Showing papers by "Malcolm L. H. Green published in 1995"
TL;DR: In this paper, a brief review on the recent developments of alternative routes for synthesis gas production, namely catalytic methane partial oxidation and methane reforming with carbon dioxide, is presented, with particular attention given to reaction thermodynamics, catalyst formulation, reaction mechanism and problems of carbon deposition.
446 citations
TL;DR: In this article, the filling of carbon nanotubes with palladium metal crystallites is described and it is shown that surface acid groups (CO2H and OH) are present on both the nanoteubes and nanoparticles.
Abstract: The filling of carbon nanotubes with palladium metal crystallites is described and it is shown that when the carbon nanotube samples are opened using nitric acid, surface acid groups (CO2H and OH) are present on both the nanotubes and nanoparticles and these interact strongly with palladium ions: ultrasound pre-treatment of the carbon nanotube samples prior to the oxidation with nitric acid increases the number of these groups
124 citations
119 citations
TL;DR: In this article, the morphologies of small proteins Zn2Cd5-metallothionein, cytochrome c3 and β-lactamase I were studied by high-resolution transmission electron microscopy (HRTEM).
Abstract: The morphologies of the small proteins Zn2Cd5-metallothionein, cytochrome c3 and β-lactamase I immobilized inside carbon nanotubes have been studied by high-resolution transmission electron microscopy (HRTEM); single protein molecules and their associated forms were clearly observed inside the central cavity and a significant amount remained catalytically active indicating that no drastic conformational change had taken place.
106 citations
TL;DR: Unilateral magnetic phrenic nerve stimulation is easy to apply and is a reproducible technique in the assessment of hemidiaphragm contractility because precise positioning of the coils is not necessary.
Abstract: BACKGROUND--Electrical stimulation of the phrenic nerve is a useful non-volitional method of assessing diaphragm contractility During the assessment of hemidiaphragm contractility with electrical stimulation, low twitch transdiaphragmatic pressures may result from difficulty in locating and stimulating the phrenic nerve Cervical magnetic stimulation overcomes some of these problems, but this technique may not be absolutely specific and does not allow the contractility of one hemidiaphragm to be assessed This study assesses both the best means of producing supramaximal unilateral magnetic phrenic stimulation and its reproducibility This technique is then applied to patients METHODS--The ability of four different magnetic coils to produce unilateral phrenic stimulation in five normal subjects was assessed from twitch transdiaphragmatic pressure (TwPDI) measurements and diaphragmatic electromyogram (EMG) recordings The results from magnetic stimulation were compared with those from electrical stimulation To determine whether the magnetic field affects the contralateral phrenic nerve as well as the intended phrenic nerve, EMG recordings from each hemidiaphragm were compared during stimulation on the same side and the opposite side relative to the recording electrodes The EMG recordings were made from skin surface electrodes in five normal subjects and from needle electrodes placed in the diaphragm during cardiac surgery in six patients Similarly, the direction of hemidiaphragm movement was evaluated by ultrasonography To determine the usefulness of the technique in patients the 43 mm mean diameter double coil was used in 54 patients referred for assessment of possible respiratory muscle weakness These results were compared with unilateral electrical phrenic stimulation, maximum sniff PDI, and TwPDI during cervical magnetic stimulation RESULTS--In the five normal subjects supramaximal stimulation was established for eight out of 10 phrenic nerves with the 43 mm double coil Supramaximal unilateral magnetic stimulation produced a higher TwPDI