earlier this year the Royal Society of
Chemistry decided they would mark the
Olympic year by creating a special
molecule that would look like the
Olympic symbol the five rings they
commissioned a professor at the
University of Warwick to work and make
this molecule
because it's a new molecule hasn't got a
name
so they called it a limb piscine which
is quite a nice name once it had been
made and I presume it was a whitish
powder they then worked with scientists
in the IBM lamp in Zurich to actually
produce an image so you can see the
shape of the molecule which is really
quite a good feat of science to image
the molecule I looked at the image
really excited and then I suddenly felt
disappointed because the rings were not
linked in the way that the Olympic rings
ought to be linked
I thought could you actually make the
real Olympic rings where you have
molecules linked together it turns out
that people have made molecules of rings
linked together like these two rings
here they even have a name they called
cata names and the first time that they
were made they took a molecule which
essentially a straight string of carbon
atoms and common hydrogen atoms with
reactive groups at the end so you can
react them together and make a ring if
you dissolve these molecules in solution
and get them to react if the solution is
concentrated different molecules just
stick together and you get long chains
but if the solution is very dilute the
molecule will as it were bite its own
tail and form a ring so now you have a
solution of rings you then add some more
material but now more concentrated and
hope that one or two of these molecules
poke through the hole so that when you
add the reagent to make them react they
will react together and you will get two
linked one inside the other when I was a
student in the late 1960s after a huge
amount of work some people managed to
make a very small amount of kattiline
like this with two rings joined together
more recently chemists in
came up with a much cleverer way of
making cattle names in which you can
make them in quite large quantities you
begin with a solution of metal ions like
copper or something like that and you
have the same sort of long molecules but
this time you have some sort of group in
the middle which will bond onto the
metal and so you bond first of all one
one of these molecules onto the metal
and then you bond on a second one so now
if you imagine you have these two long
straight molecules joined together by
the metal atom you then do the reaction
which joins if I can do it which joins
the two rings together and it's easier
to do it with a molecule than it is with
this piece of rubber and then you've got
the two rings joined together
oops then you've got the two rings still
joined with the metal and the final
stage you do a bit more chemistry and
the metal comes out so now instead of
relying on chance you've got the linked
rings because the metal acted as a sort
of mold to join these things two
together and you can imagine that you
could keep on doing this and make a
longer chain of rings you may not have
realized because I didn't realize until
a few days ago Olympic rings although it
has one ring under another these two are
not joined together so in fact there's a
chain of rings there five rings in the
Olympic symbol and the problem is that
and I still haven't thought how to do
this is that if you use one of these
copper atoms you're always going to get
an even number of rings so I could
imagine how you can make two rings full
rings six rings but I haven't worked out
yet how you don't make five so I think
that's a problem which I should leave
for the students like you to solve I've
given you the basic idea like
good teacher now I leave it to the
students as their homework exercises to
work out how you'd make five rings in a
row