Hexakis(trifluoromethyl)tefrazane

摘要

While no element can compete with carbon in the number of contiguous atoms in saturated chemical compounds, stable straight-chain species composed of other elements are known, especially if fiuorine atoms, fluorinated groups, or other elec-troneaativer.pecies are present in the molecule, for example CF_3(O)_nCFP3 (n=1 -3) and O_nF_2 (n =1, 2, 4). Fluorinated N_n compounds do exist and do exhibit surprising hydrolytic, ther-mal and chemical stabilities. In contrast, the hydrogen-substituted analeguessuch as diazane, triazane, and tetrazanc are increas--ingly unstabie with increasing chain length. While tris(perfiuoroalkyl)arrines N(R_f)_3 and tetrakis(perfluoroalkyl)diazanes (R_f):NN(R_f), are well known, and their gas-phase structures determined,only recently have the synthesis and property characterization of per- and polyfluoroalkyl-substituted tetra-zanes been reported. All of the known fluorine-containing tetrazanes are relatively dense liquids of low volatility which solidify as glasses, precluding single-crystal X-ray structural analyses. As a consequence, the smallest, most symmetric per-fluoroalkylated compound of this type, hexakis(trifluoro-rr.ethyl)tetrazane (4). was selected for a structural study in the gas phase using electron diffraction (GED).