sizes of molecules

[nightingale]

Hello:)

 

I am interested in structures of hydrates and I want to get information about some hydrate former guest molecules. The reason why I am writing here is to ask whether there is some way of finding the molecular sizes of molecules, such as carbon tetrachloride, trichloroethylene, 1,1,2-trichlorotrifluoroethane and tetrachloroethylene. I will be glad if anyone can recommend a computer program or method to determine the molecular sizes. Thanks:)

[MetaFrizzics]

Hello:)

 

I am interested in structures of hydrates and I want to get information about some hydrate former guest molecules. The reason why I am writing here is to ask whether there is some way of finding the molecular sizes of molecules' date=' such as carbon tetrachloride, trichloroethylene, 1,1,2-trichlorotrifluoroethane and tetrachloroethylene. I will be glad if anyone can recommend a computer program or method to determine the molecular sizes. Thanks:)[/quote']

Yes there has been a large accumulation of data on atomic and molecular sizes.

Start with an excellent introduction:

 

Nuclear Sizes by L.R.B. Elton 1961 Oxford University Press.

This book goes carefully through all the methods used to determine and calculate effective sizes of nuclei etc. And there are many methods with divergent results and for different purposes. This will be the best introduction, and help you hone in on what kind of definition and approach for size measurement will be relevant to your chemical problem.

[nightingale]

Yes there has been a large accumulation of data on atomic and molecular sizes.

Start with an excellent introduction:

 

Nuclear Sizes by L.R.B. Elton 1961 Oxford University Press.

This book goes carefully through all the methods used to determine and calculate effective sizes of nuclei etc. And there are many methods with divergent results and for different purposes. This will be the best introduction' date=' and help you hone in on what kind of definition and approach for size measurement will be relevant to your chemical problem.[/quote']

 

Thank you for your answer:) I will check this book as soon as possible:)

[budullewraagh]

if you want approximate numbers, you can just do some 3 dimensional geometry/trigonometry.

 

use bond lengths, van der waals' radii, etc

[DQW]

Thank you for your answer:) I will check this book as soon as possible:)

No, please do not waste your time/money looking up Elton's book. You will find NOTHING of relevance to your question there.

 

Take budu's advice instead. You can estimate molecular sizes from bond lengths and molecular geometries. Here's some bond lengths : http://www.science.uwaterloo.ca/~cchieh/cact/c120/bondel.html

 

You can also estimate moolecular sizes in liquids from knowledge of density and molecular weight. This may give you a small overestimate (that depends on how you define molecular size).

[DQW]

Yes there has been a large accumulation of data on atomic and molecular sizes.

Start with an excellent introduction:

 

Nuclear Sizes by L.R.B. Elton 1961 Oxford University Press.

This book goes carefully through all the methods used to determine and calculate effective sizes of nuclei etc. And there are many methods with divergent results and for different purposes. This will be the best introduction' date=' and help you hone in on what kind of definition and approach for size measurement will be relevant to your chemical problem.[/quote']I'M COMPLETELY DUMBFOUNDED BY THIS RECOMMENDATION !!!!

 

Did you even understand the OP's question, or are you just trying to prove that you've read something that most of us haven't ?

 

Please tell me where in Elton's book I can find molecular sizes for alkyl halides. I have read this book (in parts, not cover to cover) and have it right on my table as I'm typing this. Okay, let's forget alkyl halides, for now. Where in Elton, does he talk about or list sizes of any organic molecules ? Oh, let's not even demand that - just tell me in which chapter he discusses molecular sizes of any molecules ? Am I asking for too much here ? Well then, tell me what page number I will find the word "molecule" written ?

 

Elton's book talks about electron, neutron, alpha and meson scattering (among a few other things) experiments to study nuclear surfaces. Don't you know that nulclear sizes are about 5 or 6 orders of magnitude smaller than molecular sizes ? Don't you know that the two are essentially uncorrelated ? Did you even read the book and understand any part of it ? If you did, it confounds me that you will suggest this book to a chemistry student looking for certain molecular sizes.

 

Do you realize that you have probably wasted someone's time by making this completely useless recommendation ? Do you take someone else's time this lightly ?

[MetaFrizzics]

I am not going to respond further to this. it would certainly be off-topic then. Your questions are likewise off-topic so I will take them as rhetorical. I have been peacefully and helpfully posting here for months. Since posting yesterday in the AIDS thread and starting a post on the Northwoods Operation in the Politics forum where it belongs, I have been under fire.

 

It is clear to me that now you are looking for excuses to escalate matters for the purpose of banning me. I suggest you do it now and save us the trouble of all the hand waving and lies.

 

Many others have encouraged me for my helpful and insightful contributions to many threads here. If you don't like me, or have been offended because we disagree on some scientific matters, who cares? There are plenty of science boards where helpful and knowledgable people are welcome, as well as free opinion.

 

If everyone were as brilliant as you we'd all agree, but there'd be no point in a forum of any kind.

 

 

You have been warned for one of your posts, which violated Science Forums and Debate Rules. The reason you have been warned is because:

 

Offtopic post. (Warning Type = Offtopic)

 

For this violation, you have been given : 5 point(s).

The point(s) will remain in your account for 30 days.

 

The admin/moderator who warned you, entered this comment:

 

=======================================

I get many complaints about inaccuracy regarding your posts

=======================================

 

Your total Warning Level at the moment is: 9 point(s).

 

 

Penalizing someone for recommending the wrong book? over the top and childish.

 

Good thing you didn't recommend a restaurant!

[DQW]

Is this addressed at me ? I am not an administrator and take no part in any administrative decisions on this forum. Unless you specifically ask me a question, I shall not respond to your posts henceforth.

 

Admins : Please feel free to delete these last two posts of mine. I'm sorry this thread has digressed thus. I apologize. We should get the thread back on track if we wish to do any justice to the OP.