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You searched for: Journal name Journal of the American Chemical Society Remove constraint Journal name: Journal of the American Chemical Society Publication year rev 7986-2014 Remove constraint Publication year rev: 7986-2014 Source 2014 v.136 no.48 Remove constraint Source: 2014 v.136 no.48
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1. Cobalt-Catalyzed Enantioselective Intramolecular Hydroacylation of Ketones and Olefins

Author:
Yang Junfeng; Yoshikai Naohiko
Source:
Journal of the American Chemical Society 2014 v.136 no.48 pp. 16748-16751
ISSN:
1520-5126
Subject:
aldehydes; alkenes; chemical bonding; enantiomers; indans; isotopes; ketones
Abstract:
... Cobalt–chiral diphoshine catalytic systems promote intramolecular hydroacylation reactions of 2-acylbenzaldehydes and 2-alkenylbenzaldehydes to afford phthalide and indanone derivatives, respectively, in moderate to good yields with high enantioselectivities. The ketone hydroacylation did not exhibit a significant H/D kinetic isotope effect (KIE) with respect to the aldehyde C–H bond, indicating t ...
DOI:
10.1021/ja509919x

2. Determination of Redox Reaction Rates and Orders by In Situ Liquid Cell Electron Microscopy of Pd and Au Solution Growth

Author:
Sutter Eli A.; Sutter Peter W.
Source:
Journal of the American Chemical Society 2014 v.136 no.48 pp. 16865-16870
ISSN:
1520-5126
Subject:
aqueous solutions; electrons; equations; gold; image analysis; nanoparticles; palladium; redox reactions; transmission electron microscopy
Abstract:
... In-situ liquid cell transmission and scanning transmission electron microscopy (TEM/STEM) experiments are important, as they provide direct insight into processes in liquids, such as solution growth of nanoparticles, among others. In liquid cell TEM/STEM redox reaction experiments, the hydrated electrons e–ₐq created by the electron beam are responsible for the reduction of metal-ion complexes. He ...
DOI:
10.1021/ja508279v

3. Facile Synthesis of Ba1–xKxFe2As2 Superconductors via Hydride Route

Author:
Zaikina Julia V.; Batuk Maria; Abakumov Artem M.; Navrotsky Alexandra; Kauzlarich Susan M.
Source:
Journal of the American Chemical Society 2014 v.136 no.48 pp. 16932-16939
ISSN:
1520-5126
Subject:
X-ray diffraction; barium; hydrides; hydrogen; mixing; potassium; powders; temperature; transmission electron microscopy
Abstract:
... We have developed a fast, easy, and scalable synthesis method for Ba₁–ₓKₓFe₂As₂ (0 ≤ x ≤ 1) superconductors using hydrides BaH₂ and KH as a source of barium and potassium metals. Synthesis from hydrides provides better mixing and easier handling of the starting materials, consequently leading to faster reactions and/or lower synthesis temperatures. The reducing atmosphere provided by the evolved h ...
DOI:
10.1021/ja509907r

4. Ferromagnetic Ordering in Superatomic Solids

Author:
Lee Chul-Ho; Liu Lian; Bejger Christopher; Turkiewicz Ari; Goko Tatsuo; Arguello Carlos J.; Frandsen Benjamin A.; Cheung Sky C.; Medina Teresa; Munsie Timothy J. S.; D’Ortenzio Robert; Luke Graeme M.; Besara Tiglet; Lalancette Roger A.; Siegrist Theo; Stephens Peter W.; Crowther Andrew C.; Brus Louis E.; Matsuo Yutaka; Nakamura Eiichi; Uemura Yasutomo J.; Kim Philip; Nuckolls Colin; Steigerwald Michael L.; Roy Xavier
Source:
Journal of the American Chemical Society 2014 v.136 no.48 pp. 16926-16931
ISSN:
1520-5126
Subject:
fullerene; magnetic properties; nickel; phase transition; temperature
Abstract:
... In order to realize significant benefits from the assembly of solid-state materials from molecular cluster superatomic building blocks, several criteria must be met. Reproducible syntheses must reliably produce macroscopic amounts of pure material; the cluster-assembled solids must show properties that are more than simply averages of those of the constituent subunits; and rational changes to the ...
DOI:
10.1021/ja5098622

5. General Strategy for Fabricating Thoroughly Mesoporous Nanofibers

Author:
Hou Huilin; Wang Lin; Gao Fengmei; Wei Guodong; Tang Bin; Yang Weiyou; Wu Tom
Source:
Journal of the American Chemical Society 2014 v.136 no.48 pp. 16716-16719
ISSN:
1520-5126
Subject:
biocompatible materials; cost effectiveness; foaming; nanofibers; photocatalysis; porous media; titanium dioxide; vapors
Abstract:
... Recently, preparation of mesoporous fibers has attracted extensive attentions because of their unique and broad applications in photocatalysis, optoelectronics, and biomaterials. However, it remains a great challenge to fabricate thoroughly mesoporous nanofibers with high purity and uniformity. Here, we report a general, simple and cost-effective strategy, namely, foaming-assisted electrospinning, ...
DOI:
10.1021/ja508840c

