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Reaction of [Pt(en)Cl2] (en = ethane-1,2-diamine) with thallium(I) carbonate (or in some cases K2CO3) and a polyfluorobenzene in hot pyridine (py) or 3-methylpyridine (tmpy) yields the [N,N′-bis(polyfluorophenyl)ethane-1,2-diaminato(2-)platinum(II) complexes, [Pt{N(R)CH2}2L2] (L = py, R = p-HC6F4, C6F5, p-BrC6F4, p-IC6F4, p-C6F5C6F4, 2,3,5-F3C6H2, p-O(H)CC6F4, p-MeOC4F4; L = tmpy, R = p-HC6F4). Yields were markedly greater with the use of Tl2CO3 than reported for reactions of [Pt(en)Cl2] with thallium(I) polyfluorobenzoates. A new class of platinum(II) amides, namely [N-(phenyl)-N′-(polyfluorophenyl)ethane-1,2-diaminato(2-)]platinum(II) complexes, [Pt{N(Ph)CH2CH2N(R)}L2] (L = py, R = p-HC6F4, C6F5, p-MeC6F4, p-ClC6F4, p-BrC6F4; L = 4-methylpyridine, R = p-HC6F4), has been prepared by reaction of [Pt(PhNHCH2CH2NH2)I2] with Tl2CO3 or a thallium(I) polyfluorobenzoate and a polyfluoroaromatic compound in pyridine or 4-methylpyridine. The complexes where R = p-MeC6F4, p-ClC6F4, p-BrC6F4 could be prepared only with Tl2CO3, which also provided cleaner products where both routes were used. The crystal structure of [Pt{N(Ph)CH2CH2N(p-MeC6F4)}(py)2] has been determined and shows a slightly distorted square planar coordination for platinum, with two amide and two cis pyridine nitrogen donors.

Eleven cobalt complexes of the types [Co(CO) 2 (NO)L](L = PEt 3 , TeMe 2 or TeEt 2 ) and[(η 3 -C 3 H 3 R 2 )Co(CO) 2 L](R=H or Me; L CO, PEt 3 , TeEt 2 or CNR′ with R′ Pr i , Bu t or Cy; Cy is cyclohexyl) have been prepared and assessed for MOCVD applications. Measurement of vapour pressures by the Knudson effusion method has established that the room-temperature volatilities of [Co(CO) 2 (NO)(TeMe 2 )], and the allyl complexes[(η 3 -C 3 H 5 )Co(CO) 3 ,],[(η 3 -C 3 H 4 Me)Co(CO) 3 ], [(η 3 -C 3 H 3 Me 2 )Co(CO) 3 ] and [(η 3 -C 3 H 5 )Co(CO) 2 (CNBu t )] are sufficient (0.1–4.0 mmHg) to achieve high concentrations in the vapour state. Vapour-phase thermal degradation at 180–250°C of seven complexes carried in a stream of hydrogen gave metal deposits, which were analysed by EDX or XPS. The best behaved complexes were [Co(CO) 2 (NO)(TeMe 2 )] and[(η 3 -C 3 H 5 (Co(CO) 3 ], which gave clean Co films after decomposition at 150 and 250°C, respectively.

Treatment of MeMn(CO)5 with the dialkyltellurium compounds TeR2 (R = Me, Et, Pri gave the acyl complexes MeCOMn(CO)4(TeR2) in high yield. A similar reaction between EtCOMn(CO)5 and TeR2 (R = Me, Et) yielded the related complexes EtCOMn(CO)4(TeR2). When the benzyl complex BzMn(CO)5 was treated with TeR2 (R = Me, Et), BzCOMn(CO)4(TeR2) was formed initially but, on prolonged reaction in a refluxing solvent, decarbonylation occurred to form BzMn(CO)4(TeR2). Related bromo complexes BrMn(CO)4(TeR2) were obtained when BrMn(CO)5 was treated with TeR2 (R = Me, Et). Spectroscopic results indicated that all of the TeR2 substitution products have octahedral stereochemistry about manganese with a cis-configuration of the tellurium ligand and the organo or halo group. Some of the complexes were selected for assessment as possible MOCVD single source precursors. Although most of the compounds are liquids with significant volatility, they tend to dissociate when heated with release of the dialkyltellurium. Nonetheless, pyrolysis of the compounds R′COMn(CO)4(TeR2) (with R′ = Me and R = Me, Et or Pri; R′ = Et and R = Et) under typical MOCVD conditions (H2 stream, 175–225°C) produced metal films containing manganese and tellurium

