Latent ruthenium initiators containing fluoro aryloxide ligands

A new ligand, methyl 2,3,5,6-tetrafluoro-4-oxybenzoate (C₈H₃F₄O₃), combining an electron withdrawing group (C₆F₄) to tune the reactivity with an anchor group (CO₂Me) for immobilization on supports, was used to prepare four new ruthenium initiators, viz. Ru(C₈H₃F₄O₃)₂(CHPh)(3-Br-C₅H₅N)(H₂IMes) and Ru(C₈H₃F₄O₃)₂XL, where X = C,N-(CHCH₂CH₂-2-C₅H₄N) and L = PⁱPr₃, PCy₃ or H₂IMes. The new ligand greatly reduced the reactivity of the ruthenium centre at room temperature. The ¹H NMR and DSC investigation for the ROMP of norbornene dicarboximide monomers clearly demonstrated that the Ru(C₈H₃F₄O₃)₂XL initiators were inactive at room temperature and required elevated temperatures for their activation.     

The metallation of imino(triphenyl)phosphorane by ethylmagnesium chloride: The synthesis, isolation and X-ray structure of [Ph3P=NMgCl·O=P(NMe2)3]2

Imino(triphenyl)phosphorane, Ph₃P=NH 1a, is metallated by ethylmagnesium chloride to give the N-magnesioiminophosphorane complex [Ph₃P=NMgCl·O=P(NMe₂)₃]₂ 4, whose X-ray structure has been determined.     

Emergence of Quantum Mechanics from Theory of Random Fields

Our aim in this paper is to enlighten the possibility to treat quantum mechanics as emergent from a kind of classical physical model, in spite of recent remarkable experiments demonstrating a violation of the Bell inequality. To proceed in a rigorous way, we use the methodology of ontic–epistemic modeling of physical phenomena. This methodology is rooted in the old Bild conception about theoretical and observational models in physics. This conception was elaborated in the fundamental works of Hertz, Boltzmann, and Schrödinger. Our ontic model (generating the quantum model) is of the random field type, prequantum classical statistical field theory (PCSFT). We present a brief review of its basic features without overloading the presentation by mathematical details. Then we show that the Bell inequality can be violated not only at the epistemic level, i.e., for observed correlations, but even at the ontic level, for classical random fields. We devote the important part of the paper to an analysis of the internal energy structure of prequantum random fields and their coupling with the background field of subquantum fluctuations. Finally, we present a unified picture of the microworld based on the composition of prequantum random fields from elementary fluctuations. Since quantum systems are treated as the symbolic representation of prequantum fields, this picture leads to a unifying treatment of all quantum systems as special blocks of elementary fluctuations carrying negligibly small energies.     

LOBSTER: A tool to extract chemical bonding from plane‐wave based DFT

The computer program LOBSTER (Local Orbital Basis Suite Towards Electronic‐Structure Reconstruction) enables chemical‐bonding analysis based on periodic plane‐wave (PAW) density‐functional theory (DFT) output and is applicable to a wide range of first‐principles simulations in solid‐state and materials chemistry. LOBSTER incorporates analytic projection routines described previously in this very journal [J. Comput. Chem. 2013 , 34, 2557] and offers improved functionality. It calculates, among others, atom‐projected densities of states (pDOS), projected crystal orbital Hamilton population (pCOHP) curves, and the recently introduced bond‐weighted distribution function (BWDF). The software is offered free‐of‐charge for non‐commercial research. © 2016 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc.     

Optically active 4- and 5-coordinate transition metal complexes of bifurcated dipeptide Schiff bases

Symmetrical and unsymmetrical benzophenone Schiff bases of bifurcated dipeptides [e.g., Ar2C=N-CHR1- CONH-HNCO-CHR2-N=CAr2] have been synthesized using Boc methodology. These ligands may be regarded as chiral porphyrin mimics because of the alpha-carbons of the amino acids. The Schiff bases function as effective ligands for transition metals, particularly the late transition metals Ni(II), Cu(II), and Zn. Upon metal insertion, there is loss of the amide protons, resulting in N4 chelating ligands that retain the amino acid based chirality as well as newly generated metal-centered chirality, which for the Ni(II) complexes have been shown by X-ray analysis to be lambda (left-handed helix) if the amino acids are S. For Ni(II) and Cu(II), metal insertion results in highly colored complexes and is easily followed by UV-vis spectrophotometry. Several Ni(II) complexes were also characterized by 1H NMR. Co(II) and Mn(II) complexes were characterized by CW EPR. Two Cu(II) complexes, 7f.CuII and 7k.CuII, were characterized by EPR (ENDOR and ESEEM), which clearly showed the pentacoordinate nature of 7k.CuII.     