than electrical stimulation (mean (SD) 134 (25) cm H2O with 35 mm coil; 141 (38) cm H2O with 43 mm coil; 100 (17) cm H2O with electrical stimulation) Spread of the magnetic field to the opposite phrenic nerve produced a small amplitude contralateral diaphragm EMG measured from skin surface electrodes which reached a mean of 15% of the maximum EMG amplitude produced by ipsilateral stimulation Similarly, in six patients with EMG activity recorded directly from needle electrodes, the contralateral spread of the magnetic field produced EMG activity up to a mean of 3% and a maximum of 6% of that seen with ipsilateral stimulation Unilateral magnetic stimulation of the phrenic nerve was rapidly achieved and well tolerated In the 54 patients unilateral magnetic TwPDI was more closely related than unilateral electrical TwPDI to transdiaphragmatic pressure produced during maximum sniffs and cervical magnetic stimulation Unilateral magnetic stimulation eliminated the problem of producing a falsely low TwPDI because of technical difficulties in locating and adequately stimulating the nerve Eight patients with unilateral phrenic nerve paresis, as indicated by a unilaterally elevated hemidiaphragm on a chest radiograph and maximum sniff PDI consistent with hemidiaphragm weakness, were all accurately identified by unilateral magnetic stimulation CONCLUSIONS--Unilateral magnetic phrenic nerve stimulation is easy to apply and is a reproducible technique in the assessment of hemidiaphragm contractility It is well tolerated and allows hemidiaphragm contractility to be rapidly and reliably assessed because precise positioning of the coils is not necessary This may be particularly useful in patients In addition, the anterolateral positioning of the coil allows the use of the magnet in the supine patient such as in the operating theatre or intensive care unit
102 citations
TL;DR: In this article, the crystal structures of the new compounds {M(eta-C(5)R(5))[eta-cPh(NSiMe(3))(2)]]Cl-2} (where R = H, M = Ti, Zr, Hf or R = Me, R = Ti or Zr) have been determined.
94 citations
Patent•
24 Apr 1995TL;DR: In this article, a method of converting a reactant gas mixture of CO 2, O 2, and CH 4 into a product gas mixture comprising H 2 and CO was proposed.
Abstract: A method of converting a reactant gas mixture of CO 2 , O 2 and CH 4 comprises contacting the reactant gas at 750°-850° C. with a solid catalyst, which is a d-block transition metal or oxide such as a group VIII metal on a metal oxide support such as alumina, and which selectively converts the reactant gas into a product gas mixture comprising H 2 and CO.
65 citations
TL;DR: The compounds [Zr(η-C5H5){CPh(NSiMe3)2}2Cl], this article ] and [M(M(m, R = H or Me; M = Ti, R=H or Me) have been synthesized and the crystal structures of three of them determined.
Abstract: The compounds [Zr(η-C5H5){CPh(NSiMe3)2}2Cl], [{Zr(η-C5H5)[CPh(NSiMe3)2]Cl}2{µ-CPh(NSiMe3)2}][{Zr(η-C5H5)[CPh(NSiMe3)2]Cl}2(µ-O)], [Zr(η-C5R5){CPh(NSiMe3)2}(CH2Ph)Cl](R = H or Me), [Zr(η-C5R5){CPh(NSiMe3)2}(CH2Ph)2](R = H or Me) and [M(η-C5R5){CPh(NSiMe3)2}Me2](M = Zr, R = H or Me; M = Ti, R = H have been synthesized and the crystal structures of three of them) determined.
48 citations
TL;DR: The reaction of LiBH4 with [Mo(η-C5H4R)Cl4] gave the dimetallaborane bicapped closo as discussed by the authors, which has been characterised by X-ray crystallography.
Abstract: The reaction of LiBH4 with [Mo(η-C5H4Me)Cl4] gives the dimetallaborane bicapped closo-[{Mo(η-C5H4R)}2B5H9], which has been characterised by X-ray crystallography. The reaction of LiBH4 with [W(η-C5H4R)Cl4], for R = Me, gives closo-[{W(η-C5H4Me)H2}2B3H7] or, for R = Pri, both closo-[{W(η-C5H4Pri)H2}2}B3H7] and nido-[{W(η-C5H4Pri)H3}B4H8]. The reaction between [Mo(η-C5H4Me)(PMe3)2Cl2] and LiBH4 yields bicapped closo-[{Mo(η-C5H4Me)}2B5H9] or nido-[{Mo(η-C5H4Me)(PMe3)H}B4H8], depending on the reaction conditions. Also LiBH4 reacts with [W(PMe3)3Cl4] to give a mixture of nido-[{W(PMe3)2H4}B4H8] and arachno-[{W(PMe3)3H3}B3H8].
