[adam667]

My query is in regard to organic molecules ( in general ) which structurally and/or empirically decompose as opposed to having a melting point and perhaps also boiling point, hence triple point etc.

Could anyone possibly help me regarding a generalized procedure for predicting decomposition pathway?

Given how complicated some structures get and how drastically properties can differ in small empirical and structural changes, i have made the assumption that it  is not as simple a procedure as for one to simply rank the individual bonds that exist in the molecule, and predict a decomposition pathway starting from weakest bond to strongest along a temperature gradient "timeline" .

I apologize if my terminology is not on par i am not a professional organic chemist, i just study physical sciences in general as a hobby/obsession.

[Arkcon]

Briefly, no, your request is not easily possible.   Let's try to work through your question, a little bit at a time, and see if we can come up with something we can answer.

I apologize if my terminology is not on par i am not a professional organic chemist, i just study physical sciences in general as a hobby/obsession.

Thank you for taking the time to mention this.  I hope you'll keep it in mind as we try to work through your problem.

My query is in regard to organic molecules ( in general ) which structurally

With you so far ...

and/or empirically decompose as opposed to having a melting point and perhaps also boiling point, hence triple point etc.

... and you lost me.  You use two terms "empirically" and "triple point" in a manner that isn't correct.  I can't answer those questions.  You can't blame me for that.

Could anyone possibly help me regarding a generalized procedure for predicting decomposition pathway?

I'm not aware of one no.  Such a question is too complicated.

Given how complicated some structures get and how drastically properties can differ in small empirical and structural changes, i have made the assumption that it  is not as simple a procedure as for one to simply rank the individual bonds that exist in the molecule, and predict a decomposition pathway starting from weakest bond to strongest along a temperature gradient "timeline" .

Now this does make some sense, you can make some predictions for a particular organic molecule, in a thermogravimetric profile, as to what might start happening where.  But it would be a better task to start with a particular example, instead of looking for a generalized procedure.

[adam667]

ok well in thinking about it now it makes sense since the molecules behavior is of course dependant on what chemical environment it is in so it would be a waste of time trying to establish a generalised form.

Thanks very much for your reply btw.

Ok ive got a better question now, still related indirectly but again its entirely up to you if you want to help or dismiss me.This is one that gets me into a real mental state everytime i think of it, would be quite hilarious to see me facial expressions anyway here:

 Suppose you have a molecule 'M' that is comprised of 'n' distinct functional groups, each in known quantities m(1), m(2),...m(n).

knowing the electronegativities of the atomic species contained in the empirical formula of 'M' determine the electronegativities of each of M's functional groups, hence produce a 3 dimensional modelling of M's "electronegativity topology"

OR

demonstrate why this cannot be determined with the given information, and provide simply names of experiment procedures i can read about that relate.

[Arkcon]

Summarizing briefly, the length discussion of incorrect application of chemical concepts in your last posting ... no.  I wouldn't use the electronegativities of atoms in a particular function group, but would instead use bond energy of functional groups and molecules.  How to know what those are, and how to apply this is up to you to find out, as it may not be possible.

[adam667]

so asking if or how there is a means of deriving the electronegativity of a molecular species can be derived some how from known atomic component's electronegativities  is an incorrect application of the concept of electronegativity?  ok im sorry is there a forum available where individuals wish to discuss concepts as opposed to dictating things already known? im having trouble finding forums of that nature. and preferably one which is labelled as such but in reality a forum where people on drugs paraphrase the achilles and the tortise paradox. if you link me to one of 'those' forums im not going to laugh im just going to be disappointed in the internet again.

[orgopete]

I understand the objective to derive molecular properties from an algorithm of atomic components, science is still a very long ways off. Perhaps you may think of it as similar to sitting a very large number of monkeys at typewriters in hopes of randomly producing one of Shakespeare's plays. It is just very improbable. Even if we know a great deal more about structural elements, we cannot determine which amino acids catalyze a reaction from the primary sequence of a protein. I think if you were to add vector properties for structures and reactions, you would find the mathematical possibilities will become very very large. I have a reasonable amount of experience in predicting the products of reactions, yet there are many reactions that I cannot reliably predict the products. If (organic) chemistry were sufficiently predictable, chemists would have devised a system of robots to carry out the reactions. There are some areas of chemistry where this can be done, but not in a general sense.

I think the way to approach your question is to try to find problems that one might find an answer to. That is, you probably won't find many people discussing their monkey results in trying to write plays because it is too improbable. You can find people are searching for ways to predict, mp, bp, bond lengths, activation energies, bond energies, preferred conformations, self assembly systems, etc, etc. There is nothing wrong with the question. You need to have some knowledge as to how it might be answered. For example, you might ask whether one could predict some properties of bimolecular combinations. If you look at the range of properties, this will begin to teach you how formidable that problem might be. Don't give up just yet, limit the types of atoms, can you make a prediction? That is how science operates.

[adam667]

I will start with thanking you greatly for your response and contribution, and have made a note to purchase your publication.

When you say things  will get very complicated in computing the electronegativity of the molecule based on the atomic constituents... yes i agree, and the approximations that will be needed in regard to bond strength is (dare i even suggest, hopefully no physicists are reading) far beyond the capacity of quantum mechanics.

But thats what i have always been tied between, having studied physics for a long time, and now returning to university to approach chemistry next year, i have always wanted to find an approach that "fills the gap" between the approach of the chemist and the physicist.

From the point of view of the Chemist, one is far more  honest about the complexity that exists when accounting for the behavior of matter, and has given up on any hope of being able to generalize chemical properties to the nth degree.

from the point of view of the Physicist, one is less honest about how unpredictable the trends chemical properties are, but is however making an attempt to generalize.

An example of what i am talking about is the disparity between the physics definition of ionization energy and the chemistry definition of ionization energy. The physics definition is more concise, however it leaves the student ignorant of a lot of behaviors and properties of atoms that exist in differing physical conditions other than observing a diatomic gas sample ionize at particular temperatures.