Preparation and crystal structures of [μ-SbPh2]2[Mo(CO)2(η5-C5H5)]2·CHCl3 and SbPh[Fe(CO)2(η5-C5H5)]2

Antimony is reduced when [SbPh₂BrO]₂ is treated with Na[Mo(CO)₃(η⁵-C₅H₅)] to produce [μ-SbPh₂]₂[Mo(CO)₂(η⁵-C₅H₅)]₂. A structure determination shows diphenylstibido groups bridging between two Mo(CO)₂(η⁵-C₅H₅) moieties giving a central ‘butterfly’ shaped Sb₂Mo₂ ring. The cyclopentadiene rings are trans to each other and Mo–Sb and Sb–Sb separations are both short. An iron analogue could not be obtained from [SbPh₂BrO]₂ and Na[Fe(CO)₂(η⁵-C₅H₅)] but a mixture of SbPh[Fe(CO)₂(η⁵-C₅H₅)]₂ and SbPh₂[Fe(CO)₂(η⁵-C₅H₅)] was obtained using SbPh₂Cl. An X-ray structure for SbPh[Fe(CO)₂(η⁵-C₅H₅)]₂ shows an open stibinidine structure.     

Comparative studies of the photochemical and thermal reactivities of the molybdenum-molybdenum single bond in [Mo2(η5-C5H5)2(CO)6] and triple bond in [Mo2(η5-C5H5)2(CO)4] towards nitrite and nitrate

Irradiation at λ = 507 and 391 nm of [Mo₂(η⁵-C₅H₅)₂(CO)₆] in a degassed tetrahydrofuran (THF) or THF-MeOH solution containing nitrite gives [Mo(η⁵-C₅H₅)₂NO] and several oxo complexes including [{Mo(η⁵-C₅H₅)(O)₂}₂O] in good yields. The quantum yields for the disappearance of [Mo₂(η⁵-C₅H₅)₂(CO)₆] in the reaction with NO₂⁻ depend on the nitrite concentration, thus suggesting participation of the metal-radical intermediate in the reduction of nitrite. Reactions of [Mo₂(η⁵-C₅H₅)₂(CO)₄] with nitrite or nitrate in the dark give the same nitrosyl and oxo complexes as above. An oxygen atom in nitrite or nitrate is mainly transferred onto the molybdenum atom both in the photochemical and the dark reactions.     

Structural study of complex [Rh(NH3)5(NO2)](NO3)2·H2O, [Rh(NH3)5(NO2)][Pd(NO2)4], and K2[Rh(NH3)(NO2)5]·H2O salts

Compounds [Rh(NH₃)₅(NO₂)](NO₃)₂·H₂O (I) with a = 7.6230(3) Å, b = 7.6230(3) Å, c = 10.3584(4) Å, space group I-42m, Z = 2, d _calc = 2.026 g/cm³, V = 601.93(4) ų, Rh-NH_{3 eq} = 2.074 Å, Rh-NH_{3 ax} (NO₂) = 2.048 Å; [Rh(NH₃)₅(NO₂)][Pd(NO₂)₄] (II) with a = 8.095(3) Å, b = 22.422(8) Å, c = 7.887(3) Å, β = 98.559(17)°, space group Cc, Z = 4, d _calc = 2.461 g/cm³, V = 1415.6(9) ų, Rh-NH_{3 eq} = 2.069 Å, Rh-NH_{3 ax} = 2.090 Å, Rh-NO₂ = 2.002 Å; K₂[Rh(NH₃)(NO₂)₅]·H₂O (III) with a = 7.5177(5) Å, b = 20.9856(15) Å, c = 7.7017(5) Å, space group Cmc2₁, Z = 4, d _calc = 2.439 g/cm³, V = 1215.05(14) ų, Rh-NH_{3 ax} (NO₂) = 2.094 Å, Rh-NO_{2 eq} = 2.030 Å are synthesized and studied using single crystal X-ray diffraction.     

Darstellung und reaktionen von diphosphen-komplexen RPPR[M(CO)5]3 (M = Cr,Mo, W)

Decacarbonyldimetallates Na₂M₂(CO)₁₀ (M = Cr, Mo, W) react with dihalophosphanes, (R)P(Cl)₂, to yield trinuclear diphosphene complexes of the form RPPR[M(CO)₅]₃. The by-products of these reactions are diphosphane- and phosphido-bridged complexes.The trinuclear diphosphene compounds add HX (X = CH₃COO, CH₃O) or dienes to the PP double bond; in the course of these additions one M(CO)₅ group is cleaved and binuclear derivatives of diphosphanes are obtained.     

