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Synthesis, structure, and some reactions of the cluster complex [(μ-H)2Fe5(μ3-Se)2(CO) 14]
In the reaction of Na2Se with [Fe(CO)5] in isopropanol with subsequent acidification with HCl, which is used to synthesize [(μ-H)2Fe3(μ3-Se)(CO)9] (II), the cluster [(μ-H)2Fe5(μ3-Se) 2(CO)14] (I) was detected. In assumption that compound I could serve as a suitable synthon for preparing the bulky heterometallic clusters, its reactions with the Rh-containing complexes were studied. The reaction of I with [Rh(CO)2Cp*] (Cp*is pentamethylcyclopentadienyl) was found to give a mixture of the products. The main reaction products were isolated and their structures were determined: [Fe2Rh(μ3-Se)2(CO)6Cp*], [Fe2Rh(μ3-Se)(μ3-CO)(CO) 6Cp*], [FeRh2(μ3-Se)(μ-CO)(CO) 3Cp 2 * ], [Fe2Rh2(μ 4-Se)(μ-CO)4(CO)2Cp 2 * ]. Potassium hydride treatment of II with subsequent addition of [Cp*Rh(CH3CN)3](CF3SO3) 2 leads to the well-known cluster complex [Fe3Rh(μ 4-Se)(CO)9Cp*]. A set of the reaction products indicates that the {Fe5Se2} core cannot be used as one-piece building block in the synthesis of heterometallic clusters.
Bashirov,Pushkarevsky,Vitovets,Fuhr,Konchenko
p. 739 - 749
(2008)
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Microwave spectra and the molecular structure of tetracarbonylethyleneiron
Microwave spectra of seven isotopomers of tetracarbonylethyleneiron were recorded using a Pulse-Beam Fourier Transform Microwave Spectrometer. Rotational transitions for a c dipole moment with J′ ← J from 2 ← 1 to 6 ← 5 were measured in the 4-12 GHz range. Rotational constants were determined by fitting the measured microwave spectra to a Watson A reduced Hamiltonian with centrifugal distortion parameters. The measured rotational constants of the main isotopomer are A = 1031.1081(4) MHz, B = 859.8055(4) MHz, and C = 808.5675(3) MHz. Data were also obtained for three 13C-substituted species and two 18O-substituted species in natural abundance. Additional spectra were measured for an isotopically enriched sample of perdeuterated tetracarbonylethyleneiron. The moments of inertia of the seven isotopomers were used in a Kraitchman analysis and in two different least-squares fitting analyses to determine the molecular structure of the compound. The ethylene ligand exhibits significant structural changes upon complexation to iron, primarily an increase in C-C bond length with movement of the hydrogen atoms away from the metal center. The C-C and C-H bond lengths were found to be ro = 1.419(7) and = 1.072(4) A, respectively. The C-C-H angle and the Fe-C-C-H dihedral angle were found to be 〈(C-C-H)o = 120.6(5)° and 〈(Fe-C-C-H)o = 103.6(9)°, respectively. The plane of the hydrogen atoms is displaced 0.217(2) A above the ethylene carbon atoms, along the c axis. Extensive DFT calculations were carried out prior to the experimental research. The calculated structure proved extremely valuable in obtaining accurate predictions for the spectra, and provided structural parameters in excellent overall agreement with measured parameters.
Drouin, Brian J.,Kukolich, Stephen G.
p. 4023 - 4030
(1999)
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Surface-Modified Photochemistry. Preparation of Silica-Supported Fe3(CO)12 via Irradiation of Adsorbed Fe(CO)5
The photochemistry of silica-adsorbed Fe(CO)5 has been studied.IR and UV-visible spectra show that the only significant product is Fe3(CO)12 rather than Fe2(CO)9, which is the product observed following irradiation of Fe(CO)5 in the gas or liquid phase or in solution.Formation of Fe3(CO)12 is discussed in terms of a mechanism involving rapid secondary thermal reactions of a surface-complexed form of Fe(CO)4.
Jackson, Robert L.,Trusheim, Mark R.
p. 6590 - 6596
(1982)
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Synthesis and expansion reaction of ferrocenylacetylene dimetal carbonyl compounds. The molecular structures of μ-FcCCHCoMo(CO)5Cp and μ3-FcCHCFeCo2(CO)9
Two ferrocenylacetylene dimetal carbonyl clusters μ-FcCCHCo(CO)3M(CO)2Cp (2, M=Mo; 3, M=W) were obtained from the reactions of the precursor μ-FcCCHCo2(CO)6 1 with metal exchange reagents NaM(CO)3Cp in THF under reflux. The dimetal compounds 1, 2, and 3 can further react with Fe2(CO)9 in the presence of benzylideneacetone (BDA) to give the corresponding μ3-ferrocenylvinylidene bridged trimetal clusters μ3-FcCHCFeCo2(CO)9 4 and μ3-FcCHCFeCoM(CO)8Cp (5, M=Mo; 6, M=W), respectively, probably through the formation of the intermediate (BDA)Fe(CO)3 which acts as an Fe(CO)3 transfer-reagent. The new compounds 2-6 were characterized by C/H analysis, IR and 1H-NMR spectrocopies. The molecular structures of 2 and 4 were determined by X-ray structural analysis. 2 is triclinic with space group P1 (#2), a=8.733(2) A, b=14.870(3) A, c=8.200(2) A, α=92.77(2)°, β=101.78(2)°, γ=78.41(2)°, V=1021.2(4) A3, and Z=2; final R=0.025, Rw=0.034 for 2988 reflections. Cluster 4 is orthorhombic with space group P212121 (#19), a=12.186(5) A, b=14.870(5) A, c=7.800(6) A, V=2340(2) A3 and Z=4; final R=0.062, Rw=0.065 for 2401 reflections.
Wu, Shu-Lin,Ding, Er-Run,Yin, Yuan-Qi,Sun, Jie
p. 71 - 78
(1998)
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Synthesis and structural characterization of bimetallic iron-nickel carbido cluster complexes
In acetonitrile solvent, Fe5(CO)15(μ5- C), 1, reacts with Ni(COD)2 at room temperature to afford the iron-nickel complex Fe5NI(NCMe)(CO)15(μ6-C), 3. The acetonitrile ligand In 3 can be replaced by CO and NH3 to yield Fe5Ni(CO)16(μ6-C), 4, and Fe 5Ni(NH3)(CO)15(μ6-C), 6, respectively. When refluxed In acetonitrile solvent, compound 3 loses a vertex to form the square pyramidal Fe4Ni complex Fe4Ni(NCMe) 2(CO)12(μ5-C), 7. Compound 7 readily converts to Fe4Ni(NCMe)(CO)13(μ5-C), 8, by losing one of Its acetonitrile ligands. Addition of acetonitrile to 8 gives compound 7. When heated to 110 o°C under an atmosphere of CO, both compounds 7 and 8 furnish the octahedral Fe4NI2 complex Fe 4Ni2(CO)15(μ6-C), 9. All six compounds were structurally characterized by single-crystal X-ray diffraction analyses.
Saha, Sumit,Zhu, Lei,Captain, Burjor
p. 3465 - 3472
(2010)
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INSERTION D'ALLENES. VI. IDENTIFICATION DU SITE REACTIONNEL DES COMPLEXES ANIONIQUES RESULTANT DE LA REACTION D'ALLENES AVEC DES ACYL FERRATES DANS LEURS REACTIONS AVEC CERTAINS ELECTROPHILES. FORMATION DE COMPLEXES η4-TRIMETHYLENE METHANE DU FER. ISOMERISATION D'UN LIGAND η4-TR...
Aninos derived from the reaction between allenes and an alkylferrate are potential ambident nucleophiles which could react either at the metallic fragment site or at the oxo ligand oxygen atom.This last centre, which was already interacting preferentially with the cation Na+ in the starting metalate, has been shown to react with electrophiles such as trimethylsilyl chloride or H+.Neutral iron η4-trimethylenemethene is produced in high yield.With H+, the kinetic product is subsequently isomerised into a η4heterodiene complex.
Roustan, J. L.,Guinot, A.,Cadiot, P.
p. 191 - 202
(1980)
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The reaction of (μ3-CCO2R)Co2M(CO)8L (M = Co, Mo, W ; L = CO, MeCp ; R = Me, Et) with Na2[Fe(CO)4]. X-ray crystal structure analysis of (EtO2CCCCO2Et)Co4(CO
The reactions of clusters [(μ3-CCO2Et)Co2M(CO)8(MeCp)][M = Mo (2a), W (2b)], derived from the reactions of (μ3-CCO2Et)Co3(CO)9 with Na[M(CO)3(MeCp)], with N
Wu, He-Ping,Zhao, Zhuan-Yun,Liu, Sheng-Ming,Ding, Er-Run,Yin, Yuan-Qi,Huang, Xiao-Ying,Yu, Kai-Bei
p. 4117 - 4126
(1996)
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MIXED-METAL CLUSTER DERIVATIVES OF Co3(μ3-CPh)(CO)9: CRYSTAL STRUCTURES OF Co3(μ3-CPh)(CO)9, HFeCo2(μ3-CPh)(CO)9, AND FeCo2(μ-AuPPh3)(μ3-CPh)(CO)9
The compound Co3(μ3-CPh)(CO)9 (1) reacts with Na2 in tetrahydrofuran to afford the mixed-metal hydride cluster HFeCo2(μ3-CPh)(CO)9 (2) after acid treatment.The structures of 1 and 2 have been determined by X-ray diffraction.The cluster 1 crystallizes in space group P1 (Z=4) with a 8.034(3), b 15.760(7), c 15.900(7) Angstroem, α 101.11(3), β 100.99(3), γ 100.13(3) deg, and the cluster 2 in the space group C2/c (Z=8) with a 14.114(4), b 7.804(3), c 33.844(12) Angstroem, β 96.13(3) deg.The two structures are similar, with a M3 triangle triply bridged by the alkylidyne carbon atom and with three terminal carbonyl ligands bonded to each metal atom.The hydride ligand in 2 could not be located from the difference Fourier maps, but the structure of its gold triphenylphosphine derivative FeCo2(μ-AuPPh3)(μ3-CPh)(CO)9 (3), which was synthesized in toluene by a direct reaction of 2 with Au(PPh3)Cl in the presence of TlPF6, indicates that the hydride ligand is in an edge bridging position.The cluster 3 crystallizes in space group Pna21 (Z=4) with a 34.617(6), b 8.793(2), c 11.226(2) Angstroem.
Ahlgren, Markku,Pakkanen, Tuula T.,Tahvanainen, Ilpo
p. 91 - 102
(1987)
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Cluster expansion reactions of group 6 and 8 metallaboranes using transition metal carbonyl compounds of groups 7-9
The reinvestigation of an early synthesis of heterometallic cubane-type clusters has led to the isolation of a number of new clusters which have been characterized by spectroscopic and crystallographic techniques. The thermolysis of [(Cp*Mo)2B4H4E2] (1: E = S; 2: E = Se; Cp* = η5-C5Me5) in presence of [Fe2(CO)9] yielded cubane-type clusters [(Cp*Mo)2(μ3-E)2B2H(μ-H) {Fe(CO)2}2Fe(CO)3], 4 and 5 (4: E = S; 5: E = Se) together with fused clusters [(Cp*Mo)2B4H 4E2Fe(CO)2Fe(CO)3] (8: E = S; 9: E = Se). In a similar fashion, reaction of [(Cp*RuCO)2B 2H6], 3, with [Fe2(CO)9] yielded [(Cp*Ru)2(μ3-CO)2B2H(μ- H){Fe(CO)2}2Fe(CO)3], 6, and an incomplete cubane cluster [(μ3-BH)3(Cp*Ru) 2{Fe(CO)3}2], 7. Clusters 4-6 can be described as heterometallic cubane clusters containing a Fe(CO)3 moiety exo-bonded to the cubane, while 7 has an incomplete cubane [Ru 2Fe2B3] core. The geometry of both compounds 8 and 9 consist of a bicapped octahedron [Mo2Fe2B 3E] and a trigonal bipyramidal [Mo2B2E] core, fused through a common three vertex [Mo2B] triangular face. In addition, thermolysis of 3 with [Mn2(CO)10] permits the isolation of arachno-[(Cp*RuCO)2B3H7], 10. Cluster 10 constitutes a diruthenaborane analogue of 8-sep pentaborane(11) and has a structural isomeric relationship to 1,2-[{Cp*Ru} 2(CO)2B3H7].
Geetharani,Bose, Shubhankar Kumar,Sahoo, Satyanarayan,Varghese, Babu,Mobin, Shaikh M.,Ghosh, Sundargopal
p. 5824 - 5832
(2011)
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A 10-vertex iron - Dicarbollide system formed by insertion of Fe(CO) 4J into 8-vertex [closo-1-CB7H8]_: Synthesis and reactivity studies
Reaction of [NBu4n][closo-1-CB7H 8] with [Fe2(CO)9] in refluxing THF (tetrahydrofuran) gives the neutral ferradicarborane [2,2,2-(CO) 3-1-OH-closo-2,1, 10-FeC2B7H8] (3), which, upon treatment with PEt3 in the presence of Me3NO, yields [2,2-(CO)2-2-PEt3-1-OH-closo-2,1,10-Fe 2B7H8] (4). In 3 and 4 the 10-vertex (FeC 2B7] cluster has two carbon vertices in antipodal, four-connected positions and the iron atom in a five-coordinate site adjacent to a carbon vertex that bears an OH substituent. Treatment of 4 in THF with NaH and then R-X (X = Br, I) affords [2,2-(CO)2-2-PEt3-1-OR- closo-2,1,10-FeC2B7H8] (R = Me (5), CH 2CH=CH2 (6), CH2C=CH (7), CH2CCMe (8)). The pendant allyl group in 6 becomes η2-bonded to the iron center upon treatment with Me3NO in CH2Cl2, giving [2-CO-2-PEt3-1,2-η2OCH2CH=CH 2-closo-2,1, 10-FeC2B7H8] (9), which then with CNXyl (Xyl = C6H3Me2-2,6) in the presence Of PEt3 gives [2,2-(CNXyl)2-2-PEt 3-1-OCH2CH=CH2-closo-2,1,10-FeC 2B7H8] (10). Reaction between compound 7 and [Co2(CO)8] in petroleum ether yields [2,2-(CO) 2-2-PEt3-l-{OCH2-(μ- η2η2-CCH)Co2(CO)6}-closo-2, 1, 10-FeC2B7H8] (12), in which a [C 2Co2} tetrahedron is linked to the 10-vertex (FeC 2B7} cluster by an -OCH2- bridge. Heating compound 7 with [CO(CO)2(η-C5H5)] in refluxing toluene gives the complex [2,2-(CO)2-2-PEt 3-1,4-μ-(OC(H)=C(Me)-B}-closo-2,1, 10-FeC2B 7H7] (13a), which contains a 5-membered ring that involves one carbon vertex and an adjacent boron atom. Compound 13a yields [2-CO-2,2-(PEt3)2-1,4-μ-(OC(H)=C(Me)-B}-closo-2,1,10- FeC2B7H7] (13b) upon addition of further PEt3 in the presence of Me3NO. Treatment of compounds 7 and 8 with PEt3 in CH2Cl2 and in the presence of Me3NO affords the zwitterionic ylide species [2-CO-2-PEt 3-1,2-μ-{OCH2C(=C(R′)PEt3} }-closo-2,1,10-FeC2B7H8] (R′ = H (15), Me (17), respectively). In the latter pair, an -OCH2C{=C(R′) PEt3J group bonded to a cage carbon atom is also directly σ-bonded (at the β-position) to the adjacent iron vertex, forming a 5-membered ring. The novel structural features of compounds 4, 10, 12, 13, 15, and 17 have been confirmed by single-crystal X-ray diffraction studies.
Franken, Andreas,McGrath, Thomas D.,Stone, F. Gordon A.
p. 908 - 917
(2008)
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Thermal dissociation of iron carbonyls during growth of iron whiskers
Methods for the preparation of iron whiskers in chemical transport reactions of thermal dissociation of iron penta- and dodecacarbonyls and carbidocarbonyl clusters Fe5C(CO)15 were described. The morphology, structure, and chemical composition of the whiskers were studied. The main factors determining the growth rate and mechanical properties of the whiskers were revealed. A model for the mechanism of thermal dissociation of iron carbonyls was proposed. This process was shown to be a chain radical ion reaction initiated via the scheme of activating complex formation. Analogies between the thermal dissociation of iron carbonyls in the adsorption layer and the known radical ion processes in the liquid and gas phases were found.
Babin,Belousov,Dobryakova,Nekrasov,Syrkin,Uel'skii
p. 1903 - 1913
(2004)
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Polynuclear Iron and Rhodium Complexes of 7-Oxahericene (2,3,5,6-Tetramethylidenebicycloheptan-7-one
μ-Carbonyl(Rh - Rh)di(η5-indenyl)heptan-7-one)>-dirhodium(I)(Rh-Rh) (7) and cis-μ-heptan-7-one)>bis5-indenyl)dirhodium(I)(Rh-Rh)> (8) have been prepared.Complex 7 reacts with Fe2(CO)9 in hexane/MeOH and gives cis-μ- (9), trans-μ-heptan-7-one)>-μ-carbonyldi(η5-indenyl)dirhodium(I)(Rh-Rh)-(tricarbonyliron) (10), and μ-carbonyl(Rh-Rh)hept-2-en-7-one)>di(η5-indenyl)dirhodium(I)Rh-Rh) (11).Treatment of 7-oxahericene (4) with Fe2(CO)9 or (cyclooctene)2Fe(CO)3 gave a 1 : 2 mixture of cis-μ- (12) and trans-μ-heptan-7-one)>bis(tricarbonyliron) (13).
Rubello, Albino,Vogel, Pierre
p. 158 - 164
(1989)
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Deprotonation of ferraborane clusters and their relative acidities
The relative Bronsted acidities for a series of ferraborane clusters were determined. Relative acidities were studied by proton competition reactions between neutral and anionic species followed by IR spectroscopy. From these studies the relative trend in acidities was determined to be B2H6Fe2(CO)9 3(CO)9BH4 = HFe4(CO)12BH2 3(CO)10BH2.
McCarthy,Durie,Embry,Imbur,Marhoefer
p. 1972 - 1974
(2001)
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Wasserloesliche Metallkomplexe und Katalysatoren III. Neue wasserloesliche Metallkomplexe des sulfonierten Triphenylphosphans (TPPTS): Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Ag, Au.
The metals Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Ag, and Au are present in 24 new water-soluble complexes containing the ligand tris(sodium-m-sulfonatophenyl) phosphane (TPPTS) which were synthesized from readily accessible precursor compounds and were isolated pure by gelpermeation chromatography.Some of these compounds are the first authentic examples of homoleptic TPPTS metal complexes, viz., Ni(TPPTS)3, Pd(TPPTS)3, Pt(TPPTS)4, Ag(TPPTS)2(TPPTS*), and Au(TPPTS)2(TPPTS*) *: P(C6H4-m-SO3-Na+)2(C6H4-m-SO3-)>, each containing one water molecule per sodium ion.It is noted that the homoleptic TPPTS complexes have lower coordination numbers (TPPTS/metal ratios) than those of corresponding complexes of the parent triphenylphosphane (TPP).
Herrmann, Wolfgang A.,Kellner, Juergen,Riepl, Herbert
p. 103 - 128
(1990)
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Stereoselective Double Functionalization of Iron-Carbonyl Complexes of 5,6,7,8-Tetramethylidenebicyclooct-2-ene. Crystal Structure and Absolute Configuration of (-)-trans-μ-<(2S,5R,7S)-C,5,6,C-η:C,7,8,C-η-(6,7,8-trimethylidene-5-((Z)-2-oxopropylide
The Friedel-Crafts monoacylation of trans-μ-octyl acetate)>-bis(tricarbonyliron) ((+/-)-5) is highly stereoselective and yields trans-μ-(1RS,2RS,4RS,5SR,6RS,7RS,
Tagliaferri, Enrico,Campiche, Philippe,Roulet, Raymond,Gabioud, Raphy,Vogel, Pierre,Chapuis, Gervais
p. 126 - 134
(1985)
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Synthesis and reaction of new metal cluster complexes containing a WRuCoSe core
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Zhang, Jie,Ding, Er-Run,Chen, Xue-Nian,Zhang, Yu-Hua,Song, Cui-Ping,Yin, Yuan-Qi,Sun, Jie
p. 1315 - 1329
(1999)
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DIPHOSPHOR, PHOSPHOR-, ARSEN- UND ANTIMONATOME ALS CLUSTERBAUGRUPPEN
Reactions of Fe2(CO)9 with LnM-PHal3 (LnM = 16-electron fragment: Cp(CO)2Mn, (CO)5Cr, (CO)5Mo, (CO)5W) yield clusters of the type Fe3(CO)9(μ4-P)2(MLn)2 (II).Compounds II contain the trigonal bipyramidal cluster framework Fe3(CO)9(μ3-P)2, the basis of which is a closed triangle formed by three Fe(CO)3 units; the apical positions of the trigonal bipyramid are occupied by phosphorus atoms.Each of the capping phosphorus atoms binds an additional MLn fragment.Compounds of type II are also obtained from Fe2(CO)6(μ3-P)2(MLn)2 (I) by formal addition of an Fe(CO)3 group.A further general synthetic approach to clusters Fe3(CO)9(μ4-X)2(MLn)2 (X = P, As, Sb) is the reaction of halo-phosphinidene, arsinidene ar stibinidene complexes, (LnM)2X-Hal (X= P, As, Sb) with Na2Fe(CO)4.Similar procedures are used for the construction of compounds II and IV.Complexes III contain phosphorus as a μ4-spiro centre; compounds IV contain metallacyclic phosphanes as ligands.From (CO)5CrPBr3 and Fe2(CO)9 the cluster Fe2(CO)7(PP)2 (V) is obtained in which a diphosphorus unit is side-on and end-on coordinated as an eight-electron ligand.The identity of the new compounds is documented by analytic and spectroscopic data as well as by X-ray-structure analyses of seven compounds.
Lang, Heinrich,Huttner, Gottfried,Zsolnai, Laszlo,Mohr, Gerhard,Sigwarth, Beate,et al.
p. 157 - 180
(1986)
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Oligomerisation of isopropenylacetylene in the presence of Fe3(CO)12. Crystal and molecular structure of the open-cluster isomers (see abstract)
The reaction of 2-methyl-1-buten-3-yne (isopropenylacetylene, IPA) with triiron dodecacarbonyl in refluxing benzene leads to medium yields of four main derivatives. Two of them are the trinuclear open-cluster isomers Fe3(CO)10[H
Gatto, Elisabetta,Gervasio, Giuliana,Marabello, Domenica,Sappa, Enrico
p. 1448 - 1454
(2002)
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syn-BIS-DIAZENE ALS MATRICES FUER DEN AUFBAU FLAECHIGER OLIGOMETALL-AGGREGATE
Compounds with the syn-bis-diazene structural unit containing two cis-diazene groups in almost parallel orientation to each other may act as matrices for the stabilisation of pentametallic aggregates.The synthesis and structure of (μ5-η4-C11H16N4)Fe5(CO)13 (2) in which an Fe5(CO)13 entity is bound to a syn-bis-diazene ligand is reported.
Fischer, G.,Sedelmeier, G.,Prinzbach, H.,Knoll, K.,Wilharm, P.,et al.
p. 307 - 312
(1985)
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Crystal Structure and Absolute Configuration of (+)-(1S,2R)-5,6-Dimethylidene-2exo-norbornyl-exo-irontricarbonyl p-Bromobenzoate
The title complex (+)-13x has been prepared in an enantiomerically pure form.Its absolute configuration has been determined by single-crystal X-ray diffraction and has been correlated chemically to that of the 5,6-dimethylidene-2-norbornyl derivatives (-)-1, (-)-2, (-)-3 and to (-)-(1S,2R)-benzonorborn-5-en-2-yl acetate (s.Scheme 1), whose configuration was deduced by indirect techniques.A critical analysis of the chiroptical propeties of the exocyclic dienes 1-3 is now possible.These compounds are limiting systems for the application of the allylic axial chirality rule, the generalized octant rule and the symmetry rule for β,γ-unsaturated ketones.
Barras, Charles,Roulet, Raymond,Vieira, Eric,Vogel, Pierre,Chapuis, Gervais
p. 2328 - 2337
(1981)
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A tungstendiiron cluster 3-η3,η5-CH=C=C(tBu)C(O)C2B9H8Me2>(CO)8> derived from and CCCtBu)(CO)2(η5-C2B9H9Me2)>
Treatment of a tetrahydrofuran solution of CCCtBu)(CO)2(η5-C2B9H9Me2)> with affords the trimetal complex 3-η3,η5-CH=C=C(tBu)C(O)C2B9H8Me2>(CO)8>, the structure of which has been etablished by X-ray diffraction.The anion has a core based on an essentially isosceles triangle of metal atoms .Each iron atom carries three CO groups, whereas the tungsten atom is co-ordinated by two such groups, and by the open face of a nido-icosahedral C2B9 cage.In the five-membered ring forming the face of the cage, the boron atom occupying the β site with respect to the two carbon atoms is ? bonded to the carbon atom of a ketonic group .The latter in turn is linked to an allenyl fragment C(tBu)=C=CH which spans the face of the WFe2 triangle.The terminal CH group is attached to the tungsten and to an iron atom , and the central carbon is linked to the tungsten atom and also to the second iron atom .The latter is also bonded to the C(tBu) fragment which in turn is connected to the ketonic group tBu)-C(O) 1.47(2) Angstroem> linking the μ3-C3 moiety to the cage.The NMR data (1H, 13C-, and 11B-) for the new cluster compound are reported and discussed.
Carr, Nicholas,Dossett, Stephen J.,Stone, F. Gordon A.
p. 223 - 232
(1991)
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Cyclopentannulation reactions with organoiron reagents. facile construction of functionalized hydroazulenes
Troponeiron tricarbonyl, 2-methyltroponeiron tricarbonyl, and 4-methyltroponeiron tricarbonyl are converted to fluxional tropyliumiron tricarbonyl salts by treatment with either trimethylsilyl or di-n-butylboron triflate. These pentadienyliron cations react with (η1-allyl) (η1-propargyl)-, and (η1-allenyl)Fp complexes [Fp = C5H5Fe(CO)2] to give ketohydroazulene cycloadducts derived, in each reaction, from a single tautomeric tropylium cation. The further reaction of two such cycloadducts 14 and 22b with lithium dimethyl cuprate gave tricyclic ketones 25a and b, through a sequence depicted as involving initial formation of an anionic acyliron complex, followed by migratory insertion and an intramolecular aldol condensation.
Rosenblum,Watkins
p. 6316 - 6322
(1990)
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The structure of 2,η4-CPhCHCHCPh)> a cobalt analogue of the 'ferroles'
4-CPhCHCHCPh)>, a new cobaltacyclopentadiene dinuclear compound, was isolated and characterized by spectroscopic techniques.The X-ray structure of this compound has been determined.Keywords: Cobalt; Carbonyl; Metallacycle; Alkyne; ?-bonding; Cluster
Moldes, Isabel,Papworth, Trevor,Ros, Josep,Alvarez-Larena, Angel,Piniella, Joan F.
p. C65 - C67
(1995)
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Novel class of heterometallic cubane and boride clusters containing heavier group 16 elements
Thermolysis of an in situ generated intermediate, produced from the reaction of [CpMoCl4] (Cp* = η5-C 5Me5) and [LiBH4.THF], with excess Te powder yielded isomeric [(CpMo)2B4TeH5Cl] (2 and 3), [(CpMo)2B4(μ3-OEt)TeH3Cl] (4), and [(CpMo)4B4H4(μ4-BH) 3] (5). Cluster 4 is a notable example of a dimolybdaoxatelluraborane cluster where both oxygen and tellurium are contiguously bound to molybdenum and boron. Cluster 5 represents an unprecedented metal-rich metallaborane cluster with a cubane core. The dimolybdaheteroborane 2 was found to be very reactive toward metal carbonyl compounds, and as a result, mild pyrolysis of 2 with [Fe2(CO)9] yielded distorted cubane cluster [(CpMo)2(BH)4(μ3-Te){Fe(CO)3}] (6) and with [Co2(CO)8] produced the bicapped pentagonal bipyramid [(CpMoCo)2B3H2(μ3-Te) (μ-CO){Co3(CO)6}] (7) and pentacapped trigonal prism [(CpMoCo)2B3H2(μ3-Te)(μ-CO) 4{Co6(CO)8}] (8). The geometry of 8 is an example of a heterometallic boride cluster in which five Co and one Mo atom define a trigonal prismatic framework. The resultant trigonal prism core is in turn capped by two boron, one Te, and one Co atom. In the pentacapped trigonal prism unit of 8, one of the boron atoms is completely encapsulated and bonded to one molybdenum, one boron, and five cobalt atoms. All the new compounds have been characterized in solution by IR, 1H, 11B, and 13C NMR spectroscopy, and the structural types were unambiguously established by crystallographic analysis of 2 and 4-8
Thakur, Arunabha,Sao, Soumik,Ramkumar,Ghosh, Sundargopal
p. 8322 - 8330
(2012)
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Electrochemistry of iron and ruthenium flyover bridge complexes
The redox chemistry of dimetallacycloheptadiene (flyover bridge) complexes M2(CO)6[C(R)=C(R′)COC(R″)=(R?)] (M = Fe or Ru) has been investigated by electrochemical and spectroscopic techniques. For the Fe2(CO)6[(PhC2Ph)2CO] derivative the bulk of the data indicates a sequence of electrochemical events involving the formation of the monoanion and its decomposition to solvated [Fe(CO)3]- and Fe(CO)3[(PhC2Ph)2CO] fragments, which are able to recombine together on electrochemical or chemical reoxidation giving back the parent complex. Electron paramagnetic resonance features of electroreduced solutions of 13CO-enriched sample of Fe2(CO)6[(PhC2Ph)2CO] and its monophosphine derivative Fe2(CO)5(PPh)3[(PhC2Ph) 2CO] lend support to the proposed mechanism. The influence of the dienone substituents, R, as well as the effect of the replacement of group V (15) donor ligands for CO on the trend of the electrode potentials is discussed.
Osella, Domenico,Botta, Mauro,Gobetto, Roberto,Laschi, Franco,Zanello, Piero
p. 283 - 288
(1988)
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Surface-supported Metal Carbonyl Clusters: Formation of - by Interaction of Fe3(CO)12 and Fe(CO)5 with Alumina and Magnesia
Interaction of Fe3(CO)12 and Fe(CO)5 with the surface of alumina and magnesia results in the formation of the anionic hydrido cluster carbonyl -M+, M+ = Al(O-)x+ or Mg(O-)y
Hugues, Francois,Smith, A. K.,Taarit, Y. Ben,Basset, J. M.
p. 68 - 70
(1980)
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Cluster chemistry LXVI. Some iron-iridium clusters. X-ray structures of Fe2Ir(μ3-C2Ph)(CO)8(PPh3), FeIr2(μ3-η2-PhC2C2Ph)(CO)7(PPh3)2 and Fe2Ir(μ3-PhC2PEt3)(CO)7(PEt3).
Reactions between Ir(C2Ph)(CO)2(PPh3)2 and iron carbonyls (Fe(CO)5, Fe2(CO)9) have given Fe-Ir clusters Fe2Ir(μ3-C2Ph)(CO)9-n(PPh3)n (n = 1 (8), 2) and FeIr2(μ3-PhC2C2Ph)(CO)7(PPh3)2 (9).The Rh analogue of 8 was obtained similarly.Su
Bruce, Michael I.,Koutsantonis, George A.,Tiekink, Edward R.T.
p. 391 - 412
(1991)
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Synthesis of blue imino(pentafluorophenyl)phosphane
The reaction of AgC6F5 with monomeric iminophosphanes of Mes*-N=P-X (X = Cl, I) in CH2Cl2 at ambient temperature gives imino(pentafluorophenyl)phosphane, Mes*N=P(C 6F5) (1), in almost quantitative yield (96%), which could be isolated as a highly viscous blue oil. The same reaction with LiC 6F5 results in the formation of imino(amino)phosphane (C6F5)2P-N(Mes*)-P=NMes* (2) (yield 93%). In the second series of experiments the analogous reaction of MC 6F5 (M = Ag, Li) with dimeric [Cl-P(μ-N-Dipp)] 2 was studied, leading to the formation of [R-P(μ-N-Dipp)] 2 (R = C6F5) (3) for M = Ag, while only decomposition products such as P(C6F5)3 were observed in the reaction with the Li salt. Highly labile Mes*-N=P-C 6F5 (1) decomposes at ambient temperatures, forming among other products the diphosphane (C6F5)2P- P(C6F5)2 (4). Reaction of 1 with Fe 2(CO)9 yields the iron carbonyl complexes Mes*-N=P(C6F5)?Fe(CO)4 (5) and [Mes*-N=P(C6F5)]2?Fe(CO) 3 (6). The structure, bonding, and potential energy surface are discussed on the basis of B3LYP/6-31G(d,p) computations. According to time-dependent B3LYP calculations, the blue color of 1 arises from an n → π* electronic transition.
Kuprat, Marcus,Lehmann, Mathias,Schulz, Axel,Villinger, Alexander
p. 5784 - 5792
(2011/08/05)

