Trifluoroacetates, metal, preparation

This section will describe the range of preparative methods that have been used to obtain metal trifluoroacetates, each being illustrated by selected examples. However, no attempt will be made to give a comprehensive list of the compounds synthesized by any particular route. 

Preparation of Superconducting Oxide Films from Metal Trifluoroacetate Solution Precursors... 

Rtlssel C. A pyrolytic route to fluoride glasses. I. Preparation and thermal decomposition of metal trifluoroacetates. J. Non-Cryst. Solids 1993 152 161-166 Rywak A.A., Burlitch J.M. Sol-gel synthesis of nanocrystaUine magnesium fluoride its use in the preparation of Mgp2 films and MgF2-Si02 composites. Chem. Mater. 1996 8 60-67 Saad M., Poulain M. Fluoride glass synthesis by sol-gel process. J. Non-Cryst. Solids 1995 184 352-355... 

The driving force in the formation of complex phases is their thermodynamic stability under experimental conditions. When the desired materials have relatively large stability range in relation to both temperature stabiUty and chemical composition, such as alkaline metal rare earth fluorides, M REp4, a variety of precursor systems can be used successfully for their preparation. In particular, metal trifluoroacetates have been successfully used for this purpose [142]. For preparation of micropowders, a successful strategy may be to produce first... 

C. Russel, A pyrolytic route to fluoride glasses. I. Preparation and thermal decomposition of metal trifluoroacetates, J. Non-Cryst. Solids, 152, 161-166 (1993). 

Thallium(III), particularly as the trifluoroacetate salt, is also a reactive electrophilic metallating species, and a variety of synthetic schemes based on arylthallium intermediates have been devised.75 Arylthallium compounds are converted to chlorides or bromides by reaction with the appropriate cupric halide.76 Reaction with potassium iodide gives aryl iodides.77 Fluorides are prepared by successive treatment with potassium fluoride and boron trifluoride.78 Procedures for converting arylthallium compounds to nitriles and phenols have also been described.79... 

The imine 217, formed from acetophenone and the 1-aminoimidazole, has been transformed into the enamine 218 which is then cyclized to 219 in trifluoroacetic acid (TFA) (Equation 40) <1995SC3271 >. The diaminoimidazole 220 reacts with ynone 221 to form 222 (Equation 41) <1998CHE1189>. Bromochalcones and chalcone dibromides can also be used in place of the ynone. Similar reactions have been used to prepare the dihydro analogues of 222 <1999CHE1207>. The reaction between 1-aminoimidazoles and 1,3-diketones has been extended to prepare bis-heterocyclic compounds, for example, 223 as ligands for transition metals (Equation 42) <2005EJI4382>. 

Abstract Magnesium porphyrazines substituted with eight (phenyl-propene) groups on the peripheral positions have been prepared by cyclotetramerization of l,2-bis(3-phenyl-2-propenethio) maleonitrile and then achieved porphyrazine by 3-bromo-l-phenyl-l-propene. Metal-free derivative was obtained by its treatment with trifluoroacetic acid. The new compounds have been characterized by FT-IR, H-NMR, UV-VIS and elemental analysis methods. 

Discovered by Thorn and first communicated only a few years ago [43], electrophilic aromatic stannylation is the newest of all metalation reactions described in this chapter. The reactive Sn electrophile can be prepared by dearylation of Ph4Sn with TFAH or, preferably, by reaction of SnO with trifluoroperacetic acid generated from H202, TFAH, and trifluoroacetic anhydride. Because the structure of the Sn(IV) species (or mixtures of species) produced this way is unknown, the reactive electrophile is depicted as Sn(TFA)4 , for simplicity. The stannylation reactions of benzene and p-xylene were shown to produce tetratin clusters containing two inorganic and two organometallic Sn centers (Scheme 7). 

---