Trifluoroacetate Compounds of the s- and p-Block Elements

The simple salts MIOaCCFg) (where M = Li, Na, K, Rb, Cs, NH4, or NEt4) have been isolated and characterized in a variety of studies 4, 28, 54, 84, 105, 109, 243, 247), and their infrared spectra have been described in some detail. The crystal structure of NH4(02CCF3) has been determined 54) and each oxygen atom shown to be involved in two N—H---0 hydrogen bonds. 

The salt Na(OaCCF3) 2CF3C02H and its deutero analog have been characterized, and the structure shown in Fig. 2 has been suggested for their anions 143). 

The simple trifluoroacetates of all the alkaline earth elements have been reported (36,105, 247, 263). Compound Be(02CCF3)2 was obtained in a study of several beryllium haloacetates and, although a deliberate attempt was made to prepare basic beryllium trifluoroacetate, Be40(02CCF3)g, by the thermal decomposition of the simple salt, none could be obtained (268). Also Be40(02CCF3)e does not appear to be produced when beryllium carbonate is treated with trifluoroacetic acid and the solution extracted with chloroform (122, 174). 

The known trifluoroacetates of boron, aluminum, indium, and thallium are summarized in Table II. 

The preparation of H[B(02CCFg)4] [Eq. (10)] (25), is directly analogous to the preparation of the superacid H[B(HS04)4] in oleum (S3). Attempts to isolate B(02CCFg)3 from these trifluoroacetic acid 

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