Using chain-like polyethers consisting of two terminal –NH₂ groups and (TBA)₄[α-Mo₈O₂₆] as starting materials, two polyoxometalatocrown ethers were prepared by a cyclization reaction through the formation of Mo≡N triple bonds: (TBA)₂[Mo₆O₁₇N(o-C₆H₄OCH₂(CH₂OCH₂)_nCH₂OC₆H₄-o)N] (compounds 1, n = 1; 2, n = 2). As confirmed by single-crystal X-ray diffraction and infrared (IR) studies, the polyoxometalatocrown ether 2 can capture primary ammonium cations in solid state.