57914-22-4Relevant academic research and scientific papers
A stannatrane-like [4.4.4.01,6] heterotricyclic stannate anion possessing rhodanide antennae: A chromoreactand for Fe3+, Cu2+ and Co2+ ions
Srivastav, Neha,Singh, Raghubir,Kaur, Varinder,Wagler, J?rg,Kroke, Edwin
, p. 54 - 60 (2017)
Exploration of an aminotrisphenol ligand (H3L) to synthesise heterocyclic tin derivatives led to the unexpected formation of a stannatrane-like [4.4.4.01,6] heterotricyclic stannate anion [LSnCl2]? (1). Further, its metathesis reaction with ammonium thiocyanate provided access to its thiocyanate derivative [LSn(NCS)2]? (2), which proved to be a chromophoric probe. The characterization methods applied, such as elemental analysis, various spectroscopic methods (FT-IR, NMR (1H, 13C, 119Sn), UV–Vis, Mass) and X-ray crystallography (for 2) are in accord with the formation of these ionic compounds. The rhodanide functionalized stannatrane-like compound (2) was isolated as triethylammonium salt with distorted octahedral environment around Sn generated by the tripodal O3N donor system and the N atoms of two cis configured thiocyanates. This particular organization of rhodanides imparted chelator and chromophoric character to 2 and enhanced its colorimetric and optical response towards some metal ions (such as Fe3+, Cu2+ and Co2+ ions) as compared to the free tripodal ligand (H3L) and ammonium thiocyanate. The role of 2 as a bidentate ligand for the chelation of metal ions may be responsible for the enhanced stability of metal complexes as well as the observed spectral behaviour.
A new class of silatranes: Structure and dynamic NMR behavior
Chandrasekaran,Day, Roberta O.,Holmes, Robert R.
, p. 1066 - 1072 (2000)
A new class of silatranes N[CH2(Me2C6H2)O]3SiR was prepared by the reaction of organosilanes with tris(2-hydroxy-4,6-dimethylbenzyl) amine (5) in the case of 1, 3, and 4, and by the reaction of Si(OMe)4 with the same amine (5) to give 2. This is the first series of silatranes containing all six-membered rings. Their structures were established by X-ray analysis and correlated with 29Si NMR data. VT 1H NMR spectra reflected fluxional behavior for the chiral molecules 1-3, whereas 4 was a rigid molecule. The activation energies for enantiomeric conversion of the clockwise and anticlockwise orientations of the propeller-like silatranes 1-3 were statistically the same at about 10 kcal/mol. A simultaneous pseudorotation of all three six-membered rings is suggested to cause the racemization process. The Si-N distances for 1-4 show a large dependence on the exocyclic substituent. Over an approximate electronegativity range of 2.3-3.0, the Si-N distance varies from 2.745(4) A for 1 to 2.025(4) A for 4. Thus, the influence of substituent effects on nitrogen-silicon donor-acceptor interactions can be readily studied in the absence of constraints imposed by the use of the smaller ring-containing silatranes.
Ti(IV)-Tris(phenolate) Catalyst Systems for the Ring-Opening Copolymerization of Cyclohexene Oxide and Carbon Dioxide
Raman, Sumesh K.,Deacy, Arron C.,Pena Carrodeguas, Leticia,Reis, Natalia V.,Kerr, Ryan W. F.,Phanopoulos, Andreas,Morton, Sebastian,Davidson, Matthew G.,Williams, Charlotte K.
, p. 1619 - 1627 (2020/02/27)
Titanium(IV) complexes of amino-tris(phenolate) ligands (LTiX, X = chloride, isopropoxide) together with bis(triphenylphosphine)iminium chloride (PPNCl) are active catalyst systems for the ring-opening copolymerization of carbon dioxide and cyclohexene oxide. They show moderate activity, with turnover frequency values of ～60 h-1 (0.02 mol % of catalyst, 80 °C, 40 bar of CO2) and high selectivity (carbonate linkages >90%), but their absolute performances are lower than those of the most active Ti(IV) catalyst systems. The reactions proceed with linear evolution of polycarbonate (PCHC) molar mass with epoxide conversion, consistent with controlled polymerizations, and evolve bimodal molar mass distributions of PCHC (up to Mn = 42 kg mol-1). The stoichiometric reaction between [LTiOiPr] and tetraphenylphosphonium chloride, PPh4Cl, allows isolation of the putative catalytic intermediate [LTi(OiPr)Cl]-, which is characterized using single-crystal X-ray diffraction techniques. The anionic titanium complex [LTi(OR)Cl]- is proposed as a model for the propagating alkoxide intermediates in the catalytic cycle.
A nitrogen bridged three aryloxyacetic-based rare-earth metal compound and its preparation method and application
-
Paragraph 0058; 0060; 0061, (2017/03/08)
The invention discloses a nitrogen bridged triaryloxy rare-earth compound, and a preparation method and catalytic application thereof. The general formula of the rare-earth compound is LLn(THF)3, and the chemical structural formula is disclosed in the spe
CYTOTOXIC TITANIUM AND VANADIUM COMPLEXES
-
Paragraph 0300, (2015/12/31)
The present application provides a family of highly resistant and water-stable Titanium and Vanadium complexes, which may be administered directly without a further hydrolysis step and which solubility and cell-penetration characteristics may be modifiabl
An air stable moisture resistant titanium triflate complex as a lewis acid catalyst for C-C bond forming reactions
Bull, Steven D.,Davidson, Matthew G.,Johnson, Andrew L.,Mahon, Mary F.,Robinson, Diane E. J. E.
experimental part, p. 612 - 620 (2010/08/05)
An air and moisture stable C3-symmetric titanium(IV) triflate, supported by a tripodal amine-(tris-phenolate) ligand, has been synthesized and characterized by X-ray crystallography and shown to be a good Lewis acid catalyst for a range of aza-Diels-Alder, Diels-Alder, syn aldol, allylation, and alkylation reactions.
Vanadium-catalyzed oxidative bromination promoted by Br?nsted acid or Lewis acid
Kikushima, Kotaro,Moriuchi, Toshiyuki,Hirao, Toshikazu
experimental part, p. 6906 - 6911 (2010/09/18)
The oxidative bromination of arenes was induced by a vanadium catalyst in the presence of a bromide salt and a Br?nsted acid or a Lewis acid under molecular oxygen, which provides an eco-friendly bromination method as compared with a conventional bromination one with bromine. This catalytic reaction could be applied to the bromination of alkenes and alkynes to give the corresponding vic-bromides. Use of aluminum halide as a Lewis acid in place of a Br?nsted acid was demonstrated to provide a more practical protocol for the oxidative bromination. From ketones, α-bromination products were obtained. AlBr3 was found to serve as both a bromide source and a Lewis acid to induce the bromination smoothly. 51V NMR experiment showed that this catalytic bromination is likely to depend on the redox cycle of a vanadium catalyst under molecular oxygen.
Synthesis and structure of aluminium amine-phenolate complexes
Johnson, Andrew L.,Davidson, Matthew G.,Perez, Yolanda,Jones, Matthew D.,Merle, Nicolas,Raithby, Paul R.,Richards, Stephen P.
scheme or table, p. 5551 - 5558 (2009/12/23)
Reaction of Al(OiPr)3 with the tris-phenol amine ligand L1H3 in toluene at ambient temperature results in the formation of the iso-propanol adduct [HOiPr·Al(L 1)]. Single crystal X-ray diff
