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Solvent free 2,6-diphenylphenolates of calcium, strontium and barium have been prepared by direct reaction of the bulk metals with 2,6-diphenylphenol (HOdpp) at elevated temperatures in evacuated sealed tubes. Single-crystal X-ray diffraction studies of crystalline [Ca₂(Odpp)₂(μ-Odpp)₂]·(PhMe) (1), [Sr₂(Odpp)(μ-Odpp)₃]·(PhMe) (2) or [Ba₂(Odpp)(μ-Odpp)₃] (3), obtained by toluene extraction of the reaction mixtures, revealed different binuclear structural frameworks. In 1, both Ca atoms have one terminal and two bridging aryloxide ligands in a pyramidal array with the coordination vacancies occupied by π-bonded pendant phenyl groups (an η³- and an η¹-Ph on one Ca and an η⁶-Ph on the other). By contrast, 2 has unsymmetrical metal–oxygen coordination with one terminal and three bridging aryloxides attached to one metal and solely three bridging aryloxides bound to the other. There are additional intramolecular π-Ph–Sr interactions with three η¹-Ph groups on the four coordinate Sr and three η²-Ph groups on the three coordinate Sr. In 3, the structure exhibits a similar metal–oxygen framework to 2, but there are an increased number of π-phenyl–M interactions (one η²-Ph and two η¹-Ph on the four coordinate Ba and one η⁶-Ph, one η³-Ph and one η²-Ph on the three coordinate Ba).

Treatment of [LnCp3(THF)] (Ln=La, Nd, Sm, or Yb) (Cp, cyclopentadienyl and THF, tetrahydrofuran) and [Nd(MeCp)3(THF)] (MeCp, methylcyclopentadienyl) with OPR3 (R=Ph, o-tolyl, Bun) in either THF or DME (DME, 1,2-dimethoxyethane) gave the complexes [LnCp3(OPPh3)] (Ln=La, Nd, Sm and Yb), [Nd(MeCp)3(OPPh3)], [SmCp3(OP(o-tolyl)3)], [Nd(MeCp)3(OP(o-tolyl)3)], and [LnCp3(OPBun3)] (Ln=La, Nd). An attempt to react [GdCp3(THF)] with OPPh3 in either THF or DME crystallised unsolvated GdCp3, whilst a mixture of [GdCp3(OPPh3)] and OPPh3 was recovered from the filtrate. Attempted synthesis of [YbCp3(OPBun3)] yielded [{YbCp2(OPBun3)}2O], the connectivity established by X-ray crystallography, and impure [YbCp3(OPBun3)]. Single crystal X-ray structure determination of [YbCp3(OPPh3)] (monoclinic, space group P21, a=8.4187(7), b=17.019(11), c=9.450(7) A, β=97.97(6)°, Z=2, R=0.043 for 1576 observed data) showed the complex to contain formal ten coordinate ytterbium with distorted pseudo tetrahedral stereochemistry whilst the structure of [NdCp3(OPBun3)] (trigonal, space group P31/c, a=b=12.973(4), c=9.657(6) A, Z=2, R=0.052 for 602 observed data) showed ten coordinate neodymium with a distinctly trigonal pyramidal arrangement of oxygen and the centroids (Ct) of the Cp rings (Ct–Nd–Ct 119.8°).

Reaction of YbCp2(DME) (Cp=cyclopentadienyl; DME=1,2-dimethoxyethane) with perfluorodecalin or perfluoro(methylcyclohexane) in THF yields [YbCp2F(THF)]2. These are the first examples of C–F activation of saturated perfluorocarbons by a lanthanoid organometallic. The X-ray crystal structure of [YbCp2F(THF)]2 (monoclinic, P21/c, a=7.9901(12), b=20.411(4), c=8.5957(12) A; β=104.70(2)°, Z=2, R1=0.0495, for 1107 observed data) shows the complex to be dimeric with bridging fluorides and formal nine coordination for ytterbium. YbCp2F has also been obtained by oxidation of YbCp2(DME) with AgF or HgF2.