Tellurium does not insert directly into the MnC bond of RMn(CO)5 (R = Me or PhCH2). However, reactions between RMn(CO)5 (R = Me, PhCH2) and TePR′3 (R′ = Me, Et) result in Te insertion accompanied by CO substitution to produce RTeMn(CO)3(PR′3)2 complexes. These complexes are formed by initial substitution to give RMn(CO)3(PR′3)2 followed by Te insertion. The crystal structure of the complex with R = PhCH2 and R′ = Et has been determined from X-ray diffraction data. Crystal data: C22H37O3P2MnTe; M = 594.0; P 1 , a = 9.263(2), b = 14.650(5), c = 20.265(7)A, α = 91.27(3), β = 90.67(2), γ = 103.96(2)°, U = 2667.7(14) A3; Dcalc = 1.479 (Z = 4), Dmeas = 1.480(5) mg m−3, μ = 1.687 mm−1 for Mo-Kα radiation (λ = 0.7107 A), final R = 3.11, Rw = 5.46, from 7788 observed reflections (12974 collected). The geometry about manganese is slightly distorted octahedral with a trans-arrangement of the phosphine groups and a meridional placement of the carbonyls. Pyrolysis of PhCH2TeMn(CO)3(PEt3)2 at 300°C in a hydrogen stream gives a film of MnTe. Treatment of Mn(CO)5Br with LiTeR yields the dimeric products [Mn(CO)4(μ-TeR)]2 (R = Me, Et, Pri, CH2SiMe3, Si(SiMe3)3, and Ph). For most of these complexes, two conformations have been detected by multinuclear NMR spectroscopy. Variable temperature 1H NMR spectroscopy shows that the conformers interconvert for R = Me and CH2SiMe3. The mass spectra of [Mn(CO)4(μ-TeR)]2 (R = Me, Et, Pri) show gas phase fragmentation to MnxTey species. Pyrolysis of two of these complexes (R = Me, Et) in a hydrogen atmosphere produced a film containing MnTe. Addition of PEt3 to a solution of [Mn(CO)4(μ-TeME)]2 results in bridge cleavage to yield MeTeMn(CO)3(PEt3)2, but the reaction is slow and other unidentified products are formed. A similar reaction occurs when R = CH2SiMe3. The formation of MeTeMn(CO)3 (PEt3)2 was also achieved from the reaction between BrMn(CO)3(PEt3)2 and LiTeMe. The HgMn complex MeHgMn(CO)5 was obtained by treatment of [Mn(CO)5]− with MeHgCl. This complex readily disproportionates to Me2Hg and Hg[Mn(CO)5]2. Pyrolysis of MeHgMn(CO)5 at 300°C gives a film of manganese with no retention of mercury.

The X-ray crystal structure of [La(Odpp)3(THF)2]·THF (Odpp = OC6H3Ph2-2,6), prepared by reaction of lanthanum metal, bis(pentafluorophenyl)mercury and 2,6-diphenylphenol in THF, shows distorted trigonal-bipyramidal stereochemistry for lanthanum. A phenolate oxygen [LaO 2.25(1) A] and a THF oxygen [LaO 2.68(2) A] occupy apical positions [OLaO 165.9(4)°], whilst two phenolate oxygens [LaO 2.25(1), 2.234(9) A] and a THF oxygen [LaO 2.52(1) A] occupy trigonal positions [OLaO 122.1(4), 124.8(5), 96.5(6)°]. The apical LaO(THF) distance is exceptionally and unexpectedly long. Unit cell data for [Nd(Odpp)3(THF)2]·THF suggest that it is isostructural with the lanthanum compound.

