I hate organic chemistry it’s impossible
organic chemistry
ille these are some common reactions to
the subject of organic chemistry and
that’s not really surprising considering
how difficult the subject can actually
be when students learn organic chemistry
they don’t only learn new subject matter
but they also learn a new language to go
along with the subject matter this new
language often contains symbolism that
is unfamiliar and non-intuitive to most
people if we can take this symbolism and
make it more relatable people would be
able to understand the symbolism a
little bit better and maybe eventually
the stigma of organic chemistry being a
very hard course will go away just a
little bit in fact that’s exactly what
I’m going to try to do with you all
today if you have ever picked up a
plastic water bottle used detergent on
your clothes or your dishes if you’ve
ever worn makeup or taken medication you
have encountered an application of
organic chemistry the thing that all of
these products have in common are
molecules that contain carbon atoms an
organic chemistry is defined as the
study of carbon containing compounds it
wasn’t always defined in this way people
used to think that organic compounds
actually had to come from living sources
it wasn’t until the mid 1800s where this
theory of vitalism where the living
sources would transfer this vital force
to the organic molecules was actually
disproved an experiment was done where
two inorganic molecules were combined so
these are molecules from nonliving
sources and they produce an organic
molecule and that led to the normal
definition of organic chemistry that we
see today another breakthrough came in
the early 1900s when chemists start to
think about what exactly
is going on between these molecules in a
reaction they knew that if they combined
some molecules they would get out some
kind of product oftentimes they wouldn’t
even know what the product would be used
for but in the 1900s
people started thinking well what’s
going on behind the scenes how are these
molecules reacting to make new molecules
and they found out that the key behind
the reactions of organic compounds was
transfer of electrons so electrons are
the key movements that shift bonds
around form new molecules and once this
was discovered people needed a way to
communicate what these electron
transfers were and to tell people there
were these certain patterns that occur
in these molecules and it was then that
a chemist named Robert Robinson ended up
proposing arrow notation so this is
using arrows to show where electrons are
flowing and this is the focus of modern
organic chemistry courses students
usually learn reactions and all of these
arrows to show what exactly these
molecules are doing to produce the new
product so what do students typically
know when they start organic chemistry
they are familiar with a little bit of
this language so organic chemistry is
like learning a new language and they do
have some familiarity this is like
somebody coming into a language course
knowing a few of the words but they
won’t know how to make sentences and
they don’t usually know how to make
stories or how to write paragraphs for
example so in organic chemistry what we
assume students know is that the
molecules on the left hand side of an
arrow are the ones that we start with
the ones on the right-hand side of the
arrow are our products those are the
ones that end up that reaction arrow in
between that’s actually like an equal
sign and math would be where you’re
adding things on the left and getting
your answer on the right another thing
that students usually know coming into a
course is the fact that the dots around
that B are that bromine atom those dots
represent electrons and they’re usually
found in pairs and they usually travel
in pairs not always but this is usually
the case
there are a couple things that students
may or may not be familiar with when
they start an organic chemistry course
and these are things like line
structures organic chemists combine the
atoms to make line structures in order
to make it a little bit simpler to see
what’s going on you can see the
structure on the top is actually a lot
more convoluted than the one on the
bottom and this what we do in these line
structures is we assume that the carbon
atoms are every point so every end will
be a carbon atom and in the middle will
be a carbon atom hydrogen atoms are
assumed so this is something that we
teach in organic chemistry as well it’s
part of the language another thing
students might might or might not
already know is that plus in the minus
sign the minus sign refers to the fact
that that atom has a little bit more
electrons than it normally wants to have
and the plus sign means that the atom
has a little bit less electrons than it
normally wants to have and these are the
key behind how reactions happen so what
organic chemistry is all about we kind
of review these concepts and then we go
into the main part of the language which
is the arrow notation so this was
developed by Robinson in 1922 and this
is what we’re still teaching today to
show how molecules react there are a
couple of patterns to the way that we
show these arrows and this is sort of
like teaching students a few sentences
that they can start stringing together
to make paragraphs in for example a
language course so the few sentences are
