Search

The reaction of equimolar amounts of [Co(CO)3(NO)] and [PPN]CN, PPN+ = (PPh3)2N+, in THF at room temperature resulted in ligand substitution of a carbonyl towards the cyanido ligand presumably affording the complex salt PPN[Co(CO)2(NO)(CN)] as a reactive intermediate species which could not be isolated. Applying the synthetic protocol using the nitrosyl carbonyl in excess, the title reaction afforded unexpectedly the novel complex salt PPN[Co2(μ‐CN)(CO)4(NO)2] (1) in high yield. Because of many disorder phenomena in crystals of 1 the corresponding NBu4+ salt of 1 has been prepared and the molecular structure of the dinuclear metal core in NnBu4[Co2(μ‐CN)(CO)4(NO)2] (2) was determined by X‐ray crystal diffraction in a more satisfactory manner. In contrast to the former result, the reaction of [PPN]SCN with [Co(CO)3(NO)] yielded the mononuclear complex salt PPN[Co(CO)2(NO)(SCN‐κN)] (3) in good yield whose molecular structure in the solid was even determined and its composition additionally confirmed by spectroscopic means.

Treatment of THF solutions containing the rhodium(II) complex trans-[RhCl2(P t Bu2Ph)2] (1) with [Fe2(CO)9] in the same solvent resulted in the formation of the Vaska-type complex trans-[RhCl(CO)(P t Bu2Ph)2] (2) in high yield. The title complex 2 was obtained as pale yellow crystals, characterized by NMR and IR spectroscopy, as well as by microanalyses. Additionally, the molecular structure of 2 has been established by X-ray crystallography. As often reported for similar constituted compounds, the chlorido and carbonyl ligands in crystals of 2 are strongly disordered.

Treatment of hydrated ruthenium(III) chloride with tetra-2-pyridyl-1,4-pyrazine (tppz) in refluxing ethoxyethanol afforded the homoleptic dinuclear complex [(tppz)Ru(μ-tppz)Ru(tppz)]4+ (1) besides small amounts of the species [Ru(tppz)2]2+. The title complex 1 was obtained as purple crystals and characterized as its hexafluoridophosphate salt by NMR spectroscopy, mass spectrometry and microanalyses. The molecular structure of 1(PF6)4 has been established by X-ray crystallography.

Reactions of [{M(-Cl)(coe)(2)}(2)] (M = Rh, Ir;coe = cis-cyclooctene) with the secondary phosphane tBu(2)PH under various molar ratios were investigated. Probably, for kinetic reasons, the reaction behavior of the rhodium species differed from that of the iridium analogue in some instances. During these studies complexes [MCl(tBu(2)PH)(3)] [M = Rh (1), Ir (2)] were isolated, and solution variable-temperature P-31{H-1} NMR studies revealed that these complexes show a conformational rigidity on the NMR time scale. Spectra recorded in the temperature range from 173 to 373 K indicated in each case only one rotamer containing three chemically nonequivalent phosphanes due to the restricted rotation of these ligands about the M-P bonds and the tert-butyl substituents around the P-C(tBu) bonds, respectively. Compound 1 showed in solution already at room temperature in several solvents a dissociation of a phosphane ligand affording the known complex [{Rh(-Cl)(tBu(2)PH)(2)}(2)] beside the free phosphane. In contrast to these findings, the iridium analogue 2 remained completely unchanged under similar conditions and exhibited, therefore, some kinetic inertness. For a better understanding of the NMR spectroscopic investigations, the molecular structure of 1 in the solid state was confirmed by X-ray crystallography.

The synthesis and structural characterization of the new olefinic complex [Rh(eta(5)-C5H5)(coe)(2)] (2) (coe = cis-cyclooctene) is reported. The title compound could easily be prepared in good yield by reaction of [{Rh(mu-Cl)(coe)(2)}(2)] (1) with an appropriate amount of thallium cyclopentadienide in THF at room temperature. Single crystals of 2 were grown from n-hexane and were analyzed by X-ray crystallography. In a similar manner the compound [Rh(eta(5)-C5H5)(cod)] (4) (cod = cis, cis-1.5-cyclooctadiene) was obtained from [{Rh(mu-Cl)(cod)}(2)] and thallium cyclopentadienide in THF at room temperature and was characterized by spectroscopic means as well as by X-ray diffraction.

The reaction of [{Ir(μ-Cl)(coe)2}2] (coe=cis-cyclooctene) with triphenylphosphane (molar ratio of Ir to P=1 : 3) in dichloromethane at room temperature afforded after a short reaction time the cyclometallated complex [IrCl(H)(C6H4PPh2)(PPh3)2] (1) in almost quantitative yield. The molecular structure of the title compound 1 was determined by an X-ray diffraction study.

The synthesis and structural characterization of trans-[IrCl(NO)(PtBu2H)(2)]BF4 (1) is reported. The title compound was prepared in good yield in the reaction of in situ-prepared trans-[IrCl(coe)(PtBu2H)(2)] (coe = cis-cyclooctene) with an appropriate amount of nitrosonium tetrafluoridoborate in dichloromethane at room temperature. Single crystals of 1 were grown from dichloromethane/diethyl ether and were analyzed by X-ray crystallography.

The synthesis and structural characterization of trans-[RhCl(NO)(PtBu2H)(2)]BF4 (2) is reported. The title compound could easily be prepared in good yields by a kind of bridge-splitting reaction of [{Rh(-Cl)(PtBu2H)(2)}(2)] (1) with an appropriate amount of nitrosonium tetrafluoridoborate in dichloromethane at room temperature. Single crystals of 2 were grown from dichloromethane/diethyl ether and were analyzed by X-ray crystallography.

