3324-58-1Relevant academic research and scientific papers
Effect of solvating additives on anion-exchange extraction of trichloroacetate anions from aqueous solutions with trinonyloctadecylammonium picrate in toluene
Rakhma'ko,Gulevich,Kiiko,Kovalevich
, p. 69 - 73 (2006)
The solvation effect of trifluoroacetophenone derivatives on anion-exchange extraction of trichloroacetate anions from aqueous phase with trinonyloctadecylammonium picrate in toluene was studied. Pleiades Publishing, Inc., 2006.
Buckyball-Based Spherical Display of Crown Ethers for de Novo Custom Design of Ion Transport Selectivity
Li, Ning,Chen, Feng,Shen, Jie,Zhang, Hao,Wang, Tianxiang,Ye, Ruijuan,Li, Tianhu,Loh, Teck Peng,Yang, Yi Yan,Zeng, Huaqiang
supporting information, p. 21082 - 21090 (2020/12/21)
Searching for membrane-active synthetic analogues that are structurally simple yet functionally comparable to natural channel proteins has been of central research interest in the past four decades, yet custom design of the ion transport selectivity still remains a grand challenge. Here we report on a suite of buckyball-based molecular balls (MBs), enabling transmembrane ion transport selectivity to be custom designable. The modularly tunable MBm-Cn (m = 4-7; n = 6-12) structures consist of a C60-fullerene core, flexible alkyl linkers Cn (i.e., C6 for n-C6H12 group), and peripherally aligned benzo-3m-crown-m ethers (i.e., m = 4 for benzo-12-crown-4) as ion-transporting units. Screening a matrix of 16 such MBs, combinatorially derived from four different crown units and four different Cn linkers, intriguingly revealed that their transport selectivity well resembles the intrinsic ion binding affinity of the respective benzo-crown units present, making custom design of the transport selectivity possible. Specifically, MB4s, containing benzo-12-crown-4 units, all are Li+-selective in transmembrane ion transport, with the most active MB4-C10 exhibiting an EC50(Li+) value of 0.13 μM (corresponding to 0.13 mol % of the lipid present) while excluding all other monovalent alkali-metal ions. Likewise, the most Na+ selective MB5-C8 and K+ selective MB6-C8 demonstrate high Na+/K+ and K+/Na+ selectivity values of 13.7 and 7.8, respectively. For selectivity to Rb+ and Cs+ ions, the most active MB7-C8 displays exceptionally high transport efficiencies, with an EC50(Rb+) value of 105 nM (0.11 mol %) and an EC50(Cs+) value of 77 nM (0.079 mol %).
Biferrocene triazole ligand and ion type metal complex and preparation method thereof
-
Paragraph 0034; 0035; 00036, (2017/08/31)
The invention discloses a biferrocene triazole ligand and an ion type metal complex and a preparation method thereof. The biferrocene triazole ligand has a formula shown in the description; the energy-containing ion type metal complex with the ligand has a formula shown in the description, wherein in the formula, M is Cu, Co, Ni, Mn, Zn or Pb; when the L is the carbazotic acid monovalence anion, m is 1, and n is 4; when the L is styphnic acid diatomic anion, m is 1, and n is 2; when the L is the trinitrophloroglucinol trivalent anion, m is 3, and n is 4; r is the number of free water molecules in the compelx. The complex provided by the invention is not liable to volatilize under the natural condition; the thermal stability is high; high generation heat and combustion heat are realized; high combustion catalysis performance is realized on ammonium perchlorate. The preparation method of the complex has the advantages that the operation is simple and convenient; the target product yield is high.
Synthesis, binding properties and theoretical studies of p-tert-butylhexahomotrioxacalix[3]arene tri(adamantyl)ketone with alkali, alkaline earth, transition, heavy metal and lanthanide cations
Marcos, Paula M.,Ascenso, José R.,Segurado, Manuel A.P.,Bernardino, Raul J.,Cragg, Peter J.
experimental part, p. 496 - 503 (2009/04/07)
p-tert-Butylhexahomotrioxacalix[3]arene tri(adamantyl)ketone (1b) was synthesized for the first time. Compound 1b was obtained in a cone conformation in solution at room temperature, as established by NMR spectroscopy (1H and 13C). The binding properties of ligand 1b for alkali, alkaline earth, transition, heavy metal and lanthanide cations have been assessed by phase transfer and proton NMR titration experiments. Molecular mechanics and ab initio techniques were also employed to complement the NMR data. The results are compared to those obtained with other closely related homooxacalixarene derivatives. Although triketone 1b is a weak extractant, it shows a strong peak selectivity for Na+ and also some preference for Ag+. Proton NMR titrations indicate the formation of 1:1 complexes between 1b and the cations studied, and also that they should be located inside the cavity defined by the phenoxy and carbonyl oxygen atoms. Although the molecular mechanics results show little correlation with the NMR data, a good agreement was obtained with the ab initio models.
A study of C-F···M+ interaction: Alkali metal complexes of the fluorine-containing cage compound
Takemura,Kon,Kotoku,Nakashima,Otsuka,Yasutake,Shinmyozu,Inazu
, p. 2778 - 2783 (2007/10/03)
The C-F···M+ interaction was investigated by employing a cage compound 1 that has four fluorobenzene units. The NMR (1H, 13C, and 19F) spectra and X-ray crystallographic analyses of 1 and its metal complexes showed clear evidence of the interaction. Short C-F···M+ distances (CF···K+, 2.755 and 2.727 A; C-F···Cs+ 2.944 and 2.954 A) were observed in the crystalline state of K+ ? 1 and Cs+ ? 1. Furthermore, the C-F bond lengths were elongated by the interaction with the metal cations. By calculating Brown's bond valence, it is shown that the contribution of the C-F unit to cation binding is comparable or greater than the ether oxygen in the crystalline state. Representative spectroscopic changes implying the C-F···M+ interaction were observed in the NMR (1H, 13C, and 19F) spectra. In particular, 133Cs-19F spin coupling (J = 54.9 Hz) was observed in the Cs+ complex.