REACTIONS OF [η5−RC5H4 (CO)2Mo]2 (Mo≡Mo) WITH (μ-PhSe)2Fe2 (CO)6. SYNTHESIS AND CHARACTERIZATION OF SELENOLATO-BRIDGED TRANSITION METAL COMPLEXES [η5−RC5H4Mo (CO) (μ-SePh)]2 (R ˭ MeCO,MeO2C) AND η5−RC5H4MoFe2 (CO)4 (μ3-Se) [μ,η1: η2−C(0)Ph] (μ-SePh)2 (R ˭ H,MeCO, EtO2C)

Abstract

Mo≡Mo triply bonded dimers [η⁵?RC₅H₄ —react with (μ,-PhSe)₂Fe₂ (CO)₆ in boiling xylene to give selenolato-bridged bimetallic complexes [η⁵?RC5H₄Mo(CO) (μ-SePh)]₂ (R ? MeCO, MeO₂C). However, irradiation of a benzene solution of —(R ? H, MeCO, EtO₂C) and (μ-PhSe)₂Fe₂ (CO)₆ with a 400W high pressure mercury lamp gave rise to selenolato-bridged trimetallic clusters η⁵?RC₅H₄MoFe₂(CO)₂ (μ₃-Se) [μ,η:η²?C (O) Ph] (μ-SePh)₂ (R ? H, MeCO, EtO₂C). All products were characterized by elemental analysis and spectroscopic methods, as well as by an X-ray diffraction analysis of the product η⁵?MeCOC₅H₄MoFe₂(CO)₄ (μ-Se)[μ;η¹:η²?C(O)Ph](μ-SePh)₂.     

Reaction of Mo(CO)6 with Alkoxide: Synthesis and Structure of the Mo(0)-OR Complex [Et4N]3[Mo2(CO)6(μ-OC6H4OCH2C6H5)3]

The reaction of molybdenum hexacarbonyl with C6H5CH2OC6H4ONa and Et4NBr in CH3CN at 60 ℃ afforded the di-nuclear Mo(0) compound [Et4N]3[Mo2(CO)6(μ-OC6H4OCH2- C6H5)3] 1. 1 crystallizes in monoclinic, space group P21/c with a=15.359(2), b=18.378(3), c=24.952(2)(A), β=102.268(4)°, V=6882.3(16) (A)3, Mr=1348.34, Z=4, Dc=1.301 g/cm3, F(000)=2832 and μ= 0.424 mm-1. The final R=0.0606 and wR=0.1552 for 9396 observed reflections (Ⅰ ＞ 2σ(Ⅰ)). 1 contains a [Mo2O3]3- core in triangular bi-pyramidal configuration and each Mo atom adopts a distorted octahedral geometry with three carbon atoms from carbonyls and three μ-O atoms from C6H5CH2OC6H4O- bridging ligands. The Mo…Mo distance is 3.30(8) (A), indicating no metalmetal bonding. A formation pathway via forming a di-molybdenum(0) di-bridging OR compound [Mo2(μ-OR)2(CO)8]2- has been figured out and the reaction of Mo(CO)6 with alkoxide has also been discussed.     

Heats of reaction of HMo(CO)3C5H5 with CCl4 and CBr4 and of NaMo(CO)3C5H5 with I2 and CH3. Solution thermochemical study of the MoX bond for X = H,Cl, Br,I and CH3

