Organometallic compounds of Group III. 52. Active sites for ethylene polymerization with titanium(IV) catalysts in homogeneous media: multinuclear NMR study of ion-pair equilibria and their relation to catalyst activity

1993 ◽  
Vol 12 (10) ◽  
pp. 3856-3863 ◽  
Author(s):  
John J. Eisch ◽  
Sofya I. Pombrik ◽  
Guo Xiu Zheng
Keyword(s):  
Ethylene Polymerization ◽  
Active Sites ◽  
Catalyst Activity ◽  
Organometallic Compounds ◽  
Ion Pair ◽  
Group Iii ◽  
Multinuclear Nmr ◽  
Nmr Study ◽  
Homogeneous Media

Arylation of enelactams using TIPSOTf: reaction scope and mechanistic insight

2021 ◽  
Author(s):  
Tomasz J. Idzik ◽  
Zofia M. Myk ◽  
Łukasz Struk ◽  
Magdalena Perużyńska ◽  
Gabriela Maciejewska ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Multinuclear Nmr ◽  
Mechanistic Insight ◽  
Nmr Study ◽  
Wide Range

Triisopropylsilyltrifluoromethanesulfonate can be effectively used for the arylation of a wide range of enelactams. The multinuclear NMR study provided deep insights into the reaction mechanism.

scholarly journals Bio-DEE Synthesis and Dehydrogenation Coupling of Bio-Ethanol to Bio-Butanol over Multicomponent Mixed Metal Oxide Catalysts

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 660
Author(s):  
Izabela S. Pieta ◽  
Alicja Michalik ◽  
Elka Kraleva ◽  
Dusan Mrdenovic ◽  
Alicja Sek ◽  
...  
Keyword(s):  
Active Sites ◽  
Internal Combustion Engines ◽  
Mixed Oxides ◽  
Catalyst Activity ◽  
Product Distribution ◽  
Coke Deposition ◽  
Precipitation Method ◽  
Mixed Metal Oxide ◽  
Low Carbon ◽  
Municipal Solid Wastes

Within the Waste2Fuel project, innovative, high-performance, and cost-effective fuel production methods from municipal solid wastes (MSWs) are sought for application as energy carriers or direct drop-in fuels/chemicals in the near-future low-carbon power generation systems and internal combustion engines. Among the studied energy vectors, C1-C2 alcohols and ethers are mainly addressed. This study presents a potential bio-derived ethanol oxidative coupling in the gas phase in multicomponent systems derived from hydrotalcite-containing precursors. The reaction of alcohol coupling to ethers has great importance due to their uses in different fields. The samples have been synthesized by the co-precipitation method via layered double hydroxide (LDH) material synthesis, with a controlled pH, where the M(II)/M(III) ≈ 0.35. The chemical composition and topology of the sample surface play essential roles in catalyst activity and product distribution. The multiple redox couples Ni2+/Ni3+, Cr2+/Cr3+, Mn2+/Mn3+, and the oxygen-vacant sites were considered as the main active sites. The introduction of Cr (Cr3+/Cr4+) and Mn (Mn3+/Mn4+) into the crystal lattice could enhance the number of oxygen vacancies and affect the acid/base properties of derived mixed oxides, which are considered as crucial parameters for process selectivity towards bio-DEE and bio-butanol, preventing long CH chain formation and coke deposition at the same time.

Organometallic compounds of Group III

1971 ◽  
Vol 31 (3) ◽  
pp. C49-C54 ◽  
Author(s):  
John J. Eisch ◽  
Sue Goo Rhee
Keyword(s):  
Organometallic Compounds ◽  
Group Iii

scholarly journals 21Ne and 131Xe NMR study of electric field gradients and multinuclear NMR study of the composition of a ferroelectric liquid crystal

2018 ◽  
Vol 149 (23) ◽  
pp. 234901 ◽  
Author(s):  
Susanna K. Ahola ◽  
Petri Ingman ◽  
Reino Laatikainen ◽  
Jari Sinkkonen ◽  
Jukka Jokisaari
Keyword(s):  
Liquid Crystal ◽  
Electric Field ◽  
Ferroelectric Liquid Crystal ◽  
Electric Field Gradients ◽  
Multinuclear Nmr ◽  
Field Gradients ◽  
Nmr Study

scholarly journals Lithium-tetrahydroaluminat in Ether: eine NMR-Untersuchung / Lithiumtetrahydroaluminate in Ether: an NMR Study

1980 ◽  
Vol 35 (2) ◽  
pp. 119-124 ◽  
Author(s):  
Heinrich Nöth
Keyword(s):  
Fine Structure ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Line Width ◽  
Ion Pair ◽  
Minimum Value ◽  
Ion Formation ◽  
Nmr Study ◽  
Low Concentrations

Abstract Ether solutions of LiAlH4 have been investigated by 27Al and 7Li magnetic resonance in the concentration range 3.75-0.0075 M. The Al-signal shows a fine structure due to Al-H coupling only at concentrations below 0.15 M. The observed chemical shift 27Al is only slightly concentration dependent. The line width of the 27Al signal, which is inversely proportional to T2*, reaches a minimum value at a concentration where the best resolution of the 27Al quintet is observed. This, however, is not matched by the 7Li line width whose minimum value was found at a somewhat higher concentration. The results are consistent with multiple ion formation at the higher concentrations and with an ion pair at low concentrations.

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