Search results for " Synthesis"

Efficient Stereoselective Synthesis of o-Functionalized P-Chirogenic Phosphines Applied to Asymmetric Catalysis

2015

The stereoselective synthesis of P-chirogenic o-halogenophenylphosphines and their use for the preparation of o-functionalized derivatives are reported. The key step of this synthesis is based on t...

Designing P*-chirogenic Organophosphorus Compounds: from Ligands to Organocatalysts

2015

The interest of organophosphorus compounds bearing chirality on the phosphorus atom has greatly expanded in last decade, due to the development of efficient stereoselective synthetic methods, using...

Wet Chemical Synthesis and a Combined X-ray and Mössbauer Study of the Formation of FeSb2 Nanoparticles

2011

Understanding how solids form is a challenging task, and few strategies allow for elucidation of reaction pathways that are useful for designing the synthesis of solids. Here, we report a powerful solution-mediated approach for formation of nanocrystals of the thermoelectrically promising FeSb(2) that uses activated metal nanoparticles as precursors. The small particle size of the reactants ensures minimum diffusion paths, low activation barriers, and low reaction temperatures, thereby eliminating solid-solid diffusion as the rate-limiting step in conventional bulk-scale solid-state synthesis. A time- and temperature-dependent study of formation of nanoparticular FeSb(2) by X-ray powder dif…

A systematic study of the optical properties of mononuclear hybrid organo-inorganic lanthanoid complexes

2020

A series of hybrid organo-inorganic mononuclear lanthanoid complexes, [n-NBu4]3[LnH(PW11O39)(phen)2]·H2O, denoted as LM4-1-Ln (Ln = DyIII, TbIII, EuIII, NdIII, ErIII, HoIII and GdIII), were synthesized via hydrothermal synthesis and were structurally characterized by X-ray diffraction. The optical properties of all complexes have been investigated in the solid state. The temperature-dependent emission spectra of LM4-1-Dy, LM4-1-Tb and LM4-1-Eu complexes show intense lanthanoid emissions in the visible region, while LM4-1-Nd shows near-infrared (NIR) luminescence. The EuIII complex shows typical strong red emissions from the 5D0 → 7F0,1,2,3,4 transitions, with the CIE colour coordinates (0.6…

Hydrothermal Synthesis, Crystal Structure, and Magnetism of Na 2 [Ir(OH) 6 ] and its Dehydration to Na 2 IrO 3

2021

The First Pure Mesoporous Aluminium Phosphonates and Diphosphonates − New Hybrid Porous Materials

2004

Organophosphorus moieties have been incorporated into mesoporous ALPOs through a one-pot surfactant-assisted procedure leading, for the first time, to periodic mesoporous aluminium phosphonates and diphosphonates. The number of organic groups on the surface or in the network can be modulated continuously up to the maximum incorporation level of the respective organophosphorus entities (100 %). (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

1‐Oxa‐3‐cyclooctin

1990

1-Oxa-3-cyclooctyne According to an MNDO calculation, 1-oxa-cyclooctyne (13) and 1-oxa-3-cyclooctyne (14) are 8-membered heterocyclic ring systems with high steric energy (ring strain). On the basis of THF (1) and acetoacetic ester (4), a multi-step synthesis is described for 14. The triple bond is introduced in the last step by a thermal fragmentation of the 1,2,3-selenadiazole 12.

One‐Pot Synthesis of a New High‐Aluminium‐Content Super‐Microporous Aluminosilicate

2006

A new super-microporous aluminosilicate having a high aluminium content (Si/Al ca. 1) has been prepared through a surfactant-assisted procedure with the use of a commercially available binary precursor (di-sec-butoxyaluminooxytriethoxysilane) as a single source of both Al and Si. The formation of super-micropores is a result of a significant network shrinkage associated with the thermal elimination of the surfactant. This solid has been studied by X-ray powder diffraction, electron microscopy, nuclear magnetic resonance spectroscopy and porosimetry. A preliminary analysis of the acidity and the catalytic activity of the super-microporous solid for the selective catalytic reduction of NOx is…

Glycosylation-induced asymmetric synthesis: β-amino acid esters via Mannich reactions

2000

Abstract Activation of Schiff bases by N-glycosylation induces asymmetric Mannich reactions with O-silyl ketene acetals to give β-amino acid esters in good yields.

pH‐Controlled Assemblies of Dimethyltin‐Functionalized 9‐Tungstophosphates with Guanidinium as Structure‐Directing Cation

2010

Aqueous reaction of (CH 3 ) 2 SnCl 2 with Na 9 [A-α-PW 9 O 34 ] in a 3:1 ratio with [C(NH 2 ) 3 ] + as structure-directing agent resulted in three distinct assemblies of dimethyltin-functionalized tungstophosphates depending on the pH: [{(CH 3 ) 2 -Sn(H 2 O)}{(CH 3 ) 2 Sn}(A-α-PW 9 O 34 )] 5- ( 1 ) at pH = 4.5; [{(CH 3 ) 2 -Sn(H 2 O) 2 }{(CH 3 ) 2 Sn(H 2 O)} 2 (A-α-PW 9 O 34 )] 3- (2) at pH = 3.0; and [{(CH 3 ) 2 Sn(H 2 O)} 3 (A-α-PW 9 O 34 )] 3- (3) at pH = 2.0. All three compounds have been characterized in the solid-state by elemental and thermal analyses, infrared spectroscopy and single-crystal X-ray diffraction. The [A-α-PW 9 O 34 ] 9- trilacunary fragments have three {(CH 3 ) 2 Sn} 2…