Three new supermolecular complexes of {Na[N-(p-RPh)15C5](Et2O)}2Na2Mo8O26 (R=H, Cl, CH3) were synthesized by reaction of N-(para-substituted phenyl)-aza-15-crown-5 with [(n-Bu)4N]4Mo8O26 and Na^+ in mixed solvent of CH3OH and CH3CN and crystallized in Et2O. The supermolecular complexes were characterized by C/H analysis, IR, and 1H NMR spectra and X-ray structure determination of {Na[N-(p-CH3Ph)15C5](Et2O)}2Na2Mo8O26. This crown ether octamolybdate is monoclinic, space group P21/a, a=1.4590(4)nm, b=1.3817(3)nm, c=1.7639(5)nm, β =112.67(2)°, V=3.281(1)nm^3, Mr=2021.3, Dc=2.11g/cm^3, μ=2.37mm^-^1, F(000)=2048, R=0.045 and Rw=0.057. Comparison with [Na.(DB18C6)(CH3OH)M6O19 and [Na(DB24C8)]2M6O19 (M=W and Mo), it was indicated that the host crown ether compounds could not only recongnize the guest-metal cations, but also choose counterion anions of polymolybdates with defferent degree of polymerization to combine into the crystals.

Key words: INFRARED SPECTROPHOTOMETRY, ELEMENTAL ANALYSIS, CRYSTAL STRUCTURE, NMR SPECTROMETRY, NITROGEN HETEROCYCLICS, CROWN ETHER