The calix[4]arene niobium(III) complex ([L]Nb-N=N-Nb[L] where [L] = p-tert-butylcalix[4]arene), reported to bind N(2) in a μ(2)-linear dimeric capacity and to activate the N(2) triple bond to 1.39 Å, corresponding to the longest N(2) bond known in the end-on coordination mode, was subjected to a computational investigation involving both density functional and wavefunction based methods to esta...

Three different strategies have been followed to develop the torsional force-field parameters of the inter-ring dihedral angles for calix[4]arene-substituted poly(thiophene)s, a family of highly sensitive ion receptors. These procedures, which are based on the rotational profiles calculated using quantum mechanical methods, differ in the complexity of the model compounds and the processing appl...

Herein we report the successful synthesis and isolation of tiara[6]arene, a constitutional isomer calix[6]arene consisting six phenol units linked by para-substituted methylene bridges, from an isomeric mixture asymmetrically substituted pillar[6]arene intermediates. Similar to its pentameric analogue, tiara[6]arene displays high conformational freedom in solution rich polymorphism solid state....

Although various complex, bulky ligands have been used to functionalize plasmonic gold nanoparticles, introducing them to small, atomically precise gold clusters is not trivial. Here, we demonstrate a simple one-pot procedure to synthesize fluorescent magic number Au25 clusters carrying controlled amounts of bulky calix[4]arene functionalities. These clusters are obtained from a synthesis feed ...

Molecules of 5-methyl-2-phenyl-6,7-dihydrobenzo[h]pyrazolo[1,5-a]quinazoline, C21H17N3, (I), are linked into chains by a combination of a C-H...pi(arene) hydrogen bond and a pi-pi stacking interaction; in the closely related 5-methyl-2-(4-methylphenyl)-6,7-dihydrobenzo[h]pyrazolo[1,5-a]quinazoline, C22H19N3, (II), there are no hydrogen bonds and the molecules are linked into centrosymmetric dim...

The crystal structure of the title compound, C(64)H(52)Br(4)O(8)·1.31C(3)H(6)O·0.69CHCl(3), is described. The structure has been reported previously [Bryant, Blanda, Vincenti & Cram (1991). J. Am. Chem. Soc.113, 2167-2172]; however, the lower data acquisition temperature results in an improved refinement model. In addition, the presence of residual acetone and (disordered) chloro-form within th...

a new cesium ion selective pvc membrane based on parent calix [4] arene was developed for potentiometric determination of cesium in environmental samples. the electrode based on p-5,11,17,23tetra(tertbutyl) 25,26,27,28-tetrahydroxy calix[4]arene(thc) as ionophor ,dibutyl phthalate (dbp)as plasticizer ,sodium tetra phenyl borate(natpb)and oleic acid as lipophilic salt and additive showed the ...