Search results for "Alkoxy group"
showing 10 items of 108 documents
Phosphasalen group IV metal complexes: synthesis, characterization and ring opening polymerization of lactide.
2020
International audience; We report the synthesis of a series of Zr and Ti complexes bearing phosphasalen which differs from salen by the incorporation of two P atoms in the ligand backbone. The reaction of phosphasalen proligands (1a-1c)H2 with Zr(CH2Ph)4 led to different products depending on the nature of the N,N-linker in the ligand. In case of ethylene-linked phosphasalen, octahedral Zr complex 2a formed as a single stereoisomer in trans geometry. With the phenylene linker, it was shown by dynamic NMR spectroscopy that complex 2b exists as a mixture of trans and cis-β isomers in solution, both enantiomers (Δ and Λ) of the cis-β isomer being in fast equilibrium with respect to the NMR tim…
Tetracationic and Tetraanionic Manganese Porphyrins: Electrochemical and Spectroelectrochemical Characterization
2017
International audience; The electrochemistry and spectroelectrochemistry of four tetrapositively charged and two tetranegatively charged porphyrins were characterized in two nonaqueous solvents (dimethyl sulfoxide and N,N-dimethylformamide) containing 0.1 M tetra-n-butylammonium perchlorate. The tetrapositively charged compounds are represented by the tetrapyridylporphyrins [TRPyPM]4+(X-)4, where R is a methyl or [2-[2-(2-methoxy)ethoxy]ethoxy]ethyl group, M = MnIIII, MnIIICl, CuII, or PdII, and X = I- or Cl-. The tetranegatively charged porphyrins are represented by the tetrasulfonato derivatives [TPPSMn(OAc)]4-(NH4+)4 and [TArPSMn(OAc)]4-(NH4+)4, where Ar = 4-O-[2-[2-(2-methoxy)ethoxy]eth…
Effect of a κ1-Bonded-M-1,2,3-triazole (M = Co, Ru) on the Structure and Reactivity of Group 6 Alkoxy (Fischer) Carbenes
2017
The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.inorgchem. 6b02957. NMR data for the synthesized compounds, electrochemical data of azides 2 and 4 (PDF) Computational details and cif files containing crystal data for 3a and 5b (CIF1, CIF2)
Nucleophilic additions of sodium alkoxides to 4,4-dichloro-1,1-diphenyl- 2-azabuta-1,3-diene
2000
The reaction of some sodium alkoxides with 4,4-dichloro-1,1-diphenyl-2-azabuta-1,3-diene is described. Whereas sodium methoxide, ethoxide or isopropoxide leads to 1,3-bis(alkoxy)- and/or 1,3,4-tris(alkoxy)-2-azabut-2-enes, the sodium salt of ethyl glycolate gives a Δ2-oxazoline. Mechanisms for the formation of these products are proposed.
Endohedral Mixed Aggregates: Sodium Alkoxide Cages with Organic or Inorganic Central Anions and Variable Hull.
2021
Abstract Alkali metal alkoxides are widely used in chemistry due to their Brønsted basic and nucleophilic properties. Potassium alkoxides assist alkyllithium in the metalation of hydrocarbons in Lochmann‐Schlosser‐bases. Both compounds form mixed aggregates, which enhance the thermal stability, solubility, and the basic reactivity of these mixtures. A very unusual spherical mixed alkoxy aggregate was discovered by Grützmacher et al., where a central dihydrogen phosphide anion is surrounded by a highly dynamic shell of thirteen sodium atoms and a hull of twelve tert‐butoxide groups. This structural motif can be reproduced by a reaction of trimethylsilyl compounds of methane, halogens, or pse…
Synthesis, Thermal, and Optical Properties of Tris(5‐aryl‐1,3,4‐oxadiazol‐2‐yl)‐1,3,5‐triazines, New Star‐Shaped Fluorescent Discotic Liquid Crystals
2019
Abstract The synthesis of tris(aryloxadiazolyl)triazines (TOTs), C 3‐symmetrical star‐shaped mesogenes with a 1,3,5‐triazine center, 5‐phenyl‐1,3,4‐oxadiazole arms, and various peripheral alkoxy side chains is reported. Threefold Huisgen reaction on a central triazine tricarboxylic acid and suitable aryltetrazoles yields the title compounds. Selected analogues with a benzene center are included in this study and allow for an evaluation of the impact of the central unit on the physical properties. Thermal (differential scanning calorimetry, DSC; polarization optical microscopy, POM), optical (UV/Vis, fluorescence), electric (time of flight, TOF), and structural (single crystal; wide‐angle X‐…
Understanding the mechanism of stereoselective synthesis of cyclopentenes via N-heterocyclic carbene catalyzed reactions of enals with enones.