the bond formation so we usually start
at the source of electrons that those
two dots that lone pair that is our
source and we point towards the atom
that will end up in the bond we can also
have bonds as our source source of
electrons and in that case we do a very
similar motion in order to make a new
bond the other key aspect she’s showing
how molecules react is to break bonds
because molecules reacting are all
forming bonds and breaking bonds and so
breaking bonds we start our arrow in the
middle of the bond and we point to the
atom that gets the electrons when we put
it like this see
like there’s some nice foundation to
start with but this language is not very
intuitive to most people and most
students coming in struggle to learn
this language and about a year ago a
student by the name of Maria Thomas
approached me with an idea to relate
this electron flow to the human behavior
and so what we did where our goal was to
try to make these this electron flow a
little bit more relatable to how people
react so bonds are like bonds between
people we’re gonna see a little bit more
about this in a bit so the reaction that
we decided to start with was a common
reaction for organic chemistry courses
for introductory organic chemistry so
this is a reaction that students usually
learn it’s usually pretty difficult
because there are some trends that are a
little bit reversed in this one versus
what they normally see so this is an
example of what we show students and we
expect them to look at this and remember
how it goes and they’re sitting there
thinking that this is what it pretty
much relates to probably like some of
you are thinking that was a lot of
jumbled mess did not make any sense of
it so the students will usually see this
and they’re asking questions semester
after semester as an undergraduate I had
the exact same questions how do those
atoms end up attached that way this is a
very difficult reaction to learn so what
we do is we related the chemical
behavior on this reaction to human
behavior and we told a story of this
reaction we personalize the atoms a
little bit and Maria did this by making
videos so the key concept in this
reaction is something called
electronegativity electronegativity is
how much an atom hogs the electrons in
the bond so the line between the carbon
and the magnesium is two electrons the
red arrow is pointing towards the carbon
because the carbon actually hogs most of
the electrons in that bond so in a way
it’s like it has this burden and just
like personalize the people and their
relationships this is like one partner
in the relationship having all the
responsibility having a lot of
stress that’s not going to be the
greatest for that relationship just like
this electronegativity difference isn’t
the greatest for that bond so we’ve
really same reaction and we went
stepwise and explained this in terms of
human behavior so the main characters or
key atoms are colored we start off with
our carbon magnesium bond so the red
person and the blue person the red
person is a little bit stressed out it
has more of the burden in that
relationship but that’s okay until
another molecule comes along chemically
this is how we show that and what
happens is the carbon leaves the
magnesium with the electrons to go and
bond to a different carbon structurally
we showed this like this where we have a
line between the green carbon and the
red carbon that’s that new bond so
they’re in a nice happy relationship
carbon and carbon bonds they’re actually
the same electronegativity so they share
the burden equally it’s a very healthy
relationship it’s not gonna go back so
magnesium though he’s left all by
himself he’s not the only one who got
screwed over in this reaction now soon
as the red carbon attacked the green
carbon the oxygen also got dumped with
more electrons so it has this burden
it’s not very happy and the oxygen and
magnesium form a relationship a rebound
we show that chemically with a line
between the magnesium and the oxygen and
they sit like that for a while they’re
fine until another molecule comes along
physically what we do is we add acid
into our reaction and this provides
hydrogen atoms the pink oxygen loves the
hydrogen atoms and it’s going to go and
bond with one of those yet again
magnesium sitting there thinking what’s
wrong with me why does this keep
happening and the oxygen and the black
hydrogen end up in a bond we usually end
up stopping our analysis of this
reaction at this point because we only
care usually with what happens to the
organic material before the sense of
closure let’s talk about what happens to
this magnesium so when we added acid
into the reaction we also have water
molecules and one of these water
molecules the oxygen shown in orange
ends up through a little bit of a
process
binding to the magnesium and they live
happily ever after in the chemical waste
bin so let’s summarize the bonds that we
ended up forming in this reaction so the
red carbon ended up leaving the blue
magnesium for the green carbon the pink
oxygen also left the blue magnesium for
the black hydrogen and the magnesium
finally found its happy ending with the
oxygen anecdotally this has been shown
to be helpful for students and I hope
you enjoyed this story of this chemical
romance and I hope you learned a little
bit of organic chemistry along the way
thank you
[Applause]
