4475-42-7Relevant articles and documents
Rhodium-calix[4]pyrrole and rhodium-tetraphenyl porphyrin: preparation, surface grafting and their catalytic application in nitro-benzene reduction
Ahmed, M.,Anjali, K.,Christopher, J.,Sakthivel, A.
, p. 12353 - 12361 (2018)
Rhodium containing macromolecules calix[4]pyrrole (RhCP) and tetraphenyl porphyrin (RhTPP) were prepared and grafted on the surface of functionalised molecular sieve materials. 1H and 13C NMR, CHNS and mass spectral analyses were used for the structural elucidation of homogeneous organometallic complexes.1H NMR and CHNS analyses confirm the formation of calix[4]pyrrole (CP) and tetraphenyl porphyrin (TPP). The introduction of rhodium ions into the macromolecule is well evident from the disappearance of the 1H NMR signal characteristic of N-H proton (7.1 ppm in CP and ?2.74 ppm in TPP). Furthermore the formation of RhCP and RhTPP complexes is confirmed using CHNS and mass spectral analysis; the data are in line with theoretically calculated values. The grafting of RhCP and RhTPP on a diamino functionalised SBA-15 support was confirmed through low angle XRD, 13C MAS-NMR and SEM-EDAX analysis. Both homogeneous and heterogeneous catalysts were utilized for nitrobenzene reduction. RhCP and RhTPP heterogenized on SBA-15-F showed complete conversion of nitrobenzene with exclusive formation of aniline as a product. The catalytic activities were retained in both the systems even after several runs.
Synthesis, structure, and complexation properties of partially and completely reduced meso-octamethylporphyrinogens (calix[4]pyrroles)
Blangy, Valeria,Heiss, Christoph,Khlebnikov, Vsevolod,Letondor, Christophe,Stoeckli-Evans, Helen,Neier, Reinhard
, p. 1688 - 1691 (2009)
(Figure Presented) New tricks for an old dog: Calixpyrroles bind anions efficiently and can be transformed into transition-metal complexes only under forcing conditions. Reducing the macrocycle creates a ligand that easily forms classical Werner complexes with copper, nickel, and palladium ions. The metal complexes present an array of four directed hydrogen bonds, which specifically bind the counterions (see picture; blue N, white H, green Cl, red Cu, Ni, or Pd).
Synthesis and anion binding properties of the smallest meso-expanded calix[4]pyrrole
Kumar, B Sathish,Panda, Pradeepta K
, (2018)
Abstract: The smallest core expanded calix[4]pyrrole derivative (5) was synthesized via incorporation of an additional sp3meso-carbon at the periphery of the macrocycle. Anion binding study of the macrocycle reveals clearly the effect of core s
Calix[4]pyrrole: A new ion-pair receptor as demonstrated by liquid-liquid extraction
Wintergerst, Matthieu P.,Levitskaia, Tatiana G.,Moyer, Bruce A.,Sessler, Jonathan L.,Delmau, Laetitia H.
, p. 4129 - 4139 (2008)
Solvent-extraction studies provide confirming evidence that meso-octamethylcalix[4]pyrrole acts as an ion-pair receptor for cesium chloride and cesium bromide in nitrobenzene solution. The stoichiometry of the interaction under extraction conditions from water to nitrobenzene was determined from plots of the cesium distribution ratios vs cesium salt and receptor concentration, indicating the formation of an ion-paired 1:1:1 cesium:calix[4]pyrrole:halide complex. The extraction results were modeled to evaluate the equilibria inherent to the solvent-extraction system, with either chloride or bromide. The binding energy between the halide anion and the calix[4]pyrrole was found to be about 7 kJ/mol larger for cesium chloride than for the cesium bromide. The ion-pairing free energies between the calix[4]pyrrole-halide complex and the cesium cation are nearly the same within experimental uncertainty for either halide, consistent with a structural model in which the Cs+ cation resides in the calix bowl. These results are unexpected since nitrobenzene is a polar solvent that generally leads to dissociated complexes in the organic phase when used as a diluent in extraction studies of univalent ions. Control studies involving nitrate revealed no evidence of ion pairing for CsNO3 under conditions identical to those where it is observed for CsCl and CsBr.
The elusive β-unsubstituted calix[5]pyrrole finally captured
Cafeo, Grazia,Kohnke, Franz H.,Parisi, Melchiorre F.,Nascone, Rosetta Pistone,La Torre, Giovanna L.,Williams, David J.
, p. 2695 - 2697 (2002)
Themeso-decamethyl-calix[5]pyrrole2bwassynthesizedfromthefuran- basedanalogue1bviathehomologationofthefuranringstopyrrole,anditssolid- statestructurewasdeterminedbyX-raycrystallography:surprisingly, thebindingconstantof2btowardchlorideisfoundtobelowerthan
Supramolecular organization of calix[4]pyrrole with a methyl- trialkylammonium anion exchanger leads to remarkable reversal of selectivity for sulfate extraction vs. nitrate
Borman, Christopher J.,Custelcean, Radu,Hay, Ben P.,Bill, Nathan L.,Sessler, Jonathan L.,Moyer, Bruce A.
, p. 7611 - 7613 (2011)
meso-Octamethylcalix[4]pyrrole (C4P) enhances sulfate selectivity in solvent extraction by Aliquat 336N, an effect ascribed to the supramolecular preorganization and thermodynamic stability imparted by insertion of the methyl group of the Aliquat cation into the cup of C4P in its cone conformation.
Acid-catalyzed hydrogen-deuterium exchange in β-pyrrolic positions of calix[4]pyrrole at room temperature
He, Ying-Chun,Pan, Ji-Gang,Liu, Dian-Sheng
, p. 3133 - 3136 (2016)
Calix[4]pyrrole was found to be high deuterium incorporation and easy-to-make hydrogen-deuterium exchange in β-pyrrolic positions with the 98% sulphuric acid as catalyst in D2O/CH3CN–D2O/CHCl3–D2O. Co
A catalytic and solvent-free approach for the synthesis of diverse functionalized dipyrromethanes (DPMs) and calix[4]pyrroles (C4Ps)
Rather, Ishfaq Ahmad,Ali, Rashid
, p. 5849 - 5855 (2021/08/23)
Needless to say, the development of green and sustainable reaction media instead of using volatile organic solvents as well as corrosive and/or expensive catalysts in the new millennium is continuously attracting great attention from the scientific commun