Reaction of YbCp2(DME) (Cp  cyclopentadienyl; DME = 1,2-dimethoxyethane) with MCl2 (M  Hg, Cd, Zn, Pb, Sn, Cu, Pd, or Co) or MCl (M  Ag, Cu or Tl) in tetrahydrofuran (THF) gives the metal M and YbCp2Cl(THF)0.5, generally in excellent yield, with small amounts of TlCp and CoCp2 also detected from TlCl and CoCl2 respectively. Similarly, YbCp2X(THF) (X  Br or l) and YbCp2Cl(DME)0.5 have been prepared in good yields by analogous oxidation with suitable mercury(II) halides. However YbCp2(DME) and FeCl3 yield ferrocene. In simpler syntheses. YbCp2X(THF)n (X  Cl, n = 0.5; X  Br or I, n = 1) have been obtained by reactions of YbCp2(DME) with C2Cl6 or (CH2X)2 (X  Br or l) in THF, and (YbCp2X)2 by analogous reactions of unsolvated YbCp2 in petroleum ether. The X-ray crystal structure of YbCp2l(THF) (monoclinic, P2 1 /c, a = 8.147(1), b = 13.788(2), c = 14.149(3) A , β = 105.56(1)°, Z = 4, R = 0.042 , for 2324 observed data) shows the complex to be monomeric with formal eight coordination for ytterbium, and with a pseudo-tetrahedral array of the centroids of the Cp rings, oxygen, and iodine ( YbC > 2.565 A , YbO 2.311(5) A , Yb = 12.9316(7) A ).

The synthesis, structures and reactions of lanthanoid complexes with alkenes, alkynes and arenes have been reviewed. Whilst the discussion is centred on neutral π donors, including intramolecular π-arene-lanthanoid bonding, some formal [Sm III (C 5 Me 5 ) 2 (π-donor) − ] complexes, derived from Sm(C 5 Me 5 ) 2 and neutral π donors, have been included, especially examples which readily dissociate into the reactants. Metal-carbon bond lenghts for lanthanoid(II or III) complexes have been convenientljy analysed and compared by subtraction of the appropriate lanthanoid ionic radius for the formal coordination number. Derived values in the approximate range 1.70–2.10 A are typical, with higher values often associated with intramolecular π-areneLn coordination or dimerization through intermolecular π-areneLn bonding. Lower values, 1.40–1.70 A, can carry implications of charge transfer, e.g. Ln II L 0 → Ln III (L) −1 or may be partly a geometric consequence of other bonding in the molecule. The significantly covalent arene-lanthanoid(0) complexes have stronger bonding than in Ln(II or III)-(π donor) derivatives and occupy a unique place in organolanthanoid chemistry.

The complex Pt(C6F5)2(OH)2(en) (en = ethane-1,2-diamine) has been prepared by oxidation of Pt(C6F5)2(en) hydrogen peroxide in acetone. Treatment of the platinum(IV) complex with acid anhydrides, (RCO)2O (R = Me, Et, nPr, or iPr), in ether yields cis, trans-Pt(C6F5)2(O2CR)2(en) complexes. The stereochemistry was established by an X-ray diffraction study of Pt(C6F5)2(O2CnPr)2(en), which has an octahedral arrangement involving trans unidentate butanoate ligands and cis-C6F5 groups, and by spectroscopic similarities between the complexes. There is hydrogen bonding between uncoordinated carboxyl oxygens and NH groups, and between one ortho-fluorine of each C6F5 group and an NH group. The 19F NMR spectra show five fluorine resonances at −50 °C, indicative of unsymmetrical C6F5 groups with restricted rotation, and this is consistent with features of the solid state structure of cis, trans-Pr(C6F5)2(O2CnPr)2(en). Preliminary examination of the biological activity of the complexes against L1210 and L1210/DDP mouse leukemia cells in culture has been made.

Reaction of the divalent phosphinoytterbocene Yb(C5H4PPh2)2(THF)(THF = tetrahydrofuran) with mercuric chloride in THF or toluene yields mercury metal and the lanthanoid(III) complex Yb(C5H4PPh2)2Cl. An X-ray crystal structure of the compound revealed the presence of two independent chloride-bridged dimers (one centrosymmetric, one non-centrosymmetric, in a ratio of 1:2) with uncoordinated Ph 2P groups and pseudo-tetrahedral eight coordination (two η5-C5H4PPh2 and two η-Cl ligands) at ytterbium. The dimers differ in the arrangement (syn, anti) of the Ph2P groups. Solution spectroscopic data suggest that there is P-Yb bonding in toluene.