The reaction of [Ru3(CO)12] with pivalic acid in acetonitrile afforded the coordinatively unsaturated complex [{Ru2(μ-O2CtBu)2(CO)4}n] (1) for which a so far unknown polymeric structure is assumed. Compound 1 showed in the solid as well as dissolved in non-polar aliphatic solvents and carbon tetrachloride, respectively, a deep violet color. In common organic solvents 1 is readily dissolved resulting in solutions exhibiting a yellow to orange color. On the one hand, in such solutions the polymeric structure of 1 is broken resulting in distinct compounds as the Ru2(μ-O2CtBu)2(CO)4 units coordinate two monodentate solvent molecules, as shown for [Ru2(μ-O2CtBu)2(CO)4(py)2] (3, py = pyridine), or they coordinate ligands like phosphanes, as shown for [Ru2(μ-O2CtBu)2(CO)4(PtBu2H)2] (4). On the other hand, in solutions of 1 the Ru2 frameworks are linked by coordination of multidentate solvent molecules resulting in a coordination polymer which was confirmed by the crystal structure determination of [{Ru2(μ-O2CtBu)2(CO)4(HOC2H4OEt)}n] (2).

Reactions of coordinatively unsaturated complexes [Ru2(μ-PtBu2)(μ-H)(μ-PˆP)(CO)4] (PˆP = bisphosphanes, N,N-substituted bis(diphenylphosphanyl)amines) with the nitrosylating reagent diazald (N-methyl-N-nitroso-p-toluenesulfonamide) were investigated. Thus a convenient synthesis affording a series of new diruthenium complexes containing bridging nitrosyl ligands of the general type [Ru2(μ-PtBu2)(μ-NO)(μ-PˆP)(CO)4] was developed and the crystal and molecular structures of five new compounds were determined. Contrary, this reaction principle does not work for the closely related complex [Fe2(μ-PtBu2)(μ-H)(μ-dppm)(CO)4] (dppm = Ph2PCH2PPh2). In this case carbon monoxide was produced in side reactions and the known compound [Fe2(μ-PtBu2)(μ-H)(μ-dppm)(μ-CO)(CO)4] was obtained as the main product. The molecular structure of the latter complex was also determined by X-ray diffraction.

The addition reaction of a proton towards the nitrosyl-bridged diruthenium complexes [Ru 2 (CO) 4 (μ-NO)(μ-P t Bu 2 )(μ-P^P)] (P^P = Me 2 PCH 2 PMe 2 , dmpm, 1b ; P^P = Ph 2 PC(=CH 2 )PPh 2 , dppen, 1c ; P^P = Ph 2 PN(H)PPh 2 , dppa, 1d ) has been investigated. The species 1b–d exhibit an enhanced metal basicity and react spontaneously with a proton (from HBF 4 ) in diethyl ether to afford the corresponding oxidative addition products [Ru 2 (CO) 4 (μ-NO)(μ-H)(μ-P t Bu 2 )(μ-P^P)]BF 4 ( 2b–d ) in good yields. The molecular structures of 2b – d were confirmed by X-ray diffraction studies revealing a shortening of the metal–metal bond upon protonation in each case.

A convenient synthesis of cyclometalated complexes [{Rh(μ-Cl)(C N)2}2] [C N = ppy, 2-phenylpyridinato (2); C N = ptpy, 2-(p-tolyl)pyridinato (3); 4-Clppy = 4-chloro-2-phenylpyridinato (4)] at room temperature is described. The compounds were obtained by the oxidative addition reaction of the corresponding 2-phenylpyridines to [{Rh(μ-Cl)(coe)2}2] (1) (coe = cis-cyclooctene) in dichloromethane solution. The rate of the reaction seems to depend on the electronic influence of the substituents on the phenyl rings of the corresponding 2-phenylpyridines. The analogous iridium complex of 1 reacted markedly only at higher temperatures in suitable solvents under cyclometalation. The molecular structure of the new compound 4 was additionally confirmed by an X-ray diffraction study.

The synthesis, crystal structure, and photophysical properties of the novel bis-cyclometalated complex Λ,Δ-[Ir2(μ-biuretato-N,N′:O,O′)(ptpy)4] (2), with ptpy = 2-(p-tolyl)pyridinato, prepared in the reaction of [{Ir(μ-Cl)(ptpy)2}2] (1) with biuret under basic conditions, were investigated. This new compound displays intense green phosphorescence, e.g. with λem = 518 nm, ɸPL = 55%, and τ = 1.5 μs in poly(methyl methacrylate) at 300 K, assigned to a 3MLCT/LC excited state.

The addition reaction of a proton towards the coordinatively unsaturated diruthenium complexes [Ru 2 (CO) 4 (μ-H)(μ-P t Bu 2 )(μ-P^P)] (Ru Ru) (P^P = Ph 2 PC( CH 2 )PPh 2 , dppen, 1b ; P^P = Ph 2 PN(H)PPh 2 , dppa, 1c ; P^P = Ph 2 PN(Ph)PPh 2 , dpppha, 1d ) has been investigated. Thus the species 1b–d exhibit a high metal basicity and react with protons from tetrafluoroboric acid in dichloromethane to afford the corresponding oxidative addition products [Ru 2 (CO) 4 (μ-H) 2 (μ-P t Bu 2 )(μ-P^P)]BF 4 ( 2b–d ) in good yields. During these reactions a shortening of the metal–metal bond in each case was observed as confirmed by X-ray diffraction studies.

The synthesis of the bis-cyclometalated complexes [M(ptpy)2(S2COCH3)] (M = Rh, 1; M = Ir, 2; ptpy = 2-(p-tolyl)pyridinato) from [{M(μ-Cl)(ptpy)2}2], carbon disulfide and sodium methanolate as the base are described. Compound 1 and 2, respectively, were crystallized from dichloromethane/methanol and the molecular structures of both complexes were confirmed by single-crystal X-ray diffraction studies (both monoclinic, P21/c). The emission spectrum of 1 exhibited the new compound as a red-emitting complex.

The synthesis and the characterization of the complex salt [Au(tBu2PH)2][HCl2] (2) resulting from the reaction of hydrogen tetrachloridoaurate(III) hydrate with tBu2PH in dichloromethane at room temperature is reported. Single crystals of 2 have been analyzed by X-ray crystallography: monoclinic, P21=c, Z = 12, a = 12:0805(3), b = 12:3729(4), c = 46:7506(13) Å ; ß = 90:948(2)°; V = 6986:9(3) Å3; T = 173(2) K. The hydrogen bihalide anions [HCl2]- fill the interstices between the large complex cations [Au(tBu2PH)2]+ in the crystal.

