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Opaque blue crystals of a new mixed valence cerium germanate have been prepared at elevated temperatures (1555 K) under careful thermoanalytical control. Single crystal structure analysis shows three different types of germanate anions [GeO4]4-, [Ge2O7]6- and [Ge3O10]8-, all ger­manium atoms being in tetrahedral coordination. Due to the larger number of oxygens per unit cell (Ce2Ge2O7.2), with all the oxygens unambiguously located by X-ray single crystal structure analysis, this phase differs significantly from the corresponding cerium(III) germanate Ce2Ge2O7, which shows [GeO4]4- and [Ge3O10]8-, but no [Ge2O7]6- ditetrahedral groupings.

[Ru4(μ4-PPh)2(μ2-CO)(CO)10], in which an essentially square planar array of ruthenium atoms is capped by two phenylphosphinidene groups, readily and reversibly adds carbon monoxide to afford the tridecacarbonyl derivative [Ru4(μ3-PPh)2 (CO)13] ; crystal structure determinations on this compound and its arsenic analogue reveal that the CO addition is accompanied by a re arrangement of the cluster framework, and that these compounds can be considered as dirivatives of [Ru3(μ3-XPh)2(CO)9] (X  P or As) in which an Ru(CO)4 unit has been inserted into one of the three RuP or RuAs bonds.

As 2 est donneur de 4 electrons dans [Cp(CO) 2 M] 2 As 2 (M=Mo, W), de 6 electrons dans [Cp(CO) 2 M] 2 As 2 Cr(CO) 5 (M=Mo, W) ou de 8 electrons dans [Cp(CO) 2 M] 2 As 2 [Cr(CO) 5 ] 2 (M=Mo, W). Structures

The chloroarsinidene complexes (CO)5Cr⎓As(Cl)⎓Cr(CO)5 (I) and Cp(CO)2-Mn⎓As(Cl)⎓Mn(CO)2Cp (III) react with R3Al (R ⎓ alkyl, aryl) to give (CO)5Cr⎓As(R)⎓Cr(CO)5 (II) and Cp(CO)2Mn⎓As(R)⎓Mn(CO)2Cp (IV), respectively. The alkylarsinidene complexes obtained in this way for the first time are intensely coloured crystalline compounds, which contain trigonally planar coordinated arsenic(I) as shown by X-ray analysis of i-C4H9As[Cr(CO)5]2 (IIb). Reaction of Na2M2(CO)10 with RAsCl2 (R ⎓ alkyl; M ⎓ Cr, W) is another route to the alkylarsinidene compounds RAs[M(CO)5]2. Similarly AsCl3 and Na2Cr2(CO)10 react to give the chloroarsinidene complex I. The heterometallic arsinidene complex (CO)5Cr⎓As(Cl)⎓Mn(CO)2Cp (VIII) is obtained by thermally induced comproportionation from I and III. Like other chloroarsinidene complexes it reacts with tropolone to give an arsenic(I) chelate (IXa) stabilized by complexation. The structure of IXa has been determined by X-ray methods. In the presence of a base reaction of VIII with water leads to [(CO)5Cr] [Cp(CO)2Mn]AsOAs[Mn(CO)2Cp] [Cr(CO)5] (Xa). Under similar conditions I and III give analogous homometallic derivatives of As2O, an arsenic(I) oxide, not known in the free state. An X-ray analysis of [MeCp(CO)2Mn]2AsOAs[Mn(CO)2CpMe]2 (Xb) shows that in compounds X both arsenic atoms have a trigonal planar configuration. The arsenic atoms in X are thus coordinatively unsaturated and will add Lewis bases to give adducts like [(CO)5Cr]2As(PPh3)OAs(PPh3)[Cr(CO)5]2 (XI).

In (LnM)2X-Hal compounds which contain a trigonally planar coordinated bridging element (X = P, As, Sb) stabilized by two 16-electron LnM fragments the halogen may be substituted by monovalent organometallic groups. In the resulting molecules the bridging X atoms are coordinated to three metal atoms in a trigonal planar fashion. The syntheses and properties of 12 species of this type (I–IX) are described. The reaction of Na2W2(CO)10 with XCl4 (X = Ge, Sn) leads to [(Co)5W]3(μ3-X) compounds containing trigonally planar coordinated Ge (X) and Sn (XI), respectively. The trigonal planar coordination of the Main Group elements X is confirmed by eight X-ray analyses.

Photochemical reaction of thiols RSH or disulfides RSSR with W(CO)6 gives dinuclear complexes [W(CO)4(μ2-SR)2]2 and trinuclear open chain compounds (CO)4(μ2-SR)2W(CO)2(μ2-SR)2W(CO)4. Syntheses and properties, including solid state structures as determined by X-ray methods are described.

The complex [K(18-crown(6))][(PhSbI2)4I] (I) is obtained from the reaction of (CO)5CrPhSbI2 with K/18-crown(6). The central I− of the anion of 1 is coordinated by four PhSbI2 units in a square-planar fashion. The SbI2 parts of these ligands integrate to give an almost planar matrix via unsymmetrical SbISb bridges. The Ph groups of the centrosymmetric anion stick out on either side of this plane. EHT methods show that this unconventional square-planar coordination of I−, partly due to lattice effects, is stabilized by four 2-electron donor ligands.