Tetraethyldistibine, Et 4 Sb 2 , a new antimony source for MOCVD is evaluated. It is shown to be a useful and safe dopant feedstock for low temperature growth of p-type Hg 1- x Cd x Te. Attempted purification of Et 4 Sb 2 by adduct formation with CdI 2 resulted in isolation of a polymeric chain adduct [Et 4 Sb 2 · 2CdI 2 ] n ( 1 ). The structure of 1 has been determined by X-ray crystallography and consists of chains of iodide-bridged Et 4 Sb 2 · 2CdI 2 units which have CdI 2 bonded to each antimony atom. Antimony and two iodine atoms form a trigonal planar arrangement around cadmium, and two weak axial bonds to the iodine atoms of adjacent units give distorted trigonal bipyramidal coordination to cadmium. The distibine molecules display a skew configuration of the ethyl substituents. The Sb II -Sb II and Sb II -Cd II distances are 2.784(2) and 2.822(2) A respectively. Dropwise addition of Me 2 Cd to Et 4 Sb 2 in the absence of solvent gave an insoluble 1:1 adduct. Et 4 Sb 2 reacts with Te but not with Cd or Hg.

The complexes trans-Ir(CO)R(PPh3)2 (R  C6F5, p-HC6F4, or m-HC6F4) have been prepared by reaction of trans-Ir(CO)Cl(PPh3)2 with the appropriate thallium(I) polyfluorobenzoate in pyridine. The rate of decarboxylation falls in the sequence R  C6F5 > p-HC6F4 > m-HC6F4. Intermediate trans-Ir(CO)(O2CR)(PPh3)2 complexes were detected by 19F NMR spectroscopy, and trans-Ir(CO)(O2CC6F5)(PPh3)2 was isolated following reaction of trans-Ir(CO)Cl(PPh3)2 with thallium(I) pentafluorobenzoate in boiling benzene. Heating of trans-Ir(CO)(O2CC6F4H-o)(PPh3)2, formed in situ by a similar metathesis in pyridine, gave the complex Ir(CO)(C6F4C(O)O)H(PPh3)2, which was formed by cyclometallation and oxidative addition and which, from NMR and spectroscopic data, is considered to have trans-Ph3P ligands, hydride trans to carboxyl, and CO trans to an aryl carbon.

Treatment of bis(3- N , N -dimethylaminopropyl)manganese(II) with methyllithium and subsequently with silver tetrafluoroborate gives bis(3- N , N -dimethylaminopropyl)methylmanganese(III) ( 1 ). The related complex bis(2- N , N -dimethylaminomethylphenyl)methylmanganese(III) ( 2 ) was prepared similarly. The structure of 2 was established by single-crystal X-ray crystallography. The molecule is trigonal bipyramidal, with aryl ipso carbon atoms in the axial positions and the two nitrogen atoms plus the methyl carbon forming the equatorial plane.

Reaction of NdCP3 (CP=cyclopentadienyl) with an equimolar amount of 2,6-diphenylphenol (HOdpp) in tetrahydrofuran (thf) yields the formally ninecoordinate [NdCp2(Odpp)(thf)2]. The crystal structure shows a distorted trigonal bipyramidal arrangement of oxygen donor atoms and cyclopentadienyl ring centroids, with the thf oxygens in the axial positions and a twofold axis along NdOdpp bond

The complexes P t[C 6 F 4 - o -C(O)O ](PPh3)L (L = py, 2,4-Me2C5H3N or 2,6-Me2C5H3N) and P t[C 6 F 4 - o -C(O)O ]L2 [L2 = (Ph2PCH2)2 or (Ph2P)2(CH2)3] have been prepared by decarboxylation reactions between cis-PtCl2(PPh3)2 or PtCl2L2 and thallium(I) tetrafluorophthalate in boiling pyridine, or 2,4- or 2,6-dimethylpyridine. Reaction of cis-PtCl2(PPh3)2 with o-C6F4(CO2Tl)2 in pyridine at room temprature gives Pt[o-(O2C)2C6F4](PPh3)2, which undergoes decarboxylation at 160–165°C in the absence of a solvent to give P t[C 6 F 4 - o -C(O)O ](PPh3)2. 31P NMR data suggest that in P t[C 6 F 4 - o -C(O)O ](PPh3L comlexes, triphenylphosphine is trans to the coordinated oxygen. The crystal structure for L = 2.6-Me2C5H3N as a chloroform solvate shows a,b,c,d-Pt(O,C,P.N) square planar stereochemistry with 2,6-dimethylpyridine near perpendicular to the coordination plane and the tetrafluorophenyl ring near coplanar with this plane.

