Thermodynamic properties of binary mixtures of α-Picoline and ISO-aliphatic alcohols

The relationships enthalpy of mixing and excess Gibbs energyvs. composition were studied. We report hereH ^E andG ^E for 2-CH₃-c-C₅H₄N (α-picoline)+ (1?x) CH₃CH(OH)CH₃, (1?x) CH₃CHCH₃CH₂OH, (1 ?x) CH₃CH₂(OH)CHCH₃ or (1 ?x) CH₃C(CH₃) (OH)CH₃     

An examination of the product-catalyzed reaction of trimethylgallium with arsine

The reaction of (CH₃)₃Ga with AsH₃ at 203°C and 259°C has been examined over the product surfaces which were (CH₃)₃- GaAsH₃-x where the average values of x were 1.1 and 2.2 203°C and 259°C respectively. The surface reaction (catalyzed by the product surface) forming (CH₃)₂GaAsH₂ occurred on the surface between adsorbed molecules of (CH₃)₃Ga and ASH₃. The surface coverages of the reactants (gas pressures between 18 and 36 mmHg) were clearly less than monomolecular and for AsH₃ possibly as low as 0.01. For AsH₃ at a surface coverage of 0.12, adsorption data were consistent with AsH ₃ bound to the surface as a mobile film. The formation of GaAs via CH₄ elimination from (CH₃)₂GaAsH₂ or CH₃GaAsH was hindered by deposition of films of (CH₃)₃-x GaAsH₃-x even at 420°C. This was most significant for formation of GaAs (or even CH₃GaAsH) from (CH₃)₂-GaAsH₂ formed at 203°C and then heated at 420°C. The product surfaces also served as a catalyst for decomposition of AsH₃ to form H₂ and decomposition of (CH₃)₃Ga to form CH₄.     

Densities and excess volumes of the ternary system butyl ethanoate + n-decane + 1-chlorobutane at 298.15 K

Excess molar volumes at 298.15 K and atmospheric pressure were measured for {x₁ CH₃CO₂(CH₂)₃CH₃ + x₂ C₁₀H₂₂ + (1 − x₁ − x₂) Cl(CH₂)₃CH₃} and the corresponding binary mixtures, with an Anton Paar densimeter. All the experimental values were compared with the results obtained by different prediction methods.     

Sterically crowded diolates of group 13 metals

The dependence of the structure of complexes of sterically crowded 2,4-dimethylpentane-2,4-diol with group 13 metals trialkyls on the kind of metal, as well as steric bulk of the substituents on the metal atoms is reported. The reaction of ^tBu₃Ga with 2,4-dimethylpentane-2,4-diol leads to the formation of an unstable dimeric product {^tBu₂Ga[(OC(CH₃)₂CH₂C(CH₃)₂OH]}₂ (1) possessing a four-membered Ga₂O₂ core and two unreacted hydroxyl groups. Compound 1 undergoes further intramolecular reaction to yield the unusual (monoalkyl)gallane O,O^′-chelate complex {^tBuGa[OC(CH₃)₂CH₂C(CH₃)₂O]}₂ (2). In contrast to ^tBu₃Ga, ^tBu₃In reacts with 2,4-dimethylpentane-2,4-diol to give the stable dimeric complex ^tBu₄In₂[OC(CH₃)₂CH₂C(CH₃)₂OH]₂ (4) stabilised by two intramolecular O-H?O bonds. At higher temperature compound 4 reacts with an excess of ^tBu₃In to form the trinuclear complex ^tBu₅In₃[OC(CH₃)₂CH₂C(CH₃)₂O]₂ (5). The reactions of 2,4-dimethylpentane-2,4-diol with trialkylmetallane with small alkyl groups, i.e. Me₃Ga and Me₃In allow for the isolation of the trinuclear diolates {Me₅M₃[OC(CH₃)₂CH₂C(CH₃)₂O]₂} [M=Ga (3), M=In (6)]. The crystal structures of 2, 3 and 4 have been determined by single crystal X-ray diffraction. The reactions of tert-butylmetallane diolates with trimethyl metallanes have been studied. The interaction of the allane complex {^tBuAl[OC(CH₃)₂CH₂C(CH₃)₂O]}₂ with Me₃Al results in the formation of the trialuminium mixed-ligand product {Me₃(^tBu)₂Al₃[OC(CH₃)₂CH₂C(CH₃)₂O]₂} (7). Compounds 2 and 4 undergo a total transmetallation reaction in the presence of Me₃M to yield [Me₅M₃(diol-(2H))₂] [M=Al, Ga] products.     