Novel carbonyl iron-bismuth clusters - Synthesis, structure, CO2 insertion and potential as molecular precursors for BiFeO3
The reaction of Fe2(CO)9 with Bi(OSiMe 2tBu)3 gave soluble [(CO) 4FeBi(OSiMe2tBu)]2 (1) in moderate yield whereas in case of Bi(OtBu)3 used as starting material both [(CO)4FeBi(OtBu)]n (2) and the bismuth-iron cluster [(CO)3FeBi3(OtBu) 4{OCO(OtBu)}]2 (3) were isolated. The latter forms upon insertion of CO2, released during reaction of diiron nonacarbonyl with bismuth tert-butoxide, into a Bi-OtBu bond. The compounds were characterized by IR and 1H NMR spectroscopy as well as thermogravimetric analyses. Additionally, the molecular structures of compounds 1 and 3 were elucidated by single crystal X-ray diffraction. The core structure of [(CO)4FeBi(OSiMe2tBu)]2 (1) is build up by a four-membered Bi2Fe2 ring whereas [(CO) 3FeBi3(OtBu)4{OCO(O tBu)}]2 (3) is composed of two tetrahedral FeBi 3 cluster cores that dimerise via bridging -OCO(OtBu) ligands. Analysis of the TGA residues by PXRD revealed that compound 2 is the best precursor for multiferroic BiFeO3 among the compounds studied here, although Bi25FeO39 was detected as minor impurity.
Wójcik, Katarzyna,Rüffer, Tobias,Lang, Heinrich,Auer, Alexander A.,Mehring, Michael
p. 1647 - 1651
(2011/05/28)