The product from the reaction of triphenylindium with sulphur dioxide, previously considered to be O-benzenesulphinatodiphenylindium(III), is now formulated as the 1 1 adduct, Ph3In(O2S).

Summary Cleavage reactions of six phenylene- and polyphenylene-mercury heterocycles with the mercuric halides and mercuric acetate in suitable refluxing solvents readily produce 1,2-C 6 X 4 (HgX) 2 ; 2,2′-C 6 H 4 C 6 H 4 (HgX) 2 and 2,2″-C 6 H 4 C 6 H 4 C 6 H 4 (HgX) 2 (X = Cl, Br, I or CH 3 CO 2 ). Addition of silver acetate to 2,2′-C 6 H 4 C 6 H 4 (HgBr) 2 gives 2,2′-C 6 H 4 C 6 H 4 (HgO 2 CCH 3 ) 2 which reacts with concentrated hydrochloric acid to form 2,2′-C 6 H 4 C 6 H 4 (HgCl) 2 . Treatment with sodium iodide, or in some cases simply the application of heat under vacuum, causes symmetrization of these cleavage products back to the original heterocycles in high yield. The terphenylenemercury dimer, (C 6 H 4 C 6 H 4 C 6 Hg) 2 , forms solvates with a wide variety of donor and non-donor solvents. Pyrolysis of mercuric 2,3,4,5-tetrafluorobenzoate at 190°C yields 2-mercurio-3,4,5,6-tetrafluorobenzoate and 2,3,4,5-tetrafluorobenzoic acid; at 300°C the former gives tetrafluorophenylenemercury, (C 6 F 4 Hg) 3 .

Bis(pentafluorophenyl)ytterbium, prepared from reaction of bis(pentafluorophenyl)mercury with ytterbium metal in tetrahydrofuran (THF), has been isolated as the highly air-sensitive, thermally unstable complex (C6F5)2Yb(THF)4, which yielded pentafluorobenzene on acidolysis. The 19F NMR, IR, and UV/Vis spectra of the complex are discussed. A tetrahydrofuran complex of bis(2,3,5,6-tetrafluorophenyl)ytterbium has been prepared in a similar manner and was identified spectroscopically, thermal instability preventing satisfactory analytical characterization. Reaction was observed between ytterbium and bis(2,3,4,5-tetrafluorophenyl)mercury, but the product decomposed too rapidly for isolation. Ytterbium metal failed to react with diphenylmercury or bis(Dentachlorophenyl)mercury.

The preparations, stabilities and structures of the complexes R2TlX and R2 LTlX (R = C6F5, p-HC6F4, or o-HC6F4; X = Br or Cl; L = Ph3PO, 2,2′-bipyridyl (bpy) or Ph3P) have been examined or (R = C6 F5) reinvestigated. The derivatives R2TlX are monomeric in acetone, from which the complex (p-HC6F4)2 Me2COTIBr has been isolated. In this solvent, the complexes R2LTlX (L = Ph3PO, bpy, or Ph3P) undergo partial dissociation by loss of L. When L = bpy, there is also slight ionization into R2LTl+ and R2TlX−2. The acceptor properties of R2TlX compounds towards uncharged ligands decrease R = C6F5 ⋍ p-HC6F4 > o-HC6F4 > Ph. Dimeric behaviour is observed for R2TIX compounds in benzene, whilst R2LTlX (L = Ph3PO or bpy) derivatives show slight but significant association. In the solid state, R2TlX compounds are considered to be polymeric with five coordinate thallium, and R2LTlX derivatives to be dimeric with five (L = Ph3PO) or six (L = bpy) coordinate thallium by contrast with four coordinate dimeric and four or five coordinate monomeric structures previously proposed for the respective pentafluorophenyl derivatives. Halogen bridging is unsymmetrical for R = C6F5 or p-HC6F4, but may be more symmetrical for R = o-HC6F4 when L = Ph3PO or bpy. Reported structural data for the complexes (C6F5)LTlX (L = Ph3AsO, Ph3P, Ph3As, or 1,10-phenanthroline; X = Br or Cl) and (C6F5)2TlCl−2 are reinterpreted and the proposed structures revised.

