The conversion of light alkanes to olefins is crucial to the chemical industry. The quest for improved catalytic performance for this conversion is motivated by current drawbacks including: expensive noble metal catalysts, poor conversion, low selectivity, and fast decay of efficiency. The in situ visualization of complex catalysis at the atomic level is therefore a major advance in the rational framework upon building the future catalysts. Herein, the catalytic C−H bond activations of ethylbenzene on TiO 2 (110)-(1 × 1) were explored with highresolution scanning tunneling microscopy and first-principles calculations. We report that the first C−H bond scission is a two-step process that can be triggered by either heat or ultraviolet light at 80 K, with near 100% selectivity of β-CH bond cleavage. This work provides fundamental understanding of C−H bonds cleavage of ethylbenzene on metal oxides, and it may promote the design of new catalysts for selective styrene production under mild conditions.
A two-dimensional van der Waals supramolecular framework is created by self-assembled cocrystallization of C 60 and octanethiol molecules on the Au(111) surfaces. The framework is characterized by the two-dimensional C 60 network, in which the pores are filled by RS-Au-SR (R = CH 3 (CH 2 ) 7 S) staples. The framework is stabilized by cooperative interactions involving collective self-assembly instead of the commonly observed pairwise interactions between the nearest neighbors. The pairing of two adjacent C 60 molecules and the formation of C 60 dimer are visualized by low temperature scanning tunneling microscopic imaging, in conjunction with first-principles calculations, suggesting a charge transfer in each C 60 dimer. Such van der Waals C 60 supramolecular framework with intermolecular charge transfer, serving a rare example in artificial 2D molecular crystal for inert C 60 molecules, is very promising in applications of optics and devices.
A self-assembled monolayer (SAM) consisting of a mixture of CHS-Au-SCH, CHS-Au-S(CH)CH, and CH(CH)S-Au-S(CH)CH was studied systematically using scanning tunneling microscopy and density functional calculations. We find that the SAM is subjected to frequent changes at the molecular level on the time scale of ∼minutes. The presence of CHS or CHS-Au as a dissociation product of CHS-Au-SCH plays a key role in the dynamical behavior of the mixed SAM. Slow phase separation takes place at room temperature over hours to days, leading to the formation of methyl-thiolate-rich and propyl-thiolate-rich phases. Our results provide new insights into the chemistry of the thiolate-Au interface, especially for ligand exchange reaction in the RS-Au-SR staple motif.
Link to publication on Research at Birmingham portal
General rightsUnless a licence is specified above, all rights (including copyright and moral rights) in this document are retained by the authors and/or the copyright holders. The express permission of the copyright holder must be obtained for any use of this material other than for purposes permitted by law.•Users may freely distribute the URL that is used to identify this publication.•Users may download and/or print one copy of the publication from the University of Birmingham research portal for the purpose of private study or non-commercial research.•User may use extracts from the document in line with the concept of 'fair dealing' under the Copyright, Designs and Patents Act 1988 (?) •Users may not further distribute the material nor use it for the purposes of commercial gain.Where a licence is displayed above, please note the terms and conditions of the licence govern your use of this document.When citing, please reference the published version. Take down policy While the University of Birmingham exercises care and attention in making items available there are rare occasions when an item has been uploaded in error or has been deemed to be commercially or otherwise sensitive.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.