Organic chemistry based on Si?

I didn't do a lot of chemisrty in my studies, but one thing striked me some day, and I've been wondering whether it would be possible to have an organic chemistry based on silicon (Si) instead of Carbon (C) ?

Before going into it, please excuse me if I don't use the correct words for everything, as English is not my mother language and I didn't do any chemistry in English.

What I think is that C and Si have a lot of common properties, and the same structure of electrons (Si has 1 more full layer under the last one, having 4 free electrons, just as C has).

"Our" current organic chemistry is based on chains of C, and life forms are composed of chains of C as well, DNA, RNA and aminic (?) acids. Thinking about it, I wonder if it would be possible to create such chains all based on Si. The electron structure of Si would allow that, but the question is whether the necessary reactions would take place... Also, one can wonder, if it is all possible, if Si-based chemistry would allow some life? That would be a completely different kind of life maybe...

Any specialist having thoughts on that? I've been looking around a bit, but I couldn't find anything interesting on the subject... All links, thoughts and comments are more than welcome.

Do you believe that all of the processes needed for life to begin and remain could take place with silicon instead of carbon? Can basic microbes convert silicon into methane as it can with acetates and carbon?

The reason us humans have used carbon thus far is because it is the basic building block that we associate with life, "as we know it". This doesn't mean we know what all life is based on, for we surely don't. Humans have just used this as the base because it is the base required for life.

Carbon has the ability to bond to itself, as well as most other nonmetallic elements like nitrogen, phosphorus, oxygen, sulfur, and hydrogen.

That is why animal and plant life is primarily composed of it.

I'm not suggesting that you are wrong, but can you explain in more detail on why you believe that it is a possibilty to base it on Silicon.

Thanks

Well I don't actually believe it to be possible, I wonder... I mean, there are really a lot of common properties between C and Si, and if Si can link to itself in the same kind of processes that C does it, then we could have something, another kind of organic chemistry.

Even if that doesn't bring another form of life, it would be potentially a great advance, and could bring many new discoveries, like new materials,... As I said, I didn't do a lot of chemistry, and I am certainly not able enough to investigate it myself and come to conclusions about the feasability of it, but it seems to me that there is a possibility, I "feel" it... I may be wrong...

On the other hand, what makes me think that it is probably not possible (or at least with our current knowledge) is that if I have been thinking about that, then surely enough some other people with greater minds have thought of it also... But again, why not?

Silicon can certainly be used for many important things, and I'm sure we will discover more as time goes by. Though Silicon is tetravalent and can form tetrahedral compounds, some of the main problems with Silicon is its inability to form a double-bond like carbon.

On your note of Silicon being used as a different for of Silicon based chemistry, this may be possible when studying Space as oppossed to planetary bodies. Space dust has a high composition of Silica (SiO2) in it, as well as Carbon.

It has been determined that Silicon and Carbon are essential, and at one time believed that there was no Silicon-Carbon compound existed in a life form until 3 years ago.

I cannot refute what you say, but would love to hear what other more experienced people have to say. I would love to learn more.

Some members, including myself, have written a research project article about Silicon-Based Life. You can get the 12-page pdf file here. Our conclusion was the following:

Silicon-based life similar to terrestrial life is probably not possible. In a naive view of chemistry it may seem possible, but all the evidence points in the other direction. The problems with solid SiO2 and the fact that problems forming long stable chains make silicon-based life similar to terrestrial life impossible. Totally different life may be possible though (see chapter 9). That chapter, however, is only speculation and there is no indication that such organisms exist.

We start by reviewing the chemistry of long silicon chains and find that there is no existing silicon compound with the same properties as carbon in organic chemistry.

Thanks a lot for the link amantine, it's been a really interesting read. Even if it does not answer all the questions, this articles states it as one might expect: it it not possible on earth, maybe, maybe elsewhere...

Anyway, by reading this article, I'm only wondering a bit more about the actual possiblity... Who knows, in another place, another world somewhere in our vast universe, maybe then it exists... The possibility is not wiped out then by current knowledge, it is just barely moved aside of our own world.