A.G. Massey

Perfluorophenyl derivatives of the elements

Abstract Tris(pentafluorophenyl)boron (I) is found to be very stable thermally and does not react with pure oxygen. Displacement reactions between adducts of (I) and BX3 compounds give inconclusive results; a correlation between the 1H NMR chemical shift of several adducts and the acceptor strength of the parent boron compounds is assumed and leads to the acceptor strength series BI3 > BBr3 > BCl3 > B(C6F5)3 ∼ BF3. 19F NMR data are also presented.

Perfluorophenyl derivatives of the elements XXVI. Tetrafluorobenzobarrelene complexes of Mn, Co, Rh, Pd and Pt☆

Abstract The non-conjugated diolefin ligand tetrafluorogenzobarrelene (5,6,7,8-tetrafluoro-1,4-ethenonaphthalene) forms air-stable complexes with Mn, Co, Rh, Pd and Pt. In the complex formed from cyclopentadienylmanganese tricarbonyl C 6 F 4 C 6 MnC 5 (CO) 2 , tetfluorobenzobarrelene coordinates to the metal using only one of the olefinic bonds; in all the other complexes the ligand behaves as a chelating diolefin.

Phenyls and alkyls of the Group IIIA metals

Abstract Reaction of scandium, yttrium, lanthanum or praseodymium chlorides with phenyl-or methyllithium gives air-sensitive solid products. Simple reactions, infrared spectra and analyses indicate that the phenyls are Sc(C6H5)3, Y(C6H5)3, LiLa(C6H5)4 and LiPr(C6H5)4; the constitution of the methyls is uncertain. Sc(CCC6H5)3 is also described.

Perfluorophenyl derivatives of the elements XV. Perfluoroaromatic derivatives of sulphur, selenium and tellurium☆

Abstract The syntheses of several pentafluorophenyl derivatives of sulphur, selenium and tellurium and of four heterocycles containing sulphur and selenium are described.

Perfluorophenyl derivatives of the elements XX. Some reactions of the bis(pentafluorophenyl)dichalcognides

The preparation of bis(pentafluorophenyl)ditelluride is described. Bis(pentafluorophenyl) disulphide and bis(pentafluorophenyl)diselenide react together on heating to give C6F5SSeC6F5. Similarly, bis(pentafluorophenyl)disulphide and diphenyldisulphide give C6F5SSC6H5. Heating of the dichalcognides with mercury and germanium produces C6F5MHgM′C6F5(M = M′ = S or Se; M = S, M′ = Se) and Ge(SC6F5)4. The Mossbauer, NMR, IR and mass spectra of ten chalcogen-bridged iron carbonyl complexes of formula C6F5MFe2(CO)6M′R (M, M′ = S, Se, Te; R = C6F5, C6H5) are discussed in the light of their electronic and molecular structure.

Perfluorophenyl derivatives of the elements : XII. 2,2′-disubstituted octafluorobiphenyls☆

Abstract The preparations and reactions of several 2,2′-disubstituted octafluorobiphenyls and heterocyclic organometallic derivatives of Group IV elements and titanium are described. Some evidence is given for the organometallic titanium intermediate postulated in the coupling reaction for the syntheses of polyfluorobiphenyls.

Perfluorophenyl derivatives of the elements XI. Metal carbonyl derivatives of tetrafluorobenzobicyclo[2.2.2]octatriene

Abstract On treatment with various metal carbonyls tetrafluorobenzobicyclo-[2.2.2]octatriene (which is formed when pentafluorophenyllithium decomposes in the presence of benzene) gives complexes of the type triene M(CO)n when M = Fe, n = 3 or M = Cr, Mo, W, n = 4; the bonding of the trience to the metal is shown to occur via the aliphatic CC bonds. Thermal decomposition of these complexes gives mainly carbon monoxide and 1,2,3,4-tetrafluoronaphthalene with only a trace of free triene ligand.

Perfluorophenyl derivatives of the elements XXV. The reaction of tetrafluorobenzyne with some transition metal complexes

Abstract Decomposing “(pentafluorophenyl)magnesium bromide” in dioxane provides a convenient system for generating tetrafluorobenzyne in the presence of transition metal complexes. Four benzyne “adducts”, C 5 H 5 NiC 5 H 5 C 6 F 4 (two isomers), Co 4 (CO) 10 C 6 F 4 and Fe 2 (CO) 8 C 6 F 4 , have been isolated during the initial survey of this highly promising synthetic technique.

Electronic effects and the infrared spectra of μ2-alkynehexacarbonyldicobalt compounds☆

The influence of the electronic structure of R and R′ in species of general formula (RC2R′)Co2(CO)6 on their infrared spectra in the v(CO) region provides independent evidence for the assignment of the carbonyl stretching bands.

Perfluorophenyl derivatives of the elements XIX. Reactions of some polyfluorobenzyne derivatives

Abstract The synthesis of 2-chlorononafluorobiphenyl is described but it cannot be obtained by decomposing pentafluorophenyllithium in the presence of chloropentafluorobenzene. Tetrafluorobenzyne adds to styrene to give 1,2,3,4-tetrafluorophenanthrene and 1,2,3,4-tetrafluorodihydrophenanthrene. 2,2′-Dilithiooctafluorobiphenyl readily loses one molecule of lithium fluoride at 0° to give 1-lithioheptafluorobiphenylene from which other substituted heptafluorobiphenylenes may be synthesised.