homogeneity of the Si and Ti centers in the oxide matrix was also investigated.

05 Jul 16:10

Reversible carbon-carbon bond formation between carbonyl compounds and a ruthenium pincer complex

Chem. Commun., 2013, 49,7147-7149
DOI: 10.1039/C3CC43517B, Communication
Chelsea A. Huff, Jeff W. Kampf, Melanie S. Sanford
This communication describes the reversible reaction of a ruthenium pincer complex with a variety of carbonyl compounds.
The content of this RSS Feed (c) The Royal Society of Chemistry
25 Apr 18:28

[Report] Direct Evidence of a Dinuclear Copper Intermediate in Cu(I)-Catalyzed Azide-Alkyne Cycloadditions

by B. T. Worrell
The mechanism of a common and highly versatile molecular coupling reaction is elucidated.

Authors: B. T. Worrell, J. A. Malik, V. V. Fokin
18 Apr 18:26

The Cinchona Primary Amine-Catalyzed Asymmetric Epoxidation and Hydroperoxidation of α,β-Unsaturated Carbonyl Compounds with Hydrogen Peroxide

by Olga Lifchits, Manuel Mahlau, Corinna M. Reisinger, Anna Lee, Christophe Farès, Iakov Polyak, Gopinadhanpillai Gopakumar, Walter Thiel and Benjamin List

TOC Graphic

Journal of the American Chemical Society DOI: 10.1021/ja402058v