Synthesis and Characterization of New NCN´ Pincer Ni(II) Complexes
(2019) KEMK02 20182Department of Chemistry
- Abstract
- Transition metal complexes can activate otherwise unreactive C-H bonds to form C-C bonds, which is of great use for the synthetic chemist. One type of organometallic framework that has gained fame in the last decade is the pincer complex because of its stability, and how easily its steric and electronic properties can be altered. Palladium is one of the transition metals commonly used in pincer complexes but is a very rare and expensive metal. Its less valuable analogue nickel shares similar activity with palladium in Kumada coupling. Nitrogen donor groups are hard donors, making it possible to stabilize nickel Ni(III) species, and hence being able to do radical reactions such as Kharasch addition. Nickel is also abundant and inexpensive,... (More)
- Transition metal complexes can activate otherwise unreactive C-H bonds to form C-C bonds, which is of great use for the synthetic chemist. One type of organometallic framework that has gained fame in the last decade is the pincer complex because of its stability, and how easily its steric and electronic properties can be altered. Palladium is one of the transition metals commonly used in pincer complexes but is a very rare and expensive metal. Its less valuable analogue nickel shares similar activity with palladium in Kumada coupling. Nitrogen donor groups are hard donors, making it possible to stabilize nickel Ni(III) species, and hence being able to do radical reactions such as Kharasch addition. Nickel is also abundant and inexpensive, making it a very interesting alternative. In this work the synthesis of different NCN´ pincer Ni(II) complexes was tried, only N-(propan-2-yl)-N-{[3-(pyridin-2 yl)phenyl]methyl}propan-2-amine was successfully synthesized and characterized, but with an unsuccessful cyclometalation. (Less)
- Popular Abstract
- The importance of organometallic chemistry and its reactions can be reflected in the three Nobel prizes in chemistry that this field has been awarded in the last twenty years. Organometallic chemistry has given the synthetic chemist a completely new toolbox to create new molecules. Transition metals, such as iron, nickel and silver, give the organometallic molecules the special properties to perform reactions that pure organic chemistry cannot.
Organometallic molecules are often utilized as catalysts. The requirement for a molecule to be a catalyst is that it needs to increase the rate of reaction without itself being consumed. The catalyst provides the framework needed for catalysis to happen. An example of this are proteins where... (More) - The importance of organometallic chemistry and its reactions can be reflected in the three Nobel prizes in chemistry that this field has been awarded in the last twenty years. Organometallic chemistry has given the synthetic chemist a completely new toolbox to create new molecules. Transition metals, such as iron, nickel and silver, give the organometallic molecules the special properties to perform reactions that pure organic chemistry cannot.
Organometallic molecules are often utilized as catalysts. The requirement for a molecule to be a catalyst is that it needs to increase the rate of reaction without itself being consumed. The catalyst provides the framework needed for catalysis to happen. An example of this are proteins where their protein structure creates an active pocket where the reaction can take place. An alternative reaction pathway of lower energy compared to the usual route is provided by the catalyst, increasing the reaction rate. A good parable is to see the energy levels of the catalysed and uncatalyzed reactions as hills; the more energy required higher the hill. A smaller hill requires less energy to climb and will be done faster than if one would try to climb the larger hill.
There are many different types of catalysts, but one kind that is getting a rise in attention the last decade is the pincer complex. A metal atom is kept in place by surrounding atoms, connected in a chelated fashion. This means that the ligand creates a “jaw” that locks the metal in place, making it more stable and reactive in a productive way. Pincer ligand metal complexes are of interest because of their stability, as well as the simple ways of adjusting both its steric and electronic properties by changing the nature of the donor groups.
Catalysts provide higher yield, consume less solvent and require lower temperatures to perform the same reactions and these are just a few pros of using these organometallic molecules. Today catalysts are used to produce a wide variety of products that we use in our everyday life, such as plastic, pharmaceuticals and soap, to name a few.
In this work, we have tried to synthesize pincer complexes with nickel as the transition metal. Nickel share similarities with the extremely valuable palladium metal. However, nickel is more abundant and less expensive than its more valuable analogue, and this makes it a very attractive alternative for palladium catalysed reactions. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/8974384
- author
- Gunnarsson, Ludvig LU
- supervisor
- organization
- course
- KEMK02 20182
- year
- 2019
- type
- M2 - Bachelor Degree
- subject
- keywords
- Oorganisk kemi, Inorganic chemistry, Pincer complex, NCN, Nickel
- language
- English
- id
- 8974384
- date added to LUP
- 2023-06-28 11:47:02
- date last changed
- 2023-06-28 11:47:02
@misc{8974384,
abstract = {{Transition metal complexes can activate otherwise unreactive C-H bonds to form C-C bonds, which is of great use for the synthetic chemist. One type of organometallic framework that has gained fame in the last decade is the pincer complex because of its stability, and how easily its steric and electronic properties can be altered. Palladium is one of the transition metals commonly used in pincer complexes but is a very rare and expensive metal. Its less valuable analogue nickel shares similar activity with palladium in Kumada coupling. Nitrogen donor groups are hard donors, making it possible to stabilize nickel Ni(III) species, and hence being able to do radical reactions such as Kharasch addition. Nickel is also abundant and inexpensive, making it a very interesting alternative. In this work the synthesis of different NCN´ pincer Ni(II) complexes was tried, only N-(propan-2-yl)-N-{[3-(pyridin-2 yl)phenyl]methyl}propan-2-amine was successfully synthesized and characterized, but with an unsuccessful cyclometalation.}},
author = {{Gunnarsson, Ludvig}},
language = {{eng}},
note = {{Student Paper}},
title = {{Synthesis and Characterization of New NCN´ Pincer Ni(II) Complexes}},
year = {{2019}},
}