Atranes

The PMR spectra of acidified solutions of metalloatrane-3,7,10-trione dihydrates containing a group-IIIB metal atom (M=Al, Ga, In, Tl) in D₂O were studied. The equivalence of the three atrane half-rings in all of the investigated molecules and of the methylene protons in each half-ring was proved. Spin-spin coupling of²⁰³Tl and²⁰⁵Tl with protons, which is apparently realized through a TlN transannular coordinate bond, is observed in the PMR spectrum of thallatrane-3,7,10-trione (M=Tl). The factors that determine the magnitudes of the chemical shifts of the methylene protons are discussed.See 1] for communication XXXII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 312–314, March, 1973.