The reaction of ortho-halogenated aromatic aldazine ligands with Fe2(CO)9: Symmetrical cleavage of the azine and carbon-halogen activation
Azine ligands derived from hydrazine and benzaldehyde derivatives bearing halogen substituents in ortho-position with respect to the carbonyl function upon treatment with Fe2(CO)9 show two typical reaction principles. One is the symmetrical cleavage of the N-N bond of the azine to yield either di- or trinuclear iron carbonyl compounds [Fe2(CO)6(μ2-N - CHR)2] and [Fe3(CO)9(μ2-N - CHR)(μ2-η2-N - CHR)] each showing two arylidenimido moieties. In addition, a trinuclear iron carbonyl cluster compound exhibiting a tetrahedral Fe3N cluster core is isolated. The cluster shows only one half of the former azine ligand. It is a ionic compound of the general formula [Fe3(CO 9(μ3-η2-N - CHR ]Na×H2O. This trinuclear cluster compound is quantitatively converted into [Fe3(CO 9(μ2-H) (μ3-η2-N - CHR)] upon treatment with phosphorous acid. Most interestingly, we were also able to isolate two types of compounds in which an activation of one of the carbon halogen bonds in ortho-position with respect to the imine functions of the azine has occured in terms of an ortho-metallation reaction. In [Fe2(CO 6(μ3-η2-C=C(F)-C(H)= C(H)-C(H =C-CH2-N-N=CHR)] the N-N bond of the azine is still preserved, whereas in [Fe3(CO 9(μ3-η3-N - CHR)] again only one half of the former azine ligand is coordinated in an arylidenimido fashion. In both types of compounds one additional iron carbon bond is present due to the activation of an aromatic carbon halogen bond. The reaction of iron carbonyls with 2,6-difluorobenzonitrile produces [Fe3(CO )9(μ3-η2-N≡CR)] as the sole product. All new iron carbonyl compounds are characterized by means of X-ray crystallography.
D?nnecke, Daniel,Halbauer, Kathi,Imhof, Wolfgang
p. 2707 - 2719
(2007/10/03)

