Very efficient, reusable copper catalyst for carbene transfer reactions under biphasic conditions using ionic liquids

[reaction: see text] The complex {[HC(3,5-Me(2)pz)(3)]Cu(NCMe)}BF(4) catalyzes the transfer of the :CHCO(2)Et unit from ethyl diazoacetate to several saturated and unsaturated substrates with very high yields and under biphasic conditions using the ionic liquid [bmim][PF(6)] and hexane as the reaction medium. The catalyst has been tested for several cycles of recovery and reuse without any loss of activity.     

Macrocyclic chiral receptors toward enantioselective recognition of naproxen

[structure: see text] A macrocyclic receptor based on a bischromenylurea and an alpha,alpha'-(o,o'-dialkyl)diphenyl-p-xylylenediamine spacer provides a C(2) chiral cavity to associate carboxylates by H-bonds. The extent of the selectivity obtained for the racemic receptor 2 and enantiomerically pure (S)-naproxen is 7.2:1. Steric repulsions close to the cavity are decisive for the chiral selectivity.     

Planning federal public investment in Mexico using multiobjective decision making

The scope of this article is showing how multicriteria decision making can be anefficient tool to manage public investment planning in complex situations. Forthis aim, we will analyse the problem in all its aspects: building the modelfrom data using econometrical tools, solving the resulting highly complex modelusing modern efficient techniques (multiobjective meta-heuristics) and helpingthe decision maker to introduce his preferences in order to achieve the mostpreferred solution. This holistic approach let us provide an efficient solutionto a complex public investment planning situation, improving the current stateof the country relating not only economical aspects, but also social and humandevelopment aspects. The real situation studied is focused on Mexico, where, inrecent decades, has undergone remarkable improvements in terms of economicgrowth, which has not been matched by significant improvements in several otherbasic aspects of human development, nor by reductions in regional inequalities.This suggests the need to establish policies aimed at improving these aspectsand reducing inequalities. Federal public investment is an important tool inregional policy to promote and improve these aspects; so we introduce amultiobjective programming problem for planning federal public investment inMexico. This model will focus on improving national levels in four maindimensions of human development (economic growth, education, health andhousing), and on reducing regional inequalities for those dimensions.     

Angular spectrum of diffracted wave fields with apochromatic correction

We report on compensation of diffraction-induced angular dispersion of ultrashort pulses up to a second order. A strategy for chromatic correction profits from high dispersion of kinoform-type zone plates. Ultraflat dispersion curves rely on a saddle point that may be tuned at a prescribed wavelength. Validity of our approach may reach the few-cycles regime.     

Role of the Bridge in Photoinduced Electron Transfer in Porphyrin–Fullerene Dyads

The role of π‐conjugated molecular bridges in through‐space and through‐bond electron transfer is studied by comparing two porphyrin–fullerene donor–acceptor (D–A) dyads. One dyad, ZnP–Ph–C₆₀ (ZnP=zinc porphyrin), incorporates a phenyl bridge between D and A and behaves very similarly to analogous dyads studied previously. The second dyad, ZnP–EDOTV–C₆₀, introduces an additional 3,4‐ethylenedioxythienylvinylene (EDOTV) unit into the conjugated bridge, which increases the distance between D and A, but, at the same time, provides increased electronic communication between them. Two essential outcomes that result from the introduction of the EDOTV unit in the bridge are as follows: 1) faster charge recombination, which indicates enhanced electronic coupling between the charge‐separated and ground electronic states; and 2) the disappearance of the intramolecular exciplex, which mediates photoinduced charge separation in the ZnP–Ph–C₆₀ dyad. The latter can be interpreted as a gradual decrease in electronic coupling between locally excited singlet states of D and A when introducing the EDOTV unit into the D–A bridge.     