Innovation and learning performance implications of free revealing and knowledge brokering in competing communities: insights from the Netflix Prize challenge

Firms increasingly use open competitions to extend their innovation process and access new diverse knowledge. The Netflix Prize case we study in this paper is a multi-stage repeat-submission open competition involving the creation of new knowledge from across knowledge domains, a process which benefits from knowledge sharing across competing communities. The extant literature says little about the effects of different types and levels of knowledge sharing behavior on the learning and innovation outcomes of such a competitive system, or what the performance boundaries may be for the system as a result of such differences. Our research explores those boundaries unveiling important tradeoffs involving free revealing behavior—defined as voluntarily giving away codified knowledge and making it into a ‘public good’—and knowledge brokering behavior—defined as using knowledge from one domain to innovate in another—on the learning performance of competing communities. The results, analyzing the system-level average and volatility of learning outcomes, lead to three conclusions: (i) greater knowledge sharing, as portrayed by greater free revealing and knowledge brokering, helps achieve better average learning for the system as a whole, however, (ii) achieving the best overall outcome possible from the system actually requires controlling the amount of knowledge brokering activity in the system. The results further suggest that (iii) it should not be possible to simultaneously achieve both the best overall outcome from the system and the best average learning for the system. The tradeoffs that ensue from these findings have important implications for innovation policy and management. This research contributes to practice by showing how it is possible to achieve different learning performance outcomes by managing the types and levels of knowledge sharing in open competitive systems.     

Maximum modulus sets in pseudoconvex boundaries

LedD be a strictly pseudoconvex domain in ? ⁿ withC ^∞ boundary. We denote byA ^∞(D) the set of holomorphic functions inD that have aC ^∞ extension to \(\bar D\) . A closed subsetE of ?D is locally a maximum modulus set forA ^∞(D) if for everyp∈E there exists a neighborhoodU ofp andf∈A ^∞(D∩U) such that |f|=1 onE∩U and |f|<1 on \(\bar D \cap U\backslash E\) . A submanifoldM of ?D is an interpolation manifold ifT _p (M)?T _p ^c (?D) for everyp∈M, whereT _p ^c (?D) is the maximal complex subspace of the tangent spaceT _p (?D). We prove that a local maximum modulus set forA ^∞ (D) is locally contained in totally realn-dimensional submanifolds of ?D that admit a unique foliation by (n?1)-dimensional interpolation submanifolds. LetD =D ₁ x ... xD _r ? ? ⁿ whereD _i is a strictly pseudoconvex domain withC ^∞ boundary in ? ⁿ _i ,i=1,…,r. A submanifoldM of ?D ₁×…×?D _r verifies the cone condition if \(II_p (T_p (M)) \cap \bar C[Jn_1 (p),...,Jn_r (p)] = \{ 0\} \) for everyp∈M, wheren _i (p) is the outer normal toD _i atp, J is the complex structure of ? ⁿ , \(\bar C[Jn_1 (p),...,Jn_r (p)]\) is the closed positive cone of the real spaceV _p generated byJ _{n 1}(p),…,J _{n r}(p), and II _p is the orthogonal projection ofT _p (?D) onV _p . We prove that a closed subsetE of ?D ₁×…×?D _r which is locally a maximum modulus set forA ^∞(D) is locally contained inn-dimensional totally real submanifolds of ?D ₁×…×?D _r that admit a foliation by (n?1)-dimensional submanifolds such that each leaf verifies the cone condition at every point ofE. A characterization of the local peak subsets of ?D ₁×…×?D _r is also given.     

On the p-adic Navier–Stokes equation

ABSTRACT

We prove the local solvability of the p-adic analog of the Navier–Stokes equation. This equation describes, within the p-adic model of porous medium, the flow of a fluid in capillaries.     

A Zn(II)-Based Sql Type 2D Coordination Polymer as a Highly Sensitive and Selective Turn-On Fluorescent Probe for Al3+

A luminescent coordination polymer with the overall formula {[Zn(tr₂btd)(bpdc)]∙DMF}_n (where tr₂btd = 4,7-di(1H-1,2,4-triazol-1-yl)-2,1,3-benzothiadiazole; bpdc = 4,4′-biphenyldicarboxylate) was synthesized and characterized by single-crystal and powder X-ray diffraction, thermogravimetric, infrared spectroscopy, and elemental analyses. Luminescent properties of the obtained compound were studied in detail both in the solid state and as a suspension in N,N-dimethylacetamide (DMA). It was found that {[Zn(tr₂btd)(bpdc)]∙DMF}_n exhibits bright turquoise luminescence with excellent quantum efficiency and demonstrates turn-on fluorescence enhancement effect upon soaking in DMA Al³⁺ solution. Fluorescence titration experiments were carried out and the detection limit for Al³⁺ ions was calculated to be 120 nM, which is among the lowest reported values for similar materials. Moreover, compound demonstrated excellent selectivity and reusability, and the mechanism of the response is discussed. These results indicate that {[Zn(tr₂btd)(bpdc)]∙DMF}_n is a promising probe for sensitive fluorescent Al³⁺ detection.     

Plasmonic finite-thickness metal–semiconductor–metal waveguide as ultra-compact modulator

We propose a plasmonic waveguide with semiconductor gain material for optoelectronic integrated circuits. We analyze properties of a finite-thickness metal–semiconductor–metal (F-MSM) waveguide to be utilized as an ultra-compact and fast plasmonic modulator. The InP-based semiconductor core allows electrical control of signal propagation. By pumping the core we can vary the gain level and thus the transmittance of the whole system. The study of the device was made using both analytical approaches for planar two-dimensional case as well as numerical simulations for finite-width waveguides. We analyze the eigenmodes of the F-MSM waveguide, propagation constant, confinement factor, Purcell factor, absorption coefficient, and extinction ratio of the structure. We show that using thin metal layers instead of thick ones we can obtain higher extinction ratio of the device.