41 citations
TL;DR: In this article, the ansa-bridged metallocene dichlorides have been determined by X-ray diffraction and the crystal structures of these compounds have been discussed in terms of the modifications of the electronic structure as a consequence of the Ansa bridge.
Abstract: Reaction between [MCl4(dme)](M = W or Mo; dme = 1,2-dimethoxyethane) with Li2[C5H4CMe2C5H4] gave the ansa-bridged metallocene dichlorides [M{(η-C5H4)CMe2(η-C5H4)}Cl2](M = W or Mo). Treatment of these with LiAlH4 or ZnMe2 gave respectively the dihydrides [M{(η-C5H4)CMe2(η-C5H4)}H2](M = W or Mo) and the dimethyl derivatives [M{(η-C5H4)CMe2(η-C5H4)}Me2](M = W or Mo). Treatment of [W{(η-C5H4)CMe2(η-C5H4)}Me2] with HX (X = PhCO2 or NH3l) gave [W{(η-C5H4)CMe2(η-C5H4)}Me(Y)] with Y = PhCO2 or l, respectively. Both of these react with Na[AlH2(OCH2CH2OMe)2] giving the methylhydride [W{(η-C5H4)CMe2(η-C5H4)}Me(H)]. The latter is thermally stable in refluxing benzene. Ultraviolet photolysis of [Mo{(η-C5H4)CMe2(η-C5H4)}H2] in benzene gave the phenylhydride derivative [Mo{(η-C5H4)CMe2(η-C5H4)}Ph(H)]; the corresponding tungsten derivative [W{(η-C5H4)CMe2(η-C5H4)}H2] is not photosensitive. The crystal structures of [W{(η-C5H4)CMe2(η-C5H4)}Cl2], [W{(η-C5H4)CMe2(η-C5H4)}H2], (two modifications) and [Mo{(η-C5H4)CMe2(η-C5H4)}H2] have been determined by X-ray diffraction. The ansa-bridged bis(η-cyclopentadienyl) compounds show marked differences in reactivity compared to non-ansa analogues and this is discussed in terms of the modifications of the electronic structure as a consequence of the ansa bridge.
34 citations
TL;DR: In this article, the first ionization band of the photoelectron (PE) spectra, assigned to the 2A1 ion state is very sharp, indicating a non-bonding orbital.
TL;DR: In this article, the ansa-bridged compounds exhibit substantially different reactivities from those of the unbridged analogues, and are characterized by the crystal structures for the complexes marked with an asterisk.
TL;DR: In this paper, a cyclopentadienyl-imido compound of molybdenum (and tungsten) was shown to be a 4-electron donor ligand.
