Ammonium (18-Crown-6)(Triphenylphosphine Oxide) Perchlorate: Synthesis and Crystal Structure

A new compound, ammonium (18-crown-6)(triphenylphosphine oxide) perchlorate (I), is synthesized, and its crystal structure is studied using X-ray diffraction analysis (space group R3m, a = 14.432 Å, c = 14.034 Å, Z = 3, direct method, full-matrix least-squares method in the anisotropic approximation, R = 0.064 for 1945 independent reflections, CAD4 automated diffractometer, λMoKα radiation). In the structure, the NH ₄ ⁺ cation resides in the 18-crown-6 macrocycle cavity and is hydrogen-bonded with three symmetrically equivalent O atoms of the 18-crown-6 molecule and with the phosphoryl O atom of the Ph₃PO molecule. The P=O H-N and Cl atoms occupy the partial position 3m. The oxygen atoms of the ClO ₄ ^? anion are disordered over the 3m position.