Mary Frances Richardson

Rare-earth trishexafluoroacetylacetonates and related compounds☆

Abstract Rare-earth trishexafluoroacetylacetonates, Ln(hfac)3·nH2O, have been prepared and characterized by chemical analyses, infra-red spectra, and X-ray powder diffraction patterns. Two series of hydrates exist: Ln(hfac)3·3H2O (Ln = LaNd) and Ln(hfac)3·2H2O (Ln = LaLu). No evidence for a lower hydrate was found. A mixed ligand chelate, Ln(hfac)2CF3CO2·2H2O, is a byproduct of the tris chelate preparations. Several series of salts were also prepared, including NH4Ln (hfac)4·nH2O (n = 0 and 1 for Ln = LaNd; n = 0 for Ln = SmLu), pyHLn(hfac)4·nH2O (n = 0 and 1 for Ln = LnNd; n = 0 for Ln = SmLu), and (pyH)2Ln(hfac)5 (Ln = LaNd). Ln(hfac)3·3H2O. NH4Ln(hfac)4·H2O, and pyHLn(hfac)4·H2O are reversibly converted with great ease to Ln(hfac)3·2H2O, NH4Ln(hfac)4, and pyHLn(hfac)4, respectively. Most of the chelates studied are probably eight-co-ordinate, including Ln(hfac)3·3H2O, NH4Ln(hfac)4·H2O, and pyHLn(hfac)4·H2O, but (pyH)2Ln(hfac)5 may be ten-co-ordinate.

Schiff bases prepared from ethylenediamine and hexafluoroacetylacetone

Abstract Bis(hexafluoroacetylacetone)ethylenediimine(H2hfacen) was prepared by sublimation of the hexafluoroacetylacetone salt of ethylenediamine, en·2Hhfa. In addition to H2hfacen, the sublimation method yields 2,3-dihydro-5,7-bis(trifluoromethyl)-1H-1,4-diazepine(cyclohfa-en) and a hexafluoroacetylacetone salt of 1-amino-2-(trifluoroacetamido)ethane, tfe·Hhfa. H2hfacen is not stable and readily loses a mole of Hhfa to give cyclohfa-en. Attempts to prepare Cu(hfacen) by normal solution methods yielded only solvated Cu(hfa)2. Gas transport reactions and reactions of CuCl2 with the ligands in benzene resulted in the synthesis of the following new compounds: CuCl2·H2hfacen, Cu(hfa)2·H2hfacen, Cu(hfa)2·cyclohfa-en, and Cu(hfa)2·2tfe. The structures of the ligands were confirmed by NMR and i.r. spectra. Thermogravimetric data show that some of the Cu complexes are quite volatile. One of the reasons that template synthesis of H2hfacen has failed in solution may be that hydroxylic solvents (water, methanol) add across the carbonyl group to Hhfa to give compounds such as 1,1,1,5,5,5-hexafluoro-2,2,4,4-tetrahydroxypentane and 1,1,1,5,5,5-hexafluoro-2,4-dihydroxy-2,4-dimethoxypentane.

Some adducts of rare earth acetylacetonates

Abstract Several previously unreported adducts of rare earth acetylacetonates have been prepared and characterized by chemical analyses (including Karl Fischer titrations for water), i.r. spectra, and X-ray powder diffraction patterns. These adducts include compounds with methanol, ethanol, propanol, butanol, dioxane, pyridine, 2- and 4- methylpyridine, 2,4- and 2,6-dimethylpyridine, acetone, benzene, and acetylacetoneimine. Most of the adducts contain one or more moles of water per mole of chelate. It is concluded that when water and an organic donor are both present, only the water is coordinated to the rare earth ion and that the organic donor molecules are hydrogen-bonded or held in the crystal by lattice forces.