Organoytterbium(III) complexes [(η-C 5 H 5 ) 2 )YbX] (X = O 2 CMe, O 2 CC 6 F 5 , O 2 CC 5 H 4 N, Cl, Br, I, CCPh, C 6 F 5 , (MeCO) 2 CH, (PhCO) 2 CH) have been synthesized in high yield from [η-C 5 H 5 ) 2 ]Yb(MeOCH 2 ) 2 ] and the corresponding HgX 2 , TlX, AgX 2 or CuX species. An X-ray diffraction study of the pentafluorobenzoate has shown it to be dimeric, with a somewhat unsymmetrical bridging carboxylate.

Crystals of di-η5-cyclopentadienyl-1,2-dimethoxyethaneytterbium(II) are mono-clinic, space group Cc, with a 9.25(2), b 23.49(5), c 8.23(2) A, β 123.59(4)° and Z  4. The ytterbium ion is pseudo-tetrahedrally coordinated by two cyclopentadienyl groups and a bidentate 1,2-dimethoxyethane ligand, and there is no inter-molecular association. The sites of the cyclopentadienyl ligands are disordered.

The complexes PtR 2 (diene) (R = C 6 F 5 or p -HC 6 F 4 ; diene = cis , cis -cycloocta-1,5-diene (cod), dicyclopentadiene (dcy), norbornadiene (nbd) or hexa-1,5-diene (hex)) have been prepared by the organolithium route. Reaction of PtCl 2 (cod) with an equimolar amount of TlO 2 CR (R = C 6 F 5 or p -HC 6 F 4 ) in pyridine yields Pt(R)Cl(cod), which have been converted into Pt(R)X(cod) (X = Br or I) by halogen exchange reactions. Other decarboxylations result in diene displacement giving cis -Pt(C 6 F 5 )Cl(py) 2 and cis - and trans -Pt(C 6 F 5 ) 2 (py) 2 . The complexes, cis -Pt(C 6 F 5 ) 2 L 2 (L = py or Ph 3 P) and cis -Pt( p -HC 6 F 4 ) 2 (PPh 3 ) 2 ) are formed by ligand replacement reactions of PtR 2 (cod), but Pt(C 6 F 5 ) 2 (cod) does not react with N , N , N ′, N ′-tetramethylethylenediamine (tmed) nor Pt(C 6 F 5 ) 2 (nbd or dcy) with ethylenediamine (en). Diene displacement occurs more readily from PtR 2 (hex) giving Pt(C 6 F 5 ) 2 L 2 (L 2 = cis -(NH 3 ) 2 , en, tmed or 1,10-phenanthroline) and cis -Pt( p -HC 6 F 4 ) 2 (PPh 3 ) 2 .

The triphenyltin carboxylates, Ph3SnO2CR (R = C6F5,p-MeOC6F4, p-EtOC6F4, or o-HC6F4), p-(Ph3SnO2C)2C6F4.H2O, and O-(Ph3SnO2C)2C6F4.H2O have been prepared by reaction of triphenyltin hydroxide with the appropriate polyfluorocarboxylic acids in methanol. Thermal decomposition of Ph3SnO2CR (R = C6F5, p-MeOC6F4, or p-EtOC6F4) in boiling pyridine gave the corresponding polyfluorophenyltriphenyltin compounds Ph3SnR. For R = p-MeOC6F4, the yield was lowered owing to competing formation of tetraphenyltin. Similar decomposition of p-(Ph3SnO2C)2C6F4.H2O gave p-(Ph3Sn)2C6F4 (major product) and Ph3Sn-p-HC6F4, whilst o-(Ph3SnO2C)2C6F4 gave triphenyltin fluoride, and Ph3SnO2C-o-HC6F4 failed to react. Di (phenylmercuric)tetrafluoroterephthalate and tetrafluorophthalate underwent decarboxylation in boiling pyridine giving p-(PhHg)2C6F4 and o-PhgC6C6F4CO2HgPh respectively, whilst p-(Ph3PbO2C)2C6F4 gave p-(Ph3Pb)2C6F4, Ph3Pb-p-HC6F4, and tetraphenyllead. Reaction of bromotriphenylgermane with silver pentafluorobenzoate in boiling pyridine gave pentafluorophenyltriphenylgermane, but analogous reactions with silver p-ethoxytetrafluorobenzoate and disilver tetrafluoroterephthalate gave, after work up, mixtures of polyfluorophenylgermanes, Ph4Ge, and (Ph3Ge)2O.

