[FlutterGuy123]

Hello, I've been doing some extra study into the properties of elements for some research that I'm conducting, and I've been looking all over the internet but I can't find this answer.

My question is as follows:
        Say you have an Si-Si and a C-C bond.

        The carbon bonds have a shorter bond length and a stronger bond than their silicon counterpart.

        If the silicon bond was forced to a higher pressure it should force the atoms closer together and shorten the bond length and strengthen the bond to the point that it's the same as carbon at STP.

        In this case that the silicon is under this increased pressure, will it's properties become similar to the carbon, and if so, can this apply to other bonds such as between C-O and Si-S bonds? I'm sorry for such a long and complicated question.

If anyone needs any clarification as to what I'm asking, I'll try my hardest to clear it up.

Thank you for reading my question and helping in any way you can.

I'm posting in this forum because the nature of my research is in biochemistry even though it may seem otherwise by my question. Sorry if I cause any confusion or inconvenience to anyone.

[Arkcon]

        If the silicon bond was forced to a higher pressure it should force the atoms closer together and shorten the bond length and strengthen the bond to the point that it's the same as carbon at STP.

This probably belongs in Physical Chemistry, even if your interest is mainly biological.  Anyway, I'd like to hear some peer-reviewed references to atomic bond length actually being affected by physical pressure.  If you put enough pressure, wouldn't you get subatomic fusion?  And isn't that .. you know ... impossible, outside of pseudoscience?

[Corribus]

I'm no expert on fusion, but the potential energy due to electrostatic repulsion of nuclei rises quite steeply for short bond distances. You have to get a lot closer than that before the nuclear strong force takes over and allows you to fuse nuclei. Surmounting that energy barrier would take an incredible amount of pressure. This kind of stuff happens naturally in stars, of course, but in a chemistry lab... I don't think you'll have to worry about it.

Addressing the original question - you can affect chemical structure by applying pressure, but the primary effect is on intermolecular forces and other interactions. If you're wondering whether you can make silicon behave like carbon under high pressures - maybe to some extent, but it wouldn't really be very practical, and under high pressure too many other things change to make it easy to say there'd be a lot of similarities. For instance, increasing pressure may cause chemical reactions to start occurring. I also haven't looked into the literature very much so I don't have a good feeling about how much pressure it would take to effect noticeable changes in bond length.

@Arkcon

Some relevant articles, chosen at random:

http://pubs.acs.org/doi/pdf/10.1021/jp0016479

http://neutrons.ornl.gov/conf/nxs2009/pdf/High_pressure_phenomena.pdf?origin=publication_detail

http://iopscience.iop.org/0953-8984/22/4/045701

http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.80.1912

[FlutterGuy123]

Thank you for the quick replies. 

I couldn't find anything on talking about the affect of pressure on physical properties, and I'm sorry for miss posting.

To Corribus:
        Thank you for your reply it sheds some light on a question that I've had since early June. I know this is a rather unorthodox question, and I'm happy to have an answer. I can't wait to read these studies.

To shed a little light on the nature of my research, This last school year, I had to do a power point on Silicon for my Chemistry final, and that got me interested in the possibility of Silicon based life. I know it's not likely and that Carbon does a much better job, but my thought was that if the conditions were just right, that it would be possible. So I started a quest to find out just what those conditions are if they were even there.

Thank you again for your support. Everything helps a lot. 

[Yggdrasil]

There was a recent paper in Nature from the National Ignition Facility where they used lasers to compress diamond to a density greater than that of lead.  In the paper, the authors write, "at several terapascals, matter is approaching an atomic-scale pressure (for example, the quantum-mechanical ‘pressure’ that counteracts the electrons’ Coulomb attraction in a Bohr atom), at which material structure and chemistry, and even the properties of atoms themselves, are expected to change," so the idea is not so far fetched.  The scientists are using the experiments to better understand what may be going on in the core or carbon-rich exoplanets.

Also, if you are interested in the possibility for life based on alternate biochemistries, this essay by Isaac Asimov (who has a PhD in biochemistry) is an interesting read.

[FlutterGuy123]

Thank's for all the support.  All this helps a tun. I can't wait to read all of it. I can tell already that I'm going to like this forum.