organic chemistry
ille these are some common reactions to
the subject of organic chemistry and
that’s not really surprising considering
how difficult the subject can actually
be when students learn organic chemistry
they don’t only learn new subject matter
but they also learn a new language to go
along with the subject matter this new
language often contains symbolism that
is unfamiliar and non-intuitive to most
people if we can take this symbolism and
make it more relatable people would be
able to understand the symbolism a
little bit better and maybe eventually
the stigma of organic chemistry being a
very hard course will go away just a
little bit in fact that’s exactly what
I’m going to try to do with you all
today if you have ever picked up a
plastic water bottle used detergent on
your clothes or your dishes if you’ve
ever worn makeup or taken medication you
have encountered an application of
organic chemistry the thing that all of
these products have in common are
molecules that contain carbon atoms an
organic chemistry is defined as the
study of carbon containing compounds it
wasn’t always defined in this way people
used to think that organic compounds
actually had to come from living sources
it wasn’t until the mid 1800s where this
theory of vitalism where the living
sources would transfer this vital force
to the organic molecules was actually
disproved an experiment was done where
two inorganic molecules were combined so
these are molecules from nonliving
sources and they produce an organic
molecule and that led to the normal
definition of organic chemistry that we
see today another breakthrough came in
the early 1900s when chemists start to
think about what exactly
is going on between these molecules in a
reaction they knew that if they combined
some molecules they would get out some
kind of product oftentimes they wouldn’t
even know what the product would be used
for but in the 1900s
people started thinking well what’s
going on behind the scenes how are these
molecules reacting to make new molecules
and they found out that the key behind
the reactions of organic compounds was
transfer of electrons so electrons are
the key movements that shift bonds
around form new molecules and once this
was discovered people needed a way to
communicate what these electron
transfers were and to tell people there
were these certain patterns that occur
in these molecules and it was then that
a chemist named Robert Robinson ended up
proposing arrow notation so this is
using arrows to show where electrons are
flowing and this is the focus of modern
organic chemistry courses students
usually learn reactions and all of these
arrows to show what exactly these
molecules are doing to produce the new
product so what do students typically
know when they start organic chemistry
they are familiar with a little bit of
this language so organic chemistry is
like learning a new language and they do
have some familiarity this is like
somebody coming into a language course
knowing a few of the words but they
won’t know how to make sentences and
they don’t usually know how to make
stories or how to write paragraphs for
example so in organic chemistry what we
assume students know is that the
molecules on the left hand side of an
arrow are the ones that we start with
the ones on the right-hand side of the
arrow are our products those are the
ones that end up that reaction arrow in
between that’s actually like an equal
sign and math would be where you’re
adding things on the left and getting
your answer on the right another thing
that students usually know coming into a
course is the fact that the dots around
that B are that bromine atom those dots
represent electrons and they’re usually
found in pairs and they usually travel
in pairs not always but this is usually
the case
there are a couple things that students
may or may not be familiar with when
they start an organic chemistry course
and these are things like line
structures organic chemists combine the
atoms to make line structures in order
to make it a little bit simpler to see
what’s going on you can see the
structure on the top is actually a lot
more convoluted than the one on the
bottom and this what we do in these line
structures is we assume that the carbon
atoms are every point so every end will
be a carbon atom and in the middle will
be a carbon atom hydrogen atoms are
assumed so this is something that we
teach in organic chemistry as well it’s
part of the language another thing
students might might or might not
already know is that plus in the minus
sign the minus sign refers to the fact
that that atom has a little bit more
electrons than it normally wants to have
and the plus sign means that the atom
has a little bit less electrons than it
normally wants to have and these are the
key behind how reactions happen so what
organic chemistry is all about we kind
of review these concepts and then we go
into the main part of the language which
is the arrow notation so this was
developed by Robinson in 1922 and this
is what we’re still teaching today to
show how molecules react there are a
couple of patterns to the way that we
show these arrows and this is sort of
like teaching students a few sentences
that they can start stringing together
to make paragraphs in for example a
language course so the few sentences are
the bond formation so we usually start