The reaction of the electronically and coordinatively unsaturated compounds [Ru 2 (CO) 4 ( μ -H)( μ -PBu t 2 )( μ -L 2 )] ( 1 ) (Ru Ru) with nitric oxide afforded four new trans -hyponitrito complexes of the general formula [Ru 2 (CO) 4 ( μ -H)( μ -PBu t 2 )( μ -L 2 )( μ - η 2 -ONNO)] ( 2 ) in good yields. Thus the complexes 2a – e were obtained using the following bridging biphosphane ligands ( μ -L 2 ): dppm ( 2a , dppm = Ph 2 PCH 2 PPh 2 ), dppen ( 2b , dppen = Ph 2 PC( CH 2 )PPh 2 ), dpppha ( 2c , dpppha = Ph 2 PN(Ph)PPh 2 ), dpppra ( 2d , dpppra = Ph 2 PN(Pr n )PPh 2 ), and dppbza ( 2e , dppbza = Ph 2 PN(CH 2 Ph)PPh 2 ). The molecular structures of the complexes 2a – e were determined by X-ray diffraction. Furthermore the molecular structure of the known compound 2a was reinvestigated in light of a better refinement of the short intramolecular contact between the hyponitrite O atom in close vicinity to the C atom of a neighbouring carbonyl group. This unusual effect in crystals of all compounds 2a – e can be interpreted as a nucleophilic intramolecular attack of a hyponitrito ligand towards an electrophilic carbon center of a carbonyl ligand.

The synthesis of the trans-hyponitrite compounds Ph3E(μ-ONNO)EPh3 [E = Ge (1), Pb (2)] as well as their crystal and molecular structure are reported. Compound 1 crystallized from toluene/pentane in the trigonal space group R with a = 29.7969(18), b = 29.7969(18), c = 11.8465(6) A; γ = 120°; V = 9108.8(9) A3; Z = 12, ρ = 1.461 g·cm–3,T = 173(2) K. Compound 2 crystallized from toluene/iso-hexane in the triclinic space group P with a = 10.0330(2), b = 11.0615(2), c = 24.2080(4) A; α = 97.3730(10), β = 95.8550(10), γ = 115.3940(10)°; V = 2369.69(7) A3; Z = 3, ρ = 1.970 g·cm–3, T = 173(2) K.The crystal structure determination revealed that two conformational isomers exist in the row of related group 14 element compounds. Whereas the species of tin and lead exhibit a S-shaped arrangement of the hyponitrite group between the two EPh3 fragments, the corresponding germanium compound shows instead of a N-shape within the hyponitrite group. DFT calculations revealed that S-shaped conformers should be in all three cases the more stable ones. This stands in contrast to the observed N conformation of 1 in the crystal.

A convenient synthesis and the characterization of six new electronically and coordinatively unsaturated complexes of the formula [Ru2(CO)4(μ-H)(μ-PtBu2)(μ-L2)] (2b–g) (Ru Ru) is described exhibiting a close relation to the known [Ru2(CO)4(μ-H)(μ-PtBu2)(μ-dppm)] (2a). The complexes 2b–g were obtained in a kind of one-pot synthesis starting from [Ru3(CO)12] and PtBu2H in the first step followed by the reaction with the bidentate bridging ligand in the second step. The method was developed for the following bridging ligands (μ-L2): dmpm (2b, dmpm = Me2PCH2PMe2), dcypm (2c, dcypm = Cy2PCH2PCy2), dppen (2d, dppen = Ph2PC(=CH2)PPh2), dpppha (2e, dpppha = Ph2PN(Ph)PPh2), dpppra (2f, dpppra = Ph2PN(Pr)PPh2), and dppbza (2g, dppbza = Ph2PN(CH2Ph)PPh2). The molecular structures of all new complexes 2b−g were determined by X-ray diffraction.

The reaction of the coordinatively unsaturated complex [Ru2(CO)4(μ-H)(μ-PtBu2)(μ-dppm)] (1, dppm = Ph2PCH2PPh2)] with the nitrosonium ion was revisited. Even by variation of the reaction conditions, the reaction afforded in each case not the sole addition product [Ru2(CO)4(μ-NO)(μ-H)(μ-PtBu2)(μ-dppm)]+ (2) as reported by us in an earlier paper. Instead always a mixture of three compounds containing the complexes [Ru2(CO)4(μ-H)2(μ-PtBu2)(μ-dppm)]+ (3), [Ru2(CO)4(μ-NO)(μ-PtBu2)(μ-dppm)] (4), beside the originally described complex 2 was obtained. A new synthetic procedure affording compound 4 as the sole product by reaction of 1 with the nitrosylating reagent diazald (N-methyl-N-nitroso-p-toluenesulfonamide) is described. It was found that complex 2 can act as an acid strong enough to protonate the starting complex 1. Thus, the formation of the mixture of components in the title reaction could be explained. A mixing experiment of equimolar amounts of 1 and 2 showed unambiguously the formation of complexes 3 and 4. A clean preparation of complex 2 as the sole product in form of its tetrafluoridoborate salt is only possible by reaction of 4 with tetrafluoridoboric acid in diethyl ether solution. The X-ray crystal structure of [2]BF4 is reported confirming the molecular structure of the complex 2. Using the originally described preparation route for 2 afforded in each attempt of crystallization the complexes 2 and 3 as 1:1 mixture in the solid.

The reaction of [AuCl(tht)] (tht = tetrahydrothiophene) with an equimolar amount of the electron-rich ligand N-diphenylphosphino-triphenylphosphinimine, Ph3PNPPh2, in THF afforded the new complex [AuCl(Ph3PNPPh2)] (1) in good yield. Furthermore, the reaction of [AuHCl4] with Ph3PNPPh2 in a molar ratio of 1:3 in dichloromethane at room temperature yielded the complex salt [Au(Ph3PNPPh2)2]Cl (2) as the dichloromethane solvate beside Ph3PNPPh2Cl2 as the side-product of oxidation. The molecular structures of metal complexes 1 and 2 were determined by single-crystal X-ray diffraction. Because of the bulkiness of the ligand Ph3PNPPh2 no short intermolecular gold–gold interactions (aurophilic aggregation) could be observed in the solid-state structures.

