Synthesis,characterization and Hirshfeld surface analysis of a mixed-ligand copper (II) coordination polymer from 1,4,8,11-tetraazacyclotetradecane and pyromellitic dianhydride

Transition Metal Chemistry - One pot synthesis of a new mixed-ligand coordination polymer has been carried out by combining copper salt, macrocyclic ligand 1,4,8,11-tetraazacyclotetradecane...     

Uranyl complexation by a schiff-base, polypyrrolic macrocycle

Mononuclear uranyl (UO(2)(2+)) complexes supported by the polypyrrolic macrocycle L have been synthesized and exhibit hinged macrocyclic structures with an expanded cavity and enforced pi-stacking and hydrogen bonding motifs.     

Dendron-protected Au nanoparticles--effect of dendritic structure on chemical stability

A series of gold nanoparticles stabilised by 'Newkome-type' dendritic branching has been synthesised and fully characterised. In particular, the properties and behaviour of these hybrid materials are compared with those of a previously reported set of nanoparticles stabilised by dendrons constructed using l-lysine building blocks. The rates of cyanide-induced nanoparticle decomposition were determined, and it was found that the rate of decomposition increased on the introduction of dendritic branching. Furthermore, 'Newkome-type' dendrons were significantly more effective at protecting the encapsulated gold nanoparticle than the l-lysine based dendrons. It is proposed that this observation can be explained on the basis of more effective packing and surface coverage by the 'Newkome-type' dendrons. Importantly, this study therefore demonstrates that the organic chemical structure of dendritic ligands plays a crucial role in controlling the reactivity of self-assembled hybrid nanostructures.     

Diophantine approximation with multiplicative functions

Let σ(n) denote the sum of divisors function. Our main result shows that, given any real α > 1 there are infinitely many integers n such that $$\left|\frac{\sigma(n)}{n}-\alpha \right| < n^{-0.52}.$$ We prove this result by modifying an argument given by Wolke (Monatsh Math 83:163–166, 1977) which in its original form could not produce an exponent greater than 0.5. We also explain how the exponent can be improved to 0.61 on the Riemann Hypothesis.     

Exploring structural feature of aldose-reductase inhibition by 5-[[2-(omega-carboxyalkoxy)aryl]methylene]-4-oxo-2-thioxothiazolidine derivatives employing Fujita-Ban and Hansch approach

Designing of a highly selective, potent and safe inhibitor of aldose reductase (ALR) capable of potentially blocking the excess glucose flux through the polyol pathway that prevails under diabetic condition has been a long standing challenge. In our study, we did quantitative structure-activity relationship (QSAR) analysis, based on Fujita-Ban and classical Hansch approach, on 5-[[2-(omega-carboxyalkoxy)aryl]methylene]-4-oxo-2-thioxothiazolidine derivatives. Study gave structural insight into the binding mode of the molecules to the aldose reductase enzyme. The Fujita-Ban approach revealed that benzylidene thiazolidine nucleus is more potent as compare to naphthyl-methylene thiazolidine analogs. The bulkierness of naphthyl-methylene might be inquisitive with receptor. Hansch approach suggested that electron-withdrawing groups are conducive to aldose reductase inhibitory activity.