The discovery of a new chemical element with atomic number Z=117 is reported. The isotopes (293)117 and (294)117 were produced in fusion reactions between (48)Ca and (249)Bk. Decay chains involving 11 new nuclei were identified by means of the Dubna gas-filled recoil separator. The measured decay properties show a strong rise of stability for heavier isotopes with Z > or = 111, validating the concept of the long sought island of enhanced stability for superheavy nuclei.

Molecular beam scattering experiments are used to explore collisions of 60 kJ/mol Ne, CD 4 , ND 3 , and D 2 O with long-chain CH 3 -, NH 2 -, and OH-terminated self-assembled monolayers (SAMs) created via the chemisorption of alkanethiols on gold. Time-of-flight measurements for the scattered gases reveal the extent of energy exchange and the propensity for a gas to thermally accommodate with the surface during a collision. Of the four gases studied, Ne transfers the least amount of translational energy into the monolayers and D 2 O the most. Neon atoms recoil from the OH-SAM with an average of 14.4 kJ/mol of energy, while D 2 O retains only 6.4 kJ/mol of its 60 kJ/mol incident energy when scattering from the same surface. Overall, the trend in final translational energies follows the order Ne > CD 4 > ND 3 > D 2 O for scattering from all three SAMs. The observed trend in the energy exchange is correlated with the gas-surface attractive forces, as determined by ab initio calculations. The thermal accommodation efficiencies of the four gases follow the opposite trend. Thermalization for the Ne atoms is nearly negligible for all three monolayers, whereas D 2 O and ND 3 approach near complete accommodation on all of the monolayers studied. The overall energy exchange and thermal accommodation efficiencies also depend markedly on the terminal group of the SAM. For Ne scattering, the trend for the overall energy transfer follows: CH 3 -> NH 2 -≈ OH-SAMs. In contrast, the overall D 2 O energy transfer is greater when colliding with the OH-SAM than the nonpolar CH 3 -SAM. Together, the results show that the extent of energy transfer depends on a balance between the rigidity of the surface, as affected by intrasurface hydrogen bonding, and the strength of the gas-surface attractive forces, as determined by intermolecular interactions.

The biocatalytic asymmetric synthesis of amines from carbonyl compounds and amine precursors presents an important advance in sustainable synthetic chemistry. Oxidoreductases (ORs) that catalyze the NAD(P)Hdependent reductive amination of carbonyl compounds directly to amines using amine donors present advantages complementary to those of amine transaminases (ATAs) with respect to selectivity, stability and substrate scope. Indeed some ORs accept alkyl and aryl amines as reaction partners enabling access to chiral secondary amine products that are not directly accessible using ATAs. Moreover, superior atom economy can usually be achieved as no sacrificial amines are required as with ATAs. In recent years a number of ORs that apparently catalyze both imine formation and imine reduction in the reductive amination of carbonyls has been identified using structure informed protein engineering, sequence analysis from natural biodiversity and increasingly a mixture of both. In this review we summarize the development of such enzymes from the engineering of amino acid dehydrogenases (AADHs) and opine dehydrogenases (OpDHs) to become amine dehydrogenases (AmDHs), which are active toward ketones devoid of any requisite carboxylate and/or amine functions, through to the discovery of native AmDHs and reductive aminases (RedAms), and the engineering of all of these scaffolds for improved or altered activity. Structural and mechanistic studies have revealed similarities, but also differences in the determinants of substrate binding and mechanism in the enzymes. The survey reveals that a complementary approach to enzyme discovery that utilizes both natural genetic resources and engineering can be combined to deliver biocatalysts that have significant potential for the industrial synthesis of chiral amines.

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Ho with the maxima at 12.6 ± 1.9 mb, 12.6 ± 1.7 mb, and 9.4 ± 1.3 mb, respectively. For the reaction with 154 Gd, the maximum is slightly lower at 4.0 ± 0.6 mb. A simple model to describe the measured production cross sections was employed. Capture was estimated using the "diffused barrier formula" from the "fusion by diffusion" model proposed byŚwiątecki et al. The fusion probability was estimated using a phenomenological expression presented by Siwek-Wilczyńska et al. The survival probability was calculated according to the formula of Vandenbosch and Huizenga, derived from transition-state theory. Best agreement is reached between calculation and experiment upon inclusion of collective effects in the calculation of the survival probability, shown previously to be important for production of weakly deformed nuclei. This, in turn, challenges the expectation of strong shell-stabilization benefiting the production cross section. The present data is compared with earlier studies on production of neutron-deficient nuclei in Ca-induced reactions with lanthanide targets. PACS number(s): 25.70.Gh, 25.70.Jj

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Small optically active molecules, and more particularly short-chain chiral amines, are key compounds in the chemical industry and precursors of various pharmaceuticals. Their chemo-biocatalytic production on a commercial scale is already established, mainly through lipase-catalyzed resolutions leading to ChiPros™ products among others. Nevertheless, their biocatalytic synthesis remains challenging for very short-chain C4 to C5 amines due to low enantiomeric excess. To complement the possibilities recently offered by transaminases, this work describes alternative biocatalytic access using amine dehydrogenases (AmDHs). Without any protein engineering, some of the already described wild-type AmDHs (CfusAmDH, MsmeAmDH, MicroAmDH, and MATOUAmDH2) were shown to be efficient for the synthesis of hydroxylated or unfunctionalized small 2-aminoalkanes. Conversions up to 97.1% were reached at 50 mM, and moderate to high enantioselectivities were obtained, especially for (S)-1-methoxypropan-2-amine (98.1%), (S)-3-aminobutan-1-ol (99.5%), (3S)-3-aminobutan-2-ol (99.4%), and the small (S)-butan-2-amine (93.6%) with MsmeAmDH. Semi-preparative scale-up experiments were successfully performed at 150 mM substrate concentrations for the synthesis of (S)-butan-2-amine and (S)-1-methoxypropan-2-amine, the latter known as “(S)-MOIPA”. Modeling studies provided some preliminary results explaining the basis for the challenging discrimination between similarly sized substituents in the active sites of these enzymes.

Metamaterials typically consist of metallic and dielectric repeating structures. Electrodeposition of copper is the preferred approach to fabricating the metallic part of the metamaterials of interest in this study. The highly variant topography requires chemical additives, like chloride ions, 3-mercapto-1-propanesulfonic acid (MPSA), polyethylene glycol (PEG), and polyvinylpyrrolidone (PVP) to enhance bottom-up superfilling while maintaining terrace flatness. This study focuses on both experimental and computational investigations of the degradation potential of the additives and their adsorption mechanism in a highly acidic copper electrolyte in order to optimally parametrize the copper electrodeposition process. Results show Cl-MPSA-PEG-PVP additives perform well, but substitution of PVP with Janus Green B provides better terrace leveling. Additionally, NMR data show a quick and complete conversion of MPSA to bis(3-sulfopropyl) disulfide (SPS) in the acidic copper bath. Finally, FEM simulations further show that the accelerator species may initially accumulate and be transported vertically until overplating, whereby they are transported laterally.