The polyfluoroarylmercuric chlorides, RHgCl (R = C6F5, p-MeOC6F4, p-MeC6F4, m-HC6F4, o-HC6F4, p-HC6F4, m-O2NC6F4, o-O2NC6F4, p-BrC6F4, m-BrC6F4, o-BrC6F4, p-HOC6F4, p-H2NC6F4, m-HO2CC6F4, p-(p-HC6F4)C6F4, 3,5-H2C6F3, 3-bromo-2,4,6-trifluorophenyl or 3-bromo-2,5,6-trifluorophenyl), and the bis (polyfluorophenyl)mercurials, R2Hg (R = C6F5, p-MeOC6F4, p-MeC6F4, p-HC6F4, m-O2NC6F4,o-O2NC6F4, p-BrC6F4, m-BrC6F4, o-BrC6F4, p-HOC6F4, orp-H2NC6F4) have been prepared by mercuration of the appropriate polyfluoroarenes with mercuric trifluoroacetate and trifluoromethanesulphonic acid in trifluoroacetic acid, followed by treatment of the products with hydrochloric acid (RHgCl derivatives) or potassium bromide (R2Hg derivatives). For R = p-MeOC6F4, the actual mercuration product has been isolated and identified as 2,3,5,6-tetrafluoro-4-methoxyphenylmercuric trifluoromethane sulphonate. Interaction of mercuric trifluoroacetate with trifluoromethanesulphonic acid in trifluoroacetic acid yields mercuric trifluoromethanesulphonate, which is considered to be the mercurating agent, and which has been characterized as the complex, [Hg(bpy)3](O3SCF3)2·H20 (bpy = 2,2′-bipyridyl). The mercuration syntheses are very simple and convenient, and should become the preferred method for most polyfluoroarylmercurials.

The main thermal decomposition path for mercuric 2,6-disubstituted benzoates, (RCO2)2Hg (R = 2,6-X2C6H3; X = F, Cl, Br, or Me), can be varied considerably. In boiling dimethyl sulphoxide, decarboxylation occurs giving the corresponding diarylmercurial (X = F or Cl) or RHgO2CR derivative (X = Me or Br). There is considerable competition from reaction of the mercuric salt with the solvent in the last three cases. With boiling pyridine as medium, the 2,6-difluorobenzoate yields a mixture of R2Hg and RHgO2CR derivatives, but the 2,6-dichlorobenzoate only gives (RCO2)2Hg(py)2. Thermal decomposition of the mercuric benzoates under vacuum yields the carboxylic acids and complex mercuration products, mainly based on 3-mercurated 2,6-disubstituted benzoates, with partial additional mercuration and/or decarboxylation. Pyrolysis of mercuric 2,6-dichlorobenzoate at atmospheric pressure results in both mercuration and decarboxylation, giving m-dichlorobenzene as the main volatile product and a complex mercurial with 1,3-dimercurated-2,6-dichlorobenzene repeating units and 2,6-dichlorophenyl terminal groups.