Prolonged reaction of manganese metal with bis(pentafluorophenyl)mercury in thf or 1,2-dimethoxyethane (dme) yields Mn(C 6 F 5 ) 2 (thf) 2 or Mn(C 6 F 5 ) 2 (dme). The latter reacts with N,N,N′,N′-tetramethylethane-1,2-diamine(tmen) in toluene to give Mn(C 6 F 5 ) 2 (tmen). Mass spectra indicate the complexes have associated structures. Impure Mn( p -HC 6 F 4 ) 2 (dme) was obtained from manganese metal and Hg( p -HC 6 F 4 ) 2 .

The N,N′-bis(polyfluorophenyl)ethane-1,2-diaminato(2−)platinum(II) complexes [Pt (N( p -HC 6 F 4 )CH 2 CH 2 N R)(py)2] (R = p-HC6F4, p-BrC6F4, C6F5 or p-MeC6F4; py = pyridine) have been prepared by decarboxylation reactions between [PtI2(p- HC6F4NHCH2CH2NH2)], thallium(I) 2,3,5,6-tetrafluorobenzoate and a suitable polyfluorobenzene, RF, in hot dry pyridine. When R ≠ p-HC6F4, the two different polyfluorophenyl groups can be distinguished by different F3,5 resonances in the 19F NMR spectra. The reactant and analogous complexes [PtX2(RNHCH2CH2NH2)](R = p-HC6F4, X = I or Cl; R = C6F5, X = I) were prepared by treatment of K2PtX4 (X = I or Cl) with the appropriate N-polyfluorophenylethane-1,2-diamine.

Organometallic feedstocks of cadmium, mercury and tellurium, as well as dopants to create n-type, p-type or diluted magnetic semiconductors, can impose limits on the range of programmable parameters in the MOCVD reactor. The influence of the chosen organometallics on the crystal growth process is critically reviewed.

The complexes, Pt[N( p -HC 6 F 4 )CH 2 CH 2 N Me2]X(L)(X = Cl, L = Ph3P; X = I, L = pyrazine) have been prepared by reaction of PtX2(dmen) (dmen = N,N-dimethylethane-1,2-diamine) with TlO2CC6F4H-p, C6F5H and L in hot 2,6-dimethylpyridine (dmpy), and are considered to have L trans to —NMe2. The pyrazine complex was also obtained in very low yield from an analogous synthesis in 1,4-dioxan. Reaction of PtBr2 (dmen) with TlO2CC6F4H-p and C6F5H in 2,6-dimethylpyridine without an added ligand gave a low yield of Pt[N( p -HC 6 F 4 )CH 2 CH 2 N Me2](O2CC6F4H-p)(dmpy).

Reaction of Cp 2 Yb(DME) (Cp = cyclopentadienyl; DME = 1,2-dimethoxyethane) with triphenylphosphine oxide yields Cp 2 Yb(OPPh 3 ) 2 . The X-ray crystal structure shows eight-coordinate ytterbium with a pseudo-tetrahedral arrangement of two oxygen donor atoms and the centroids of two eclipsed η 5 -cyclopentadienyl rings. Surprisingly short Yb—O distances (2.30(2); 2.33(2) A) and the absence of major inter-ligand contacts indicate an uncrowded arrangement.

Reaction of the complexes Ru(CO)2Cl2L [L = 2,2′-bipyridyl (bpy) or 1,10-phenanthroline (phen)] with trifluoromethanesulphonic acid under carefully controlled conditions yields Ru[cis-(CO)2] [cis-(O3SCF3)2] (bidentate complexes. From reactions of the trifluoromethanesulphonates with the appropriate bidentate ligands, the new complexes [cis-Ru(CO)2-L(L′)]2+ (L as above; L′ = 4,4′-dimethyl-2,2′-bipyridyl or 4,4′-diisopropyl-2,2′-bipyridyl) as well as the known [cis-Ru(CO)2L2]2+ and [cis-Ru(CO)2bpy(phen)]2+ have been prepared.

