Synthesis and conformation studies of a dodecaazanona-cyclotetratetracontane

Compound 3 was prepared by self-assembly of 1,3,5-pentanetriamine and aqueo us formaldehyde in quantitative yield (Figure 1). This molecule can exist i n four well-defined diamond-lattice conformations of symmetries D-2d, S-4. C-2v and D-2d Low-temperature C-13 NMR spectroscopy indicates the existence of three main conformers; their relative populations depend on the solvent used. An extra set of low-intensity lines is also observed. A conformation interconversion scheme is proposed; it involves two additional less popula ted quasi-diamond-lattice intermediates derived from a helix compressed alo ng its axis. One of these is trapped as a 1:2 clathrate with 1,4-dioxane; i ts crystal structure is reported.