A novel facet of carbonyliron-diene photochemistry: The η4-s-trans isomer of the classical Fe(CO)3(η4-s-cis-1,3-butadiene) discovered by time-resolved IR spectroscopy and theoretically examined by density functional methods
The photolysis of Fe(CO)3(η4-s-cis-1,3-butadiene) (1) and Fe(CO)4(η2-1,3-butadiene) (2), formerly studied in low-temperature matrixes, is reexamined in cyclohexane solution at ambient temperature using time-resolved IR spectroscopy in the v(CO) region. Flash photolysis of 2 (λexc = 308 nm) generates Fe(CO)3(η4-s-trans-1,3-butadiene) (5) as a transient product, which then rearranges to form the classical η4-s-cis-1,3-butadiene complex 1. Species 5, previously addressed as the coordinately unsaturated Fe(CO)3(η2-1,3-butadiene) (3), is also photogenerated from 1, in this case along with the very short-lived CO loss fragment Fe(CO)2(η4-1,3-butadiene) (τ ? = 17.3 kcal·mol-1) with nearly complete recovery of 1. According to density functional calculations at the BP86 level of theory, 5 resides in a distinct energy minimum, 20.3 kcal·mol-1 above 1 and separated from it by a barrier of 15.0 kcal·mol-1. Its computed structure involves a diene dihedral angle of 129°. Species 3 (with a diene dihedral angle of -150.1°), by contrast, is predicted to exist in a rather flat minimum, which makes it too short-lived for detection with our instrumentation. Flash photolysis of Fe(CO)5 generates the very short-lived (3(solv) species in addition to the familiar Fe(CO)4(solv) fragment (τ = 10-15 μs), Fe2(CO)9 being the ultimate product in the absence of potential trapping agents other than CO. Deliberate contamination of the system with water gives rise to the formation of Fe(CO)4(H2O) as a longer lived transient (ca. 1 ms). In the presence of 1,3-butadiene, both 2 and 5 appear almost instantaneously. The latter decays, again in the millisecond time range, with formation of 1, thus providing clear evidence of a single-photon route from Fe(CO)5 to 1 in addition to the established two-photon sequence via the monosubstituted complex 2.
Bachler, Vinzenz,Grevels, Friedrich-Wilhelm,Kerpen, Klaus,Olbrich, Gottfried,Schaffner, Kurt
p. 1696 - 1711
(2008/10/08)

Synthesis and characterization of organometallic complexes, [C8H4N2CH2BrCH 2Fe(CO)4][C8H11Fe(CO)3] and [(C8H11)2Fe3(CO)10] obtained by ion pair annihilation reactions
Photochemical reaction of 1,5-cyclooctadiene with Fe(CO)5 gives the complex 1,5-cyclooctadienetricarbonyliron 1, which on treatment with Ph3CBF4 at room temperature affords the dienyl salt 1,5-cyclooctadienyltricarbonyliron tetrafluoroborate, [C8H11Fe(CO)3I+BF4 - 2. 2-Bromomethyl-3-σ-methylenequoinoxaline sodiumtetracarbonylferrate [C8H4N2CH2BrCH 2Fe(CO)4Na] 3 reacts with the dienyl salt in THF at low temperature to give a novel organometallic complex [C8H4N2CH2BrCH 2Fe(CO)4]- [C8H11Fe(CO)3] 4 by ion pair annihilation reaction. Similarly, the dienyl salt on nucleophilic attack by metal carbonylate anion [Na2Fe(CO)4] 5 gives an organometallic complex [(C8H11)2Fe3(CO)10] 6 at -10°C.
Ullah,Shamsur Rahman,Alam,Haque
p. 456 - 459
(2007/10/03)

Preparation and properties of carbonyliron complexes of 1-aza-4-oxa-1,3- butadiene (α-imino ketone) - X-ray crystal structures of Fe(CO)3[MeN=C(Ph)C(Ph)=O] and Fe2(CO)4[tBuN=C(H)(Me)C(O)(O)C(Me)C(H)=NtBu]
The reaction of Fe2(CO)9 at room temperature in THF or toluene with the α-imino ketones R1N=C(R2)-C(R3)=O (L) (R1 = alkyl, R2 = H, Me, Ph, R3 = Me, Ph) (a-k), initially results in the formation of the mononuclear chelate Fe(CO)3(α-imino ketone) complexes 6 which can be isolated in moderate (6h) to high (6e-g) yield. Under these reaction conditions, complexes 6 subsequently react with [Fe(CO)4] fragments or dimerise, to form the dinuclear complexes Fe2(CO)6(α-imino ketone) (7a-j) or Fe2(CO)4(L-L) (8a,b,k), respectively. The complexes 8 contain two α-imino ketone ligands C-C coupled at the ketone carbon atoms. Complexes 8a,b react with CO at elevated temperatures to quantitatively yield Fe(CO)3(α-imino ketone) (6a,b). This reaction can be reversed photochemically. Irradiation of a solution of 6a,b in the low-energy band results in the reformation of 8a,b in almost quantitative yield. The extremely air-sensitive complexes 6 and the dinuclear complexes 7 and 8 have been characterised spectroscopically (IR, UV/Vis, 1H and 13C NMR) and by elemental analysis. The solid state structures of complexes 6g and 8a have been determined by single-crystal X- ray diffraction. The molecular structure of 6g confirms the flat σ-O, σ-N chelate coordination of the α-imino ketone. The structure of 8a consists of two metal-metal-bonded Fe(CO)2 units, bridged by a formally 10e-donating dianionic C-C coupled (tBu-ADO) ligand. A mechanism for the formation of complexes 8 is discussed.
Siebenlist, Ron,Fruehauf, Hans-Werner,Vrieze, Kees,Smeets, Wilberth J. J.,Spek, Anthony L.
p. 907 - 919
(2007/10/03)

Reactivity of naphthylimines toward Fe2(CO)9: observation of three different hydrogen migration pathways
The reaction of Fe2(CO)9 with imine ligands derived from α- or β-naphthylcarbaldehydes leads to the formation of a series of iron carbonyl complexes. Most of them are produced by a C-H activation reaction in ortho position with respect to the exocyclic imine function. The reaction then proceeds via subsequent intramolecular hydrogen shift reactions and leads to several dinuclear compounds. Three different types of these hydrogen-transfer reactions were observed: a 1,3 hydrogen shift toward the former imine carbon atom, a 1,4 hydrogen shift toward the former imine nitrogen atom, or a 1,3 shift reaction toward one of the aromatic carbon atoms of the naphthalene system, which thus leaves the exocyclic imine function unreacted. In the reaction of β-naphthyl derivatives the formation of trinuclear complexes is observed by the η4-coordination of a third Fe(CO)3 group to the second ring of the naphthalene. Besides this, the first example of a structurally characterized (η4-1-azadiene)-Fe(CO)3 complex with the C-C double bond formally being part of a cyclic aromatic system is obtained as a byproduct.
Imhof, Wolfgang
p. 4845 - 4855
(2008/10/08)

Organometallics of transition metals in supercritical carbon dioxide: Solubilities, reactions, catalysis
Monomeric compounds of the type Cp2M (p.e. M = Fe, Co, Ni) are soluble in liquid or supercritical CO2 ( ScCO2 ) without any reaction with the solvent. The polymeric compounds zincocene or manganocene form with CO2 insoluble CO2 insertion products. As well homoleptic metal carbonyls as a number of ligand-stabilized metal carbonyls are also soluble in scCO2. Fe(CO)5 reacts photochemically in this solvent to Fe2(CO)9 and thermically to Fe3(CO)12. The highly reactive (cdt)Ni(0) (cdt: cyclododeca-1,5,9-triene) is soluble in liquid CO2. A reaction with the solvent could not been observed. Solved in scCO2 (cdt)Ni reacts thermically to form Ni after a short time. CpCo(cod) catalyzes slowly the cyclo-cooligomerization of hex-3-yne with acetonitrile to form 2,3,4,5-Tetraethyl-6-methylpyridine. Propargylic alcohol reacts under formation of cyclotetrameres with a selectivity of 90% using (cod)2Ni or (cdt)Ni as catalysts, hex-3-yne in and with carbon dioxide under selective formation of tetraethyl-2-pyrone when the catalyst system R3P/(cod)2Ni (R: Me, Et) is used. In situ IR measurements show that the catalytically active species will be desactivated by formation of nickel carbonyl complexes. The catalytic oxidation of cyclooctene to form cycloocteneoxid with t-BuOOH using Titan(IV)-isopropylate as soluble catalyst proceeds less selectively, however in the presence of Mo(CO)6 the epoxid is formed in good yields and in a highly selective reaction.
Kreher, Ulf,Schebesta, Sebastian,Walther, Dirk
p. 602 - 612
(2008/10/09)

