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The synthesis of the lanthanide chelates of α′-(trifluoromethyl)polyfluoroalkyl β-dike-tones Ln {CF_3CF_2 [CF_2OCF(CF_2)]_n COCHCOC(CH_3)_3}_3[1,n=1;Ln=Eu(1a),Pr(1b),Nd(1c),Sm(1d),Gd(1e),Tb(1f),Dy(1g),Er(1h).2,n=2;Ln=Eu(2a),Pr(2b),Nd(2c),Sm(2d),Gd(2e),Tb(2f),Dy(2g)and Er(2h)] was reported and the ~1H NMR shift properties were studied using alcohol,ketone,ether and amine as substrates.Compounds 1a,1b,2a and 2b induce shifts similar to that induced byLn(fod)_3(Ln=Eu,Pr).However compounds la and 2a are superior to Eu(fod)_3,because their ~1Hsignal shifts to higher field in the presence of substrate than that of Eu(fod)_3 does.For example,δ_Hfor la and 2a is close to zero ppm in the presence of alcohol.A very satisfactory first order spectracan be obtained using 1a,2a,1b and 2b as ~1H NMR shift reagents,1c,1f,1g,2c,2f and 2g produceupfield shifts,and 1h and 2b produce downfield shifts,1c and 2c induce shifts smaller than that of1b and 2b,whereas 1f,1g,1h,2f,2g and 2h induce very large shifts.
The synthesis of the lanthanide chelates of α ’- (trifluoromethyl) polyfluoroalkyl β-dike-tones Ln {CF_3CF_2 [CF_2OCF (CF_2)] _ n COCHCOC (CH_3) _3} _3 [1, n = 1; Pr (1b) Nd (1c) Sm (1d) Gd (1e) Tb (1f) Dy (1g) Er (1h) 2 n = 2 Ln = Eu (2a) Pr 1H NMR shift properties were studied using alcohol, ketone, ether, 2b, Nd (2c), Sm (2d), Gd (2e), Tb (Ln = Eu, Pr) .However compounds 1a and 2a are superior to Eu (fod) _3, because their ~ 1Hsignal shifts to higher field in the presence of substrate than that of Eu (fod) _3 does. For example, δ_Hfor la and 2a is close to zero ppm in the presence of alcohol. A very first order order spectacle be obtained using 1a, 2a, 1b and 2b as ~ 1H NMR shift reagents, 1c, 1f, 1g, 2c, 2f and 2g produce upfield shifts, and 1h and 2b produce downfield shifts, 1c and 2c induce fewer than that of 1b and 2d, 1f, 1g, 1h , 2f, 2g and 2h induce very large shifts.