at the source of electrons that those
two dots that lone pair that is our
source and we point towards the atom
that will end up in the bond we can also
have bonds as our source source of
electrons and in that case we do a very
similar motion in order to make a new
bond the other key aspect she’s showing
how molecules react is to break bonds
because molecules reacting are all
forming bonds and breaking bonds and so
breaking bonds we start our arrow in the
middle of the bond and we point to the
atom that gets the electrons when we put
it like this see
like there’s some nice foundation to
start with but this language is not very
intuitive to most people and most
students coming in struggle to learn
this language and about a year ago a
student by the name of Maria Thomas
approached me with an idea to relate
this electron flow to the human behavior
and so what we did where our goal was to
try to make these this electron flow a
little bit more relatable to how people
react so bonds are like bonds between
people we’re gonna see a little bit more
about this in a bit so the reaction that
we decided to start with was a common
reaction for organic chemistry courses
for introductory organic chemistry so
this is a reaction that students usually
learn it’s usually pretty difficult
because there are some trends that are a
little bit reversed in this one versus
what they normally see so this is an
example of what we show students and we
expect them to look at this and remember
how it goes and they’re sitting there
thinking that this is what it pretty
much relates to probably like some of
you are thinking that was a lot of
jumbled mess did not make any sense of
it so the students will usually see this
and they’re asking questions semester
after semester as an undergraduate I had
the exact same questions how do those
atoms end up attached that way this is a
very difficult reaction to learn so what
we do is we related the chemical
behavior on this reaction to human
behavior and we told a story of this
reaction we personalize the atoms a
little bit and Maria did this by making
videos so the key concept in this
reaction is something called
electronegativity electronegativity is
how much an atom hogs the electrons in
the bond so the line between the carbon
and the magnesium is two electrons the
red arrow is pointing towards the carbon
because the carbon actually hogs most of
the electrons in that bond so in a way
it’s like it has this burden and just
like personalize the people and their
relationships this is like one partner
in the relationship having all the
responsibility having a lot of
stress that’s not going to be the
greatest for that relationship just like
this electronegativity difference isn’t
the greatest for that bond so we’ve
really same reaction and we went
stepwise and explained this in terms of
human behavior so the main characters or
key atoms are colored we start off with
our carbon magnesium bond so the red
person and the blue person the red
person is a little bit stressed out it
has more of the burden in that
relationship but that’s okay until
another molecule comes along chemically
this is how we show that and what
happens is the carbon leaves the
magnesium with the electrons to go and
bond to a different carbon structurally
we showed this like this where we have a
line between the green carbon and the
red carbon that’s that new bond so
they’re in a nice happy relationship
carbon and carbon bonds they’re actually
the same electronegativity so they share
the burden equally it’s a very healthy
relationship it’s not gonna go back so
magnesium though he’s left all by
himself he’s not the only one who got
screwed over in this reaction now soon
as the red carbon attacked the green
carbon the oxygen also got dumped with
more electrons so it has this burden
it’s not very happy and the oxygen and
magnesium form a relationship a rebound
we show that chemically with a line
between the magnesium and the oxygen and
they sit like that for a while they’re
fine until another molecule comes along
physically what we do is we add acid
into our reaction and this provides
hydrogen atoms the pink oxygen loves the
hydrogen atoms and it’s going to go and
bond with one of those yet again
magnesium sitting there thinking what’s
wrong with me why does this keep
happening and the oxygen and the black
hydrogen end up in a bond we usually end
up stopping our analysis of this
reaction at this point because we only
care usually with what happens to the
organic material before the sense of
closure let’s talk about what happens to
this magnesium so when we added acid
into the reaction we also have water
molecules and one of these water
molecules the oxygen shown in orange
ends up through a little bit of a
process
binding to the magnesium and they live
happily ever after in the chemical waste
bin so let’s summarize the bonds that we
ended up forming in this reaction so the
red carbon ended up leaving the blue
magnesium for the green carbon the pink
oxygen also left the blue magnesium for
the black hydrogen and the magnesium
finally found its happy ending with the
oxygen anecdotally this has been shown
to be helpful for students and I hope
you enjoyed this story of this chemical
romance and I hope you learned a little
bit of organic chemistry along the way
thank you
[Applause]
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