A new convenient synthesis and the crystallographic characterization of [Ir(acac)(coe)2] (2, acac = acetylacetonato; coe = cis-cyclooctene) are described. The title compound crystallized from THF/ethanol in two modifications (monoclinic P21/c, 2a, and triclinic P 1 ¯ , 2b). Complex 2 represents an efficient starting material in the synthesis of mononuclear iridium(III) complexes containing cyclometalated 2-phenylpyridinato ligands using oxidative addition reactions of the corresponding ligands towards 2. Thus [Ir(acac)(ppy)2] (3, ppy = 2-phenylpyridinato) and [Ir(ppy)3] (4) (mer, 4a; fac, 4b) were prepared in excellent yields and short reaction times in a kind of one-pot procedure starting from [{Ir(μ-Cl)(coe)2}2] (1). Furthermore a convenient synthesis of [{Ir(μ-Cl)(ppy)2}2] (5) from 1 and Hppy is described.

The reaction of hydrated rhodium(III) chloride with formic acid in refluxing ethoxyethanol afforded in a convenient way the known rhodium carbonyl chlorido complex anion cis-[RhCl2(CO)2]-. This species was formed in good yield and was characterized as its PPN salt (PPN+ = bis(triphenylphosphane)iminium cation). The molecular structure of the title compound PPN[RhCl2(CO)2] was confirmed by X-ray diffraction and shown to be isomorphous to PPN[IrCl2(CO)2]

The reaction of [{Rh(μ-Cl)(coe)2}2] (coe = cis-cyclooctene) with tBu2PH in different solvents in various molar ratios was investigated. Working with a molar ratio of Rh to P = 1 : 2 in heptane overnight afforded [{Rh(μ-Cl)(tBu2PH)2}2] (1) in nearly quantitative yield. Upon tuning the molar ratio (Rh/P) in the range from 1 : 2 to 1 : 0.5, 31P{1H} NMR spectroscopy indicated the formation of [(tBu2PH)2Rh(μ-Cl)2Rh(coe)2] (3) besides the complexes [{Rh(μ-Cl)(coe)(tBu2PH)}2] (cis, 2a; trans, 2b). The constitution of 3 was established by an independent synthesis mixing 1 with [{Rh(μ- Cl)(coe)2}2] or [{Rh(μ-Cl)(cod)}2] (cod = 1.4-cyclooctadiene), respectively, which also yielded [(tBu2PH)2Rh(μ-Cl)2Rh(cod)] (4). Single crystals of 1 have been analyzed by X-ray crystallography (monoclinic, Cc, Z = 8, a = 32.7375(3), b = 11.1294(1), c = 24.5134(3)Å ; β = 106.7228(4)◦; V = 8553.70(15) Å3; T = 200 (2) K).

The reactions of [{M(μ-Cl)(η4-cod)}2] (M = Rh, 1a; M = Ir, 1b; cod = 1,5-cyclooctadiene) and [Rh(acac)(olefin)2] (acac = acetylacetonate; olefin = ethene, 3a; olefin = cis-cyclooctene = coe, 3b) with tBu2PH in dichloromethane at room temperature were investigated, and the compounds [MCl(tBu2PH)(η4-cod)] (M = Rh, 2a; M = Ir, 2b) as well as [Rh(acac)(tBu2PH)2] (4) were obtained in good yields. Furthermore, a one-pot synthesis of trans-[IrCl(C2H4)(tBu2PH)2] (6b) starting from [{Ir(μ-Cl)(coe)2}2] (5), ethene and tBu2PH is described. All novel complexes were characterized using spectroscopic methods and the molecular structures of 2b, 6b, and trans-[RhCl(C2H4)(tBu2PH)2] (6a) determined using X-ray crystallography.

The reaction of [{Ir(μ-Cl)(coe)2}2] (1) (coe = cis-cyclooctene) with the secondary phosphane tBu2PH afforded, under defined conditions, the novel complex trans-[IrCl(coe)(tBu2PH)2] (2), which has been characterized by spectroscopic methods as well as by X-ray diffraction. Compound 2 represents the first isolated and structurally characterized type of complex trans-[IrCl(coe)L2] (L = phosphane). The compound is presumably isolable because of the convenient electronic effects of the chosen phosphane ligands.

A convenient synthesis of trans - [ Rh ( NO ) ( NO 2 ) 2 ( Bu 2 t PH ) 2 ] (1) from rhodium(III) chloride trihydrate, sodium nitrite, and Bu 2 t PH in ethanolic solution is described. The crystal and molecular structure of 1 was determined by a single-crystal X-ray diffraction study.

[Fe2(CO)4(μ-H)(μ-PtBu2)(μ-dppm)] (1a) reacts with elemental sulfur to give [Fe2(CO)4(μ-H)(μ-S)(μ-PtBu2)(μ-dppm)] (2a) (dppm=Ph2PCH2PPh2). The reaction of 1a with CCl4 or CHCl3 affords spontaneously in nearly quantitative yield [Fe2(CO)4(μ-Cl)(μ-PtBu2)(μ-dppm)] (3a). [Ru2(CO)4(μ-H)(μ-PtBu2)(μ-dppm)] (1b) reacts with SO2 in THF under normal conditions to [Ru2(CO)4(μ-H)(μ-SO2)(μ-PtBu2)(μ-dppm)] (5b). 5b is also formed by oxidation of the sulfido ligand in [Ru2(CO)4(μ-H)(μ-S)(μ-PtBu2)(μ-dppm)] (2b) by means of 3-chloroperoxybenzoic acid or H2O2 as oxidizing reagent. As the primary oxidation products of 2a or 2b the sulfur monoxide complexes [M2(CO)4(μ-H)(μ-SO)(μ-PtBu2)(μ-dppm)] (MFe, 4a; MRu, 4b) are obtained by using 3-phenyl-2-(phenylsulfonyl)-oxaziridine as oxidizing reagent. The molecular structures of 4a and 5b were confirmed by crystal structure analyses.

