hydrosilicons (or silicon hydrogen chemistry)

[zeocrash]

yesterday i was walking home after dropping my girlfriend off at the station, when i started thinking about alteriative fuels for cars. so anyway one of the ideas that i had was using silicon based compounds instead of carbon based petrol (Si8H10 instead of C8H10). this seemed the perfect idea, until i realised that the silicon dioxide produced would be a solid and would eat up a car cylinder in no time.
this idea got me thinking "you could use this idea for other things". the first thing to come to mind was a undetectable nerve gas.
from what i remember nerve gas detectors operate much like IR spectrometers, and the C-F and C-P bonds they look for causes absorbtion or interferes with a particular frequency of light. Using Si - F and Si-P bonds would completely change the wavelength of the light refrected, causing the detectors to completely ignore the gas.

now i was wondering if anyone had any idea how to make Simple silicon hydrogen compounds. on any scale at all.

this topic is completely theoretical as i doubt i have/will ever have the means to manufacture such a chemical, i'm sure someone like 80r15 does though :D

[simply RED]

Actually this si a well ducumented phenomenon. Nerve gas uses complete analogue with ac-holine and inhibits holinesterase. Using Si, you will never have full alalogue between ac-holine and your poison, not that it won't be toxic, but it won't have a high tox.
But if you manage to compose a good structure of your component (see natural toxins inhibiting holinest.). Then it will be very nice.

[vulture]

You are referring to silanes.
While silicon has the same bond properties as carbon, being tetravalent, it does not form the same amounts of Si - H based compounds.

The reason is quite simple, the radius of the Si atom is too large to form stable enough Si-H bonds, that's why most silanes are spontaneously flammable in air.

Polymers like:


CH3...CH3...CH3..CH3...CH3
|........|.......|.......|.......|
Si -O- Si -O-Si -O-Si -O-Si-O...
|........|.......|.......|.......|
CH3...CH3...CH3..CH3...CH3


are commonly known as "silicone".

Burning this is an easy way to get fairly pure SiO2.

[Tuatara]

I recall making a simple silane in chemistry class at school (SiH4?). Thoroughly useless as it decomposes instantly in air into SiO2 and H2O. Trouble is I can't remember how I did it :o
Can't be too hard though ...

[megalomania]

Another problem silicon has is it does not form Si-Si bonds like carbon. This pretty much limits the idea of hydrosilanes beyond SiH4.

[Mr Cool]

It does form Si-Si bonds. In the silane produced by the method below, it is Si2H6 that causes ignition in air, not SiH4. So those bonds can form, but are very unstable, as shown by the pyrophoric nature of the gas...

4 Mg + SiO2 -heat-> Mg2Si + 2 MgO
Mg2Si + 4 HCl(aq) --> 2 MgCl2 + SiH4

Silanes are toxic, just like all non-metal hydrides seem to be (arsenane, phosphane, selenane etc), but are probably not comparable to nerve gases. H2Se is around ten times more toxic than HCN.