Monophosphine and diphosphine ligands for diplatinum polyynediyl complexes: Efficient syntheses of new functionality-containing systems and model compounds

Br(CH₂)₄Br and NaO(CH₂)₂CHCH₂ react under suitable conditions to give Br(CH₂)₄O(CH₂)₂CHCH₂ (55%), which is treated with KPPh₂ to yield the ether-containing phosphine Ph₂P(CH₂)₄O(CH₂)₂CHCH₂ (83%). The reaction of CH₃CH₂OC(O)CHC(CH₃)₂ and BrMg(CH₂)₃CHCH₂ in the presence of CuCl (cat.) and ClSiMe₃ yields CH₃CH₂OC(O)CH₂C(CH₃)₂(CH₂)₃CHCH₂ (67%), which is reduced to an alcohol that is brominated, reacted with Grubbs’ catalyst, hydrogenated, and treated with KPPh₂ to give the bis(geminally dimethylated) diphosphine Ph₂P(CH₂)₂C(CH₃)₂(CH₂)₈C(CH₃)₂(CH₂)₂PPh₂ (47% overall). The photochemical reaction of I(CF₂)₈I and H₂CCHCH₂SnBu₃ yields H₂CCHCH₂(CF₂)₈CH₂CHCH₂ (52%), which is converted with 9-BBN to a diol (92%) that is brominated and treated with LiPR₂ to give the fluorinated diphosphines R₂P(CH₂)₃(CF₂)₈(CH₂)₃PR₂ (R = a, p-tol, 67%; b, t-Bu, 69%; c, o-tol, 86%). Reactions of Br(CH₂)_mBr and LiPR₂ similarly yield R₂P(CH₂)_mPR₂ (m/R = 8/a, 95%; 14/a, 96%; 14/p-C₆H₄-t-Bu, 98%). Reactions of KPPh₂ with Br(CH₂)_m′CHCH₂and Br(CH₂)₇CH₃ give the corresponding monophosphines Ph₂P(CH₂)_m′CHCH₂ (m′ = 7, 82%; 10, 84%) and Ph₂P(CH₂)₇CH₃ (85%). When the former is combined with [Pt(μ-Cl)(C₆F₅)(tht)]₂ (tht = tetrahydrothiophene), trans-(C₆F₅)(Ph₂P(CH₂)_m′CHCH₂)₂PtCl (77-70%) is isolated. When the latter (excess) is combined with trans,trans-(C₆F₅)(p-tol₃P)₂Pt(CC)₄Pt(Pp-tol₃)₂(C₆F₅) (RT, 65 °C), trans,trans-(C₆F₅)(Ph₂P(CH₂)₇CH₃)₂Pt(C C)₄Pt(Ph₂P(CH₂)₇CH₃)₂(C₆F₅) (53%) is isolated.     

Excess enthalpies of { ethyl tert -butylether + hexane + heptane,or octane } at the temperature 298.15 K

Excess molar enthalpies, measured at the temperature 298.15 K in a flow microcalorimeter, are reported for the ternary mixtures {x₁CH₃CH₂OC(CH₃)₃ + x₂CH₃(CH₂)₄CH₃ + (1  − x₁ − x₂)CH₃(CH₂)₅CH₃} and {x₁CH₃CH₂OC(CH₃)₃ + x₂CH₃(CH₂)₄CH₃ + (1  − x₁ − x₂)CH₃(CH₂)₆CH₃}. Smooth representations of the results are described and used to construct constant-enthalpy contours on Roozeboom diagrams. It is shown that useful estimates of the enthalpies of the ternary mixtures can be obtained from the Liebermann and Fried model, using only the physical properties of the components and their binary mixtures.     