Na[Fe2(μ-CO)(CO)6(μ-PtBu2)] (1) reagiert mit [NO][BF4] bei —60 °C in THF zum Nitrosylkomplex [Fe2(CO)6(NO)(μ-PtBu2)] (2). Die nachfolgende Umsetzung von 2 mit Phosphanen (L) ergibt unter milden Bedingungen in guten Ausbeuten die Komplexe [Fe2(CO)5(NO)L(μ-PtBu2)], L = PPh3, (3a); η-dppm (dppm = Ph2PCH2PPh2), (3b). Durch die Kristallstrukturanalyse von 3a wurde bestatigt, dass dabei in 2 ein Carbonylligand am Eisentetracarbonylfragment durch das Phosphan substituiert wird. In Losung spaltet 3b sehr leicht einen CO-Liganden ab und dppm koordiniert schlieslich als Bruckenligand uber der Fe-Fe-Bindung. Die so gebildete Verbindung [Fe2(CO)4(NO)(μ-PtBu2)(μ-dppm)] (4) liegt in verschiedenen Losungsmitteln in einem grosen Temperaturbereich stets als Mischung der Koordinationsisomere [Fe2(μsb-CO)(CO)3(NO)(μ-PtBu2)(μ-dppm)] (4a) und [Fe2(CO)4(μ-NO)(μ-PtBu2)(μ-dppm)] (4b) vor. 4a konnte eindeutig durch Rontgenkristallstrukturanalyse charakterisiert werden, wahrend 4b durch NMR-Untersuchungen in Losung und in Kombination mit quantenchemischen DFT-Berechnungen bestatigt wurde. Des weiteren liefert die spontane Reaktion von [Fe2(CO)4(μ-H)(μ-PtBu2)(μ-dppm)] (5) mit NO bei —60 °C in Toluen ein komplexes Produktgemisch, das neben [Fe2(μ-CO)(CO)4(μ-H)(μ-PtBu2)(μ-dppm)] (6) als Hauptprodukt die Komplexe 4a und 4b nur in sehr geringer Ausbeute enthalt. [Fe2(μsb-CO)(CO)3(NO)(μ-PtBu2)(μ-Ph2PCH2PPh2)]: Synthesis, X-ray Crystal Structure and Isomerization Na[Fe2(μ-CO)(CO)6(μ-PtBu2)] (1) reacts with [NO][BF4] at —60 °C in THF to the nitrosyl complex [Fe2(CO)6(NO)(μ-PtBu2)] (2). The subsequent reaction of 2 with phosphanes (L) under mild conditions affords the complexes [Fe2(CO)5(NO)L(μ-PtBu2)], L = PPh3, (3a); η-dppm (dppm = Ph2PCH2PPh2), (3b). In this case the phosphane substitutes one carbonyl ligand at the iron tetracarbonyl fragment in 2, which was confirmed by the X-ray crystal structure analysis of 3a. In solution 3b loses one CO ligand very easily to give dppm as bridging ligand on the Fe-Fe bond. The thus formed compound [Fe2(CO)4(NO)(μ-PtBu2)(μ-dppm)] (4) occurs in solution in different solvents and over a wide temperature range as a mixture of the two isomers [Fe2(μsb-CO)(CO)3(NO)(μ-PtBu2)(μ-dppm)] (4a) and [Fe2(CO)4(μ-NO)(μ-PtBu2)(μ-dppm)] (4b). 4a was unambiguously characterized by single-crystal X-ray structure analysis while 4b was confirmed both by NMR investigations in solution as well as by means of DFT calculations. Furthermore, the spontaneous reaction of [Fe2(CO)4(μ-H)(μ-PtBu2)(μ-dppm)] (5) with NO at —60 °C in toluene yields a complicated mixture of products containing [Fe2(μ-CO)(CO)4(μ-H)(μ-PtBu2)(μ-dppm)] (6) as main product beside the isomers 4a and 4b occuring in very low yields.

The reaction of hydrated iridium chloride with formic acid in refluxing ethoxyethanol afforded by an efficient way the known iridium carbonyl chlorido complex cis-[IrCl2(CO)2]–. The latter species was isolated and characterized as its corresponding PPN salt (PPN+ = bis(triphenylphosphane)iminium cation). The molecular structure of PPN[IrCl2(CO)2] (1) was confirmed by X-ray diffraction.

A convenient synthesis of the cyclometalated complex [{Rh(μ-Cl)(ptpy)2}2] (2, ptpy = 2-(p-tolyl)pyridinato) is described. Compound 2 was obtained by oxidative addition of Hptpy towards [{Rh(μ-Cl)(coe)2}2] 1 (coe = cis-cyclooctene) in refluxing toluene in good yield. The complex 2 crystallized from chloroform/iso-hexane in the space group P21/n as solvate 2*2 CHCl3 and its molecular structure was confirmed by a single-crystal X-ray diffraction study. The emission spectrum exhibits the new compound as green-emitting phosphorescent complex.

New convenient syntheses of the cyclometalated complexes [Rh(acac)(ptpy)2] (3, ptpy = 2-(p-tolyl)pyridinato) and fac-[Rh(ptpy)3] (4) are described. The compounds were prepared in a kind of one-pot synthesis starting from in situ prepared [Rh(acac)(coe)2] (2) (coe = cis-cyclooctene) followed by reaction with Hptpy in refluxing toluene. Under these conditions oxidative addition occurred and the new complex 3 was obtained in good yields. Compound 4 was prepared in good yields by reaction of 3 with Hptpy in excess. The complex 3 crystallized from dichloromethane/iso-hexane in the space group P − 1 and its molecular structure was confirmed by a single-crystal X-ray diffraction study. The absorption and emission spectra exhibit the new compounds as red-emitting phosphorescent complexes.

