Syntheses, X-ray Structures, Complexation, and Thermal Stability Studies of Bis(5-carbomethoxy-1,3-phenylene)-(3x + 2)-crown-x Compounds

Article abstract of DOI:10.1021/jo00108a009

Bis(5-carbomethoxy-1,3-phenylene)-(3x + 2)-crown-x compounds have been synthesized in one step by reaction of methyl 3,5-dihydroxybenzoate (1) and the corresponding oligo(ethylene glycol) dichlorides (2a, 2b, and 2c) in the presence of NaH or KH in N,N-dimethylformamide (DMF).The smaller monoester, 5-carbomethoxy-1,3-phenylene-16-crown-5 (4c), was also isolated along with 3c.The X-ray crystal structures of these macrocycles (3b, 3c, and 4c) have been determined.Macrocycle 3b crystallizes in the triclinic space group P-1 with unit cell parameters of a = 8.632(2) Angstroem, b = 10.006(2) Angstroem, c = 11.527(2) Angstroem, α = 78.30(3) deg, β = 71.98(3) deg, γ = 65.00(3) deg.Macrocycle 3c crystallizes in the triclinic space group P-1 with unit cell parameters of a = 8.911(2) Angstroem, b = 9.497(2) Angstroem, c = 10.140(2) Angstroem, α = 93.66(2) deg, β = 94.03(1) deg, γ = 105.95(1) deg.Macrocycle 4c crystallizes in the triclinic space group with unit cell parameters of a = 8.748(2) Angstroem, b = 9.163(2) Angstroem, c = 12.025(3) Angstroem, α = 74.90(2) deg, β = 86.81(2) deg , γ = 61.73(2) deg.The thermal stabilities of these macrocycles and the complexation abilities of the bis(m-phenylene)-32-crown-10 derivatives with methyl viologen bis(hexafluorophosphate) (8) have been examined by 1H NMR spectroscopy.