Methyl group exchange in methyllithiumlithium bromide solutions in diethyl ether

The 220 MHz ¹H NMR spectrum of an ether solution of CH₃Li and LiBr in 10–1 ratio has been examined as a function of temperature. At low temperature distinct resonances, assignable to Li₄(CH₃)₄ and Li₄(CH₃)₃Br, are seen. Methyl group exchange between the two tetramers is observed in the NMR spectra in the temperature interval ?32 to 0°. The exchange is shown to be much slower than the dissociation of Li₄(CH₃)₄ tetramer, measured in other work. It is proposed that the rate-determining step is dissociation of Li₄(CH₃)₃Br to form Li₂(CH₃)₂ and Li₂(CH₃)Br. The rate constant for dissociation, k₂, obeys the equation ln k₂ = 36.0?83303/T.     

Alkyl- und arylkomplexe des iridiums und rhodiums: XXI. Chelatphosphan-stabilisiertepentakoordinierte organoiridium(I)-komplexe Ir(R)(CO)( chel-P33)

Novel five-coordinate organoiridium(I) complexes of the type Ir(R)(CO)(chel-P₃) (chel-P₃=PhP(CH₂CH₂CH₂PPh₂)₂: R = CH₂CMe₃, CH₂SiMe₃; chel-P₃ = MeP-(CH₂CH₂CH₂PPh₂)₂: R = CH₂SiMe₃; chel-P₃PhP(CH₂CH₂PPh₂)₂; R = CH₂SiMe₃, 4-MeC₆H₄) have been prepared from Ir(R)(CO)(PPh₃)₂ and the respective triphosphine. According to ³¹P NMR, these compounds are stereochemically rigid at normal temperatures. The reaction of Rh(R)(CO)(PPh₃)₂, where R = CH₂CMe₃ or 2-MeC₆H₄, with PhP(CH₂CH₂CH₂PPh₂)₂ yielded the four-coordinate derivatives Rh(CH₂CMe₃)[PhP(CH₂CH₂CH₂PPh₂)₂] and Rh(2-MeC₆H₄)[PhP(CH₂CH₂CH₂PPh₂)₂]), which arealready known from the literature.     

Effect of mixed thiols on the adsorption,capacitive and hybridization performance of DNA self-assembled monolayers on gold

In this article, we investigated the effect of mixed thiols (HS(CH₂)₅CH₃, HS(CH₂)₆OH and HS(CH₂)₂NH₂) on the adsorption, capacitive and hybridization performance of thiol-modified probe DNA self-assembled monolayers on gold by chronocoulometry (CC) and cyclic voltammetry (CV). Co-assembly of HS(CH₂)₅CH₃ with probe DNA availed DNA surface adsorption on gold more than HS(CH₂)₆OH and HS(CH₂)₂NH₂. With the increase of the assembly concentration ratio of probe DNA and mixed thiols (C _DNA/C _thiols), DNA surface coverage (Γ _m) was almost constant for DNA/HS(CH₂)₅CH₃ mixed SAMs and increased gradually for DNA/HS(CH₂)₆OH or DNA/HS(CH₂)₂NH₂ mixed SAMs. Interfacial capacitance (C _d) value of DNA/thiol-mixed SAMs on gold mainly depended on the capacitance of thiols SAMs. DNA hybridization almost did not change the capacitance value of DNA/thiol-mixed SAMs on gold. Hybridization experiments indicated that the maximal DNA hybridization density (H _D) was 1.2 × 10^?11 and 1.1 × 10^?11 mol cm^?2 with HS(CH₂)₅CH₃ or HS(CH₂)₆OH as mixed thiols respectively, much bigger than that with short-chain thiols (HS(CH₂)₂NH₂). The size fitting coefficient d _c/d _t values for the optimal hybridization of DNA/HS(CH₂)₅CH₃ and DNA/HS(CH₂)₆OH mixed SAMs were 0.70 and 0.93, respectively. This indicated that probe DNA with much bigger Γ _m should be co-assembled with HS(CH₂)₅CH₃ on gold to obtain the biggest H _D than with HS(CH₂)₆OH. These conclusions provided the important reference for optimally designing DNA sensor.     