[Ru3(CO)6(μ-H)2(μ-PCy2)2(μ-dppm)] (1) (dppm = Ph2PCH2PPh2) reagiert unter milden Bedingungen mit CS2 und ergibt unter oxidativer Decarbonylierung und CS-Insertion in einen Phosphanidoliganden den an einer M–M-Kante geoffneten 50 VE-Cluster [Ru3(CO)5(μ-H)2(μ-PCy2)(μ-dppm){μ-η2-PCy2C(S)}(μ3-S)] (2). Die Verbindung 2 kristallisiert in der triklinen Raumgruppe P 1 mit a = 19.093(3), b = 12.2883(12), c = 20.098(3) A; α = 84.65(3), β = 77.21(3), γ = 81.87(3)° und V = 2790.7(11) A3. Die Reaktion von [Ru3(CO)7(μ-H)(μ-PtBu2)(μ-PCy2)2] (3) mit CS2 in siedendem Toluol liefert den 50 VE-Cluster [Ru3(CO)5(CS)(μ-H)(μ-PtBu2)(μ-PCy2)2(μ3-S)] (4). Die Verbindung kristallisiert in der monoklinen Raumgruppe P 21/a mit a = 19.093(3), b = 12.2883(12), c = 20.098(3) A; β = 104.223(16)° und V = 4570.9(10) A3. Obwohl in der Festkorperstruktur eine aufgeweitete Ru–Ru-Bindung gefunden wurde, kann der Komplex 4 anhand der 31P-NMR-Daten als ein elektronenreicher Metallcluster angesehen werden. Activation of Carbon Disulfide on Triruthenium Clusters: Synthesis and X-Ray Crystal Structure Analysis of [Ru3(CO)5(μ-H)2(μ-PCy2)(μ-Ph2PCH2PPh2){μ-η2-PCy2C(S)}(μ3-S)] and [Ru3(CO)5(CS)(μ-H)(μ-PtBu2)(μ-PCy2)2(μ3-S)] [Ru3(CO)6(μ-H)2(μ-PCy2)2(μ-dppm)] (1) (dppm = Ph2PCH2PPh2) reacts under mild conditions with CS2 and yields by oxidative decarbonylation and insertion of CS into one phosphido bridge the opened 50 VE-cluster [Ru3(CO)5(μ-H)2(μ-PCy2)(μ-dppm){μ-η2-PCy2C(S)}(μ3-S)] (2) with only two M–M bonds. The compound 2 crystallizes in the triclinic space group P 1 with a = 19.093(3), b = 12.2883(12), c = 20.098(3) A; α = 84.65(3), β = 77.21(3), γ = 81.87(3)° and V = 2790.7(11) A3. The reaction of [Ru3(CO)7(μ-H)(μ-PtBu2)(μ-PCy2)2] (3) with CS2 in refluxing toluene affords the 50 VE-cluster [Ru3(CO)5(CS)(μ-H)(μ-PtBu2)(μ-PCy2)2(μ3-S)] (4). The compound cristallizes in the monoclinic space group P 21/a with a = 19.093(3), b = 12.2883(12), c = 20.098(3) A; β = 104.223(16)° and V = 4570.9(10) A3. Although in the solid state structure one elongated Ru–Ru bond has been found the complex 4 can be considered by means of the 31P-NMR data as an electron-rich metal cluster.

Addition of tetrafluoroboric acid to the coordinatively unsaturated species [M 2 (CO) 4 (μ-H)(μ-P t Bu 2 )(μ-dppm)] ( M  M ) (M=Fe, 1 ; M=Ru, 2 ; dppm=Ph 2 PCH 2 PPh 2 ) in diethylether results in rapid protonation of the dimetal vector to give the corresponding complex salts [M 2 (CO) 4 (μ-H) 2 (μ-P t Bu 2 )(μ-dppm)][BF 4 ] ( 1a and 2a ) in nearly quantitative yield. In the same manner [Ru 2 (CO) 4 (μ-Cl)(μ-P t Bu 2 )(μ-dppm)] ( 3 ) is protonated to yield [Ru 2 (CO) 4 (μ-H)(μ-Cl)(μ-P t Bu 2 )(μ-dppm)][BF 4 ] ( 3a ). In order to show the acid–base character of these reactions 1a , 2a , 3a and [Ru 2 (CO) 4 (μ-H)(μ-NO)(μ-P t Bu 2 )(μ-dppm)][BF 4 ] ( 4a ) were deprotonated by the base 1,8-diazabicyclo[5.4.0]undec-7-ene DBU to regenerate 1 , 2 , 3 and the novel complex [Ru 2 (CO) 4 (μ-NO)(μ-P t Bu 2 )(μ-dppm)] ( 4 ), respectively. The molecular structures of 1a , 2a , 3a and 4 have been established by single-crystal X-ray structure analysis. Upon protonation in each case the metal–metal distance is reduced.

The reaction of [Ru3(CO)12] with [Ir(But 2PH)3Cl] (1) in refluxing toluene leads to [Ru3Ir(CO)8(μ3-H)(μ-Cl)2(μ-PBut 2)2(But 2PH)] (4). The molecular structure in the solid reveals 4 as species containing a butterfly metal framework, Electron counting exhibits 4 with 64 cluster valence electrons as an electron-rich cluster. The reaction of [{Cu(But 2PH)Cl}4] (5) with [Ru3(CO)12] in refluxing toluene yields as main product the electron-rich 50e-cluster [Ru3(CO)6(μ-Cl)3(μ-PBut 2)(But 2PH)] (6). Furthermore, thermolysis of [Ru3(CO)12] with Cy2PH in toluene leads to [Ru3(CO)7(μ-H)(μ-PCy2)3] (7). 7 reacts with carbon monoxide under pressure yielding the 52e-complex [Ru3(CO)9(μ-H)(μ-PCy2)3] (8). The preliminary X-ray crystal structure investigation reveals 8 as species with three metal-metal bonds and therefore as an electron-rich cluster.

The new trans-hyponitrite derivative complex [Ru2(CO)4(μ-PtBu2)(μ-dppm)(μ-η2-ONNOMe)] (2, dppm = Ph2PCH2PPh2) was prepared by deprotonation of [Ru2(CO)4(μ-H)(μ-PtBu2)(μ-dppm)(μ-η2-ONNOMe)][BF4] (1) with the base DBU (1.8-diazabicyclo[5.4.0]undec-7-ene). The latter complex salt has been obtained in an improved synthesis starting from the trans-hyponitrite complex [Ru2(CO)4(μ-H)(μ-PtBu2)(μ-dppm)(μ-η2-ONNO)]. Compound 2 has been characterized by spectroscopic methods as well as by X-ray diffraction and represents the first neutral complex bearing a deprotonated monoester of the hyponitrous acid as the bridging ligand.

