Tetraacetyldinitrosohexaazaisowurtzitane (TADNIW•H₂O) was synthesized from tetraacetyldi- benzylhexaazaisowurtzitane (TADBIW) by using three inorganic reagents as the nitrosolysis reagents. The molecular structure of purified TADNIW•H₂O was determined by ¹H NMR, IR, MS spectra and elemental analysis. The single crystal of TADNIW•H₂O was prepared from a mixture solvent of ethyl acetate, acetone and DMF. Its structure was testified by X-ray diffraction study. The crystal contains one molecule of TADNIW and one molecule of water, and belongs to monoclinic system with space group P2₁/n and parameters: a＝1.0738(2) nm, b＝1.4870(3), c＝1.1185(2) nm, ＝98.95(3)°, V＝1.7642(6) nm³, Z＝4, D_c＝1.553 g• cm^－3, F(000)＝864, ＝0.126 mm^－1. It is easier to prepare HNIW from TADNIW than from any other else precursors with higher yield and purity.

Key words: debenzylation, tetraacetyldinitrosohexaazaisowurtzitane, synthesis, crystal structure