Cluster Expansion Reactions of Group 6 Metallaboranes. Syntheses, Crystal Structures, and Spectroscopic Characterizations of (Cp*Cr)2B5H9, (Cp*Cr)2B4H8Fe(CO)3, (Cp*Cr)2B4H7Co(CO)3, and (Cp*Mo)2B5H9Fe(CO)3
The targeted high-yield syntheses of a number of new clusters by the controlled addition of BH, Fe(CO)3, or Co(CO)3 fragments to dinuclear group 6 metallaboranes are reported. The reaction of the chromaborane, (Cp*Cr)2B4H8 (1), Cp* = η5-C5Me5, with BHCl2·SMe2 results in a cluster expansion reaction giving the green-brown diamagnetic species (Cp*Cr)2B5H9 (2) in 43% yield. The six skeletal electron pair (sep) cluster has a structure based on a trigonal bipyramidal Cr2B3 unit with adjacent Cr2B faces capped by BH3 fragments. Reaction of 1 with the dinuclear metal carbonyls Fe2(CO)9 and Co2(CO)8 leads to the isolation of the mixed-metal metallaboranes (Cp*Cr)2B4H8Fe(CO)3 (3) and (Cp*Cr)2B4H7Co(CO)3 (4) in yields of 76 and 87%, respectively. 3 and 4 can also be viewed as six-sep bicapped trigonal bipyramidal clusters with the metal carbonyl occupying one of the capping positions. Alternatively, they can be viewed as complexes between M(CO)3 transition metal fragments (M = Fe, Co) and the four-electron (Cp*Cr)2B4H8 (M = Fe) or three-electron (Cp*Cr)2B4H7 (M = Co) ligands. In this way, by forming two M-Cr bonds and utilizing either one (M = Co) or two (M = Fe) BH→M donor-acceptor bonds, each metal attains an 18-electron configuration. At elevated temperatures (ca. 80 °C), 3 is fluxional, with the Fe(CO)3 fragment swinging between equivalent pairs of BH2 donor groups. Reaction of the molybdaborane (Cp*Mo)2B5H9 (5) with Fe2(CO)9 gives the orange mixed-metal cluster (Cp*Mo)2B5H9Fe(CO)3 (6) in 48% yield. 6 has a bicapped octahedral geometry with the Fe(CO)3 fragment occupying one of the high-connectivity cluster vertexes, rather than a capping position. That 5 undergoes the expected geometric changes (bicapped trigonal bipyramid → bicapped octahedron) on addition of the two-electron Fe(CO)3 fragment (giving 6) contrasts with the minimal structural perturbation on addition of the same fragment to 1 (yielding 3). This in turn provides further evidence for the description of 1 as an electronically unsaturated cluster.
Aldridge, Simon,Hashimoto, Hisako,Kawamura, Kazumori,Shang, Maoyu,Fehlner, Thomas P.
p. 928 - 940
(2008/10/08)

C,H bond activation of imino substituted heterocycles: Synthesis and crystal structure of [μ2-η3-( R) N-CH2-C=C-C(H) =C(H)-X ]Fe2( CO) 6 and the isomeric clusters [μ2-η3-(R)N-CH2-C=C-X-C(R′)=C(R″)]Fe2(CO)6
The reaction of Fe2(CO)9 with heterocyclic imines derived from thiophene-2-carbaldehyde or N-methyl-pyrrole-2-carbaldehyde produces the dinuclear compounds [μ2-η3-(R)N-CH2-C=C-C(H)-X(H)-X]Fe2(CO)6 (R = Ph, C6H11, p-tBu-C6H4; X = S, NMe). The analogous reaction with imines of thiophene-3-carbaldehyde or indole-3-carbaldehyde yields the corresponding isomeric clusters [μ2-η3-(R)N-CH2-C=C-X-C(R′)=C(R″)Fe2(CO)6 (R = Ph, C6H11, R′ = R″ = H, X = S; R = Ph, p-tBu-C6H4, R′ = R″ = -C6H4-, X = NH). The reaction proceeds via activation of the C,H bond in β-position relative to the exocyclic C,N double bond of the imine ligands. A 1,3 hydrogen shift reaction then leads to the formation of a methylene group instead of the former imine carbon atom. So, the imine ligands are transformed into μ2-η3-enyl-amido ligands being coordinated to an Fe2(CO)6 moiety, which is confirmed by X-ray structure analyses of six compounds.
Imhof, Wolfgang
p. 31 - 43
(2007/10/03)

Organometallic Iron Indium Derivatives Prepared by the Reaction of Carbonyliron Compounds with the Alkylindium(I) Derivative In4[C(SiMe3)3]4
The monomeric fragment In-C(SiMe3)3 with a monovalent indium atom is isolobal with carbon monoxide. It is probably formed as a reactive intermediate on heating solutions of the tetrahedral cluster compound In4[C(SiMe3)3]4 (1) in hexane and reacts with Fe3(CO)12 and Fe2(CO)9 to yield by the substitution of bridging CO ligands three novel iron indium compounds, Fe3(CO)10(μ-InR)2 (2), Fe2(CO)8(μ-InR) (3), and Fe2(CO)6(μ-CO)(μ-InR)2 (4), which all were characterized by crystal structure determinations (2: C30H54Fe3In2O10Si 6, monoclinic, P21, a = 1436.1(2) pm, b = 1992.9(3) pm, c = 1764.8(3) pm, β= 107.02(2)°. 3: C18H27Fe2InO8Si3, monoclinic, C2/c, a = 1527.8(3) pm, b = 960.3(2) pm, c = 3755.4(8) pm, β= 90.17(3)°. 4: C27H54Fe2In2O7Si 6, triclinic, P1?, a = 959.3(1) pm, b = 1506.7(2) pm, c = 1561.4(1) pm, α = 86.11(1)°, β= 88.76(1)°, γ = 73.57(1)°). While both products 2 and 4 are isostructural with the pure carbonyls with two or three bridging groups, respectively, compound 3 has only one bridging InR group besides eight terminal carbonyl ligands. The Fe-In bond lengths are quite similar (255.9-260.5 pm), but the Fe-Fe distances differ significantly with 286.7(1) pm for the bridged Fe-Fe bond in 2, 289.3(1) pm in 3, and 275.87(5) pm in 4. They all are much elongated compared to the starting carbonyl complexes.
Uhl, Werner,Keimling, Sven Uwe,Pohlmann, Michael,Pohl, Siegfried,Saak, Wolfgang,Hiller, Wolfgang,Neumayer, Markus
p. 5478 - 5482
(2008/10/09)

Lewis base stabilized transition metal complexes of divalent silicon species
A direct photochemical synthesis of silanediyl-iron tetracarbonyl complexes Ph2Si(B)=Fe-(CO)4 [B = 1,3-dimethylimidazolidinone (DMI) or hexamethylphosphoric triamide (HMPA)] is described. The Lewis base character of DMI is strong eno
Chauhan, Bhanu P. S.,Corriu, Robert J. P.,Lanneau, Gérard F.,Priou, Christian,Auner, Norbert,Handwerker, Hermann,Herdtweck, Eberhardt
p. 1657 - 1666
(2008/10/09)

Charge-transfer crystals of octacarbonyldiferrate. Solid-state structure and oxidation-reduction of an iron-iron-bonded electron donor
The dinuclear carbonylmetalate [Fe2(CO)8]2- forms deeply colored crystals A2[Fe2(CO)8] with various phosphonium and pyridinium cations (A+) by metathesis in aqueous solution. Diffuse reflectance absorption spectroscopy and X-ray crystallography establish the colors to derive from anion-to-cation charge-transfer (CT) within the triple ion [A+, Fe2(CO)82-, A+] extant in the solid state. Partial electron transfer in the charge-transfer salts is established by the significant shortening of the iron-iron bond in the [Fe2(CO)8]2- moiety when it is ion paired with the N-methyllutidinium acceptor. In solution, the charge-transfer salts can undergo interionic electron transfer, and they lead to the dimeric A2 and a series of iron carbonyl products that are uniquely dependent on the solvent (water, ether, and acetonitrile).
Bookman,Cho,Kochi
p. 5221 - 5231
(2008/10/09)

Synthesis, Structure, and Ligand Behavior of the 1,2-Diphosphaferrocene 5-1,3-tBu2C5H3)(η5-Fe>
Reaction of equimolar amounts of (η5-1,3-tBu2C5H3)(CO)2FeP(SiMe3)2 with bis(trimethylsilyl)methylenechlorophosphane afforded the 1-metallo-1,2-diphosphapropene (η5-1,3-tBu2C5H3)(CO)2FeP(SiMe3)P=C(SiMe3)2 (1b).Treatment of 1b with an excess of Cr(CO)5 furnished 1,2-diphosphaferrocene (η5-1,3-tBu2C5H3)(η5--3,4-(Me3SiO)2-5-(Me3Si)P2C3>Fe (4b).Chromium complex 4b was freed from the pentacarbonylchromium fragment by heating with 1.5 equiv. of in toluene solution at 80-90 deg C affording sandwich 5.In contrast, treatment of 4c with in refluxing n-pentane yielded the trinuclear complex (η5-1,3-tBu2C5H3)5-1,2--3,4-(Me3SiO)2-5-(Me3Si)P2C3>Fe (6).The ligation of sandwich 5 to the unit in 7 was achieved by irradiation with in n-pentane solution.A tricarbonylnickel adduct 8 resulted from the reaction of 4b with an excess of in toluene at ambient temperature.The molecular structures of the complexes 6 and 8 were established by single-crystal X-ray structure analyses.Cyclovoltammetric studies with 4b, 5, and 8 revealed an anodic shift of the oxidation potential when changing from 5 to 8 and 4. - Keywords: 1,2-Diphosphaferrocene; Carbonylmetal complexes; Metallo-diphosphapropene
Weber, Lothar,Sommer, Oliver,Stammler, Hans-Georg,Neumann, Beate,Koelle, Ulrich
p. 665 - 672
(2007/10/03)

Substituted Variants of the Cluster Type Fe3(CO)9(μ3-η2-RCN)
Various aromatic nitriles were used for the preparation of the nitrile-capped clusters Fe3(CO)9(μ3-η2-RCN) (2) by reaction with Fe3(CO)12 under hydrogen.Electron-rich nitriles decrease, electron-poor nitriles increase the thermal stability of cluster 2.With CN-substituted pyridines only traces of cluster 2 could be obtained.CO replacement in Fe3(CO)9(PhCN) (2a) by isonitriles also causes a lowering of the stability.Conversely, more stable products were obtained by substitution reaction with trimethyl phosphite.On PPh3 and two dppm derivatives were also obtained.The structure of Fe3(CO)8-P(OMe)3(μ3-η2-PhCN (5a) was determined. - Keywords: Triiron clusters / Capping nitrile ligands / Phosphine substitutions / Structure determination
Suter, Pierre,Vahrenkamp, Heinrich
p. 793 - 798
(2007/10/02)