6. Highly Selective Solar-Driven Methanol from CO2 by a Photocatalyst/Biocatalyst Integrated System

Author:
Yadav Rajesh K.; Oh Gyu Hwan; Park No-Joong; Kumar Abhishek; Kong Ki-jeong; Baeg Jin-Ook
Source:
Journal of the American Chemical Society 2014 v.136 no.48 pp. 16728-16731
ISSN:
1520-5126
Subject:
biocatalysts; carbon dioxide; enzymes; graphene; methanol; photocatalysts
Abstract:
... The successful development of a photocatalyst/biocatalyst integrated system that carries out selective methanol production from CO₂ is reported herein. The fine-tuned system was derived from a judicious combination of graphene-based visible light active photocatalyst (CCG-IP) and sequentially coupled enzymes. The covalent attachment of isatin-porphyrin (IP) chromophore to chemically converted grap ...
DOI:
10.1021/ja509650r

7. Intramolecular Iron-Mediated C–H Bond Heterolysis with an Assist of Pendant Base in a [FeFe]-Hydrogenase Model

Author:
Zheng Dehua; Wang Ning; Wang Mei; Ding Shengda; Ma Chengbing; Darensbourg Marcetta Y.; Hall Michael B.; Sun Licheng
Source:
Journal of the American Chemical Society 2014 v.136 no.48 pp. 16817-16823
ISSN:
1520-5126
Subject:
active sites; crystal structure; disulfide bonds; ferredoxin hydrogenase; hydrogen; iron; models
Abstract:
... Although many metalloenzymes containing iron play a prominent role in biological C–H activation processes, to date iron-mediated C(sp³)–H heterolysis has not been reported for synthetic models of Fe/S-metalloenzymes. In contrast, ample precedent has established that nature’s design for reversible hydrogen activation by the diiron hydrogenase ([FeFe]-H₂ase) active site involves multiple irons, sulf ...
DOI:
10.1021/ja5078014

8. Mechanistic Insight into Size-Dependent Activity and Durability in Pt/CNT Catalyzed Hydrolytic Dehydrogenation of Ammonia Borane

Author:
Chen Wenyao; Ji Jian; Feng Xiang; Duan Xuezhi; Qian Gang; Li Ping; Zhou Xinggui; Chen De; Yuan Weikang
Source:
Journal of the American Chemical Society 2014 v.136 no.48 pp. 16736-16739
ISSN:
1520-5126
Subject:
adsorption; ammonia; catalysts; dehydrogenation; durability; hydrogen production; models; particle size; platinum
Abstract:
... We report a size-dependent activity in Pt/CNT catalyzed hydrolytic dehydrogenation of ammonia borane. Kinetic study and model calculations revealed that Pt(111) facet is the dominating catalytically active surface. There is an optimized Pt particle size of ca. 1.8 nm. Meanwhile, the catalyst durability was found to be highly sensitive to the Pt particle size. The smaller Pt particles appear to hav ...
DOI:
10.1021/ja509778y

9. Molecular Dynamics Simulations Reveal a Dielectric-Responsive Coronal Structure in Protein–Polymer Surfactant Hybrid Nanoconstructs

Author:
Brogan Alex P. S.; Sessions Richard B.; Perriman Adam W.; Mann Stephen
Source:
Journal of the American Chemical Society 2014 v.136 no.48 pp. 16824-16831
ISSN:
1520-5126
Subject:
annealing; aqueous solutions; freeze drying; lysozyme; molecular dynamics; myoglobin; nanotechnology; polymers; surfactants; temperature
Abstract:
... Solvent-free liquid proteins are a new class of thermally stable hybrid bionanomaterials that are produced by extensive lyophilization of aqueous solutions of protein–polymer surfactant nanoconjugates followed by thermal annealing. The hybrid constructs, which consist of a globular protein core surrounded by a monolayer of electrostatically coupled polymer surfactant molecules, exhibit nativelike ...
DOI:
10.1021/ja507592b

10. Multi-State Regulation of the Dihydrogen Phosphate Binding Affinity to a Light- and Heat-Responsive Bis-Urea Receptor

