This discussion is now closed.

Check out other Related discussions

How does polyethyne conduct electricity?

Hiya guys! I've been asked to "suggest why poly(ethyne) conducts electricity. I was thinking that its maybe because that the pie bond is slightly exposed - but my teacher was like eeeeeer no. Any ideas?

Reply 1

Da Mouse

ooooooooooooh! I think I know why! Is it because the alternate single and double carbon carbon bonds "merge" together to form a continueos delocalised electrons (if that makes sense :s:

) ? Like with benzene rings?

Reply 2

BCHL85

You are quite right, but single bonds cannot merge. The electrons in doubles can merge to create a delocalised electrons because the C-C is short enough so that the double bonds can merge.

Same reason for benzen :smile:

Reply 3

charco

Study Forum Helper

polythene doesn't conduct electricity - it is used as an insulator in electrical installations!

Reply 4

BCHL85

Question asks about poly(ethyne) ... which has formula -CH=CH-CH=CH-
While polyethen has formula -CH2-CH2-
No related

Reply 5

vinny221

Ethyne has a triple carbon carbon bond:

H - C Triple bond C - H

When polymerized, it will contain alternating double and single bonds in a conjugated system. The delocalised electrons can thus carry charge.

Reply 6

Da Mouse

kinda strange for a plastic to conduct electricity :s-smilie:

: - do you think it actuallt conducts electricity in real life?

Reply 7

RMIM

Da Mouse

kinda strange for a plastic to conduct electricity :s-smilie:

: - do you think it actuallt conducts electricity in real life?

I am not 100% sure (so someone who knows..) but just about anything/if not everything can conduct electricity if the voltage is high enough - even air (lighting). If you look at electricians screwdrivers/pliers etc. they have a rating where above this the insulating properties break down and will conduct.

Reply 8

cobra

Plastics that conduct are a developing area in chemistry, I don't know how well poly ethylene will but it will better than most non metal things

Reply 9

AngelofPeace

Why does trans(E) polyethyne conduct better than cis(Z) polyethyne?

Reply 10

Zedd

I've been told that they are using this technology to design new tv screens that can be made to have very bright colours (meaning the image isn't lost in direct sunlight like conventional screens). It's a cool application imo.

Poly(ethyne) can be made to conduct electricity because the electrons used for double bonding are actually delocalised (like benzene), allowing a current to be carried through it.

Reply 11

charco

Study Forum Helper

AngelofPeace

Why does trans(E) polyethyne conduct better than cis(Z) polyethyne?

Dont quote me on this one, but my feeling is that...

the trans isomer will have (relatively) straight chains and can align alongside one another allowing some degree of crosslinking and overlapping of the delocalised electrons.

the cis-isomer contains 'kinks' (yah Ray Davies rocks) preventing good alineation.

Reply 12

cpchem

Pure polyacetylene is a semiconductor, at best (band gap of about 2 eV). Peierls' theorem states that a one-dimensional metallic system is unstable with respect to a structural distortion to a lower energy state in which a band gap opens up at the Fermi level.

Doping of polyacetylenes, however, results in a substantial increase in conductivity - you need to either add or remove electrons, to form non-neutral solitons that can effectively migrate down the chain.