Using (1)H, (13)C, and (133)Cs NMR spectra, it is shown that calix[4]arene-bis(t-octylbenzo-18-crown-6) (L) forms complexes with one (L·Cs(+)) two (L·2Cs(+)) Cs(+) ions offered by cesium bis(1,2-dicarbollide) cobaltate (CsDCC) in nitrobenzene-d(5). The interact all six oxygen atoms the crown-ether ring π electrons of calixarene aromatic moieties. According to extraction technique, stability constant first complex log β(nb)(L·Cs(+)) = 8.8 ± 0.1. value equilibrium second K(nb)((2))(L·2Cs(+))...

The hydration numbers of the complexes ML + formed by some univalent cations (M = Li , Na NH 4 K Rb and Cs ) polyethylene glycol ligands (L PEG 200, 300 400) in nitrobenzene saturated with water were determined. highest differences between M found systems cation.

The stability constants for the ML + complex species, where M is an alkali metal cation and L dibenzo-18-crown-6, in nitrobenzene saturated with water were calculated by employing published equilibrium data. found to increase order Li < Cs Rb K Na . For NaL , KL RbL CsL cations individual extraction water-nitrobenzene system determined; their values series

Interaction of dibenzo-18-crown-6 (DBC) with H3O+ (HP) in nitrobenzene-d5 and dichloromethane-d2 was studied by using 1H 13C NMR spectra relaxations, FTIR spectra, quantum chemical DFT calculations. shows that the DBC•HP complex is a dynamic equilibrium reactants, constant K being 0.66 × 103, 1.16 104, 1.03 104 L·mol−1 CD2Cl2, nitrobenzene, acetonitrile, respectively. The appears to have C2v symmetry NMR, but combined normal mode calculations suggest such high only apparent due exchange...

Interaction of trioctylphosphine oxide (TOPO) with fully ionized hydrated protons (HP) was studied in acetonitrile-d(3) and nitrobenzene-d(5) using (1)H, (13)C, (31)P NMR, PFG magnetic relaxation, the experimental results were confronted high-precision ab initio DFT calculations. Relative chemical shifts NMR signals TOPO (0.02 mol/L) under presence HP molar ratio beta = 0-2.0 mol/mol show binding between HP. Self-diffusion measurements (1)H demonstrate that larger complexes higher content...

Extraction of microamounts Sr 2+ and Ba from 0.2-1.0M-HClO 4 by the nitrobenzene solutions dicarbolide H + [Co(C 2 B 9 11 ) ] - in presence polyethylene glycols (PEG) (M r = 200, 300, 400) has been investigated. It found that extraction protonized glycol molecule (H L ##e HL , where bar denotes species present organic phase) complex between extracted ion glycol, i.e. M +L ML are predominant reactions this system. The respective equilibrium constants have determined. hydration numbers ions...

Abstract Valinomycin is shown to form a stable complex with protons in the of H 3 O + ions. Using 1 and 13 C nuclear magnetic resonance (NMR), Fourier transform (FT) infrared spectroscopy, ab initio–density functional theory (DFT) quantum mechanical calculations, it that , produced by hydrogen bis(1,2‐dicarbollyl) cobaltate (HDCC) presence water, interacts valinomycin 1,1,2,2‐tetrachloroethane‐ d 2 give relatively complex. The equilibrium constant K formation was derived from chemical shifts...

Using (1)H and (13)C NMR DFT calculations, the structure interactions of symmetric ethereally fenced hexaarylbenzene receptor 1 with hydronium ions were studied. Both its equimolecular complex 1.H(3)O(+) exhibit C(3v) symmetry. According to DFT, two similar optimal structures exist, more stable one being 15.4 kJ/mol lower in energy. The equilibrium between complexes is characterized by stabilization constant K = 1.97 x 10(6) (i.e., binding eta 6.3) according both proton carbon spectra....