Desulphination reactions between sodium mesitylenesulphinate and the thallic salts TlX 3 (X = MeCO 2 , CF 3 CO 2 or Cl) in aqueous acetic acid or water gave mesitylthallium(III) diacetate or the complexes RTl(O 2 SR)X (R = 2,4,6-Me 3 C 6 H 2 ; X = MeCO 2 or Cl) at room temperature and dimesitylthallium(III) mesitylenesulphinate at 100°C. The diacetate was independently synthesized by metathesis from mesitylthallium(III) dichloride, and was converted into RTl(O 2 SR)O 2 CMe by sodium mesitylenesulphinate. The derivatives RTl(O 2 SR)X gave mesitylthallium(III) dichloride on treatment with HCl and rearranged into dimesitylthallium mesitylenesulphinate in boiling aqueous acetic acid or water. Thermal decomposition of RTl(O 2 SR)O 2 CMe under vacuum yielded dimesitylthallium(III) acetate. The structures of the mesitylthallium sulphinate and acetate complexes are discussed. Reaction of thallic acetate or trifluoroacetate with sodium 2,4,6-triisopropylbenzenesulphinate in aqueous acetic acid gave Tl I [Tl III (O 2 SR 1 ) 4 ] [R 1 = 2,4,6-(Me 2 CH) 3 C 6 H 2 ] at room temperature and the thiosulphonate R 1 SO 2 SR 1 at 100°C, whilst reactions with sodium benzenesulphinate and p -toluenesulphinate gave the diaryl disulphones.

Crystals of dibromo-η5-cyclopentadienyltris(tetrahydrofuran)ytterbium(III) are monoclinic, P21/n (C2n5, No. 14), with a 15.310(15), b 16.900(17), c 7.968(8) A, β 96.66(5)° and Z = 4. The ytterbium is pseudo-octahedrally coordinated by a cyclopentadienyl ligand, trans bromines, and mer tetrahydrofuran ligands, and the ytterbium—oxygen distance trans to cyclopentadienyl is longer than the other ytterbium—oxygen bonds.

Bis(2,4,6-trichlorophenoxymethyl)mercury has been prepared by reaction of bis(bromomethyl)mercury with thallium(I) 2,4,6-trichlorophenoxide. The compound has a centrosymmetric structure with linear CHgC bonding (HgC 2.11(1) A). Each mercury has contacts with two intramolecular and two intermolecular oxygen atoms (Hg … O 2.970(6) and 3.105(6) A, respectively) and with an ortho-chlorine from each trichlorophenyl ring (Hg Cl 3.419(2) A). The other ortho-chlorines have contacts with a methylene hydrogen (H … Cl 2.874(3) A).

The organoplatinum compounds, PtR2L2 (R = C6F5 or p-HC6F4, L2 = trans-(py)2; R = C6F5, L2 = 2,2′-bipyridyl (bipy)) have been prepared by reaction of the corresponding PtCl2L2 complexes and barium polyfluorobenzenesulphinates in boiling pyridine. Similar reactions gave PtCl(C6F5)phen (phen = 1,10-phenanthroline), Pt(p-HC6F4)2bipy, PtCl(p-HC6F4)bipy, Pt(p-HC6F4)2phen, and PtCl(p-HC6F4) phen either impure or in mixtures. Reaction of Ba(O2S-o-HC6F4)2 with trans-PtCl2(py)2 in boiling pyridine gave trans-PtCl(O2S-o-HC6F4)(py)2, which lost SO2 at 210–215°C to give trans-PtCl(o-HC6F4)(py)2. Treatment of trans-PtCl2(py)2 with thallous pentafluorobenzenesulphonate in boiling pyridine did not result in desulphonation but [Pt(py)4](O3SC6F5)2 was obtained.

An X-ray crytallographic study has shown that the complex ( p -HC 6 F 4 ) 2 TlCl-(OPPH 3 ) is dimetric with unsymmetrical chlorine bridging (TlCl 2.541 A TlCl' 2.936 A) and five coordinate thallium atoms. The stereochemistry of each thallium is approximately trigonal bipyramidal, the equatorial positions being occupied by two carbon atoms and the more tightly held chlorine. Similar structures are likely for ( p -HC 6 F 4 ) 2 TlBr(OPPh 3 ) and (C 6 F 5 ) 2 TIX(OPPh 3 ) (X  Br or Cl).