The heats of reaction of HMo(CO)₃C₅H₅ with CX₄ (X = Cl, Br) producing XMo(CO)₃C₅H₅ have been measured by solution calorimetry and are −31.8±0.9 and −34.4±2.0 kcal/mole, respectively. The heats of reaction of NaMo(CO)₃C₅H₅ with I₂ and CH₃I producing IMo(CO)₃C₅H₅ and H₃CMo(CO)₃C₅H₅ are −32.3± 1.3 and −7.7± 0.3 kcal/mole. Oxidation with Br₂CCl₄ yielding Br₃Mo(CO)₂C₅H₅ was measured for the following complexes: (C₅H₅(CO)₃Mo)₂, (−92.0±1.0 kcal/mole), BrMo(CO)₃C₅H₅ (−24.9± 2.0 kcal/mole) and HMo(CO)₃C₅H₅ (−60.7± 2.0 kcal/mole). These and other data are used to calculate the Mo–X bond strength for X = H, Cl, Br, I, and CH₃. These bond strength estimates are compared to those reported for X₂Mo(C₅H₅)₂. Iodination of H₃CMo(CO)₃C₅H₅, reported in the literature to yield CH₃I and IMo(CO)₃C₅H₅, actually produces CH₃C(O)I and I₃Mo(CO)₂C₅H₅.     

Carbonylmetall-verbindungen des bis(di-t-butylphosphino)schwefeldiimids: Bildung von zweikernkomplexen S{NPtBu2[MLn]}2 (MLn = Cr(CO)5), Mo(CO)5, W(CO)5, Fe(CO)4) und chelatkomplexen S(NPtBu2)2M(CO)4 (M = Cr,Mo, W). Kristall- und molekülstruktur von S(NPtBu2)2Cr(CO)4

The reaction of bis(di-t-butylphosphino) sulphur diimide, S(NP^tBu₂)₂ (1) ¹, with coordinatively unsaturated 16-electron complex fragments [M(CO)₅] leads to both binuclear 1 : 2 adducts S{NP^tBu₂[M(CO)₅]}₂ (M = Cr (2B), Mo (3B) and W (4B)) and mononuclear chelate complexes S(NP^tBu₂)₂M(CO)₄ (M = Cr (2C), Mo (3C) and W (4C)). A binuclear compound S{NP^tBu₂[Fe(CO)₄]}₂ (5B) is obtained from the reaction of 1 with Fe₂(CO)₉. The new complexes which all contain the intact sulphyr diimide 1 are characterized on the basis of their infrared, ¹H, ¹³C and ³¹P NMR spectra. An X-ray structure analysis of S(NP^tBu₂)₂Cr(CO)₄ (2C) reveals a distorted octahedral coordination sphere around the central chromium atom and an almost planar but twisted six-membered Cr(PN)₂S heterocycle with angles of 91.98(2)° at chromium (P(1)CrP(2)) and 124.6(1)° at sulphur (N(1)SN(2)).     

Synthesis and characterisation of [AgL(μ-PR2)M(CO)5], L= 1,10-phenanthroline or tricyclohexylphosphine; M = Cr,Mo, W

The new heterobimetallic phosphide-bridged compounds [AgL(μ-PR₂)M(CO)₅], (L = 1,10-phenanthroline or tricyclohexylphosphine: M = Cr, M, W) have been prepared from AgO₃SCF₃, M(CO)₅PR₂H and the ligand L in the presence of Et₂NH or MeO⁻ as base, and characterized by ³¹P NMR spectroscopy.     

Synthesis and structures of the η5-C5H5Cl(CO)2W-η1,η5-(PPh2)C5H4(CO)2Fe-η1,η5-C5H4Mn(CO)3 and MeSi[C5H4(CO)2Fe-η1,η5-C5H4Mn(CO)2PPh3]3 complexes

The metallation of the η⁵-C₅H₅(CO)₂Fe-η¹,η⁵-C₅H₄Mn(CO)₃ complex with BuⁿLi (THF, ?78 °C) followed by the treatment of the lithium derivative with Ph₂PCl afforded the η⁵-Ph₂PC₅H₄(CO)₂Fe-η¹,η⁵-C₅H₄Mn(CO)₃ complex. The reaction of the latter with η⁵-C₅H₅(CO)₃WCl in the presence of Me₃NO produced the trinuclear complex η⁵-C₅H₅Cl(CO)₂W-η¹,η⁵-(Ph₂P)C₅H₄(CO)₂Fe-η¹,η⁵-C₅H₄Mn(CO)₃. The structure of the latter complex was established by IR, UV, and 1H and ³¹P NMR spectroscopy and X-ray diffraction. The reaction of MeSiCl₃ with three equivalents of LiC₅H₄(CO)₂Fe-η¹,η⁵-C₅H₄Mn(CO)₂PPh₃ gave the hexanuclear complex MeSi[C₅H₄(CO)₂Fe-η¹,η⁵-C₅H₄Mn(CO)₂PPh₃]₃.     