Further studies on organonickel compounds: the synthesis of some new alkyl-, acyl- and cyclopentadienyl-derivatives and the crystal structure of trans-[Ni(CH2SiMe3)2(PMe3)2]

The complex [NiCl₂(PMe₃)₂] reacts with one equivalent of mg(CH₂CMe₃)Cl to yield the monoalkyl derivative trans-[Ni(CH₂CMe₃)Cl(PMe₃)₂], which can be carbonylated at room temperature and pressure to afford the acyl [Ni(COCH₂CMe₃)Cl(PMe₃)₂]. Other related alkyl and acyl complexes of composition [Ni(R)(NCS)(PMe₃)₂] (R = CH₂CMe₃, COCH₂CMe₃) and [Ni(R)(η-C₅H₅)L] (L = PMe₃, R = CH₂CMe₃, COCH₂CMe₃; L = PPh₃, R = CH₂CMe₂Ph) have been similarly prepared. Dialkyl derivatives [NiR₂(dmpe)] (R = CH₂SiMe₃, CH₂CMe₂Ph; dmpe = 1,2-bis(dimethylphosphine)ethane, Me₂PCH₂ CH₂PMe₂) have been obtained by phosphine replacement of the labile pyridine and NNN′N′-tetramethylethylenediamine ligands in the corresponding [Ni(CH₂SiMe₃)₂(py)₂] and [Ni(CH₂CMe₂Ph)₂(tmen)] complexes. A single-crystal X-ray determination carried out on the previously reported trimethylphosphine derivative [Ni(CH₂SiMe₃)₂(PMe₃)₂] shows the complex belongs to the orthorhombic space group Pbcn, with a = 14.345(4), b = 12.656(3), c = 12.815(3) Å, Z = 4 and R 0.077 for 535 independent observed reflections. The phosphine ligands occupy mutually trans positions P-Ni-P 146.9(3)° in a distorted square-planar arrangement.     

Mass spectra of boron compounds

The infrared and Raman spectra of six compounds (trimethylsiloxyethylene, (CH₃)₃SiOCHCH₂, methoxytrimethylsilane, (CH₃)₃SiOCH₃, and their deuterated derivatives: (CD₃)₃SiOCHCH₂, (CH₃)₃SiOCDCD₂, (CD₃)₃SiOCH₃, (CH₃)₃SiOCD₃ have been analysed.The majority of the bands observed have been assigned, in particular those due to ν(SiO).The study of the vinyl compounds shows that the enoxysilane exists in two conformers, the major being the gauche and the minor the s-cis one.     

Synthesis and structural characterisation of alkylaluminium and alkylgallium pinacolates

The influence of the steric repulsion of ligands on the structure of alkylaluminium and alkylgallium 2,3-dimethylbutane-2,3-diolates (pinacolates) has been studied. Reaction of Me₃Al and pinacol afforded the compound Me₅Al₃[OC(CH₃)₂C(CH₃)₂O]₂ (1) possessing two diolate ligands. The treatment of pinacol with the more sterically hindered ^tBu₃Al resulted in the formation of aluminium tripinacolate ^tBu₃Al₃[OC(CH₃)₂C(CH₃)₂O]₃ (2) as the only product. In contrast, the reaction of the less reactive ^tBu₃Ga with pinacol stopped at the stage of the compound ^tBu₃Ga₂[OC(CH₃)₃C(CH₃)₂O] [OC(CH₃)₃C(CH₃)₂OH] (3), which is an intermediate product of the reaction of 1,2-diols with group 13 trialkyls. Compounds 1, 2 and 3 were crystallographically characterised.     