2010
The N-heterocyclic carbene (NHC) catalyzed addition of enals to enones to yield trans-cyclopentenes has been investigated using DFT methods at B3LYP/6-31G** computational level. This NHC catalyzed reaction comprises several steps. The first one is the formation of a Breslow intermediate, which nucleophilically attacks to the conjugated position of the enone to yield an enol-enolate. This second step is responsible for the trans relationship at the final cyclopentene. An intramolecular aldolic condensation allows for the formation of the alkoxy cyclopentane intermediate, that by intramolecular nucleophilic attack on the carbonyl group yields a bicyclic ether. The extrusion of the NHC catalys…
Cobalt Electrolyte/Dye Interactions in Dye-Sensitized Solar Cells: A Combined Computational and Experimental Study
2012
We report a combined experimental and computational investigation to understand the nature of the interactions between cobalt redox mediators and TiO2 surfaces sensitized by :ruthenium and organic dyes, and their impact on. the performance of the corresponding dye-sensitized solar cells (DSSCs). We : focus: on different ruthenium dyes and fully organic dyes, to understand the dramatic loss of efficiency observed for the prototype Ru(II) N719 dye in conjunction with :Cobalt: electrolytes. Both N719- and Z907-based DSSCs showed an increased lifetime in iodine-based electrolyte compared to the cobalt-based redox-shuttle; While the organic D21L6 and D25L6 cycles endowed.With long alkoxy chains,…
1,3-Dipolar cycloaddition of diaryldiazomethanes across N-ethoxy-carbonyl-N-(2,2,2-trichloroethylidene)amine and reactivity of the resulting 2-azabut…
2016
Abstract 1,3-dipolar cycloaddition of diaryldiazomethanes Ar2C N2 across Cl3C–CH N–CO2Et 1 yields Δ3-1,2,4-triazolines 2. Thermolysis of 2 leads, via transient azomethine ylides 3, to diaryldichloroazabutadienes [Ar(Ar')C N–CH CCl2] 4. Treatment of 4a (Ar = Ar' = C6H5) and 4c (Ar = Ar' = p-ClC6H4) with NaSR in DMF yields 2-azabutadienes [Ar2C N–C(H) C(SR)2] 5. In contrast, nucleophilic attack of NaStBu on 4 affords azadienic dithioethers [Ar2C N–C(StBu) C(H)(StBu)] (7a Ar = C6H5; 7b Ar' = p-ClC6H4). The reaction of 4a with NaSEt conducted in neat EtSH produces [Ph2C N–C(H)(SEt)–CCl2H] 8, which after dehydrochloration by NaOMe and subsequent addition of NaSEt is converted to [Ph2C N–C(SEt) C…
Comparison of Alkoxy-substituted 4,4´-Distyrylbiphenyls and the Corresponding 4,4´-Distyrylbenzenes
2008
Abstract Configurationally highly pure (E,E)-4,4´-bis(styryl)biphenyls 2a - e were obtained by Siegrist reactions of 4,4´-dimethylbiphenyl 3 and alkoxy-substituted benzaldimines (4a - e). DSC measurements have indicated different crystalline modifications of these conjugated compounds. The stilbenoid chromophores of 2a - e are compared to the stilbenoid chromophores in the OPV series, which have a similar length of conjugation. The intense fluorescence and the high transparency in the visible region are promising properties for an application of the donor-substituted compounds 2a - e in twophoton absorption (TPA) techniques.