Tetrasubstituted Phenanthrolines as Highly Potent,Water‐Soluble,and Selective G‐Quadruplex Ligands

Small molecules capable of stabilizing the G‐quadruplex (G4) structure are of interest for the development of improved anticancer drugs. Novel 4,7‐diamino‐substituted 1,10‐phenanthroline‐2,9‐dicarboxamides that represent hybrid structures of known phenanthroline‐based ligands have been designed. An efficient synthetic route to the compounds has been developed and their interactions with various G4 sequences have been evaluated by Förster resonance energy transfer (FRET) melting assays, fluorescent intercalator displacement (FID), electrospray ionization mass spectrometry (ESI‐MS), and circular dichroism (CD) spectroscopy. The preferred compounds have high aqueous solubility and are strong and potent G4 binders with a high selectivity over duplex DNA; thus, they represent a significant improvement over the lead compounds. Two of the compounds are inhibitors of HeLa and HT1080 cell proliferation.     

Electronic structure and excited states of rhenium(I) amido and phosphido carbonyl-bipyridine complexes studied by picosecond time-resolved IR spectroscopy and DFT calculations

UV-vis absorption and picosecond time-resolved IR (TRIR) spectra of amido and phosphido complexes fac-[Re(ER2)(CO)3(bpy)] (ER2 = NHPh, NTol2, PPh2, bpy = 2,2'-bipyridine, Tol = 4-methylphenyl) were investigated in conjunction with DFT and TD-DFT calculations in order to understand their ground-state electronic structure, low-lying electronic transitions and excited-state character and dynamics. The HOMO is localized at the amido/phosphido ligand. Amide and phosphide ligands are sigma-bonded to Re, the pi interaction being negligible. Absorption spectra show a weak band at low energies (1.7-2.1 eV) that arises from essentially pure ER(2) --> bpy ligand-to-ligand charge transfer (LLCT). The lowest excited state is the corresponding triplet, (3)LLCT. Low triplet energies and large distortions diminish the excited-state lifetimes to 85 and 270 ps for NHPh and NTol(2), respectively, and to ca. 30 ps for PPh2. nu(CO) vibrations undergo only very small ( bpy MLCT character, is a unique feature of the amido/phoshido complexes, whose lowest excited state can be viewed as containing a highly unusual aminyl/phosphinyl radical-cationic ligand. For comparison, the amino and phosphino complexes fac-[Re(NHPh(2))(CO)3(bpy)]+ and fac-[Re(PPh3)(CO)3(bpy)]+ are shown to have the usual Re --> bpy (3)MLCT lowest excited states, characterized by upshifted nu(CO) bands.     

Integrating liquid crystal based optical devices in photonic crystal fibers

Liquid crystal photonic bandgap fibers form a versatile and robust platform for designing optical fiber devices, which are highly tunable and exhibit novel optical properties for manipulation of guided light. We present fiber devices for spectral filtering and polarization control/analysis.     

In Situ Observation of Surface Species on Iridium Oxide Nanoparticles during the Oxygen Evolution Reaction

An iridium oxide nanoparticle electrocatalyst under oxygen evolution reaction conditions was probed in situ by ambient‐pressure X‐ray photoelectron spectroscopy. Under OER conditions, iridium undergoes a change in oxidation state from Ir^IV to Ir^V that takes place predominantly at the surface of the catalyst. The chemical change in iridium is coupled to a decrease in surface hydroxide, providing experimental evidence which strongly suggests that the oxygen evolution reaction on iridium oxide occurs through an OOH‐mediated deprotonation mechanism.     

Immense Multiple Realization

In his latest book Physicalism, or Something near Enough, Jaegwon Kim argues that his version of functional reductionism is the most promising way for saving mental causation. I argue, on the other hand, that there is an internal tension in his position: Functional reductionism does not save mental causation if Kim’s own supervenience argument is sound. My line of reasoning has the following steps: (1) I discuss the supervenience argument and I explain how it motivates Kim’s functional reductionism; (2) I present what I call immense multiple realization, which says that macro-properties are immensely multiply realized in determinate micro-based properties; (3) on that background I argue that functional reductionism leads to a specified kind of irrealism for mental properties. Assuming that such irrealism is part of Kim’s view, which Kim himself seems to acknowledge, I argue that Kim’s position gets the counterfactual dependencies between macro-causal relata wrong. Consequently, his position does not give a conservative account of mental causation. I end the paper by discussing some alternative moves that Kim seems to find viable in his latest book. I argue on the assumption that the supervenience argument is sound, so the discussion provides further reasons to critically reevaluate that argument because it generalizes in deeply problematic ways.     

Critical conditions for improved fermentability during overliming of acid hydrolysates from spruce

Bioethanol can be produced from wood via acid hydrolysis, but detoxification is needed to achieve good fermentability. Overliming was investigated in a factorial designed experiment, in which pH and temperature were varied. Degradation of inhibitory furan aldehydes was more extensive compared to monosaccharides. Too harsh conditions led to massive degradation of sugars and formation of inhibiting acids and phenols. The ethanol productivity and yield after optimal overliming reached levels exceeding reference fermentations of pure glucose. A novel metric, the balanced ethanol yield, which takes both ethanol production and losses of fermentable sugars into account, was introduced and showed the optimal conditions within the investigated range. The findings allow process technical and economical considerations to govern the choice of conditions for overliming.     

Temperature-dependent facet development in the deposition of GaInP on non-planar surfaces

The low-pressure (20 mbar) organometallic vapour-phase epitaxy (LP-OMVPE) of GaInP on non-planar {001} GaAs substrates has been examined. The encountered and {1 0} faceting features develop along the bottom corner and the top edge configurations of the inverted and dovetail grooves, respectively. At higher temperatures (T ≥ 720°C) these features are no longer present. The results have been compared to computer simulations of surface concentration profiles, whereby the inversely proportional relation between temperature and supersaturation, along with varying growth rate on adjacent surfaces of different crystallographic orientations, is found to be the driving force behind the occurrence of these features. The stability of the observed facets is related to the decrease in dangling-bond densities upon surface reconstruction.     

Enumerative Geometry for Plane Cubic Curves in Characteristic 2

Consider the plane cubic curves over an algebraically closed field of characteristic 2. By blowing up the parameter space P⁹ twice we obtain a variety B of complete cubics. We then compute the characteristic numbers for various families of cubics by intersecting cycles on B.     

Abstraction of preadsorbed oxygen from CaO(100) by carbon monoxide

The mechanism for abstraction of preadsorbed oxygen from CaO(100) by CO(g) to form CO₂(g) is investigated by electronic structure calculations. The reaction mechanism is assumed to be the reverse of the one obtained for the decomposition of N₂O(g) at CaO(100) [Surf. Sci 292 (1993) 317]. A 32 kcal/mol barrier for reaction is calculated. Adsorbed oxygen, O_ads, to surface vibration frequencies in the range 840–930 cm⁻¹ are calculated. These values are in qualitative agreement with experiment.