Novel generation ponytails in fluorous chemistry: Syntheses of primary, secondary, and tertiary (nonafluoro-tert-butyloxy)ethyl amines

(Nonafluoro-tert-butyloxy)ethyl tosylate 4 was prepared in 65% yield from nonafluoro-tert-butanol 1 using commercially available reagents. Further reaction of 4 with HNR¹R² (R¹ = R² = H, CH₃; R¹ = H, R² = CH₃, (CH₂)₃C₈F₁₇, CH₂CH₂OC(CF₃)₃) affords the appropriate (CF₃)₃COCH₂CH₂NR¹R² amines in 20-69% yields. Improved overall yields of [(CF₃)₃COCH₂CH₂]_3−nNR_n to 1 were obtained by the reaction of (CF₃)₃CONa 2 and (XCH₂CH₂)_3−nNR_n (X = Cl, n = 0, 1, 2, R = CH₃; X = CH₃SO₂O, n = 1, R = CH₃SO₂) nitrogen mustards and a similar reactive β-substituted ethyl amine. The title amines are mobile colorless liquids and volatile with steam. The bulky fluorous ponytail (CF₃)₃CO(CH₂)₂ displays high acidic stability and increases fluorous character almost as much as the classical straight-chain C₈F₁₇(CH₂)₃ ponytail.     

Synthesis and properties of fluorous arenes and triaryl phosphorus compounds with branched fluoroalkyl moieties (“split pony tails”)

Most compounds designed for immobilization in fluorous media feature linear pony tails of the formula (CH₂)_m(CF₂)_n−1CF₃ [(CH₂)_mR_fn]. This paper presents a first-generation approach to compounds with branched or “split” pony tails of the formula (CH₂)_lCH[(CH₂)_mR_fn]₂. Allyl tri(n-butyl)tin is reacted twice with perfluorooctyl iodide (R_f8I; first, photochemical, 78-81%; second, thermal with radical initiator, 71%; 13-18 g scales) to give the secondary alkyl iodide ICH(CH₂R_f8)₂ (3). A subsequent Ni(Cl)₂(PPh₃)₂-catalyzed reaction with allyl tri(n-butyl)tin yields the branched alkene H₂CCHCH₂CH(CH₂R_f8)₂ (74%). A palladium-catalyzed Heck coupling with OP(p-C₆H₄Br)₃ gives the fluorous phosphine oxide OP(p-C₆H₄CHCHCH₂CH(CH₂R_f8)₂)₃ (84%), and Pd/C-catalyzed hydrogenation affords OP(p-C₆H₄(CH₂)₃CH(CH₂R_f8)₂)₃ (>99%). Reduction with SiHCl₃ gives P(p-C₆H₄(CH₂)₃CH(CH₂R_f8)₂)₃, which is protected as the air-stable borane adduct H₃B·P(p-C₆H₄(CH₂)₃CH(CH₂R_f8)₂)₃ (9, 64%). The CF₃C₆F₁₁/toluene partition coefficient of 9 is much higher than that of the analog with p-(CH₂)₃R_f8 groups (96.6:3.4 versus 37.3:62.7). The iodide 3 is unreactive towards PAr₃ at 175-250 °C. However, a CuBr-catalyzed reaction with C₆H₅MgBr gives C₆H₅CH(CH₂R_f8)₂, which also exhibits a high partition coefficient (97.9:2.1).     

Cationic methyl complexes of rhodium(III): synthesis, structure, and some reactions