The cluster [Ru3Ir(CO)8(μ3-H)(μ-Cl)2(μ-PtBu2)2(tBu2PH)] (3) has been isolated from the reaction of [Ru3(CO)12] with [Ir(tBu2PH)3Cl] in refluxing toluene. The analogous reaction of [Ru3(CO)12] with [Au(tBu2PH)Cl] in refluxing THF gave [Ru3Au(CO)10(μ-Cl)(tBu2PH)] (4) in good yield. The single-crystal X-ray structure analyses reveal both clusters to contain a Ru3M butterfly skeleton. With respect to the EAN electron count of 62e, 3 can be considered as electron-rich (64e), while 4 is electron-poor (60e).

[Ru2(CO)4(μ-H)(μ-PtBu2)(μ-dppm)] (1) reagiert mit verschiedenen Phosphanen (L) in siedendem Toluol unter Substitution eines Carbonylliganden und liefert die Verbindungen [Ru2(CO)3L(μ-H)(μ-PtBu2)(μ-dppm)] (L = PnBu3, 2 a; L = PCy2H, 2 b; L = dppm-P, 2 c; dppm = Ph2PCH2PPh2). Die Reaktivitat von 1 sowie der aktivierten Komplexe 2 a–c gegenuber Phenylethin wurde untersucht. So reagieren 1 bzw. 2 a und 2 b mit PhC≡CH in siedendem Toluol unter Eliminierung von Wasserstoff zu den acetylidverbruckten Komplexen [Ru2(CO)4(μ-η1 : η2-C≡CPh)(μ-PtBu2)(μ-dppm)] (3) bzw. [Ru2(CO)3L(μ-η1 : η2-C≡CPh)(μ-PtBu2)(μ-dppm)] (4 a und 4 b). Die Molekulstrukturen von 3 und 4 a wurden durch Kristallstrukturanalysen bestimmt. Coordinatively Unsaturated Diruthenium Complexes: Synthesis and X-ray Crystal Structures of [Ru2(CO)3L(μ-η1 : η2-C≡CPh)(μ-PtBu2)(μ-Ph2PCH2PPh2)] (L = CO, PnBu3) [Ru2(CO)4(μ-H)(μ-PtBu2)(μ-dppm)] (1) reacts with several phosphines (L) in refluxing toluene under substitution of one carbonyl ligand and yields the compounds [Ru2(CO)3L(μ-H)(μ-PtBu2)(μ-dppm)] (L = PnBu3, 2 a; L = PCy2H, 2 b; L = dppm-P, 2 c; dppm = Ph2PCH2PPh2). The reactivity of 1 as well as the activated complexes 2 a–c towards phenylethyne was studied. Thus 1, 2 a and 2 b, respectively, react with PhC≡CH in refluxing toluene with elimination of dihydrogen to the acetylide-bridged complexes [Ru2(CO)4(μ-η1 : η2-C≡CPh)(μ-PtBu2)(μ-dppm)] (3) and [Ru2(CO)3L(μ-η1 : η2-C≡CPh)(μ-PtBu2)(μ-dppm)] (4 a and 4 b). The molecular structures of 3 and 4 a were determined by crystal structure analyses.

[Fe2(μ-CO)(CO)6(μ-H)(μ-PtBu2)] (1) reagiert spontan mit dppm (dppm = Ph2PCH2PPh2) unter Bildung von [Fe2(μ-CO)(CO)4(μ-H)(μ-PtBu2)(μ-dppm)] (2 c). 2 c spaltet thermolytisch oder durch Fotobestrahlung sehr leicht einen Carbonylliganden ab und ergibt den korrespondierenden elektronisch und koordinativ ungesattigten Komplex [Fe2(CO)4(μ-H)(μ-PtBu2)(μ-dppm)] (3). 3 weist eine Fe–Fe-Doppelbindung auf, die durch Addition von Methylen zum entsprechenden Dimetallacyclopropan [Fe2(CO)4(μ-CH2)(μ-H)(μ-PtBu2)(μ-dppm)] (4) nachgewiesen werden konnte. Die Reaktion von 1 mit dppe (Ph2PC2H4PPh2) liefert [Fe2(μ-CO)(CO)4(μ-H)(μ-PtBu2)(μ-dppe)] (5). Im Gegensatz zur Thermolyse von 2 c, die 3 ergibt, verlauft das Erhitzen von 5 in Toluol rasch unter kompletter Zersetzung. Die Reaktion von 1 mit PPh3 liefert den Komplex [Fe2(CO)6(H)(μ-PtBu2)(PPh3)] (6 a), wahrend mit tBu2PH die Verbindung [Fe2(μ-CO)(CO)5(μ-H)(μ-PtBu2)(tBu2PH)] (6 b) gebildet wird. Die Thermolyse von 6 b ergibt [Fe2(CO)5(μ-PtBu2)2] sowie die Abbauprodukte [Fe(CO)3(tBu2PH)2] und [Fe(CO)4(tBu2PH)]. Die Molekulstrukturen von 3, 4 und 6 b wurden durch Rontgenkristallstrukturanalysen bestimmt. Coordinatively Unsaturated Diiron Complexes: Synthesis and Crystal Structures of [Fe2(CO)4(μ-H)(μ-PtBu2)(μ-Ph2PCH2PPh2)] and [Fe2(CO)4(μ-CH2)(μ-H)(μ-PtBu2)(μ-Ph2PCH2PPh2)] [Fe2(μ-CO)(CO)6(μ-H)(μ-PtBu2)] (1) reacts spontaneously with dppm (dppm = Ph2PCH2PPh2) to give [Fe2(μ-CO)(CO)4(μ-H)(μ-PtBu2)(μ-dppm)] (2 c). By thermolysis or photolysis, 2 c loses very easily one carbonyl ligand and yields the corresponding electronically and coordinatively unsaturated complex [Fe2(CO)4(μ-H)(μ-PtBu2)(μ-dppm)] (3). 3 exhibits a Fe–Fe double bond which could be confirmed by the addition of methylene to the corresponding dimetallacyclopropane [Fe2(CO)4(μ-CH2)(μ-H)(μ-PtBu2)(μ-dppm)] (4). The reaction of 1 with dppe (Ph2PC2H4PPh2) affords [Fe2(μ-CO)(CO)4(μ-H)(μ-PtBu2)(μ-dppe)] (5). In contrast to the thermolysis of 2 c, yielding 3, the heating of 5 in toluene leads rapidly to complete decomposition. The reaction of 1 with PPh3 yields [Fe2(CO)6(H)(μ-PtBu2)(PPh3)] (6 a), while with tBu2PH the compound [Fe2(μ-CO)(CO)5(μ-H)(μ-PtBu2)(tBu2PH)] (6 b) is formed. The thermolysis of 6 b affords [Fe2(CO)5(μ-PtBu2)2] and the degradation products [Fe(CO)3(tBu2PH)2] and [Fe(CO)4(tBu2PH)]. The molecular structures of 3, 4 and 6 b were determined by X-ray crystal structure analyses.

