Hey guys, Leah from leah4sci.com and in this video I'm going to show you how to use the
molecular visions model kit for your Organic Chemistry class.
The kit that I recommend is the Molecular Vision's Organic Model kit.
There's the small one which I'm holding right here, and there's the large one.
The two are basically the same.
The larger kit has these extra, if you see these big circles for atoms, I honestly think
they're overkill and for your Organic Chemistry class you don't wanna be spending a lot.
Something like this has everything you need and is more than enough and you can get this
on amazon just go to leah4sci.com/kit that's my referral link and I do get a small commission
if you use that link, So let's break it open and see what we have here.
That is if you don’t actually cut into the bag but at least we got it out of the box,
we're gonna have two things one is this bag over here with all the pieces and then you
have the box for storing your kit.
My advise is to get another bag because you probably won't be able to fit it back in here
once you have some of the pieces built up and you probably won't be able to get it back
into the box either so I just keep it in a bag mind you I have many kits thrown together
so I have a very big bag.
Even more challenging than the model kit itself is figuring out this box.
So here we have the instruction book which has some really impressive models but we're
not gonna use that.
For the front part, the bottom of the box, that wasn’t so painful and there we go.
Alright, so here's the box and this probably fits in your bag, keep this at home though.
If your professor allows a model kit on your exam, bring it along but bring it in a bag
with some pre-built structures that way you don't have to waste your time and I'm gonna
show you how to do this.
What do we have in this kit?
We have these black sp3 pieces and one itself is not gonna be sp3 but when you connect it
to a second one, they link up just like that, just a little bit of muscle to connect that
you have to get that click in there, that right there will be considered your sp3 carbon
so we definitely need a lot of these and we have a bunch of these.
And we have the same thing in red, grey, and blue.
These are so that you can create either different substituents or if you wanna make something
standout, also red typically refers to oxygen if you wanna call it that way.
I like to use different colors if I'm trying to emphasize a certain functional group.
Then we have these, they kinda of look black but they're slightly grey and shiny and these
are the flexible ones.
I use these when I'm demonstrating the hexagon before doing a chair conformation because
if I flatten out a hexagon with the sp3 they tend to be very weak and they start to Fray
over here but using the flexible ones gives me a little more lifespan because I have broken
a few of these already . Then we have these here which is a pi bond that is pre-built
and that is if you wanna attach a pi bond to a molecule for example if you consider
this to be your carbon with a double bound oxygen, this could be formaldehyde so that's
your pre-built pi bond but if you want to show that double bound between a carbon and
an oxygen typically the grey represents carbon to carbon, you might wanna use the half pi,
because then you have half of the grey and half of the red, and that right there would
be carbon to oxygen double bond.
Then we have this right here to represent a triple bond where that would be one carbon,
that would be another carbon and there's your triple bond, you have the y-plane and the
z-plane for your 2 pi bonds and then here you can just elongate the chain in either
direction.
And finally we have the individual atoms if we wanna attach an atom to a structure.
White is typically used for hydrogen, red for Oxygen, and you could honestly do with
whatever you want with it but it does help to have the four different colors.
So now that we have the kit, what are the main structures that you're going to see in
your Organic Chemistry course?
Obviously, we have the sp3 carbon, so we wanna build up a couple of these and I recommend
actually keeping a few of these pre-built so that you have them handy no matter what
type of structure you're trying to create.
Now that they are built up let's see what we can do with this.
But first I want you to look for the link below that says do not rely on your Organic
Chemistry model kit because it's very easy for this to become a time wasting crutch and
instead of helping you on the exams it's going to hurt you, it's going to waste your time.
But it's a very useful tool for studying because you can look at structures on paper all day
long but when you're holding a model in your hand when you are demonstrating a molecule
or a concept in three dimensions, everything becomes so much easier.
For example, here we have a 5 carbon chain pentane and instead of looking at it as a
line, notice that these 109.5 degree bond angles gives you that zigzag line structure,
this is why skeletal structures drawn in a zigzag.
Sometimes it's difficult to confuse a 5-carbon chain in a row with something that maybe looks
like this.
These look like two different molecules but no, this is the same exact structure, these
are just conformational isomers because I am turning it but they're the same exact molecule.
To get familiar, just rotate these a few times and get really really comfortable with what's
going on.
To add substituents, we just connect it wherever.
Here we go, that's your substituent.
The next topic where this comes in handy, are Newman projections.
For Newman Projections you’re used to looking at the model down to specific carbons.
For example if we have something like ethane which is two carbons bound together, and 3
hydrogens on each side for a total of six, this would be our ethane molecule and for
the Newman projection we typically look down carbons 1 to 2, so holding your model kit
just turn it and there you go, that is a beautiful Newman Projection.
That right there is the eclipsed conformation, and if we rotate it slightly, we get the staggered
conformation.
But holding it in your hand, it's very easy to see what's going on.
Maybe this doesn't fully demonstrate the power of the Newman so let's make it bigger.
Here we can imagine butane that's 1,2,3,4 carbons and if we want to look at a Newman
Projection bounce carbon 2 to 3 just rotate it so carbon 2, the first black one is the
first one you see and there's carbon number 3.
