Highly efficient catalysts for the hydrogenation of nitro-substituted aromatics

Nanoparticles of Co and NiPd, derived from colloidal precursors and supported on commercially available non-ordered mesoporous silica, are highly effective, cheap, recyclable and industrially viable catalysts for the hydrogenation of a range of nitro-substituted aromatics under mild conditions.     

Selective steroid recognition by a partially bridged resorcin[4]arene cavitand

The partially bridged resorcin[4]arene cavitand featuring a cleft-shaped recognition site formed by two anti-quinoxaline bridges and four convergent HO-groups was prepared in three steps and characterised by X-ray crystallography; cavitand was found to be a selective receptor for steroidal substrates in CDCl3, with the best binding observed for steroids with a flat A-ring and two H-bonding sites on rings A and C/D.     

A previously unrecognised hydronium di-cation in the crystal structure of a cucurbituril derivative

Examination of the crystal structure of the adduct of hydronium tetrachloroferrate dichloride with cucurbituril resulted in the discovery that the hydronium cation present therein is not the well known H7O3+ species; rather, it is an unprecedented cyclic species of composition (H14O6)2+, templated by the formation of five hydrogen bonds to cucurbituril.     

Some remarks on an existence problem for degenerate elliptic systems

The system which yields Beltrami's system if , is considered. Under a condition for the coefficients a non-existence theorem is proved.

     

Polynomial approximation of analytic functions on a finite number of continua in the complex plane

The Dzjadyk-type theorem concerning the polynomial approximation of functions on a continuum in the complex plane is generalized to the case of polynomial approximation of functions on a compact set in which consists of a finite number of continua.