Cationic methyl complex of rhodium(III), trans-[Rh(Acac)(PPh₃)₂(CH₃)(CH₃CN)][BPh₄] (1) is prepared by interaction of trans-[Rh(Acac)(PPh₃)₂(CH₃)I] with AgBPh₄ in acetonitrile. Cationic methyl complexes of rhodium(III), cis-[Rh(Acac)(PPh₃)₂ (CH₃)(CH₃CN)][BPh₄] (2) and cis-[Rh(BA)(PPh₃)₂(CH₃)(CH₃CN)][BPh₄] (3) (Acac, BA are acetylacetonate and benzoylacetonate, respectively), are obtained by CH₃I oxidative addition to rhodium(I) complexes [Rh(Acac)(PPh₃)₂] and [Rh(BA)(PPh₃)₂] in acetonitrile in the presence of NaBPh₄. Complexes 2 and 3 react readily with NH₃ at room temperature to form cis-[Rh(Acac)(PPh₃)₂(CH₃)(NH₃)][BPh₄] (4) and cis-[Rh(BA)(PPh₃)₂(CH₃)(NH₃)][BPh₄] (5), respectively. Complexes 1-5 were characterized by elemental analysis, ¹H and ³¹P{¹H} NMR spectra. Complexes 1, 2, 3 and 4 were characterized by X-ray diffraction analysis. Complexes 2 and 3 in solutions (CH₂Cl₂, CHCl₃) are presented as mixtures of cis-(PPh₃)₂ isomers involved into a fluxional process. Complex 2 on heating in acetonitrile is converted into trans-isomer 1. In parallel with that isomerization, reductive elimination of methyl group with formation of [CH₃PPh₃][BPh₄] takes place. Replacement of CH₃CN in complexes 1 and 2 by anion I⁻ yields in both cases the neutral complex trans-[Rh(Acac)(PPh₃)₂(CH₃)I]. Strong trans influence of CH₃ ligand manifests itself in the elongation (in solid) and labilization (in solution) of rhodium-acetonitrile nitrogen bond.     

Structure cristalline de l'hexachlorotellurate(IV) d'hydroxydiméthylsoufrediméthylsulfoxyde (12) [(CH3)2SOH]2(TeCl6)· 2(CH3)2SO

[(CH₃)₂SOH]₂(TeCl₆)·2(CH₃)₂SO crystallizes in the triclinic system, space group P$\text{1}$, with a 9.474(5), b 7.952(4), c 10.180(3) Å, α 109.20(3)°, β 95.75(5)° and γ 117.60(4)°, Z = 1. The structure has been determined by a single-crystal X-ray study and refined by full-matrix least squares analysis to R = 0.044 for 1332 independent reflections. The hydrogen atoms of the methyl groups were not located. The structure contains TeCl₆^2? and (CH₃)₂SOH⁺ ions and (CH₃)₂SO molecules which form layers situated along (011) planes. The TeCl₆^2? ion adopts an almost regular octahedron. The (CH₃)₂SOH⁺ cation and the (CH₃)₂SO molecule are linked by a short hydrogen bond. Interatomic distances are in good agreement with previously published values. Cohesion of the structure is due to ionic interactions, hydrogen bonds and Van der Waals interactions.     

Mixed ligand complexes of platinum(0) containing diphosphines

The reaction of PtCl₂L (L = diphosphine) with the appropriate diphosphine L′ in ethanol followed by reduction with aqueous sodium borohydride leads to either disproportionation to give mixtures of the bis(diphosphine) complexes PtL₂ and PtL′₂ or to the formation of the mixed ligand complex PtLL′ depending on the diphosphines. Mixed ligand complexes are obtained when L=Ph₂P(CH₂)₂PPh₂, L′ = Ph₂P(CH₂PPh₂cis-Ph₂PCH CHPPh₂, Ph₂P(CH₂)₂AsPh₂, Ph₂- P(CH₂)₄PPh₂, o-Ph₂PC₆H₄PPh₂; and L=(C₆H₁₁)₂P(CH₂₂P(C₆H₁₁)₂, L′= Ph₂P(CH₂)PPh₂, Ph₂P(CH₂)₂PPh₂cis-Ph₂PCHCHPPh₂, (2S,3S)-Ph₂PCH- (CH₃)CH(CH₃)PPh₂, (R)-Ph₂PCH(CH₃)CH₂PPh₂. When L=Ph₂P(CH₂)₄PPh₂ L′= Ph₂P(CH₂₃PPh₂ or cis-Ph₂PCHCHRPh₂ the mixed ligand complexes are obtained but extensive disproportionation also occurs.     

