So over the years there was a huge talk about DMT Polymerization.

When heating pure white Spice on a hot plate, most of it vaporizes, but still there is some orange residue, which will not vaporize above 180 °C. This residue seems to be dissolve slower in Acetone than regular DMT. Also I've seen some Spice crashing out very fast at Room Temperature, while another portion just came out in the Freezer. Ok ... yes this is normal for Re-X, but I mean it felt like these were different batches of Stuff.
So either its just a sort of combustion with charred products left behind, or indeed DMT may form bigger structures that dont vaporize readily.

A possible solution to distinct between combustion products and polymers would be vaporization in N2-Atmosphere obviously.

But how could any possible Multimer of DMT look like? Amines would be the most reactive part of the molecule obviously, but when looking into other examples in literature it may be something different:

1. The enzymatic polymerization of Psilocybin uses that 5-position and 2-position. Now as this is an enzymatic reaction, there is no direct translation, but if Nature is doing stuff, then it mostly means something - or in other words, it indicates that both positions may be most promising if also using heat. (source)



2. Fischer-Indole Synthesis is using Hydrazine precursors and electrophile fragments to build tryptamines. While performing such a reaction it may be possible to get fragments with higher mass which evolve by excessive nucleophile attack of that 2-position Carbon. I think this also indicates that this 2-position may be indeed quite reactive. (source)



3. Another paper even specificially talks about this pathway of general indole polymerization, so I guess that this may really be the most meaningfull way of also polymerizing (by accident) DMT. (source)



In principle that tryptamine skeletton could act as either nucleophile or electrophile, with electron-donating substitutens even increasing nucleophile character:



But this way only Dimers could be formed. To get up to multimers with more than 2x of DMT mass like Benzyme saw in MS this could then only happen by 2,3-addition. The 3-position would also be a good nucleophile, due to forming a tertiary carbo cation in acidic environments. In this picture these 2,3-polymers are shown. (Yet for substituted indols like DMT, this 3-position would be super hindered). (source)



Any easy way to verify that would be to retrieve a sample with possible polymers ...
... and extract just the DMT by pulling with a low amount of Room Temperature Naphtha for 5 min and then throw the residual stuff in NMR.
If indeed this is the way of DMT-Polymerization then the

Signals at 1H 7,1 ppm (2-Position) --> should be (nearly) gone or at least not fit anymore to stochiometry
Signals at 13C 122 ppm (2-Position) --> 127 ppm - ok ... this will be super hard to see/distinguish/verify ...

"That 1-position" is actually the 2-position, as outlined in the bottom of the last diagram you posted
That is actually the normal way of numbering an indole - the pyrrole nitrogen is the 1-postion and the atoms shared between two rings are not counted because they don't normally bear substituents. If the conjugation is disrupted they can get numbered 3a and 7a.


Interesting nonetheless - I hope you or someone else with access to the machinery gets to run the NMR on some goo soon.

Oh well ok so that may also be a way of counting. I just checked 2-Methyl-Tryptamine and so youre totally right. Guess I should now changed that "1-position" to 2



Technically I would have access, but right now I just dont have the balls to do.

As written here I think that upon heating DMT partially polymerizes as you will always have trace amounts of a dark/black residue, even when using pure Spice. This residue does not vaporize further even when heating excessively above 200 °C.

So either this is just a regular sort of combustion / charred products or this is a sign of trace formation of multimers or otherwise just single-molecule DMT combustion / degradation which forms this black stuff.

An meaningful way to check whether this is just a charred product from a combustion reaction would be to heat DMT in an inert atmosphere - then there should be no chance of forming oxidated combustion products. If that coloration still occurs, this may at least be another hint that also thermally polymerization could happen.

Here is what I tried to come as close as possible to this:

2 portions of DMT were placed on a inert surface (no metal, to prevent any oxidating effects of metal surface) which was just a petri dish - then this was covered with a beaker and with a needle there was a constant flow of N2 into that chamber (left). Also 1 portion of Spice was placed besides the beaker in full O2-contact as a reference.



Now the chamber was heated from below with the hot plate to above 160 °C. Both the reference and the N2-Spice vaporized and you can see that both produced the same pattern of black residue (right). So there is the same result in both cases with the chamber (hopefully) excluding any contact with oxidation agents. So maybe the residue may not or not fully be caused by oxidated charred combustion products, but by something else and this could be thermally-initiated oligo-/polymerization.