Correlation between coordinated water content and proton conductivity in Ca-BTC-based metal-organic frameworks

Proton conductivity of five Ca-based MOFs which depends on the amount of water molecules coordinated to the Ca-centres has been reported. These MOFs show high temperature proton conductivity due to the strong hydrogen bonding between the lattice and coordinated water molecules.     

Melting point suppression in new lanthanoid(III) ionic liquids by trapping of kinetic polymorphs: an in situ synchrotron powder diffraction study

The complexes (N(4444))(3)[Ln(dcnm)(6)] (Ln = La-Nd, Sm; N(4444) = tetrabutylammonium) display a decrease in the melting point upon fast cooling from a melt, which is shown by in situ synchrotron based X-ray powder diffraction to be due to the formation of a second, less thermodynamically stable, polymorph.     

Photophysics of norharmane in solution phase: From homogeneous to microheterogeneous environments

The photobehavior of norharmane (9H-pyrido[3,4-b]-indole) (NHM), one of the vastly used skeleton of drugs in therapeutic applications, has recently been the subject of increasing interest due to the finding of their phototoxic and photocarcinogenic properties. Its absorption and fluorescence behavior from different prototropic species show remarkable sensitivity towards the polarity, viscosity and local pH, exhibited by various microheterogeneous bio and biomimetic environments like micelles, reverse micelles, proteins, etc. The significant results obtained for NHM in homogeneous and a series of microheterogeneous environments is reviewed in this account. Much attention has been given to the properties of the excited states, location and biodistribution of NHM in different biological environments. The results can help in understanding the photophysics of the probe in biological environments and in assessing the correlation between different prototropic forms and biological activity.     

Electronic Coupling and Electron Transfer between Two Mo2 Units through meta- and para-Phenylene Bridges

A series of three Mo₂ dimers bridged by a meta-phenylene group has been studied in terms of electronic coupling (EC) and electron transfer (ET) in comparison with the para isomers. Optical analyses on the mixed-valence complexes indicate that by replacing a para-phenylene bridge with a meta one, the EC between the two Mo₂ centers is dramatically weakened; consequently, the ET rates (k_et) are lowered by two to three orders of magnitude. In the para series, the EC parameters (H_ab) and ET rates (k_et) are greatly affected by O/S atomic alternation of the bridging ligand. However, for the meta analogues, similar EC and ET parameters are obtained, that is, H_ab=300–400 cm⁻¹ and k_et≈10⁹ s⁻¹. These results suggest that through-σ-bond and/or through-space coupling channels become operative as the π conjugation is disabled. DFT calculations reveal that destructive quantum interference features seen for the meta series arise from the cancellation of two π-conjugated coupling pathways.     

Morphological Profiling Identifies the Motor Protein Eg5 as Cellular Target of Spirooxindoles

Oxindoles and iso-oxindoles are natural product-derived scaffolds that provide inspiration for the design and synthesis of novel biologically relevant compound classes. Notably, the spirocyclic connection of oxindoles with iso-oxindoles has not been explored by nature but promises to provide structurally related compounds endowed with novel bioactivity. Therefore, methods for their efficient synthesis and the conclusive discovery of their cellular targets are highly desirable. We describe a selective Rh^III-catalyzed scaffold-divergent synthesis of spirooxindole–isooxindoles and spirooxindole–oxindoles from differently protected diazooxindoles and N-pivaloyloxy aryl amides which includes a functional group-controlled Lossen rearrangement as key step. Unbiased morphological profiling of a corresponding compound collection in the Cell Painting assay efficiently identified the mitotic kinesin Eg5 as the cellular target of the spirooxindoles, defining a unique Eg5 inhibitor chemotype.     

Jakšić–Last theorem for higher rank perturbations

We consider the generalized Anderson model , where is a countable set, are i.i.d. random variables and the are rank projections. For these models we prove theorem analogous to that of Jak?i?–Last on the equivalence of the trace measure for a.e. ω. Our model covers the dimer and polymer models.