1,5-Migrations of silicon between oxygen centers in silyl β-diketones

A series of acyclic silyl diketonates, (CH₃)₃Si(dik), where dik = dipivaloyl-methanate, diisobutyrylmethanate and hexafluoroacetylacetonate, along with a new series of cyclic acetylacetonates of the type CH₃(-CH₂(CH₂)_xCH₂-)Si(acac), where x = 1, 2, and 3, have been shown to possess enol ether structures in which the acyl group is positioned cis or trans to the silyl group. The ratios of cis to trans configurations in the (CH₃)₃Si(dik) series increase from <0.02 to >50.0 in the order of diketonate substituents CF₃ < CH₃ <i-C₃H₇ < t-C₄H₉. The ratios for the CH₃(-CH₂(CH₂)xCH₂-)Si(acac) compounds increases in the order χ = 1 > 2 > 3. These data are interpreted in terms of incipient pentacoordination of silicon by the carbonyl oxygen atom in the cis isomer. Rates of 1,5-migration of silicon between oxygen centers in the cis isomers have been determined by NMR spectroscopy. The dependence of the rearrangement rates on diketonate substituent and angle strain at silicon indicate that the migration process is better viewed as an internal nucleophilic displacement, rather than a sigmatropic shift. 1,5-Migration in the chiral (C₆H₅CH₂)(CH₃)(C₆H₅)Si derivative of dipivaloylmethanate occurs exclusively with retention of configuration at silicon. The large difference in activation energy for migration and inversion (>18 kcal/mol) precludes the possibility of distinguishing between a stepwise and concerted displacement mechanism.     

Reaction studies on some functionalized alkyl transition metal compounds and the crystal structure of [Cp(CO)3W{(CH2)3NO2}]

The reactions of the halogenoalkyl compounds [Cp(CO)₃W{(CH₂)_nX}] (Cp = η⁵-C₅H₅; n = 3-5; X = Br, I) and [Cp(CO)₂(PPhMe₂)Mo{(CH₂)₃Br}] with the nucleophiles Z = CN⁻ and gave compounds of the type [Cp(CO)₃W{(CH₂)_nZ}] for the tungsten compounds, whilst cyclic carbene compounds were obtained from the reactions of the molybdenum compound. The reactions of [Cp(CO)₃W{(CH₂)_nBr}] (n = 3, 4) and [Cp(CO)₂(PPhMe₂)Mo{(CH₂)₃Br}] with gave [Cp(CO)₃W{(CH₂)_nONO₂}] and [Cp(CO)₂(PPhMe₂)Mo{(CH₂)₃ONO₂}], respectively. The reaction of [Cp(CO)₃W{(CH₂)_nBr}] with AgNO₂ gave [Cp(CO)₃W{(CH₂)_nNO₂}]. In the solid state the complex [Cp(CO)₃W{(CH₂)₃NO₂}] crystallizes in a distorted square pyramidal geometry. In this molecule the nitropropyl chain deviates from the ideal, all-trans geometry as a result of short, non-hydrogen intermolecular N-O?O-N contacts. The reactions of the heterobimetallic compounds [Cp(CO)₃W{(CH₂)₃}ML_y] {ML_y = Mo(CO)₃Cp, Mo(CO)₃Cp^∗ and Mo(CO)₂(PMe₃)Cp; Cp^∗ = η⁵-C₅(CH₃)₅} with PPh₃ and CO were found to be totally metalloselective, with the ligand always attacking the metal site predicted by the reactions of the corresponding monometallic analogues above with nucleophiles. Thus the compounds [Cp(CO)₃W{(CH₂)₃}C(O)ML_z] {ML_z = Mo(CO)₂YCp, Mo(CO)₂YCp^∗ and Mo(CO)Y(PMe₃)Cp; Y = PPh₃ or CO} were obtained. Similarly, the reaction of [Cp(CO)₂Fe{(CH₂)₃}Mo(CO)₂(PMe₃)Cp] with CO gave only [Cp(CO)₂Fe{(CH₂)₃C(O)}Mo(CO)₂(PMe₃)Cp]. Hydrolysis of the bimetallic compound, [Cp(CO)₃W(CH₂)₃C(O)Mo(CO)(PPh₃)(PMe₃)Cp], gave the carboxypropyl compound [Cp(CO)₃W{(CH₂)₃COOH}]. Thermolysis of the compound [Cp(CO)₂Fe(CH₂)₃Mo(CO)₃(PMe₃)Cp] gave cyclopropane and propene, indicating that β-elimination and reductive processes had taken place.