New electron-deficient alkene and alkyne derivatives of Ru5(μ5-C)(CO)15: The syntheses and crystal structure analyses of Ru5(μ5-C)(CO)13 [C2H2(CO2Me)2] and Ru5(μ5-C)(CO)15 [C2(CO2Me)2]

Treatment of carbido cluster Ru₅(μ ₅-C)(CO)₁₅ with Me₃NO in acetonitrile solution followed by addition of dimethyl maleate or dimethyl acetylene dicarboxylate affords new clusters Ru₅(μ ₅-C)(CO)₁₃[C₂H₂(CO₂Me)₂] (1) and Ru₅(μ ₅-C)(CO)₁₅[C₂(CO₂Me)₂] (2), respectively. Single crystal X-ray structural studies reveal that both complexes contain a wingtip-bridged butterfly pentametallic skeleton. In complex1 the maleate fragment is coordinated to one wingtip Ru atom through its carbon-carbon double bond and to the adjacent Ru atom by the formation of two O → Ru dative bonding interactions, while the acetylene dicarboxylate fragment in2 is best considered as acis-dimetallated alkene, linking one hinge Ru atom and the nearby Ru atom at the bridged position. Crystal data for1: space group P 4₂/n;a=20.199(6),c=13.941(3) Å,Z=8; finalR _F=0.025,R _w=0.026 for 3963 reflections withI>2σ(I). Crystal data for2: space group P2₁/n;a=9.634(3),b=20.062(6),c=17.372(5) Å,β=90.62(2)°,Z=4; finalR _F=0 033,R _w=0.036 for 4683 reflections withI>3σ(I).     

[Fe2(μ-SC5H4N)2(NO)4] as a New Potential NO Donor: Synthesis,Structure, and Properties

A new potential donor of nitrogen monoxide, a binuclear iron sulfur nitroso complex, was prepared by exchange reaction of Na₂Fe₂(S₂O₃)₂(NO)₄ with pyridine-2-thiol in the presence of sodium thiosulfate at pH 12. The molecular and crystal structures of [Fe₂(-SC₅H₄N)₂(NO)₄] were studied by X-ray diffraction analysis. The type of iron coordination by pyridine-2-thiol in the presence of a coordinated NO molecule was determined. In vacuum, the structure of the complex is destroyed, which is accompanied by NO evolution, while exposure to UV radiation results in decomposition of the complex and in a release of N₂O.     

SYNTHESES AND CRYSTAL STRUCTURE OF [Et_4N]{Mo(CO)_5L}(L=I~-,SPh~-)

<正> Crystal of [Et4N][Mo(CO)5I](1) (Mr = 493. 15) is tetragonal with space group P4/n, a =b==9. 374(2) ,c=10. 545(2)(?), V=926. 5(?)3, Z = 2, F(000) = 480, Dc=1. 77g/cm3and μ = 23. 6cm-1. R = 0. 040, Rw = 0.043 for 374 observed reflections. Crystal of [Et4N][Mb(CO)5(SPh)] (2) is orthorhombic ith space group Pbam, a= 15. 230(3), b = 18. 389(10), c=8. 172(3)(?), V=2288. 6 (?)3, Z = 4, Dc=1. 38gcm3, μ = 6.7cm-1.R = 0. 043, Rw = 0. 042 for 1621 observed reflections. Complexes 1 and 2 possess the same geometry. The Mo atom is octahe-drally coordinated with obvious trans drrdct, all the Mo -C bond lengths are shorter obviously and the C - O bond are longer than those of Mo(CO)6.     

Synthesis,characterization, and reactivity of the neutral metal formyl (η5-C5Me5)(CO)2(PPh3)MoCHO. A new route to monocationic secondary alkoxycarbene complexes [(η5-C5Me5)(CO)2(PPh3)Mo(CHOE)]+ X− (E = H,Me)

(η⁵-C₅Me₅)(CO)₂(PPh₃)MoCHO (2) one of the few isolated neutral metal formyls, reacts with the electrophilic reagents (CF₃COOH and CH₃SO₃F without disproportionation to give the secondary carbene complexes [(η⁵-C₅Me₅)(CO)₂(PPh₃)Mo(CHOE)]⁺ X⁻ (E = H, X = CF₃COO (4); E = Me, X = PF₆ (5)).     