The complexes, PtCl(diene)R (diene = hexa-1,5-diene (hex) or norbornadiene (nbd), R  C6F5, p-HC6F4, or p-MeOC6F4; diene = diene = dicyclopentadiene (dcy), R = C6F5) have been prepared by reaction between equimolar amounts of PtCl2(diene) and Me3SnR in dichloromethane. Most reactions also gave some of the corresponding PtR2(diene) complex, which was readily separated by chromatography, and Pt(p-MeOC6F4)2(nbd) was obtained in high yield from PtCl2(nbd) and Me3Sn(p-MeOC6F4) when a 1 2 mole ratio was used. Attempts to prepare PtCl(dcy)R (R  p-HC6F4 or p-MeOC6F4) from Me3SnR gave only PtR2(dcy) in boiling CH2Cl2 despite the use of 1 1 reactant stoichiometry, and Pt(p-MeOC6F4)2(dcy) or no reaction (R  p-HC6F4) at room temperature. Alternative reagents, R′3 SnR (R′  Bu or Et, R  C6F5 or p-MeOC6F4) had a variable effect on the selectivity of monoarylation. Thus, Bu3SnC6F5 was more selective and Et3SnC6F5 less selective in formation of PtCl(hex)C6F5 than Me3SnC6F5. With Et3SnR (R  C6F5 or p-MeOC6F4) and an equimolar amount of PtCl2(dcy), PtCl(dcy)R was the major product. The crystal structure of ptCl(dcy)C6F5 shows near square planar stereochemistry for platinum and steric congestion. The double bond from the six-membered ring of dcy is unsymmetrically coordinated to platinum trans to C6F5 and is further from the metal than the other double bond, which is symmetrically bonded trans to chlorine. The pentafluorophenyl group is approximately normal to the coordination plane, and gives two ortho-fluorine resonances in the 19F NMR spectrum.

The complexes RCo(acacen) [R = C 6 F 5 , p -HC 6 F 4 , or o -HC 6 F 4 ; H 2 acacen = N,N ′-ethylenebis(acetylacetonimine)] and RCo(salen) [R = C 6 F 5 or p -HC 6 F 4 ; H 2 salen = N,N ′-ethylenebis(salicylaldimine)] have been prepared by reaction between Co(acacen) or Co(salen) and the appropriate bromobis(polyfluorophenyl)thallium(III) compounds, and have been isolated as pyridinates. Spectroscopic evidence for formation of C 6 F 5 Co(salophen) [H 2 salophen = N,N ′-o-phenylenebis(salicylaldimine)] has also been obtained. The reactivity of the thallium compounds increased in the sequence Ph 2 TlBr ⪡ (o-HC 6 F 4 )2TlBr p -HC 6 F 4 ) 2 TlBr 6 F 5 ) 2 TlBr, and of the cobalt complexes in the sequence Co(salophen)

Thallation of anisole and phenetole with an equimolar amount of thallic trifluoroacetate in trifluoroacetic acid yields predominantly the para -thallated derivatives using short reaction times, but ortho -thallated species using long reaction times. With an excess of thallic trifluoroacetate, dithallation occurs and 2,4-bis[bis(trifluoroacetato)thallio]- anisole and -phenetole have been isolated. Each gives the corresponding 1 -alkoxy-2,4-diiodobenzene as the sole organic product on treatment with aqueous sodium iodide. Complete dithallation of thiophen has been achieved on reaction with an excess of thallic trifluoroacetate in acetonitrile, as indicated by quantitative formation of 2,5-diiodothiophen on treatment of that thallation product with aqueous iodide ions. Use of an excess of thallic trifluoroacetate in refluxing trifluoroacetic acid causes partial dithallation of toluene, m -xylene, and benzene.

Mercuration of pentafluorobenzene under basic conditions in aqueous tertbutanol by tetrabromomercurate(II) ions, phenylmercuric chloride, and p-tolylmercuric chloride yields bis(pentafluorophenyl)mercury, (pentafluorophenyl)-phenylmercury, and (pentafluorophenyl)-p-tolymercury respectively, in a single simple preparative step. Cleavage of bis(pentafluorophenyl)mercury with iodide or bromide ions in alcohols or aqueous alcohols gives pentafluorobenzene, tetrahalogenomercurate(II) ions, and base. Under alkaline conditions, tetrahalogenomercurate(II) ions are reduced to mercury by ethanol or methanol. Decomposition of (pentafluorophenyl)phenylmercury by iodide ions has also been studied.