Synthesis of [AsPh4][Fe3(CO)9(μ-CO)(μ 3-HBCl)] by oxidative chloride substitution of [Fe3(CO)9(μ3-HBCO)]2-
The deprotonation of (μ-H)Fe3(CO)9(μ-CO)(μ3-HBH) with n-butyllithium yields the dianionic complex [Li]2[Fe3(CO)9(μ3-HBCO)], which has been spectroscopically characterized. In contrast to the facile reprotonation of closely related ferraboranes, protonation of [Li]2[Fe3(CO)9(μ3-HBCO)] leads to decomposition. On the other hand, reaction of this dianionic complex with 2 equiv of FeCl3 gives a good yield of [Li][Fe3(CO)9(μ-CO)(μ3-HBCl). Metathesis with [AsPh4][Cl] yields [AsPh4][Fe3(CO)9(μ-CO)(μ 3-HBCl)], which has been crystallographically characterized (triclinic, P1, a = 9.534(3) A?, b = 13.305(4) A?, c = 15.225(4) A?, α = 104.39(2)°, β = 103.56(2)°, γ = 99.23(2)°, V = 1768.7(8) A?3, Z = 2). Comparison with the analogous osmium clusters, as well as isoelectronic organometallic clusters, reveals relationships among their structures, properties, and energetics.
Crascall, Louise E.,Thimmappa,Rheingold, Arnold L.,Ostrander, Robert,Fehlner, Thomas P.
p. 2153 - 2158
(2008/10/08)

Preparation of [K][In{Fe2(CO)8}2](THF) and Fe2{μ-InCl(THF)}2(CO)8 (THF = tetrahydrofuran)
The compound [K][In{Fe2(CO)8}2](THF) (1) (THF = tetrahydrofuran) has been synthesized by the reaction of Fe3(CO)12 with activated indium powder in the presence of potassium chloride. A single-crystal X-ray structure determination shows the iron atoms of two Fe2(CO)8 units bound to the indium in a pseudotetrahedral fashion and the potassium ion coordinated to a molecule of THF and two carbonyl oxygen atoms from each of four of the iron-indium anions to give a total coordination number of 9. Crystal data: tetragonal space group P4/n (No. 85), a = 11.850(2) ?, c = 10.696(2) ?, V = 1502.0(5) ?3, Z = 2, R = 3.61%, Rw = 5.04%. The complex Fe2{μ-InCl(THF)}2(CO)8 (2) can be prepared in high yield by the reaction of either Na2Fe(CO)4 or Na2Fe2(CO)8 with indium(III) chloride or via the reaction of Fe3(CO)12 with indium(I) chloride in tetrahydrofuran. Mechanistic studies suggest that these three reactions produce the same intermediate species, Fe(CO)4(THF) and InCl, which then combine to give the observed product. Fe2{μ-InCl(THF)}2(CO)8 forms an adduct with bromide ion in the presence of tetrabutylammonium bromide, and the complex [(C4H9)4N]2[Fe 2{μ-InClBr}2(CO)8] (3) has been characterized crystallographically. Crystal data: triclinic space group P1 (No. 2), a = 11.510(2) ?, b = 11.905(1) ?, c = 12.200(2) ?, α = 90.373(9)?, β = 117.08(1)°, γ = 107.75(1)°, V = 1396.6(5) ?3, Z = 1, R = 4.61%, Rw = 5.94%.
Lin, Chu-Chieh,Kong, Gapgoung,Cho, Hyunho,Whittlesey, Bruce R.
p. 2705 - 2710
(2008/10/08)

Interconversions Between Ru3-Bound Azoalkane and Dialkylhydrazine-Derived Building Units
Reactions involving hydrogen transfer have been investigated starting from the azoalkane-bridged clusters Ru3(CO)9(RCH2N=NCH2R) (1a, R = H; 1b, R = Me).In boiling toluene they are isomerized to the hydrazonide-bridged clusters HRu3(CO)9(RCH2N-N=CHR) (2a, R = H; 2b, R = Me).Pd/C-catalyzed hydrogenation converts both compounds types into the hydrazide-bridged clusters HRu3(CO)9(RCH2N-NHCH2R) (3a, R = H; 3b, R = Me).Hydride attachment to 1 and 2 and deprotonation of 3 yield a common anionic intermediate 4 which is converted into 3 upon protonation.While deuteration experiments and NMR spectra indicate that the anionic intermediate equilibrates between the N-H and Ru-H isomers, aurations of deprotonated clusters with Ph3PAuCl yield the Ru-Au-connected clusters Ph3PAuRu3(CO)9(EtN-N=CHMe) (5) and Ph3PAuRu3(CO)9(MeN-NHMe) (6).The reversible cluster expansion of 2b with Fe(CO)3 fragments which results in the formation of FeRu3(CO)12(μ4-ν2-N2Et2) (7) involves a reversible reconversion of the hydrazonide ligand to the azoalkane ligand. - Key Words: Ruthenium clusters/ Azoalkane ligands/ Hydrazine-derived ligands/ Interconversions
Hansert, Bernhard,Vahrenkamp, Heinrich
p. 2011 - 2016
(2007/10/02)

Trinuclear and tetranuclear iron/ruthenium carbonyl clusters stabilized by bridging selenium ligands
At room temperature, Fe2(CO)6(μ-Se2) reacts with Ru3(CO)12 to form Fe2Ru3(CO)17(μ4-Se)(μ3-Se), and with Ru(CO)4(C2H4) to form Fe2Ru(CO)9(μ3-Se)2. The latter reacts with Fe(CO)5 under visible light irradiation to give Fe3Ru(CO)11(μ4-Se)2, and with Ru(CO)4(C2H4) to form Fe2Ru2(CO)11(μ4-Se)2. Visible light irradiation of a solution containing Fe3(CO)9(μ3-Se)2 and Fe(CO)5 yields Fe4(CO)11(μ4-Se)2. A solution containing Fe3(CO)9(μ3-Se)2 and Ru(CO)4(C2H4) at room temperature with stirring yielded Fe3Ru(CO)11(μ4-Se)2.
Mathur, Pradeep,Hossain, Md. Munkir,Rashid, Raad S.
p. 83 - 86
(2007/10/02)

Structure and photochemistry of new base-stabilized silylene (silanediyl) complexes R2(HMPA)Si=M(CO)n of iron, chromium, and tungsten (R = t-BuO, t-BuS, MesO, 1-AdaO, 2-AdaO, NeopO, TritO, Me, Cl; M = Fe, n = 4; M = Cr, W, n = 5): Sila-Wittig reaction of the base-free reactive intermediate [Me2Si=Cr(CO)5] with dimethyl carbonate
The reaction of the dichlorosilanes R2SiCl2 (R = t-BuO, t-BuS, MesO (Mes = mesityl), 1-AdaO (Ada = adamantyl), 2-AdaO, NeopO (Neop = neopentyl), TritO (Trit = triphenylmethyl), Me, Cl) with the carbonylate dianions M(CO)n2- (M = Fe, n = 4; M = Cr, W, n = 5) in the presence of HMPA (hexamethylphosphoric triamide) affords an effective access to the base-stabilized silylene complexes R2-(HMPA)Si=M(CO)n. Single-crystal X-ray structure analyses of the iron complexes Me2(HMPA)Si=Fe(CO)4 (4) and Cl2(HMPA)Si=Fe(CO)4 (5) and the chromium compounds Me2(HMPA)Si=Cr(CO)5 (7) and Cl2(HMPA)Si=Cr(CO)5 (8) have been performed and are compared with the previously determined structures of (t-BuO)2(HMPA)Si=Fe(CO)4 (1) and (t-BuO)2(HMPA)Si=Cr(CO)5 (6). The structures feature relatively short M-Si bond lengths with d(FeSi) = 2.280 (1)/2.294 (1) (4) and 2.214 (1)/2.221 (1) ? (5) and d(CrSi) = 2.410 (1) (7) and 2.342 (1) (8). In contrast, the Si-O (HMPA) bonds are fairly long (1.735 (3)/1.731 (3) (4), 1.683 (3)/1.676 (3) (5), 1.743 (2) (7), 1.690 (2) ? (8)). The coordination geometry at silicon is significantly distorted from tetrahedral and subject to strong substituent effects. Both metal-silicon bond lengths and the coordination geometry at silicon in the coordination compounds correlate to frontier orbital energies and electron population densities of the free silylenes. Data from cyclic voltammetric measurements are in agreement with this description. A M?ssbauer spectrum of 1 shows an unusual negative isomer shift of -0.477, which indicates particularly for the TBP d8 compounds 1-5 (axial silylene coordination) a high ionic contribution of the Fe-Si bond in the sense of a betaine structure. The relative orientation of the substituents at silicon, as found in the crystal, is reproduced by a force field calculation as the global energy minimum. VT NMR experiments show the fluxionality of the ligand framework of the TBP Fe d8 complexes at room temperature. The free energy of activation for the Berry pseudorotation process is ΔG250.0? = 40.3 (±5) kJ/mol. A reactivity study of the base adducts 1, 4, and 6 shows the photochemical activation of the silylenes: In the presence of triphenylphosphine, the trans phosphine complexes trans-(t-BuO)2Si(HMPA)=Fe(CO)3P(C6H 5)3 (23), trans-Me2Si(HMPA)=Fe(CO)3P(C6H 5)3 (24), and trans-(t-BuO)2Si(HMPA)=Cr(CO)4P(C6H 5)3 (26) are obtained by a photochemical CO displacement reaction. Subsequently, the silylenes are displaced by a further phosphine molecule to yield the trans-bis(phosphine) complexes trans-{P(C6H5)3}2Fe(CO)3 (25) and trans-{P(C6H5)3}2Cr(CO)4 (27). The liberated silylenes form polysilanes; di-tert-butoxysilylene can be trapped in the presence of 2,3-dimethylbutadiene by an 1,4-addition to form the silacyclopentene Si(t-BuO)2CH2C(CH3)=C(CH3)CH 2 (28) (photolysis of 1). As a secondary photolysis product, (2,3-dimethylbutadiene)iron tricarbonyl, (η4-C6H4)Fe(CO)3 (29), is isolated. The base-free complex [Me2Si=Cr(CO)5] is generated in situ from Me2SiCl2 and Na2Cr(CO)5 at -50°C as a reactive intermediate and yields a variety of interesting trapping reactions: in the presence of HMPA the stable HMPA adduct 7 is formed; the thermolabile THF adduct Me2Si(THF)=Cr(CO)5 (32) dimerizes above -40°C to give 21. With dimethyl carbonate as the trapping reagent, [Me2Si=Cr(CO)5] undergoes a sila-Wittig reaction to form hexamethyltrisiloxane, [Me2SiO-]3 (30), and (dimethoxycarbene)chromium pentacarbonyl, (MeO)2C=Cr(CO)5 (31).
Leis, Christian,Wilkinson, Dallas L.,Handwerker, Hermann,Zybill, Christian,Müller, Gerhard
p. 514 - 529
(2008/10/08)