Phosphavinylidene-Carbenoids [P]˭C(Li)X (X ˭ Br,Cl, F): Structure and Dynamics

Abstract

The extraordinary reactivity of carbenoids towards electrophilic as well as nucleophilic reagents awards them for a central importance in organic chemistry. Their unusual bonding situation has been the subject of several theoretical studies'. Having shown in previous reports' that phosphoranyl carbenoids are significantly stabilized by incorporation of the carbenoid center in delocalized n-systems, we succeeded in isolating the first stable bromo. chloro and fluoro-lithio carbenoids 21-c.     

Photochemical reactions of M(CO)5THF (M = Cr, Mo, W) with thio Schiff bases

The hitherto unknown complexes, [M₂(CO)₆(μ-CO)(μ-L)], [M = Cr; 1, Mo; 2, W; 3] and [M₂(CO)₆(μ-CO)(μ-L′)], [M = Cr; 4, Mo; 5, W; 6] have been synthesized by the photochemical reactions of photogenerated intermediate, M(CO)₅THF (M = Cr, Mo, W) with thio Schiff base ligands, N,N′-bis(2-aminothiophenol)-1,4-bis(2-carboxaldehydephenoxy)butane (H ₂ L) and N,N′-bis(2-aminothiophenol)-1,7-bis(2-formylphenyl)-1,4,7-trioxaheptane (H ₂ L′). The complexes have been characterized by elemental analysis, LC-mass spectrometry, magnetic studies, FT-IR and ¹H NMR spectroscopy. The spectroscopic studies show that H ₂ L and H ₂ L′ ligands are converted to benzothiazole derivatives, L and L′ after UV irradiation and coordinated to the central metal as bridging ligands via the central azomethine nitrogen and sulphur atoms in 1–6.     

Synthesis,characterization and crystal structures of heterometallic trinuclear carbonyl sulfido clusters (η5-Cp)MoFeCo- (CO)8(μ3-S) and [(η5-Cp)Mo]2Fe(CO)7(μ3-S)

HFe2Co(CO)9(3-S) reacts with (5-Cp)Mo(CO)3Cl in refluxing THF to give heterometallic trinuclear clusters (5-Cp)MoFeCo(CO)8(3-S) and [(5-Cp)Mo]2Fe(CO)7-(3-S), which have been characterized by elemental analyses, i.r., 1H- and 13C-n.m.r. and X-ray crystal structure determination. An electrophilic addition–elimination sequence is proposed for their formation.     

The synthesis,electrochemistry and molecular structure of [Fe(η5-C5H4S)2Mo(NO){HB(3,5-Me2C3N2H)3}]

The new bimetallic complex [Fe(η⁵-C₅H₄S)₂Mo(NO){HB(3,5-Me₂C₃N₂H)₃)}] has been obtained from the reaction between [Fe(η⁵-C₅H₄SH)₂] and [Mo(NO){HB(3,5-Me₂C₃N₂H)₃}I₂]. Electrochemical studies reveal an anomalously cathodic oxidation potential for the metallocene redox centre. An X-ray diffraction study has revealed an FMo distance of 4.147(2) Å, with the ferrocenyl moiety oriented towards the nitrosyl ligand on the molybdenum atoms (Fe---O 3.976(6) Å), but provides no evidence for an interaction between the iron atom and the molybdenum-bound nitrosyl which might account for the electrochemical findings.     

The solid-state isomerization of cis- and trans-(η5-C5H4Me)Mo(CO)2(P(OiPr)3)I

The cis- and trans-(η⁵-C₅H₄Me)Mo(CO)₂(P(OⁱPr)₃)I complexes undergo a bi-directional thermal ligand isomerization reaction to yield an equilibrium mixture of isomers (30/70 cis/trans ratio, 90 °C, < 80 min) in the solid state. The activation energy barrier for the cis-trans isomerization reaction (80–100 °C) was found to be 68 ± 10 kJ mol^–1. In benzene (reflux, 2 h) this isomer ratio was found to be 70:30 cis/trans. DSC and powder XRD studies have revealed reactions that occur in the solid state entailing decomposition and isomerization. DSC experiments did not reveal the presence of the cis–trans isomerization reaction.