This is a solid synthesis used remarkably for the peptides synthesis.
Principle : Merrifield resin is a solid matrix where we bond by a chemical way molecules we want make react using notably covalent bond.
The matrix has to stay solid during the synthesis that which simplify the purification (washing then filtration of the matrix).
The matrix is a resin composed of polymers which have to be insoluble in all the solvents used for the synthesis.
Merrifield resin is a polystyrene resin based on a copolymer of styrene and chloromethylstyrene:
The first step is called “the grafting”:
Only one extremity of the molecule is bonded to the site reaction of the resin, the other one is free and only it will reacts. This free extremity has some functions which will not used so they need to be protected during the reaction. The reaction chain will grows up by steps chained.
The second step: Retrieve the molecule
When all the synthesis steps has been realized, the molecule is retrieved. When it is detached of the resin we call the step as a “cleavage” . The bond between the solid matrix and the molecule is broken is broken then the molecule is retrieved by washing and filtration of the resin.
Are you sure to know the basic of Periodic table?
If yes, play like me ! it’s a little satisfaction to have a little virtual message:
You Got: 20/20!
You completed the quiz! Congratulations!
I’ve chosen to share some very interesting web links. I think everybody working on a subject needs of small guides to advance or just to understand something well. So, don’t be stop by a chemistry abbreviation or small other thinks ans just click on the appropriate link before make all the websites !
Spectra data base for organic compounds:
The basic of NMR by Dr. Joseph P. Hornak:
Named reagents: just click on a name or abbreviation and you will have the corresponding structure :
A virtual museum of mineral and molecules:
I have drawn on Chemdraw some protections and deprotections very useful in organic chemistry, I hope these schemes will help you!
The work of a chemist is everyday a challenge, exciting when you find something new, sometimes stressful but rewarding. Having a chemistry degree in hand can open many doors such as:
You might work as a teacher at the university or in high school, teacher in primary or secondary school, or researcher in a university or industry.
Federal, State, and Local Government Agencies
- Drug Administration as a medicinal, analytical or biochemical chemist
- Department of Justice and other law enforcement agencies or analytical chemist
- Department of Agriculture as an agricultural, biochemical, Environmental, or analytical chemist
- Environmental Protection Agency, environmental, inorganic or organic chemist
- Patent Office as a patent researcher or lawyer
- National Science Foundation as a science writer and editor
- Department of Energy as an industrial and engineering, materials, or environmental chemist
Chemists produce everything from plastics and paints to pharmaceuticals products, flavors, fragrances, detergents, cosmetics, …
Some chemists also work as business owners, consultants, art conservators, or even investment bankers.
A very good video about explanation of gravitational waves
What are gravitational waves?
Colossal cosmic collisions and stellar explosions can rattle spacetime itself. Relativity rule predicts that ripples in the fabric of space-time radiate energy . After some time, they reach Earth, compress spacetime by as little as one ten-thousandth, the width of a proton.
How are they detected?
To spot a signal, LIGO uses a special mirror to split a beam of laser light and sends it down two 4-kilometer-long arms, at a 90 degree angle to each other. After ricocheting back and forth 400 times, turning each beam’s journey into a 1,600 kilometer round-trip, the light recombines near its source.
Flame tests are used in chemistry to identify metals or ions in compounds. They are more useful for some metals than others; particularly for the Group 1 metals, they provide a good way of quickly identifying the metal ion present.
This picture looks at the colour of various metal and metalloid ions that occur during flame tests. Most people probably remember have seen one flame test (often sodium) during an experiment in experimental lesson at school.
To carry out the flame tests, a small amount of the compound being tested will be held in a flame and the colour given off observed. This colour originates from the movement of the electrons in metal ion. When heated, the electrons gain energy, and are « excited » into higher energy levels; however, the electrons occupying these levels is more energetically unstable, and they tend to fall back down to their original energy levels, releasing energy as they do so. This energy is released as light, with the characteristic flame colours of different metal ions due to varying electron transitions.
“Love looks not with the eyes, but with the mind,” as Shakespeare’s Helena said and neuroscientists would agree.
Love might seem to move in mysterious ways, but scientists actually have a pretty good idea of what love does to the brain. Being in love floods the brain with chemicals and hormones that produce feelings of pleasure, obsession and attachment.
This funny little video shows you the chemical effects of love somebody on your body. And unfortunately the chemical effects of a rupture …
In fact, your body is regulated such as a machine !! But this animation explains this with humor ..don’t be worry