Synthesis and solution properties of the boron-containing clusters HM4(CO)12BAu2(dppf) (M=Fe or Ru) and the competitive formation of 2(dppf) for M=Ru (dppf=1,1'-bis(diphenylphosphino)ferrocene). Molecular structure of HRu4(CO)12BAu2(dppf)*2CHCl3
The reaction of (M=Fe or Ru) with ClAu(dppf)AuCl (dppf=1,1'-bis(diphenylphosphino)ferrocene) leads to HM4(CO)12BAu2(dppf) in which the environment of the boron atom depends upon the identity of M.For M=Ru, the boron atom is interstitial, with the hydride ligand wholly associated with the tetraruthenium framework.For M=Fe, an isomer equilibrium exists in solution between a metallaborane and a metallaboride cluster with the former, Fe4(CO)12BHAu2(dppf) (1) being the dominant species.The difference in structure is attributed to the increase in size of the tetrametal butterfly framework from Fe4 to Ru4 and follows the pattern previously noted for HM4(CO)12BAu2(PPh3)2.For M=Ru, the formation of HRu4(CO)12BAu2(dppf) (3) competes with that of the linked bicluster 2(dppf) (2).A crystallographic structural determination of 3 has revealed that the hexametal skeleton in 3 encapsulates the boron atom but is non-octahedral.The two Au atoms are related by a molecular C2 axis and each bridges one B-Ruwingtip edge.The orientation of the ferrocenyl group with respect to the cluster core is controlled by the location of the gold atoms and the two C5 rings are locked in an approximately mutually eclipsed position.In solution, 1H NMR spectroscopy in the Cp region has been used to study the fluxional behaviour of 3; three processes are mutually dependent (i) a rocking motion of the two Au atoms with respect to the Ru4B core (ii) inversion at the phosphorus atoms (iii) cyclopentadienyl ring twisting.
Draper, Sylvia M.,Housecroft, Catherine E.,Rheingold, Arnold L.
p. 9 - 20
(2007/10/02)

Azoalkane- and Nitrene-Bridged Carbonyl Metal Clusters of Iron and Ruthenium
By using cluster buildup reactions, the new azoalkane-bridged clusters Ru3(CO)9(RN=NR) (3a, R = Me, 3b, R = Et), Fe2Ru(CO)9(EtN=NEt) (4), Ru4(CO)12(RN=NR) (5a, R = Me, 5n, R = Et), and FeRu3(CO)12(EtN=NEt) (6) were obtained.Upon attempts to prepare further such compounds, the N-N bond was cleaved resulting in nitrene-bridged clusters including the new compound Fe4(CO)11(Μ4-NEt)2 (9).Cluster buildup starting from Ru3(CO)9(μ3-NPh)2 resulted in Ru4(CO)11(μ4-NPh)2 (10) and FeRu3(CO)11(μ4-NPh)2 (11).The crystal structures of 5n and 9 as well as some reactions of the nitrene-bridged clusters are described.Key Words: Clusters, trinuclear and tetranuclear / Iron clusters / Ruthenium clusters / Azoalkane and nitrene bridging
Hansert, Bernhard,Powell, Anne K.,Vahrenkamp, Heinrich
p. 2697 - 2704
(2007/10/02)

Electron transfer between mononuclear metal carbonyl anions (M(CO)5-, M = Mn, Re; CpFe(CO)2-; CpM(CO)3-, M = Cr, Mo) and trinuclear clusters (M3(CO)12, M = Fe, Ru, Os) and between trinuclear dianions (M3(CO)112-, M = Fe, Ru, Os) and metal carbonyl dimers (Mn ...
Full title: Electron transfer between mononuclear metal carbonyl anions (M(CO)5-, M = Mn, Re; CpFe(CO)2-; CpM(CO)3-, M = Cr, Mo) and trinuclear clusters (M3(CO)12, M = Fe, Ru, Os) and between trinuclear dianions (M3(CO)112-, M = Fe, Ru, Os) and metal carbonyl dimers (Mn2(CO)10 and Cp2M2(CO)6, M = Cr, Mo, W). Reaction of mononuclear metal carbonyl anions with trinuclear clusters of group 8 (M3(CO)12, M = Fe, Ru, Os) at ambient conditions leads to four separate outcomes: (1) formation of the metal carbonyl dimer and the trinuclear dianion which occurs whenever the two-electron reduction potential for the dimer is more negative than for the trinuclear cluster, (2) formation of MFe2(CO)7- by elimination of Fe(CO)5 which occurs for M = Re(CO)5, Mn(CO)5, and CpMo(CO)3, (3) formation of the adduct, MRu3(CO)11-, which occurs for Re(CO)5, and (4) no reaction when the two-electron reduction potential for the trinuclear complex is more negative than for the dimer. For complexes where the two-electron potential for the cluster is more negative than for the dimer, reaction of M3′(CO)112- with M2 to give M3′(CO)12 and 2M- is observed. The observed reactions allow an estimate of the two-electron reduction potentials for the trinuclear clusters. The kinetics of all of these reactions indicate a first-order dependence on the oxidant and on the reductant and are most consistent with outer-sphere electron transfer.
Shauna Corraine,Atwood, Jim D.
p. 2647 - 2651
(2008/10/08)

Clusters metalliques moleculaires synthetises par voie radiolytique
The radiolytic reduction of metal ions in alcohols has been achieved under CO atmosphere.Under such conditions, metal reduction, ligation and aggregation processes compete, leading to metal complexes and molecular clusters.These products are interesting for catalytic purposes.We report here the radiolytic synthesis of compounds of Fe, Ru, Os, Co, Ir, Rh, Pt, Cu, Ag, and of some intermetallic compounds.These syntheses are carried out under very mild temperature and pressure conditions (i.e., room temperature and at most 1 atmosphere of CO).Factors favoring a high nuclearity are the concentration, the high atomic number, a weak ligand/metal ratio.It is shown that chloride ions are inhibitors of complete reduction.
Remita, H.,Derai, R.,Delcourt, M. O.
p. 845 - 854
(2007/10/02)

Unusual iron-iron and Ruthenium-Ruthenium single bonds doubly bridged by two Cu(PR3) fragments: Syntheses of iron-copper, iron-silver, and Ruthenium-copper heterometallic complexes and structures of M2(CO)8(μ-CuPCy3)2 (M = Fe, Ru), [PPh4][Fe2(CO)8(μ-CuPCy3)], and [PPh ...
Full title: Unusual iron-iron and Ruthenium-Ruthenium single bonds doubly bridged by two Cu(PR3) fragments: Syntheses of iron-copper, iron-silver, and Ruthenium-copper heterometallic complexes and structures of M2(CO)8(μ-CuPCy3)2 (M = Fe, Ru), [PPh4][Fe2(CO)8(μ-CuPCy3)], and [PPh4]2{[Fe2(CO)8] 2[μ4-η2-Cu2(Cy 2PCH2CH2PCy2)]}. Heterometallic tetranuclear clusters M2(CO)8(μ-M′PCy3)2 (M = Fe, M′ = Cu (1); M = Fe, M′ = Ag (2); M = Ru, M′ = Cu (3)), trinuclear clusters X[M2(CO)8(μ-M′PCy3)] (X = Na, M = Fe, M′ = Cu (4a); X = PPh4, M = Fe, M′ = Cu (4b); X = PPh4, M = Fe, M′ = Ag (5); X = PPh4, M = Ru, M′ = Cu (6)), and the hexanuclear complex [PPh4]2{[Fe2(CO)8] 2[μ4-η2-Cu2(Cy 2PCH2CH2PCy2)]} (7) are synthesized from reactions of the transition-metal carbonylates [M2(CO)8]2- (M = Fe, Ru) with mixtures of [Cu(CH3CN)4][PF6] or AgBF4 and the phosphine ligand tricyclohexylphosphine (PCy3) or 1,2-bis(dicyclohexylphosphino)ethane (Cy2PCH2CH2PCy2). The molecular structures of 1,3,4b·0.5THF, and 7 were determined from single-crystal X-ray data. The structures of 1 and 3 are without precedent in that they contain Fe-Fe and Ru-Ru single bonds doubly bridged by two Cu(PCy3) fragments. The four-metal cores are of the butterfly type with dihedral angles of about 150°. Furthermore, two Cu(PCy3) fragments bridge the M-M bond in an asymmetric fashion, which might be caused by a second-order Jahn-Teller effect. In 4b, the Fe-Fe bond in the Fe2(CO)8 unit is bridged by one Cu(PCy3) fragment. In 7, two Fe2(CO)8 units are connected by a CuP(Cy2)-CH2CH2(Cy2)PCu moiety. Crystal data: Fe2(CO)8(μ-CuPCy3)2 (1), monoclinic, space group P21/c, a = 11.042 (2) A?, b = 17.321 (3) A?, c = 24.824 (6) A?, β = 92.32 (2)°, Z = 4, and R = 0.030; Ru2(CO)8(μ-CuPCy3)2 (3), monoclinic, space group P21/c, a = 11.013 (2) A?, b = 17.370 (3) A?, c = 25.169 (4) A?, β = 92.53 (1)°, Z = 4, and R = 0.022; [PPh4][Fe2(CO)8(μ-CuPCy 3)]·0.5THF (4b·0.5THF) triclinic, space group P1, a = 10.717 (2) A?, b = 11.703 (2) A?, c = 24.130 (7) A?, α = 90.62 (2)°, β = 92.32 (2)°, γ = 115.53 (1)°, Z = 2, and R = 0.075; [PPh4]2{[Fe2(CO)8] 2[μ4-η2-Cu2(Cy 2PCH2CH2PCy2)]} (7): triclinic, space group P1, a = 10.810 (1) A?, b = 11.976 (1) A?, c = 18.254 (2) A?, α = 81.11 (1)°, β = 82.32 (1)°, γ = 71.40 (1)°, Z = 1, and R = 0.032.
Deng, Haibin,Shore, Sheldon G.
p. 3486 - 3498
(2008/10/08)

η2- and η4-iron Carbonyl Complexes
Amino-vinylboranes can act as η2 (via the C=C bond) and as η4 ligands (via the C=C and B=N group) in iron carbonyl complexes.From bromo(dimethylamino)vinylborane and (dimethylamino)methylvinylborane and Fe2(CO)9 2-bromo(dimethylamino)vinylborane>tetracarbonyliron (1) and tetracarbonyl2-(dimethylamino)methylvinylborane>iron (2), respectively, are formed in the absence of light.The η2 coordination via the C=C group in 1 is proved by an X-ray structure analysis.The C2BN frame is trans-arranged.By the action of light, 1 and 2 are transferred into the very unstable tetrahapto complexes 4-bromo(dimethylamino)vinylborane>tricarbonyliron (3) and tricarbonyl4-(dimethylamino)methylvinylborane>-iron (4), which can only be investigated in solution.By using tert-butyl(dimethylamino)vinylborane the reaction leads, even in the absence of light, directly to 4-tert-butyl(dimethylamino)vinylborane)tricarbonyliron (5), a compound likewise easily unstable.The transition of the η2 into the η4 complexes can be followed IR- and 11B-NMR-spectroscopically.Key Words: Boranes, amino-vinyl- / Iron complexes
Schmid, Guenter,Alraun, Felix,Boese, Roland
p. 2255 - 2258
(2007/10/02)

A transient infrared spectroscopy study of coordinatively unsaturated osmium carbonyl compounds
Transient infrared spectroscopy is used to study the coordinatively unsaturated osmium carbonyl fragments generated by 248-nm photolysis of gas-phase Os(CO)5. The nascent photoproducts, predominantly Os(CO)3 with some Os(CO)4, are highly reactive toward combination with both CO and Os(CO)5. The bimolecular rate constants for reaction of Os(CO)3 and Os(CO)4 with CO are 7.6 ± 0.9 and 5.5 ± 0.6 × 10-11 cm3 molecule-1 s-1, respectively. Infrared absorptions for a new unsaturated osmium species, Os2(CO)8, formed by reaction of Os(CO)3 with Os(CO)5, are assigned. The rate constant for this reaction is 2.7 ± 0.9 × 10-10 cm3 molecule-1 s-1, on the order of gas kinetic. The reactivities of the unsaturated osmium species are similar to those of the analogous ruthenium compounds and contrast with the reactivity of Fe(CO)4. The trends observed in the photochemistry of group 8 metal carbonyl complexes and the role of spin selection rules in the reactivity of these coordinatively unsaturated fragments are discussed. Continuing depletion of the Os(CO)5 parent after photolysis indicates that polynuclear osmium carbonyl clusters are formed.
Bogdan, Paula L.,Weitz, Eric
p. 639 - 644
(2007/10/02)

