How to determine toxicity based on electron configuration

[true1990]

I have the following electron configurations:

Beryllium:

Br=[He]2s2

 

Mercury:

Hg=[Xe]6s24f145d10

 

Barium:

Ba=[Xe]6s2

 

Cadmium:

Cd=[Kr]5s24d10

 

Copper:

Cu=[Ar]4s23d9

 

Lead:

Pb=[Xe]6s24f145d106p2

 

Manganese:

Mn=[Ar]4s23d5

 

Nickel:

Ni=[Ar]4s23d8

 

Strontium:

Sr=[Kr]5s2

 

Tin:

Sn=[Kr]5s24d105p2

 

Vanadium:

V=[Ar]4s23d3

 

Zinc:

Zn=[Ar]4s23d10

 

Antimony:

Sb=[Kr]5s24d105p3

 

Arsenic:

As=[Ar]4s23d104p3

 

How do I predict, or construct a theory, as to why they are toxic based on these configurations?

[mississippichem]

Almost impossible. Thats a very important problem in the current state of medicinal chemistry and drug design. En vitro experiments and computational models are always of unpredictable accuracy. Thats why the FDA (food and drug administration in the USA) still requires animal trials for new drug candidates.

 

You have the correct notion that fundamentally this will be related to the electronic structure of the atom/ion/molecule. But physiological effects (distribution in different tissues complex "long range" biochemistry) make a first physics principles understanding of this extremely difficult.

 

Good idea. Won't happen though I'm afraid.

[true1990]

Almost impossible. Thats a very important problem in the current state of medicinal chemistry and drug design. En vitro experiments and computational models are always of unpredictable accuracy. Thats why the FDA (food and drug administration in the USA) still requires animal trials for new drug candidates.

 

You have the correct notion that fundamentally this will be related to the electronic structure of the atom/ion/molecule. But physiological effects (distribution in different tissues complex "long range" biochemistry) make a first physics principles understanding of this extremely difficult.

 

Good idea. Won't happen though I'm afraid.

 

That's strange then. I'll have to ask my teacher about this then.

 

And while I'm at it, why is organic mercury toxic, but inorganic mercury is not?

[mississippichem]

That's strange then. I'll have to ask my teacher about this then.

 

And while I'm at it, why is organic mercury toxic, but inorganic mercury is not?

 

Well you can make some arguments based on similarity to essential biological elements in your case here.

 

For example, thallium(I) is toxic because it's essentially a potassium cation mimic.

 

There may be some general rule of thumb for metallic ions that I'm not aware of so don't jump to the conclusion that your teacher is wrong.

 

I'll be surprised if there's a strong trend here between groups on the periodic table. Maybe there is some trend within a given group.

[Horza2002]

You can't predict how an element will be toxic given its electron configuration....

 

Aresenic is toxic because it mimics phosphorous (arsenic bonds are much weaker the phosphorus bonds so they hydroylse to quickly before the cell can use them)

 

One of the many ways lead is toxic is because it is sulphur-philic and so interferes with the disulphide bridges in proteins.

 

In terms of the mercury question, organomercury molecules have a better bioavalibility than inorganic mercury (i.e. its easy for the body cells to absorb it and is therefore more dangerous). The oxidations state of the mercury will also be important (as is the case for many metals)

[true1990]

Okay then.

 

How does Arsenic become Krypton 81 through neutron absorption then?

[Fuzzwood]

Because neutrons can decay into a proton and electron. That has nothing to do with your original question if you were not aware of that.

Edited November 28, 2011 by Fuzzwood

[Horza2002]

...Sorry, but I really don't see where that question has come from given the context of the questions asked so far.

 

Elements changing into other elements (i.e. arsenic changing into krypton) is the area of nuclear physics and radioactivity. Also, I'm not sure how easy it is for arsenic to be converted to krypton 81....natural arsenic is 100% As-75....so you need to add 6 neucleons (2 protons and 4 neutrons) to get from As-75 to Kr-81. With that said, I'm a chemist, not a nuclear physicist so maybe there are other ways it can be done

[mississippichem]

Okay then.

 

How does Arsenic become Krypton 81 through neutron absorption then?

 

Arsenic is toxic as a phosphorus mimic. You need not take this out to nuclear physics to account for it's toxicity.

 

Though some things are toxic because of their radioactive decay products. Like certain isotopes of Radon IIRC.

[John Cuthber]

Arsenic has pretty much the same electronic structure in this stuff

http://en.wikipedia.org/wiki/Arsenobetaine

as it has in this

http://en.wikipedia.org/wiki/Arsenic_trioxide

but the toxicity is rather different.