Author:
Wezenberg Sander J.; Vlatković Matea; Kistemaker Jos C. M.; Feringa Ben L.
Source:
Journal of the American Chemical Society 2014 v.136 no.48 pp. 16784-16787
ISSN:
1520-5126
Subject:
binding capacity; electrospray ionization mass spectrometry; heat; isomerization; isomers; nuclear magnetic resonance spectroscopy; phosphates; ultraviolet-visible spectroscopy
Abstract:
... A responsive bis-urea receptor can be switched between three isomers using light and heat as evidenced by ¹H NMR and UV–vis spectroscopy. Anion binding experiments (¹H NMR titrations, ESI-MS) reveal a high selectivity for dihydrogen phosphate. Importantly, a large difference in binding affinity to the interchangeable isomers is observed, which is further rationalized by DFT calculations. As a cons ...
DOI:
10.1021/ja510700j

11. Scope and Mechanism in Palladium-Catalyzed Isomerizations of Highly Substituted Allylic, Homoallylic, and Alkenyl Alcohols

Author:
Larionov Evgeny; Lin Luqing; Guénée Laure; Mazet Clément
Source:
Journal of the American Chemical Society 2014 v.136 no.48 pp. 16882-16894
ISSN:
1520-5126
Subject:
alcohols; catalysts; isomerization; migratory behavior; standard operating procedures
Abstract:
... Herein we report the palladium-catalyzed isomerization of highly substituted allylic alcohols and alkenyl alcohols by means of a single catalytic system. The operationally simple reaction protocol is applicable to a broad range of substrates and displays a wide functional group tolerance, and the products are usually isolated in high chemical yield. Experimental and computational mechanistic inves ...
DOI:
10.1021/ja508736u

12. Selective and Efficient Photocatalytic CO2 Reduction to CO Using Visible Light and an Iron-Based Homogeneous Catalyst

Author:
Bonin Julien; Robert Marc; Routier Mathilde
Source:
Journal of the American Chemical Society 2014 v.136 no.48 pp. 16768-16771
ISSN:
1520-5126
Subject:
carbon dioxide; carbon monoxide; catalysts; catalytic activity; climate change; energy; iron; photosensitizing agents; solar radiation
Abstract:
... Converting CO₂ into valuable compounds using sunlight as the energy input and an earth-abundant metal complex as the catalyst is an exciting challenge related to contemporary energy issues as well as to climate change. By using an inexpensive organic photosensitizer under visible-light excitation (λ > 400 nm) and a substituted iron(0) tetraphenylporphyrin as a homogeneous catalyst, we have been ab ...
DOI:
10.1021/ja510290t

13. Shading the TRF2 Recruiting Function: A New Horizon in Drug Development

Author:
Maro Salvatore Di; Zizza Pasquale; Salvati Erica; Luca Viviana De; Capasso Clemente; Fotticchia Iolanda; Pagano Bruno; Marinelli Luciana; Gilson Eric; Novellino Ettore; Cosconati Sandro; Biroccio Annamaria
Source:
Journal of the American Chemical Society 2014 v.136 no.48 pp. 16708-16711
ISSN:
1520-5126
Subject:
DNA damage; carcinogenesis; drugs; neoplasm cells; neoplasms; shade; telomeres
Abstract:
... The shelterin protein TRF2 has come to the limelight for its role in telomere maintenance and tumorigenesis. Herein, the application of rational design and synthesis allowed identifying the first TRF2TRFH binder able to elicit a marked DNA damage response in cancer cells. This work paves the way for the unprecedented employment of a chemical tool to finely tune specific mechanisms underlying telom ...
DOI:
10.1021/ja5080773

14. Simple, Chemoselective, Catalytic Olefin Isomerization

Author:
Crossley Steven W. M.; Barabé Francis; Shenvi Ryan A.
Source:
Journal of the American Chemical Society 2014 v.136 no.48 pp. 16788-16791
ISSN:
1520-5126
Subject:
alkenes; amines; catalysts; cobalt; epoxides; imidazoles; isomerization
Abstract:
... Catalytic amounts of Co(Salᵗᴮᵘ,ᵗᴮᵘ)Cl and organosilane irreversibly isomerize terminal alkenes by one position. The same catalysts effect cycloisomerization of dienes and retrocycloisomerization of strained rings. Strong Lewis bases like amines and imidazoles, and labile functionalities like epoxides, are tolerated. ...
DOI:
10.1021/ja5105602
PubMed:
25398144
PubMed Central:
PMC4277770

15. Single-Molecule Conformational Dynamics of a Biologically Functional Hydroxocobalamin Riboswitch

Author:
Holmstrom Erik D.; Polaski Jacob T.; Batey Robert T.; Nesbitt David J.
Source:
Journal of the American Chemical Society 2014 v.136 no.48 pp. 16832-16843
ISSN:
1520-5126
Subject:
Escherichia coli; binding sites; energy transfer; fluorescence; gene expression; gene expression regulation; kinetics; ligands; messenger RNA; models; molecular conformation; oligonucleotides; regulatory sequences; ribosomes
Abstract:
... Riboswitches represent a family of highly structured regulatory elements found primarily in the leader sequences of bacterial mRNAs. They function as molecular switches capable of altering gene expression; commonly, this occurs via a conformational change in a regulatory element of a riboswitch that results from ligand binding in the aptamer domain. Numerous studies have investigated the ligand bi ...
DOI:
10.1021/ja5076184
PubMed:
25325398
PubMed Central:
PMC4277777

