Material Type  

 학위논문

 

0017160155

Date and Time of Latest Transaction  

20250211150921

ISBN  

9798382841199

DDC  

547

Author  

Spivey, Jesse Alexander.

Title/Author  

The Structure and Reactivity of Potassium Alkyl- and Bis - Trimethylsilazides.

Publish Info  

[S.l.] : Cornell University., 2024

Publish Info  

Ann Arbor : ProQuest Dissertations & Theses, 2024

Material Info  

717 p.

General Note  

Source: Dissertations Abstracts International, Volume: 85-12, Section: B.

General Note  

Advisor: Collum, David.

학위논문주기  

Thesis (Ph.D.)--Cornell University, 2024.

Abstracts/Etc  

요약The solution structure and reactivity of potassium alkyl- and bis- silylamides (KN(SiMe3)R; R=SiMe3, KHMDS; R=i-Pr, KPTA; and R=t-Bu, KBTA) were investigated using spectroscopic and computational methods as well as reactions with various arenes. 29Si chemical shifts were relied upon to assign aggregation states in various aromatic and polar, aprotic O- and N-sigma donor solvents. All three potassium silazides were characterized as dimers in most solvents, including the polyamines TMEDA and PMDTA. Only THF and polyethereal solvents (DME, diglyme, 15-crown-5, 18-crown-6 and [2.2.2]cryptand) were shown to deaggregate KHMDS to monomer. THF was the only solvent to form monomeric KBTA. Monomeric KPTA was never observed. DFT optimized geometries and single point energies were used to assign the solvation numbers of spectroscopically observable aggregates. KHMDS was observed to metallate arenes slowly at ambient temperature, but KBTA was able to metallate a variety of haloarenes at -78 ºC, which were trapped and characterized with MeOD, Me3SiCl, and pivaldehyde. KBTA-mediated directed orthometallation proved to be substrate dependent; halopyridines yielded the high isolated yields of pivaldehyde adducts, which were not always reflected in deuteration yields. 3-halogenated benzotrifluorides were observed to metalate completely via in situ IR and afforded deuterated products quantitatively, but they exhibited low yields of pivaldehyde adducts. Ultimately, we suspect the large diffuse coordination sphere of potassium makes it more challenging to control and study when compared with their sodium or lithium analogs.

Subject Added Entry-Topical Term  

Organic chemistry.

Subject Added Entry-Topical Term  

Inorganic chemistry.

Index Term-Uncontrolled  

Alkali amides

Index Term-Uncontrolled  

KBTA

Index Term-Uncontrolled  

KHMDS

Index Term-Uncontrolled  

Orthometallation

Index Term-Uncontrolled  

Potassium

Index Term-Uncontrolled  

Silazides

Added Entry-Corporate Name  

Cornell University Chemistry and Chemical Biology

Host Item Entry  

Dissertations Abstracts International. 85-12B.

Electronic Location and Access  

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Control Number  

joongbu:655023