Carbon 3 is heading behind number 2 but here we have the substituents, here we have the
substituents, they are anti and staggered or we can make them eclipse and now look at
that, the eclipse structure they're starting to be very close together, and rotating this
a few times will give you a true appreciation for the energy between staggered eclipse anti,
gauche, and all that fun stuff.
The next time you wanna use your kit, is for chair conformations.
For a chair conformation we need six carbons and a hexagon and this is where that flexible
piece comes in handy because if I try to flatten it out, to prove to you why the chair conformation
is needed notice that that is straining and it almost wants to break.
To make it stable and to make that true chair, make sure that you have every other one facing
up or towards you when you're looking at it head on.
So, we have up, down, up, down, up, down, and from the side it's much easier to see,
up, down, up, down, up, and down.
And the chair concept is right here, so that would be where you lay your head, this is
where you put your body, this is where you have your feet and that's your chair.
To understand the interactions on a chair conformation, simply add a bulky group and
there we go, diaxial interaction.
Very easy to see and of course a ring flip and now the diaxial interactions are gone
and this is so much more stable, this helps explain why equatorial is more stable than
axial.
To do that ring flip, up down, everything just flipped and we're back to diaxial.
And last but not the least where everybody tends to rely on the kit is stereochemistry.
For stereochemisty, the first thing you wanna do is play around with your different color
substituents to identify and prove to yourself that when you have chiral carbons, enantiomers
are not superimposable.
This is where I love having the different color groups and this is why I like this kind
of kit.
It's so easy to build and work with but it's very obvious what is going on.
If we have enantiomers, there would be a mirror between them, if they're superimposable then
there wouldn't be enantiomers.
In this case I happen to have both two of the same thing, look at how they perfectly
line up with each other.
Every color matches up with every color.
To turn this into an enantiomer, we do one swap, coz remember an odd number of swaps
gives us the enantiomer.
Now if I try to superimpose it, if I line up the blue and the green, the red and the
white are backwards.
If I try to make the red and white line up, the blue and the green are backwards, so these
are not superimposable because they're mirror images and if I put them side by side, you
can see they're mirror images.
You can take this a step further when looking at multiple chiral centers.
To differentiate the two groups put something different on it for example a red bulkier
group and here we go same thing!
We have two molecules that look very close together.
Chiral carbon, chiral carbon, the upper carbons are mirror images of each, the lower ones
are identical, this would be considered a diastereomer and if you play with it, you'll
notice that if I try to for example rotate and make the lower carbon colors line up,
this red group is in the opposite direction and so on so just play around with it a little.
And one more thing that I should not forget is a Fischer Projection.
So a fischer projection would be for example looking at something like this, once you build
it you can say that's my fischer.
These come out towards you like the bow tie, these are going back like a spine, it's fading
away and then you just draw it exactly like this as a fischer projection.
The last thing I wanna look at is now that you know how to use the kit and you’ve practiced
with it and are comfortable with it, what do you do going into an exam?
If you have this kits, here is what I recommend doing prior to your exam.
Build up the structures that you think you might need.
That means build up two chiral carbons with the unique substituents already on them so
that if you have to pull this out on the exam you're ready to go.
Build up six more of these in case you have to do a chair, all you have to do is add two
more.
What about the rest of the chair?
build up something like this because this way you have another group ready in case you
have to build a chiral molecule with more than just one carbon, you can easily pull
off one of these attached them here that gives you a bigger chiral molecule and you have
the second one ready to go for comparison or if you have to do a chair conformation,
you can easily attach these two right here and you have your chair ready to go with substituents
and of course if you don't need the chair, you also have this ready as a potential Newman
Projection with four carbons and any unique substituents you need to place on it.
Doing this in advance will A.give you the confidence to know that if you do need to
pull out your model kit, you're not scrambling to try to build up a structure based on the
exam but you have the building box ready to go and you just have to connect them together
and B. knowing that you have it will make you confident but hopefully you're learning
the shortcuts and tricks that I teach on my other videos so that you don't even need your
model kit but you have it there for safety just in case you do.
And if you notice, this will never fit back in this bag and it certainly is not fitting
back in here.
Not if you plan to close it anyway.
So, just put it into a bag.
Bring these along in a smaller bag maybe even the initial bag.
But this right here, this is going to save you time on the exam, so have this ready to
go and of course if you like this video first make sure to give it a thumbs up, second subscribe,
and third let me know in the comments which Organic Chemistry topics you're working on
right now and what kind of videos you want to see coming to my channel in the future.
For in depth video series on all the topics we discussed using the model kit today from
isomers to newman projections, chair conformations, stereochemistry, fischer projections and so
much more, visit my website for the Organic Chemistry syllabus companion because this
will allow you to compare your syllabus to my list of videos and make sure you quickly
find what you want.
My youtube videos are shorten to the point but for even more in depth tutorials including
very detailed workshops with lots of practice, shortcuts, tips, tricks, and more, come join
me in the Organic Chemistry Study Hall which will be your new tutoring replacement at a
fraction of the cost full details on my website leah4sci.com/join.