Semi-structural formula convention (organic chemistry)

[aaronshenhao]

Hello,

I'm trying to find the semi-structural formula for 3-ethyl-3-methylpentane. I'm unsure of what to do when there are two different side chains connected to the same atom. Would it just be: \(\ce{CH3CH2C(CH3)(CH2CH3)CH2CH}\) or something else? I never seen a structural formula written with two brackets, nor any examples showing two different side chains.

Also, does anyone know where I can actually find the conventions for creating these semi-structural formulas? There is hardly any information on the web, especially when it comes to creating "semi-structural formulas". Wikipedia doesn't seem to acknowledge the existence of "semi-structural formulas" at all, instead calling them "condensed formulas", and the only information they have is that they were used "in early organic-chemistry publications, where the use of graphics were strongly limited". Also, don't we use the "condensed formula" to describe a simplified version of the "structural formula"?

"Semi-structural formulas" seem like a very VCE thing, so I couldn't find much information on the web about it. Is there another more well known term used to describe the creation of formulas for organic molecules beside "condensed/semi-structural formulas"? It would be great if someone could link a sheet outlining the conventions when writing formulas for organic chemistry.

Thanks,
Aaron.

[TheBigC]

Hello,

I'm trying to find the semi-structural formula for 3-ethyl-3-methylpentane. I'm unsure of what to do when there are two different side chains connected to the same atom. Would it just be: \(\ce{CH3CH2C(CH3)(CH2CH3)CH2CH}\) or something else? I never seen a structural formula written with two brackets, nor any examples showing two different side chains.

Also, does anyone know where I can actually find the conventions for creating these semi-structural formulas? There is hardly any information on the web, especially when it comes to creating "semi-structural formulas". Wikipedia doesn't seem to acknowledge the existence of "semi-structural formulas" at all, instead calling them "condensed formulas", and the only information they have is that they were used "in early organic-chemistry publications, where the use of graphics were strongly limited". Also, don't we use the "condensed formula" to describe a simplified version of the "structural formula"?

"Semi-structural formulas" seem like a very VCE thing, so I couldn't find much information on the web about it. Is there another more well known term used to describe the creation of formulas for organic molecules beside "condensed/semi-structural formulas"? It would be great if someone could link a sheet outlining the conventions when writing formulas for organic chemistry.

Thanks,
Aaron.

Hi there, the formula is actually rather simple, though it requires you to visualise the molecule differently. If you examine the molecule, it actually appears to have 3 ethyl alkyl groups covalently bonded to a central carbon with a methyl 'attached'. Thus, it can be represented as:



Arghhh!! for some reason, the latex is not working: I will link an image...