[kiwikissx]

i'm trying to analyze my h-nmr spectra. at around 7.65 ppm i initially thought the peaks were a triplet (given the integration value of 1), but now i think it's a triplet of triplet. i was wondering if this is correct, and if so, what does this mean? how would i be able to interpret the number of hydrogens and the number of neighbor hydrogens?

[WingmanJ]

I would be led to believe that you would have something like this, in which the neighboring methylenes would be different groups, so that they would each cause a triplet shift.  If they were the same it would just be a multiplet (quintet technically), and if they were diastereotopic, you would have a dddd, for a total of 8 peaks.  So my guess is look for something like that in your structure (if you have one yet) and if not, it hopefully would be something like this.

[Custos]

Reasonable thinking but the triplet of triplets has two very different coupling constants - the second triplet is fine structure on the first. I would guess it was more like a triplet due to a CH₂ adjacent to the proton in question and a fine structure triplet due to a more remote CH₂. Also, the chemical shift around 7.7 makes me think that the R group in my picture might be a CO or some other electron withdrawing group.