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Haloacyl Complexes of Boron, [(CF 3 ) 3 BC(O)Hal] − (Hal=F, Cl, Br, I)
Author(s) -
Finze Maik,
Bernhardt Eduard,
Willner Helge,
Lehmann Christian W.
Publication year - 2005
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200500038
Subject(s) - boron , physics , chemistry , crystallography , nuclear physics
The haloacyltris(trifluoromethyl)borate anions [(CF 3 ) 3 BC(O)Hal] − (Hal=F, Cl, Br, I) have been synthesized by reacting (CF 3 ) 3 BCO with either MHal (M=K, Cs; Hal=F) in SO 2 or MHal (M=[ n Bu 4 N] + , [Et 4 N] + , [Ph 4 P] + ; Hal=Cl, Br, I) in dichloromethane. Metathesis reactions of the fluoroacyl complex with Me 3 SiHal (Hal=Cl, Br, I) led to the formation of its higher homologues. The thermal stabilities of the haloacyltris(trifluoromethyl)borates decrease from the fluorine to the iodine derivative. The chemical reactivities decrease in the same order as demonstrated by a series of selected reactions. The new [(CF 3 ) 3 BC(O)Hal] − (Hal=F, Cl, Br) salts are used as starting materials in the syntheses of novel compounds that contain the (CF 3 ) 3 BC fragment. All borate anions [(CF 3 ) 3 BC(O)Hal] − (Hal=F, Cl, Br, I) have been characterized by multinuclear NMR spectroscopy ( 11 B, 13 C, 17 O, 19 F) and vibrational spectroscopy. [PPh 4 ][(CF 3 ) 3 BC(O)Br] crystallizes in the monoclinic space group P 2/ c (no. 13) and the bond parameters are compared with those of (CF 3 ) 3 BCO and K[(CF 3 ) 3 BC(O)F]. The interpretation of the spectroscopic and structural data are supported by DFT calculations [B3LYP/6‐311+G(d)].