Using 1H and 13C NMR spectroscopy, the interaction of tetrapropoxy-p-tert-butyl-calix[4]arene (1) with H3O+ ions produced by hydrogen bis(1,2-dicarbollyl) cobaltate (HDCC) traces water was studied in nitrobenzene-d 5. It shown that 1 readily forms an equimolecular complex H3O+. The equilibrium constant K its formation is 2.6 at 296 K. Exchange between bound free fast even under mild excess HDCC, correlation time τex being about 0.13 ms. shows to aryl-oxygen atoms this binding forces...

A study has been made of the extraction Sr and Ba in an aqueous solution perchloric acid-18-crown-6-bis-1,2-dicarbollylcobaltate-nitrobenzene. It was found that organic phase contains complexes ML 2+ org type ( M = , ) are converted to 2 when concentration crown c L is greater than bis-1,2-dicarbollylcobaltate B ). The values corresponding constants, individual constants stability extracted species were determined. system can be utilized for separation applications at concentrations here < .

Using 1H and 13C NMR together with density functional theoretical (DFT) calculations, it is shown that p-tert-butylcalix[4]arene-tetrakis(N,N-dimethylthioacetamide) (1) forms a stable equimolecular complex proton in the form of hydroxonium ion nitrobenzene-d 5. Protons were offered by hydrogen bis(1,2-dicarbollyl) cobaltate (HDCC) converted to ions traces water. The 1·H3O+ adopts slightly asymmetric but rapidly motionally averaged conformation, which distinctly more cone-like than ligand 1....

Using 1H and 13C NMR, FT IR spectroscopy together with quantum mechanical DFT calculations, we show that tetraethyl p-tert-butylcalix[4]arene tetraacetate (1) forms a stable equimolecular complex proton in the form of hydroxonium ion acetonitrile-d 3. Protons for this were offered by hydrogen bis(1,2-dicarbollyl) cobaltate (HDCC) converted to ions traces water. The 1·H3O+ adopts slightly asymmetric conformation, which is distinctly more cone-like than ligand 1. According spectral evidence,...

Abstract Interaction of H 3 O + or 5 2 with 1,3‐alternate tetrapropoxycalix[4]arene (1) was studied in nitrobenzene and dichloromethane using 1 13 C NMR including transverse rotating‐frame relaxations density functional level theory (DFT) quantum calculations. According to NMR, the ion forms an equimolecular complex equilibrium constant K being 3.97 × 10 L.mol −1 at 296 K. The ions are bound by strong hydrogen bonds phenoxy‐oxygen atoms one half a medium‐strong bond π system aromatic rings...

Abstract Extraction of microamounts calcium and strontium by a nitrobenzene solution hydrogen dicarbollylcobaltate (H + B - ) in the presence octyl-phenyl-N,N-diisobutylcarbamoylmethyl phosphine oxide (“classical” CMPO, L) has been investigated. The equilibrium data have explained assuming that complexes HL , 2 CaL 2+ 3 SrL 4 are extracted into organic phase. values extraction stability constants species saturated with water determined.

Extraction of microamounts Sr 2+ and Ba (henceforth M ) from the aqueous solutions perchloric acid (0.0125-1.02 mol/l) by means nitrobenzene dicarbolide (0.004-0.05 mol/l H + {Co(C 2 B 9 11 } - was studied in presence monoglyme (only ), diglyme, triglyme, tetraglyme (CH 3 O-(CH -CH O) n CH , where = 1, 2, 3, 4). The distribution glyme betweeen organic phases, extraction protonized molecule HL together with ion complex ion, i.e. ML (where L is glyme), were found to be dominating reactions...

Capillary affinity electrophoresis (CAE) has been employed to investigate quantitatively the interactions of valinomycin, macrocyclic depsipeptide antibiotic ionophore, with univalent cations, ammonium and alkali metal ions, K(+), Cs(+), Na(+), Li(+), in methanol. The study involved measuring change effective electrophoretic mobility valinomycin while cation concentrations BGE were increased. corresponding apparent stability (binding) constants valinomycin-univalent complexes obtained from...