Abstract The combined NMR and quantum chemical study of tellurium solution in trioctylphosphine, for the first time, revealed the new unexpected P−Te species. The observed intermediates are absolutely different from the species forming in the reaction of trialkylphosphines with chalcogens up in the group. This finding sheds new light on the mechanism of telluride nanocrystals formation and allow to rationalize the application of this key tellurium precursor in the synthesis of nanostructures. The studied solution was applied in the synthesis of HgTe colloidal quantum dots.