Single crystals of trans-[IrCl(N2)(PiPr3)2] (1), obtained during studies on the reaction of [{Ir(μ-Cl)(coe)2}2] (coe = cis-cyclooctene) with tri-iso-propylphosphane in diethyl ether under dinitrogen atmosphere, have been analyzed by X-ray crystallography (monoclinic, P21/c, Z = 2, a = 8.0855(9), b = 8.896(3), c = 16.539(3) A; β = 93.124(11)°; V = 1187.9(4); T = 200(2) K). In the course of these studies under an atmosphere of dinitrogen or argon, the formation of a variety of phosphorus-containing compounds was indicated using 31P{1H} NMR spectroscopy.

Single crystals of trans-[{Rh(μ-Cl)(CO)(coe)}2] (1) obtained from the reaction of [{Rh(μ-Cl)(coe)2}2] (coe = cis-cyclooctene) with carbon monoxide have been analyzed by X-ray crystallography (monoclinic, C2/c, Z = 4, a = 15.6271(4), b = 13.6943(4), c = 10.4169(2) Å ; β = 115.3549(17)°; V = 2014.50(9) Å3; T = 200(2) K).

The reaction of [Ru 3 (CO) 12 ] with dicyclohexylphosphine (Cy 2 PH) in refluxing toluene leads to the metal clusters [Ru 3 (CO) 7 ( μ -H)( μ -PCy 2 ) 3 ] (1) and [Ru 3 (CO) 6 ( μ -H)( μ -PCy 2 ) 3 (Cy 2 PH)] (2). Complexes 1 and 2 react with carbon monoxide under elevated pressure to give the novel 52-electron cluster [Ru 3 (CO) 9 ( μ -H)( μ -PCy 2 ) 3 ] (3), which could be isolated as a solid and characterized spectroscopically. The molecular structure of 1 has been determined by means of a single-crystal X-ray structure analysis.

[Co(But 2PH)2I2] (1) reacts with [Ru3(CO)12] in refluxing toluene to give a mixture of products including the novel metal clusters [Ru3(CO)6(μ-H)(μ-I)2(μ-PBut 2)(But 2PH)] (2) and [Ru3(CO)7(μ-H)(μ-I)(μ-PBut 2)2] (3) besides the known complex [Ru3(CO)8(μ-H)2(μ3- PBut)(But 2PH)] (4). No cluster expansion products could be observed. Thus the cobalt compound acts merely as a phosphine and iodine transfer reagent. The molecular structures of the metal complexes 1 and 2 were determined by single-crystal X-ray structure analyses. 1 crystallizes in the tetragonal space group P4̄21c with a = 13.230(3), b = 13.230(3), c = 14.788(3)Å, V = 2588.4(9)A . 2 crystallizes in the monoclinic space group P21/c with a = 18.161(2), b = 10.292(2), c = 18.381(2)Å, β = 108.73(10)°, V= 3253.7(8)Å3.

The reaction of the phosphido-bridged metal carbonyl [FeRh(CO)6(μ-PBut 2)] (1) with dppm [dppm = bis(diphenylphosphino)methane] leads to the heterobimetallic complex [FeRh(μ-CO)(CO)3(μ-PBut 2)(μ-dppm)] (2) in good yields. The molecular structure of 2 was determined at room temperature [triclinic, space group P1̄, a = 9.509(6), b = 13.637(5), c = 14.926(8) Å, α = 81.38(4), β = 82.75(4), γ = 71.25(4)°]. The compound acts as a homogeneous catalyst precursor in the hydroformylation reaction of ethylene, but it decomposes during this process.

The reactions of [IrCl(Bu 2 t PH) 3 ] ( 1 ) with the metal carbonyls [M 3 (CO) 12 ] (M = Fe, Ru) in refluxing toluene have been investigated. By using [Ru 3 (CO) 12 ] the metal cluster [Ru 3 (CO) 8 (μ-H) 2 ( μ 3 -PBu t )(Bu 2 t PH)] ( 2 ) and the butterfly configured heterometallic cluster [Ru 3 Ir(CO) 7 (μ-H) 2 (μ-PBu 2 t ) 2 (Bu 2 t PH)( μ 3 -Cl)] ( 3 ) were obtained. On the contrary, the reaction of 1 with [Fe 3 (CO) 12 ] leads under cluster degradation beside the mononuclear complex [Fe(CO) 4 (Bu 2 t PH)] ( 5 ) to the known compound [FeIr(μ-CO)(CO) 4 (μ-PBu 2 t )(Bu 2 t PH)] ( 4 ) in good yields. The molecular structures of 2 and 3 have been determined by single crystal X-ray studies.

Treatment of CuCl with Bu2t in hexane afforded a colourless crystalline material which was characterized as [}CuCl(Bu2tPH)}4] (1) by an X-ray diffraction study. The reaction of 1 with [Ru3(CO)12] in refluxing toluene leads to a mixture of products containing the electron-rich chloro-bridged cluster [Ru3(CO)6(μ-PBu2t)(μ-Cl)3(Bu2tPH)] (2) besides the electron-precise complexes [Ru 3 (CO) 7 (μ-H) (μ-PBu 2 t 2 (μ-Cl)] ( 3 ) and [Ru 3 (CO) 8 (μ-H) 2 (μ 3 - PBu t )(Bu 2 t PH)] ( 4 ) , respectively. No cluster expansion products were observed, therefore, the copper complex acts merely as phosphine and chloride transfer reagent. The molecular structures of the metal clusters 2 and 3 were determined by means of single-crystal X-ray structure analyses.