Multi-scale simulation reveals that an amino acid substitution increases photosensitizing reaction inputs in Rhodopsins

Evaluating the availability of molecular oxygen (O₂) and energy of excited states in the retinal binding site of rhodopsin is a crucial challenging first step to understand photosensitizing reactions in wild-type (WT) and mutant rhodopsins by absorbing visible light. In the present work, energies of the ground and excited states related to 11-cis-retinal and the O₂ accessibility to the β-ionone ring are evaluated inside WT and human M207R mutant rhodopsins. Putative O₂ pathways within rhodopsins are identified by using molecular dynamics simulations, Voronoi-diagram analysis, and implicit ligand sampling while retinal energetic properties are investigated through density functional theory, and quantum mechanical/molecular mechanical methods. Here, the predictions reveal that an amino acid substitution can lead to enough energy and O₂ accessibility in the core hosting retinal of mutant rhodopsins to favor the photosensitized singlet oxygen generation, which can be useful in understanding retinal degeneration mechanisms and in designing blue-lighting-absorbing proteic photosensitizers.     

A multi-start algorithm for a balanced real-world Open Vehicle Routing Problem

The aim of this paper is to solve a real-world problem proposed by an international company operating in Spain and modeled as a variant of the Open Vehicle Routing Problem in which the makespan, i.e., the maximum time spent on the vehicle by one person, must be minimized. A competitive multi-start algorithm, able to obtain high quality solutions within reasonable computing time is proposed. The effectiveness of the algorithm is analyzed through computational testing on a set of 19 school-bus routing benchmark problems from the literature, and on 9 hard real-world problem instances.     

Estimation of plasmid concentration in batch culture of <Emphasis Type="Italic">Escherichia coli</Emphasis> DH5α via simple state observer

The aim of this paper is to present an alternative state observer structure for online estimation purposes of the key dynamical variables in a class of batch culture for plasmid production; the latter has been extremely attractive to be used as DNA vaccines or gene therapy. A mathematical model for culture of Escherichia coli DH5α-harboring plasmid was considered a benchmark system for the application of the proposed estimation methodology. Local observability analysis revealed that the system is partially observable for plasmid concentration considering only the biomass concentration in the batch culture as the measured variable. The proposed observer is designed with a simple proportional–integral feedback of the measured biomass concentration, where under the proposed design, the observer gain´s array can compensate the main nonlinearities of the estimation error dynamics. The convergence of estimated variables to the real ones is mathematically analyzed, reaching an asymptotic behavior. Numerical experiments were performed, where a comparison with a standard extended Luenberger observer was done and the proposed estimation methodology revealed a satisfactory performance.     

Electroactive thiazole derivatives capped with ferrocenyl units showing charge-transfer transition and selective ion-sensing properties: a combined experimental and theoretical study

The synthesis, optical and electrochemical properties, and X-ray characterization of two thiazole derivatives capped by ferrocenyl groups (5 and 7) and their model compounds with one ferrocenyl, either at 2 or 5 position of the mono- or bis-thiazolyl rings (3, 9, 11, and 14), are presented. Bisferrocenyl thiazole 5 forms the mixed-valence species 5*+ by partial oxidation which, interestingly, shows an intramolecular electron-transfer phenomenon. Moreover, the reported heteroaromatic compounds show selective ion-sensing properties. Thus, ferrocenylthiazoles linked across the 5 position of the heteroaromatic ring are selective chemosensors for Hg2+ and Pb2+ metal ions; 5-ferrocenylthiazole 3 operates through two channels, optical and redox, for Hg2+ and only optical for Pb2+, whereas 1,1'-bis(thiazolyl)ferrocene 14 is only an optical sensor for both metal ions. Moreover, complex 3 behaves as an electrochemically induced switchable chemosensor because of the low metal-ion affinity of the oxidized 3*+ species. On the other hand, ferrocenylthiazole 9, in which the heterocyclic ring and the ferrocene group are linked across the 2 position, is a selective redox sensor for Hg2+ metal ions, and it responds optically, as does bis(thiazolyl)ferrocene 11, to a narrow range of cations (Zn2+, Cd2+, Hg2+, Ni2+, and Pb2+). Finally, bis(ferrocenyl)thiazole 5 is a dual optical and redox sensor for Zn2+, Cd2+, Hg2+, Ni2+, and Pb2+, whereas bis(ferrocenyl) compound 7, bearing a bis(thiazole) unit as a bridge, is only a chromogenic sensor for Zn2+, Cd2+, Hg2+, Ni2+, and Pb2+. The experimental data and conclusions about both the electronic and ion-sensing properties are supported by DFT calculations which show, in addition, an unprecedented intramolecular electron-transfer reorganization after the first one-electron oxidation of compound 5.