Reaction Of UO2(O2CCH3)2 with pentafluorobenzoic acid yields UO2(O2CC6F5)2, which has been converted into the solvated complexes UO2(O2CC6F5)2L2·S [L2 = 2,2′-bipyridyl (bpy), S = 0.33 (PhH) or 0.07 (t-BuOH); L = Ph3PO, S = t-BuOH; L = Ph3AsO, S = 0.40 (t-BuOH)] and the solvent free UO2(O2CC6F5)2L2 [L2 = bpy; L = Ph3PO]. The crystal structure of UO2(O2CC6F5)2bpy (orthorhombic, space group P212121; a = 18.45(2), b = 18.94(2), c = 7.069(8) A, Z = 4] reveals distorted hexagonal bipyramidal stereochemistry with a trans UO2 group, chelating pentafluorobenzoate ligands, and chelating 2,2′-bipyridyl, which is significantly displaced from the hexagonal plane. The structure of UO2(O2CC6F5)2(OPPh3)2·t-BuOH [rhombohedral, space group R3; a = 21.51(3) A, α = 117.28(5)°, Z = 3] shows trans UO2, pseudo trans Ph3PO ligands, and one unidentate and one disordered chelating pentafluorobenzoate ligand, whilst t-BuOH could not be located because it is highly disordered. Relationships between ν (CO2) frequencies and the carboxylate coordination are discussed, and UO2(O2CC6F5)2(OAsPh3)2.0.40 (t-BuOH) is considered to have stereochemistry similar to that of the phosphine oxide complex. The complexes undergo decarboxylation in dimethyl sulphoxide yielding pentafluorobenzene and carbonatodioxouranium(VI) species not UO2(C6F5)2 derivatives.

The complexes M(OR)2(thf)3 (M = Yb or Eu, R = 2,6-But2-4-MeC6H2; M = Yb, R = 2,4,6-But3C6H2 or 2,6-But2C6H3; thf = tetrahydrofuran) and M(NR2)2(thf)4 (M = Yb or Eu, R2N = carbazol-9-yl; M = Yb, R2N = 2-phenylindol-1-yl) have been prepared by reactions of (C6F5)2M (M = Yb or Eu) with substituted phenols, carbazole, or 2-phenylindole.

Reaction of the complexes PtX2(RNHCH2CH2NMe2) (X = Cl or I; R = p- HC6F4 or C6F5) with TIOR′ (R′ = Et or But) co-precipitates TlX and the organoamides [ Pt(RNCH 2 CH 2 N Me2)X]2; these react with L (pyridine (py) or Me2SO) to give [ Pt(NRCH 2 CH 2 N Me2)X(L)] complexes, which, in three cases (R = p-HC6F4 or C6F5, L = Me2SO, X =Cl; Cl; R = p-HC6F4, L = py, X = I), were obtained as the isomer with L trans to the NR group.

The reaction of PtCl2en (en = ethane-1,2-diamine) with TlO2CC6F5 in boiling pyridine unexpectedly yielded a polyfluorophenyl-stabilized ethane-1,2-diaminatoplatinum(II) complex, Pt[N(p-HC6F4)CH2]2(py)2, 1a, the structure of which has been established by X-ray crystallography.

The cyclopentadienyllanthanides, (C5H5)2Yb, (C5H5C5H5)2Yb(dme) (dme = 1,2-dimethoxyethane), and (C5H5)3M(thf) (M = Sm or Nd; thf = tetrahydrofuran) have been obtained from reactions of lanthanide elements with thallous cyclopentadienide, and (C5H5)3Yb has been prepared by oxidation of (C5H5)2Yb with Tl(C5H5).

Reaction of sodium cyclopentadienide with dipyridinium hexachlorocerate(IV) in tetrahydrofuran yields tris(cyclopentadienyl)cerium(III) and not tetrakis(cyclopentadienyl)cerium(IV).

Reaction of mercuric chloride with an excess of uranium metal in tetrahydrofuran (THF) yields UCl 4 (THF) 3 , whilst UI 3 (THF) 4 is obtained from a similar reaction with mercuric iodide. Chlorotris(cyclopentadienyl)uranium(IV) has been obtained by treatment of either (C 5 H 5 ) 2 Hg and mercuric chloride, or mercuric chloride and Tl(C 5 H 5 ) with an excess of uranium in tetrahydrofuran.

The transmetallation reaction between (C 5 H 5 ) 2 Hg and activated samarium metal in tetrahydrofuran (thf)/ether did not give (C 5 H 5 ) 2 Sm(thf) 2 but (C 5 H 5 ) 3 Sm(thf), whilst reduction of the last compound with potassium in thf gave KSm(C 5 H 5 ) 3 , a soluble organosamarium(II) complex.