16. Site-Selective C(sp3)–H Functionalization of Di-, Tri-, and Tetrapeptides at the N-Terminus

Author:
Gong Wei; Zhang Guofu; Liu Tao; Giri Ramesh; Yu Jin-Quan
Source:
Journal of the American Chemical Society 2014 v.136 no.48 pp. 16940-16946
ISSN:
1520-5126
Subject:
amino acids; ligands; peptides
Abstract:
... Although the syntheses of novel and diverse peptides rely mainly on traditional coupling using unnatural amino acids, postsynthetic modification of peptides could provide a complementary method for the preparation of nonproteinogenic peptides. Site selectivity of postsynthetic modification of peptides is usually achieved by targeting reactive moieties, such as the thiol group of cysteine or the C- ...
DOI:
10.1021/ja510233h
PubMed:
25384178
PubMed Central:
PMC4277765

17. Solution Processable MOF Yellow Phosphor with Exceptionally High Quantum Efficiency

Author:
Gong Qihan; Hu Zhichao; Deibert Benjamin J.; Emge Thomas J.; Teat Simon J.; Banerjee Debasis; Mussman Brianna; Rudd Nathan D.; Li Jing
Source:
Journal of the American Chemical Society 2014 v.136 no.48 pp. 16724-16727
ISSN:
1520-5126
Subject:
blue light; color; ethylene; fluorescent dyes; luminescence; research and development
Abstract:
... An important aspect in the research and development of white light-emitting diodes (WLEDs) is the discovery of highly efficient phosphors free of rare-earth (RE) elements. Herein we report the design and synthesis of a new type of RE-free, blue-excitable yellow phosphor, obtained by combining a strongly emissive molecular fluorophore with a bandgap modulating co-ligand, in a three-dimensional meta ...
DOI:
10.1021/ja509446h

18. Toward Molecular Recognition: Three-Point Halogen Bonding in the Solid State and in Solution

Author:
Jungbauer Stefan H.; Bulfield David; Kniep Florian; Lehmann Christian W.; Herdtweck Eberhardt; Huber Stefan M.
Source:
Journal of the American Chemical Society 2014 v.136 no.48 pp. 16740-16743
ISSN:
1520-5126
Subject:
Lewis acids; X-radiation; amines; geometry; titration
Abstract:
... A well-defined three-point interaction based solely on halogen bonding is presented. X-ray structural analyses of tridentate halogen bond donors (halogen-based Lewis acids) with a carefully chosen triamine illustrate the ideal geometric fit of the Lewis acidic axes of the former with the Lewis basic centers of the latter. Titration experiments reveal that the corresponding binding constant is abou ...
DOI:
10.1021/ja509705f

19. Alkali Metal Control over N–N Cleavage in Iron Complexes

Author:
Grubel Katarzyna; Brennessel William W.; Mercado Brandon Q.; Holland Patrick L.
Source:
Journal of the American Chemical Society 2014 v.136 no.48 pp. 16807-16816
ISSN:
1520-5126
Subject:
cations; chemical bonding; iron; nitrides; nitrogen; potassium; reducing agents; sodium
Abstract:
... Though N₂ cleavage on K-promoted Fe surfaces is important in the large-scale Haber–Bosch process, there is still ambiguity about the number of Fe atoms involved during the N–N cleaving step and the interactions responsible for the promoting ability of K. This work explores a molecular Fe system for N₂ reduction, particularly focusing on the differences in the results obtained using different alkal ...
DOI:
10.1021/ja507442b
PubMed:
25412468
PubMed Central:
PMC4277784

20. Biofunctionalization of Si(111)7×7 by “Renewable” l-Cysteine Transitional Layer

Author:
Rahsepar Fatemeh R.; Zhang Lei; Farkhondeh Hanieh; Leung K. T.
Source:
Journal of the American Chemical Society 2014 v.136 no.48 pp. 16909-16918
ISSN:
1520-5126
Subject:
X-radiation; adsorption; annealing; cations; cysteine; electrostatic interactions; hydrogen bonding; scanning tunneling microscopy; silicon; temperature; zwitterions
Abstract:
... Surface functionalization of an inorganic surface with bio-organic molecules is often aimed at creating a “permanent” bio-organic surface with receptor functional groups. We show here that l-cysteine can be used to transform a highly reactive Si(111)7×7 surface to not just a permanent bio-organic surface but also a semipermanent (or renewable) and a temporary bio-organic surfaces by manipulating t ...
DOI:
10.1021/ja509264t