Synthesis and reactivity of the metal-substituted borane (CO)4CoBH2·THF. Preparation of the ambiphilic clusters (CO)9Co3C(CH2)nOH (n = 4, 5)
The reaction Co2(CO)8 + 2BH3·THF → 2(CO)4CoBH2·THF (I) + H2 has been demonstrated to occur cleanly at -15°C in THF. I has been characterized by low-temperature 11B NMR and infrared spectroscopies as well as classical chemical analysis. The formation of I bears a remarkable similarity to that of (CO)4CoSiR3. Displacement of the bound THF of I occurs with Lewis bases, and the Lewis acidity of I relative to that of BH3·THF for SMe2 has been estimated. Displacement of [Co(CO)4]- from I occurs easily; e.g., reaction with PhMgBr yields PhBH2. I readily accepts hydride from [HFe2(CO)8]-, losing [Co(CO)4]- but reduces the CO ligands of hydride-free metal carbonylate anions. I is a very active reducing agent and above 10°C cleaves THF and condenses with hydrocarbyl and metal fragments to yield a mixture of clusters including an unusual tailed cluster (CO)9Co3C(CH2)nOH (n = 4,5) (II). A deuterium labeling experiment showed that four of the n carbons in the hydrocarbyl chain of II arise from THF. The results of an X-ray diffraction study suggest association of II in the solid state. [Crystals of II (the ratio of II with n = 5/n = 4 is 4) form in the space group R3 with unit cell parameters a = 34.409 (15) A?, b = 34.398 (21) A?, c = 8.575 (5) A?; β = γ = 90°, γ = 120°, V = 8789.8 A?3, and Z = 18. Solution was by direct methods, and all atoms were refined to R1 = 0.077 and R2 = 0.096 for 1443 independent reflections (Fo > 3σ(Fo)). Because of the disorder caused by the cocrystallization of species with different chain lengths, the last two atoms at the OH end of the chain could not be fully defined.] Association of II in solution is shown by a 1H NMR study, thereby demonstrating that II behaves as an ambiphilic cluster.
Basil, John D.,Aradi, Allen A.,Bhattacharyya, Nripendra K.,Rath, Nigam P.,Eigenbrot, Charles,Fehlner, Thomas P.
p. 1260 - 1270
(2008/10/08)

Synthesis of iron carbonyl clusters with trigonal-bipyramidal E2Fe3 cores (E = Ge, Si). Crystal structures of (μ3-GeEt)2Fe3(CO)9, [μ3-Ge{Fe(CO)2Cp}]2Fe3(CO) 9, and [μ3-Si{Fe(CO)2Cp}]2Fe3(CO) 9
The reaction of RGeH3 with Fe3(CO)12 at 50°C gives low-to-moderate yields of the trigonal-bipyramidal clusters (μ3-GeR)2Fe3(CO)9 (3) together with complexes tentatively identified as (μ-GeRH)2Fe2(CO)7 and (μ-GeRH)3Fe2(CO)6. A superior route to clusters 3 is from RGeH3 and Fe(CO)5 at 140°C. The corresponding reactions with silanes RSiH3 appear to give similar products, but the lack of stability precluded complete characterization. The stable Si2Fe3-core cluster [μ3-Si{Fe(CO)2Cp}]2Fe3(CO) 9 (5a) can be prepared in good yield by reacting SiH4 with Fe(CO)5 and [Fe(CO)2Cp]2 at 150°C; the corresponding Ge analogue 5b is similarly available from GeH4. X-ray crystal structures are reported for cluster 3 (R = Et; C13H10Fe3Ge2O9, a = 9.341 (2) A?, b = 15.264 (4) A?, c = 14.216 (3) A?, β = 91.22 (2)°, P21/n, Z = 4), for 5a (C23H10Fe5Si2O13, a = 10.020 (8) A?, b = 9.914 (6) A?, c = 28.07 (2) A?, β = 92.68 (7)°, P21/n, Z = 4), and for 5b (C23H10Fe5Ge2O13, a = 10.125 (3) A?, b = 10.024 (3) A?, c = 28.308 (9) A?, β = 92.53 (3)°, P21/n, Z = 4). The E2M3 cores are slightly irregular trigonal bipyramids with Ge-Fe ranging from 2.302 to 2.336 A? and Fe-Fe = 2.721-2.742 A? in 3; in 5a, Si-Fe = 2.294-2.324 A? (distinctly longer than the external Si-Fe value of 2.251 A?) and Fe-Fe is 2.654-2.687 A?, while in 5b Ge-Fe = 2.365-2.391 A? (external Ge-Fe = 2.318 A?) and Fe-Fe = 2.717-2.742 A?.
Anema, Skelte G.,Mackay, Kenneth M.,Nicholson, Brian K.,Van Tiel, Martin
p. 2436 - 2442
(2008/10/08)

Synthesis of metal-rich metallaborane clusters. Evidence for a mechanism involving fragment condensation
A mechanistic hypothesis of metallaborane cluster build-up the condensation of metal and boron containing fragments, which is supported by circumstantial evidence from previous work, suggests improved routes to the synthesis of ferraboranes.This work desc
Meng, Xiangsheng,Bandyopadhyay, Ananda K.,Fehlner, Thomas P.,Grevels, Friedrich-Wilhelm
p. 15 - 27
(2007/10/02)

Bis(diphenylphosphino)methane-assisted Synthesis of Iron-platinum and -palladium Clusters. Crystal Structures of and (dppm=Ph2PCH2PPH2)
Reactions of (dppm=Ph2PCH2PPh2) complexes with carbonyl reagents afforded dppm-bridged Fe-M mixed-metal complexes: (1) was best obtained using , (2) by the reaction K, (4) by the reaction with Na2, and (5) by the reaction with Na2.Reactions of Pd with Na2 afforded (6; M=Pd) and (7; M=Pt) in high yields.Cluster (7) was shown to exist in two isomeric forms.The kinetic isomer, isolated pure at -20 deg C, contains a terminal Pd-bound carbonyl whereas the thermodynamic isomer has a terminal Pt-bound carbonyl ligand.A 1:1 ratio is observed at equilibrium.The cluster (3) was obtained quantitatively by reaction of (1) or with 1 or 2 equivalents of dppm.These reactions were shown to occur first by substitution of the Pt-bound carbonyl ligand.Low-yield interconversion of (1) and (2) was observed as a result of metal-exchange reactions.The structures of clusters (1) and (2) have been established by single-crystal X-ray diffraction studies.In (1) a Fe-Pt bond is bridged by the dppm ligand and Fe(1)-Fe(2) 2.740(2), Pt-Fe(1) 2.542(1), and Pt-Fe(2) 2.557(1) Angstroem.In (2) the Pt-Pt bond is bridged by the dppm ligand and Fe-Pt(1) 2.541(3), Fe-Pt(2) 2.541(4), and Pt(1)-Pt(2) 2.581(1) Angstroem.The i.r. and n.m.r. spectra (1H, 1H-31P>, and 31P-1H>) of the new compounds are reported and discussed.
Braunstein, Pierre,Richert, Jean-Luc,Dusausoy, Yves
p. 3801 - 3814
(2007/10/02)

Reaction of mesitylenetetracobaltnonacarbonyl with 2. Syntheses and structures of the clusters C5H5(CO)2MoCo3(CO)6(μ-CO)3 and (C5H5)2(CO)3Mo2Co2(CO)4(μ-CO)3
Interaction of (mesitylene)Co4(CO)9 (I) with 2 (II) has been shown to result in a mixture of clusters Cp(CO)2MoCo3(CO)6(μ-CO)3 (III) and Cp2(CO)3Mo2Co2(CO)4(μ-CO)3 (IV).Complexes III and IV have also been obtained by an independent synthesis fr
Kaganovich, V. S.,Slovokhotov, Yu. L.,Mironov, A. V.,Struchkov, Yu. T.,Rybinskaya, M. I.
p. 339 - 350
(2007/10/02)

Synthesis, characterization, and reactivity of iron carbonyl clusters containing bismuth or antimony. Crystal structures of isomorphous [Et4N][BiFe3Cr(CO)17] and [Et4N][SbFe3Cr(CO)17] and the ring complex Bi2Fe2(CO)8Me2
The reaction of [Et4N]2[Fe2(CO)8] with BiCl3 or SbCl3 forms compounds (Ia, E = Bi; Ib, E = Sb) that are proposed to be the previously characterized [Et4N] [EClFe3(CO)12] based on elemental analyses and spectroscopic data. Treatment of Ia or Ib with Cr(CO)5(THF) produces [Et4N] [EFe3Cr(CO)17] (11a and 11b, respectively), while the methylation of Ia affords Bi2Fe2(CO)8Me2 (III). Refluxing Ia and Ib in acetonitrile gives the previously known [Et4N]2[Bi2Fe4(CO)13] and [Et4N]2[Sb2Fe5(CO)17], respectively. IIa, IIb, and III have been characterized by X-ray crystallography. IIa crystallizes in the centrosymmetric triclinic space group P1 (no. 2) with a = 12.297 (3) ?, b = 15.154 (3) ?, c = 9.791 (1) ?, α = 107.60 (1)°, β = 95.24 (2)°, γ = 92.02 (2)°, V = 1727.9 (6) ?3, and Z = 2. The structure was refined to R = 4.5% and Rw = 5.3% for those 5114 reflections with I > 3σ(I). The core framework of IIa consists of a distorted tetrahedral BiFe3Cr cluster in which a central bismuth atom is bonded to isolated Fe(CO)4 and Cr(CO)5 groups and a metal-metal-bonded Fe2(CO)8 fragment. The Fe-Fe bond distance is 2.608 (2) ?, and the Fel-Bil-Fe2 angle is 56.91 (4)°. IIb is isomorphous with IIa: centrosymmetric triclinic space group P1 (no. 2), a = 12.233 (1) ?, b = 15.108 (5) ?, c = 9.742 (3) ?, α = 107.23 (3)°, β = 94.61 (2)°, γ = 92.37 (1)°, V = 1710.0 (9) ?3, and Z = 2. Diffraction data were refined to R = 4.2% and Rw = 5.7% for those 6100 reflections with I > 3σ(I). The Fe-Fe bond distance in IIb is 2.598 (1) ?. III crystallizes in the centrosymmetric triclinic space group P1 (no. 2) with a = 7.571 (4) ?, b = 8.734 (4) ?, c = 7.136 (3) ?, α = 107.02 (4)°, β = 108.41 (4)°, γ = 79.89 (4)°, V = 426.3 (4) ?3, and Z = 1. Refinement converged at R = 4.1% and Rw = 5.3% for those 1355 reflections with I > 3σ(I). III consists of a Bi2Fe2 parallelogram situated about a crystallographic inversion center. There is one Me group bonded to each bismuth atom. The Fe(CO)4 groups are pseudooctahedral with an average Bi-Fe distance of 2.786 ?. The Bi-C distance is 2.28 (1) ?.
Whitmire, Kenton H.,Shieh, Minghuey,Cassidy, Juanita
p. 3164 - 3170
(2008/10/08)