Komplexe von Halogenphosphanen wie (R)(Hal)2P–MLn (MLn = Cr(CO)5, 1; MnCp(CO)2, 2; Fe(CO)44) oder (R)2(Hal)PMLn (MLn = MnCp(CO)2, 3) zeigen gegenuber lithiumorganischen Reagenzien eine Reihe verschiedenartiger Reaktionen: Die Umsetzung von 2 mit R′Li (R′ = CH3, n-C4H9 fuhrt zu den Substitutionsprodukten 5, (R)(R′)2PMnCp(CO)2. 3 reagiert unter Lithium-Halogen-Austausch mit t-C4H9Li/TMEDA zu [(R)2PMnCp(CO)2]− Li+, 6. Die Salze 6 werden anhand ihrer Reaktionen mit verschiedenen Elektrophilen charakterisiert, die zu 7, (R)2(R′)PMnCp(CO)2 (R′ = H, D, Alkyl, (CH3)3Si, (CH3)3Sn) fuhren. Die Salze 6 sind auch durch Deprotonierung von 7a (R′ = H) mit n-C4H9Li zuganglich. — Die Verbindungen (Aryl)(Hal)2PMnCp(CO)2, 2j–m, reagieren mit t-C4H9Li/TMEDA in Ausbeuten bis 80% zu intensiv farbigen „Phosphiniden”-Komplexen RP[MnCp(CO)2]2, 10. In analoger Reaktion entsteht aus (Ph)(Cl)2AsMnCp(CO)2 der „Arsiniden”-Komplex PhAs[MnCp(CO)2]2 (11) in 90% Ausbeute. Wahrend 11 bereits bekannt war, sind die Verbindungen 10 Beispiele fur bisher kaum beschriebene „Phosphiniden”-Komplexe mit einem RP-Bruckenliganden zwischen zwei 16-Elektronen-Fragmenten MnCp(CO)2. Der Phosphandiyl-Ligand wird durch Metall-dπ-Phosphor-pπ-Wechselwirkung bei trigonal-planarer Koordination stabilisiert. Die ungewohnlichen Bindungsverhaltnisse in 10 spiegeln sich sowohl in den Elektronenspektren als auch in den 31P-NMR-Verschiebungen, die bis zu 896 ppm reichen. Halogen-Metal Exchange in Coordinated Halophosphanes: Synthesis of “Phosphinidene” Complexes Coordination compounds of halophosphanes such as (R)(Hal)2PMLn (MLn = Cr(CO)5, 1; MnCp(CO)2, 2; Fe(CO)4, 4) or (R)2(Hal)PMLn (MLn = MnCp(CO)2, 3) react with R′Li species in various different ways: Reaction of 2 with R′Li (R′ = CH3, n-C4H9) yields the substitution products 5, (R)(R′)2PMnCp(CO)2. 3 reacts with t-C4H9Li/TMEDA to give [(R)2PMnCp-(CO)2]− Li+, 6, by lithium-halide exchange. The salts 6 are characterized by their reactions with various electrophiles leading to compounds 7, (R)2(R′)PMnCp(CO)2 with R′ = H, D, Alkyl, (CH3)3Si, (CH3)3Sn. The salts 6 are also obtained by deprotonation of 7a (R′ = H) with n-C4H9Li. — Compounds (Aryl)(Hal)2PMnCp(CO)2, 2j–m, react with t-C4H9Li/TMEDA to produce deeply coloured “phosphinidene” complexes RP[MnCp(CO)2]2, 10, in yields up to 80%. Analogously, (Ph)(Cl)2AsMnCp(CO)2 gives the “arsinidene” compound PhAs[MnCp(CO)2]2 (11) in 90% yield. Whereas 11 had already been known, the compounds 10 are rare examples of “phosphinidene” complexes containing an RP ligand bridging the two 16-electron fragments MnCp(CO)2. The phosphanediyl ligand is stabilized by metal-dπ-phosphorous-pπ-interactions with the phosphorous atom in a trigonally planar environment. The unconventional bonding situation in 10 is evident from the electron spectra as well as from the 31P NMR shifts, which range up to 896 ppm.

Reactions of primary phosphines RPH2 (R = p-CH3OC6H4, p-BrC6H4) with Ru3(CO)12 yielded clusters of the type [(μ2-H)2Ru3(CO)9(μ3-PR)] and [Ru3-(CO)9(μ3-PR)2]. The reaction of C6H5AsH2 with Ru3(CO)12 gave [(μ2-H)2Ru3-(CO)9(μ3-AsC6H5)] and [Ru2(CO)6(μ2-As(C6H5)H)2]. All the compounds have been studied by IR and NMR (31P and 1H) spectroscopy and the structure of [(μ2-H)2Ru3(CO)9(μ3-P(p-CH3OC6H4))] has been determined by single crystal X-ray diffraction (R = 0.05). The overall molecular geometry is that of a trigonal pyramid with the phosphorus atom at the apex and two of the three basal RuRu bonds bridged by hydrogens. The average RuRu, RuP and RuC distances are 2.903 A, 2.289 A and 1.941 A, respectively.

Preparation des complexes Mn(CO) 2 (CHO)(L) 2 L' avec L=P(OPh) 3 , L'=CO ou L=P(o-Otolyl) 3 , L'=CO ou L=L'=P(OPh) 3

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 411. DOI:10.1002/anie.198204110