Synthetic tools, Norbornenes

Iridium-Catalyzed Intermolecular Asymmetric Hydroheteroarylation
of Bicycloalkenes
Christo S. Sevov and John F. Hartwig* 

exo-heteroaryl-norbornenes and norbornanes are prepared in this report.

http://pubs.acs.org/doi/abs/10.1021/ja312360c

Posted by Alex Zhukhovitskiy

Photochromics

Unusual Negative Photochromism via a Short-Lived Imidazolyl Radical of 1,1′-Binaphthyl-Bridged Imidazole Dimer

 

J. Am. Chem. Soc., Article ASAP

DOI: 10.1021/ja311344u

http://pubs.acs.org/doi/abs/10.1021/ja311344u

The colored species isomerizes to the colorless species upon exposure to visible light and thermally returns to the original colored species within 20 min at room temperature. Moreover, the photodecoloration reaction proceeds via a short-lived radical with a half-life of 9.4 μs in benzene at room temperature. Both the colored and colorless species show the photoinduced homolytic bond cleavage reaction of the C–N bond between the nitrogen atom of the imidazole ring and the carbon atom of the 1-position of the 1,1′-binaphthyl moiety and that of the C–C bond between each of the carbon atoms of the 2-position of the imidazole ring, respectively, followed by their formation by rapid radical coupling.

 

Posted by Huaxing Zhou

Surface functionalization

Charged and metallic molecular monolayers
through surface-induced aromatic stabilization
G. Heimel1*, S. Duhm2*, I. Salzmann1, A. Gerlach3, A. Strozecka4, J. Niederhausen1, C. Bu ̈rker3,
T. Hosokai3,5, I. Fernandez-Torrente4, G. Schulze4, S. Winkler1,6, A. Wilke1, R. Schlesinger1, J. Frisch1, B. Bro ̈ker1, A. Vollmer6, B. Detlefs7, J. Pflaum8, S. Kera9, K. J. Franke4, N. Ueno9, J. I. Pascual4†,
F. Schreiber3 and N. Koch1,6

This work explores the idea of charge transfer from a metal surface to an organic moiety with an interrupted aromatic framework, resulting in aromatization of the latter.  This charge transfer creates an organic monolayer which behaves metallically for all practical purposes (i.e., bandgap is much smaller than before).

http://www.nature.com/nchem/journal/v5/n3/full/nchem.1572.html?WT.ec_id=NCHEM-201303
Posted by Alex Zhukhovitskiy

Drug delivery, surface effects

The Role of Surface Functionality in Determining Nanoparticle Cytotoxicity
Sung Tae Kim , Krishnendu Saha , Chaekyu Kim , and Vincent M. Rotello *

http://pubs.acs.org/doi/abs/10.1021/ar3000647

This review describes "how NP surface properties control interactions with biomolecules and cells at many scales, including the role the particle surface plays in determining in vivo behavior of nanomaterials. These interactions can be benign, beneficial, or lead to dysfunction in proteins, genes and cells, resulting in cytotoxic and genotoxic responses. Understanding these interactions and their consequences helps us to design minimally invasive imaging and delivery agents."

Posted by Alex Zhukhovitskiy

Cyclic polymers

Nickel-Catalyzed Cyclopolymerization of Hexyl- and Phenylsilanes
Makoto Tanabe, Atsushi Takahashi, Tomoko Fukuta, and Kohtaro Osakada*


Selective formation of all-silicon-backbone cyclic oligomers is accomplished via Ni catalysis.
Mn = 1450 (Mw/Mn = 1.01, GPC polystyrene standard.  Such a low PDI suggests to me that either PS standards are inappropriate for these polymers or that the size of the oligomers is controlled by some kind of unusual kinetic feature (probably the former).

http://pubs.acs.org/doi/abs/10.1021/om301052f

Posted by Alex Zhukhovitskiy

Janus particles

Influence of Janus Particle Shape on Their Interfacial Behavior at Liquid−Liquid Interfaces
Thomas M. Ruhland,† André H. Gröschel,† Nicholas Ballard,‡ Thomas S. Skelhon,‡ Andreas Walther,§ Axel H. E. Müller,† and Stefan A. F. Bon*, 

Interface behavior of Janus particles of different shapes is studied both experimentally and theoretically.

http://pubs.acs.org/doi/abs/10.1021/la3048642

Posted by Alex Zhukhovitskiy

Removal of Molecular Adsorbates on Gold Nanoparticles Using Sodium Borohydride in Water

Nano Letter

http://pubs.acs.org/doi/abs/10.1021/nl304703w

The mechanism of sodium borohydride NaBH4 removal of organothiols from gold nanoparticles (AuNPs) was studied.
Organothiols and other AuNP surface adsorbates such as thiophene, adenine, rhodamine, small anions (Br ion and I ion), and a polymer (PVP, poly(N-vinylpyrrolidone)) can all be rapidly and completely removed from the AuNP surfaces.