3109-63-5Relevant articles and documents
Electrochemistry and ion-sensing properties of calix[4]arene derivatives
Chen, Shanshan,Webster, Richard D.,Talotta, Carmen,Troisi, Francesco,Gaeta, Carmine,Neri, Placido
, p. 7036 - 7043 (2010)
The cyclic voltammetric properties of several substituted calix[4]arenes were examined in acetonitrile and dichloromethane. The compounds that contained one phenolic group in the macrocyclic cavity were able to be electrochemically oxidised at positive potentials. In acetonitrile, cyclic voltammetry experiments indicated that the phenolic compounds were oxidised in a two-electron (one-proton) process over all measured scan rates (up to 50 V s-1), while in dichloromethane, the oxidation process occurred by one-electron at scan rates ≥5 V s-1, to most likely form the radical cations. In both solvents, longer timescale (minutes to hours) controlled potential coulometry experiments indicated that the oxidation process occurred by two-electrons per molecule, to form reactive diamagnetic cations that could not be reduced back to the starting materials under electrolysis conditions. The ion-sensing properties of the compounds were investigated in polymer membrane ion-selective electrodes and it was found that they responded reversibly in a Nernstian fashion to Groups 1 and 2 metals and had the highest selectivity to the cesium cation.
METAL COMPLEXES WITH TETRAPYRROLE LIGANDS. 50. REDOX POTENTIALS OF SANDWICHLIKE METAL BIS(OCTAETHYLPORPHYRINATES) AND THEIR CORRELATION WITH RING-RING DISTANCES
Buchler, Johann W.,Scharbert, Bernd
, p. 4272 - 4276 (1988)
On the basis of prior work describing the synthesis and structure of sandwichlike metal bis(porphyrinates) M(OEP)2 (I:M=Y, La, ..., Lu, except Pm), the electron-transfer reactions of these double-deckers are presented.Apart from the CeIV complex Ce(OEP)2 (1c), all the other species contain MIII ions that are not affected in the redox reactions.The neutral MIII complexes 1 are porphyrin ?-radicals yielding the porphyrin ?-diradical cations + (2) upon reversible one-electron oxidation and the monoanions - (3) or the porphyrin ?-radical dianions 2- (4) upon reversible one- or two-electron reduction.Ce(OEP)2 (1c) is reversibly oxidized to the porphyrin ?-radical cation + (2c).The quasi-reversible reduction of (1c) gives the anion - (3c) with CeIII.For the neutral MIII complexes 1, the energies of the near-infrared absorption bands and the redox potentials for the processes 12 are correlated with the ionic radii rI. of the tervalent central ions MIII.A decrease of the ring oxidation potentials parallels a decrease of the ionic radii and, hence, the ring-ring distances in the double-deckers.
Phenylcyanamidoruthenium scorpionate complexes
Harb, Carmen,Kravtsov, Pavel,Choudhuri, Mohommad,Sirianni, Eric R.,Yap, Glenn P.A.,Lever,Crutchley, Robert J.
, p. 1621 - 1630 (2013)
Nine [Ru(Tp)(dppe)L] complexes, where Tp is hydrotris(pyrazol-1-yl)borate, dppe is ethylenebis(diphenylphosphine), and L is (4-nitrophenyl)cyanamide (NO2pcyd-), (2-chlorophenyl)cyanamide (2-Clpcyd -), (3-chlorophenyl)cyanamide (3-Clpcyd-), (2,4-dichlorophenyl)cyanamide (2,4-Cl2pcyd-), (2,3-dichlorophenyl)cyanamide (2,3-Cl2pcyd-), (2,5-dichlorophenyl)cyanamide (2,5-Cl2pcyd-), (2,4,5-trichlorophenyl)cyanamide (2,4,5-Cl3pcyd-), (2,3,5,6-tetrachlorophenyl)cyanamide (2,3,5,6-Cl4pcyd-), and (pentachlorophenyl)cyanamide (Cl5pcyd-), and the dinuclear complex [{Ru(Tp)(dppe)}2(μ-adpc)], where adpc 2- is azo-4,4-diphenylcyanamide, have been prepared and characterized. The crystal structures of [Ru(Tp)(dppe)(Cl5pcyd)] and [{Ru(Tp)(dppe)}2(μ-adpc)] reveal the RuII ion to occupy a pseudooctahedral coordination sphere in which the cyanamide ligand coordinates to RuII by its terminal nitrogen atom. For both complexes, the cyanamide ligands are planar, indicating significant π mixing between the cyanamide and phenyl moieties as well as the azo group in the case of adpc2-. The optical spectra of the nominally ruthenium(III) species [Ru(Tp)(dppe)L]+ were obtained through spectroelectrochemistry measurements and showed an intense near-IR absorption band. Time-dependent density functional theory calculations of these species revealed that oxidation of the ruthenium(II) species led to species where partial oxidation of the cyanamide ligand had occurred, indicative of noninnocent character for these ligands. The spin densities reveal that while the 3-Clpycd species has substantial RuII(3-Clpycd0) character, the Cl5pycd species is a much more localized ruthenium(III) complex of the Cl5pycd monoanion. Some bond order and charge distribution data are derived for these ruthenium(III) species. The near-IR band is assigned as a quite complex mixture of d-d, 4dπ to L(NCN) MLCT, and L(NCN) to Ru 4d LMCT with even a scorpionate ligand component. Spectroelectrochemistry was also performed on [{Ru(Tp)(dppe)} 2(μ-adpc)] to generate the mixed-valence state. The intense intervalence transition that is observed in the near-IR is very similar to that previously reported for [{Ru(trpy)(bpy)}2(μ-adpc)]2+, where trpy is 2,2′:6′,2″-terpyridine and bpy is 2,2′-bipyridine, and by analogy identifies [{Ru(Tp)(dppe)} 2(μ-adpc)]+ as a delocalized mixed-valence complex.