Design and synthesis of a new class of nonmacrocyclic alkali metal host compounds
McGarvey, Glenn J.,Stepanian, Marshall W.,Bressette, Andrew R.,Sabat, Michal
, p. 3453 - 3456 (2007/10/03)
A new class of nonmacrocyclic metal ion hosts has been examined that features a polyspirocyclic framework that offers a 1,3,5-triaxial presentation of ligating centers. These compounds are easily synthesized and exploit stereoelectronic influences to preorganize the metal ion binding site. While compounds bearing oxygen substituents (X = OH, OMe) failed to show appreciable binding of alkali metals, the aminated host (X = NHBn) exhibitied strong binding with association constants (Ka) greater than 107-108 as measured by picrate extraction analysis.
Guest inclusion properties of calix[6]arene-based unimolecular cage compounds. On their high Cs+ and Ag+ selectivity and very slow metal exchange rates
Otsuka, Hideyuki,Suzuki, Yoshio,Ikeda, Atsushi,Araki, Koji,Shinkai, Seiji
, p. 423 - 446 (2007/10/03)
The reaction of 1.3.5-tri-O-alkylated calix[6]arenes with 1,3,5- tris(bromomethyl)benzene yielded capped calix[6]arenes (2 with ten-butyl groups on the upper tim and 3 without tert-butyl groups) in unexpectedly high yields (80 - 91%). Combined studies of 2 and 3 by MM3 computation, X-ray analysis, and 1H NMR spectroscopy established that these calix[6]arenes feature a unique structure consisting of alternately-arranged three flattened mesitylene-linked phenyl units and three stand-up anisole units. Particularly, compound 2 possesses a closed ionophoric cavity: the upper hemisphere is closed by three ten-butyl groups of anisole units and the lower hemisphere is closed by a mesitylene cap and three anisole methoxy groups. The 1H NMR spectrum was scarcely changed at wide temperature range (30 ~ 130 °C), indicating that the structure is extremely rigidified. Both solvent extraction and spectroscopic studies established that this cavity shows the high selectivity toward Cs+ among alkali metal cations, the high affinity with Ag+, and the moderate affinity with RNH3+. Very surprisingly, the association-dissociation processes for 2 and cesium picrate was so slow that the rate could be followed by a conventional spectroscopic method. The thermodynamic parameters determined by kinetic studies disclosed that the major driving-force for Cs+ inclusion is the entropy term based on the desolvation.
New supramolecular hosts: Synthesis and cation binding studies of novel Troger's base-crown ether composites
Manjula, Alla,Nagarajan, Madhavarao
, p. 11859 - 11868 (2007/10/03)
A simple and straightforward synthesis of a novel class of supramolecular hosts containing the Troger's base moiety is reported. The cation binding properties of these macrocycles were investigated using Cram's picrate extraction method.
Kinetically stable complexes of alkali cations with calixspherands: An evaluation of shielding
Iwema Bakker, Wouter I.,Haas, Marijke,Khoo-Beattie, Corinne,Ostaszewski, Ryszard,Franken, Sybille M.,Den Hertog Jr., Herman J.,Verboom, Willem,De Zeeuw, Dick,Harkema, Sybolt,Reinhoudt, David N.
, p. 123 - 133 (2007/10/02)
Three new calixspherands (2-4) were synthesized in good yields (>60%) via a new method; p-tert-butylcalix-[4]arene (6) is bridged with a m-terphenyl (7-9) and subsequently alkylated. 1H NMR spectroscopy and X-ray crystallography showed that all the complexes are in a partial cone conformation. All the calixspherands form kinetically stable complexes with Na+, K+, and Rb+. The kinetic stability was determined both by 1H NMR spectroscopy, in CDCl3 saturated with D2O, and by a new method based on the exchange of radioactive rubidium or sodium in the complexes for nonradioactive sodium in different solvents. Both methods showed that the kinetic stability of the different complexes is strongly increased when the size of the group on the central aromatic ring of the m-terphenyl is increased. This effect is most pronounced for the rubidium complexes. The half-life times for decomplexation, in CDCl3 saturated with D2O, increased from 2.8 h for [1·Rb]+ to 139 h and 180 days for [2·Rb]+ and [3·Rb]+, respectively. The 'exchange method' shows that the rate of decomplexation is the rate-limiting step in the exchange of rubidium in the complex for sodium present in solution. These results can be explained in terms of increased shielding of the cavity from solvent molecules. The kinetic stabilities of the complex of 3 with Na+, K+, and Rb+ are the highest ever reported.
Reaction of (E)-O-Arylbenzaldoximes with Sodium Methoxide in Methanol. Effect of Leaving Group upon Nitrile-Forming Transition State
Cho, Bong Rae,Jung, Jinhee,Ahn, Eun Kyung
, p. 3425 - 3429 (2007/10/02)
Reactions of (E)-O-arylbenzaldoximes 1-3 with MeONa-MeOH have been studied kinetically.The reactions proceed via competing E2 and SNAr reactions, in which the first step is rate-determining.Although the reactions were strongly influenced by the electronic effect of the β- and O-aryl substituents, they were insensitive to the steric effect of the O-aryl group, except that the SNAr reaction was retarded by the CF3 group of 2.For eliminations from 1-3 promoted by MeONa-MeOH, the kH/kD value increased and the Hammett ρ value decreased with better leaving groups.From these results, the effect of leaving group variation upon the nitrile-forming transition state is assessed.