Thermal stability of quaternary ammonium hexafluorophosphates and halides
Zhuravlev,Nikol'skii,Voronchikhina
, p. 824 - 830 (2013)
Thermal decomposition of hexafluorophosphates of short-chain tetraalkylammonium salts of the general formula R3R'NPF6, where R3 = R' = CH3, C2H5, C 4H9; R3 = C2H5, R' = CH2C6H6 or CH2CH=CH2, was studied by thermal gravimetric analysis. Measurements were performed in air in the temperature interval 20-500°N. The thermal stability of halides with the same cations in the same temperature interval was studied for comparison. The effect of cation on the thermal stability of the halides and hexafluorophosphates was examined. The mechanism of thermal decomposition of quaternary ammonium hexafluorophosphates was suggested.
Deoxygenative Fluorination of Phosphine Oxides: A General Route to Fluorinated Organophosphorus(V) Compounds and Beyond
Bornemann, Dustin,Brüning, Fabian,Grützmacher, Hansj?rg,Guan, Liangyu,Küng, Sebastian,Pitts, Cody Ross,Togni, Antonio,Trapp, Nils,Wettstein, Lionel
supporting information, p. 22790 - 22795 (2020/10/06)
Fluorinated organophosphorus(V) compounds are a very versatile class of compounds, but the synthetic methods available to make them bear the disadvantages of 1) occasional handling of toxic or pyrophoric PIII starting materials and 2) a dependence on hazardous fluorinating reagents such as XeF2. Herein, we present a simple solution and introduce a deoxygenative fluorination (DOF) approach that utilizes easy-to-handle phosphine oxides as starting materials and effectively replaces harsh fluorinating reagents by a combination of oxalyl chloride and potassium fluoride. The reaction has proven to be general, as R3PF2, R2PF3, and RPF4 compounds (as well as various cations and anions derived from these) are accessible in good yields and on up to a multi-gram scale. DFT calculations were used to bolster our observations. Notably, the discovery of this new method led to a convenient synthesis of 1) new difluorophosphonium ions, 2) hexafluorophosphate salts, and 3) fluorinated antimony- and arsenic- compounds.
Gold(I) Complexes Nuclearity in Constrained Ferrocenyl Diphosphines: Dramatic Effect in Gold-Catalyzed Enyne Cycloisomerization
Nguyen, Tuan-Anh,Roger, Julien,Nasrallah, Houssein,Rampazzi, Vincent,Fournier, Sophie,Cattey, Hélène,Sosa Carrizo, E. Daiann,Fleurat-Lessard, Paul,Devillers, Charles H.,Pirio, Nadine,Lucas, Dominique,Hierso, Jean-Cyrille
supporting information, p. 2879 - 2885 (2020/08/13)
Di-tert-butylated-bis(phosphino)ferrocene ligands bearing phosphino substituents R (R=phenyl, cyclohexyl, iso-propyl, mesityl, or furyl) allow tuning the selective formation of Au(I) halide complexes. Thus, dinuclear linear two-coordinate, but also rare mononuclear trigonal three-coordinate and tetrahedral four-coordinate complexes were formed upon tuning of the conditions. Both Au(I) chloride and rarer Au(I) iodide complexes were synthesized, and their X-ray diffraction analysis are reported. The significance of the control of structure and nuclearity in Au(I) complexes is further illustrated herein by its strong effect on the efficiency and selectivity of gold-catalysed cycloisomerization. Cationic linear digold(I) bis(dicyclohexylphosphino) ferrocenes outperform other catalysts in the demanding regioselective cycloisomerization of enyne sulphonamides into cyclohexadienes. Conversely, tetrahedral and trigonal cationic monogold(I) complexes were found incompetent for enyne cycloaddition. We used the two-coordinate linear electron-rich Au(I) complex 2 b (R=Cy) to extend the scope of selective intramolecular cycloaddition of different 1,6-enyne sulfonylamines with high activity and excellent selectivity to the endo cyclohexadiene products.