Abstract: New cyclopentadienyl-imido compounds of molybdenum (and tungsten) have been prepared. They have an extensive chemistry in which the imido group behaves as a 4-electron donor spectator ligand. The structure of the bis-qcyclopentadienyl compound [ M o ( ~ C ~ H ~ R ) ~ ( N B U ~ ) ] shows the q-cyclopentadienyl rings are partially displaced from the metal by the px-donor electron pair on the imido nitrogen. In consequence a q-cyclopentadienyl ring can be readily displaced. The ansa-sandwich compounds [ M ( ~ C ~ H ~ C M ~ ~ ~ I C ~ H ~ ) X ~ I , where M = Mo or W and X2 = Cl2. H2, Me2, HPh, HMe have been prepared. These ansa bridged compounds are much more resistant to reductive elimination reactions than their nonansa analogues. New transition metal compounds of the fullerene c60 have been prepared. STUDIES IN 11-CYCLOPENTADIENYL-IMO-MOLYBDENUM CHEMISTRY Both the imido ligands NR and the q-cyclopentadienyl ligands q-CgR5 have an extensive chemistry. The mission of this research was to learn more about the properties of imido ligands in general and, more specifically, the chemistry of the combination,of both ligands in q-cyclopentadienyl-imido-molybdenum (and -tungsten) compounds. References to previous chemistry of q-cyclopentadienyl-imido transition metal compounds are available (1.2). The 17-electron compounds [Mo(q-CgHqR)(NR')X2], where, typically, R = H or alkyl, R = But, Pri, or Ph and X = C1, Br or I, (1,2) may be prepared by the reactions shown below:R R' X But H, Me, P2 c1 Pr' H c1 Ph Me C1 But Me Br The d1 compounds [Mo(q-CsH4R)(NR')C12] readily undergo a reductive substitution reaction giving the 18-electron d2 compounds [Mo(~-CSH~R)(NR')LCI], where L = CO, PR3, C2H4, MeC2Me, viz:-
TL;DR: In this article, the reaction between B(C6F5)3 and Fe(η5-C5H5)(CO)2Me gives the unexpected product {[[graphic omitted])Me)]( η5 − C 5H5(CO)}, which reacts with the donor molecules L, where L = PMe3, PPh3, or ButNC.
Abstract: The reaction between B(C6F5)3 and [Fe(η5-C5H5)(CO)2Me] gives the unexpected product {[[graphic omitted])Me)](η5-C5H5)(CO)}, which reacts with the donor molecules L, where L = PMe3, PPh3, or ButNC, giving {[[graphic omitted]O)Me)](η5-C5H5)(L)}.
TL;DR: In this article, the crystal structures of [Mo(η-C5H4R)2(NR′)Cl2] have been determined, as well as the crystal structure of the bis-cyclopentadienyl-imide compound [Mo (ηC 5H4Me)2Me(NBut)].
Abstract: The mono(η-cyclopentadienyl)imide compounds [Mo(η-C5H4R)(NR′)Cl2](R, R′= H, R″; Me, Pri; Me, R″; or Pri, R″; R″= C6H3Me2-2,6) and the new bis(η-cyclopentadienyl)imide compounds [Mo(η-C5H4R)2(NR′)](R, R′= Me, But; H, But; H, Pri; H, Ph; H, R″; Me, Pri; Me, Ph; Me, R″; Pri, But; or Pri, R″), [Mo(η-C5H5)(η-C5H4Pri)(NBut)], [Mo(η3-C9H7)(η-C5H4Pri)(NBut)] and [Mo(η- C5H4Me)2Me(NBut)]X (X = I or BF4) have been prepared. The salt [Mo(η-C5H4Me)(PMe3)2(NBut)][C5H4Me] has also been prepared. The crystal structures of the latter and of [Mo(η-C5H5)2(NBut)] have been determined.
TL;DR: The ansa-metallocene imide compounds of niobium have been prepared and their crystal structures have been determined as discussed by the authors, and they have been shown to have different crystal structures.
Abstract: The ansa-metallocene imide compounds of niobium {Nb[Me2C(η5-C5H4)(σ-C5H4)](η5-C5H5)(NBut)} and {Nb[Me2C(σ-C5H4)(η3-C9H6)](η5-C5H5)(NBut)} have been prepared and their crystal structures have been d...
TL;DR: In this article, the preparation of lanthanide-hydrogen-transition metal compounds from the potassium salts was described and their X-ray crystal structures and NMR data indicated the presence of W(μ-H 3 )Yb or W( μ-H) 2 Nb groups, respectively.
TL;DR: In this paper, the synthesis of the mixed-ring sandwich compound [Mo(η6-NC5H3Me2-2,6)(η 6-C6H5Me)] is reported.
Abstract: Synthesis of the mixed-ring sandwich compound [Mo(η6-NC5H3Me2-2,6)(η6-C6H5Me)] is reported. Photoelectron spectroscopic studies of [M(η6-NC5H3Me2-2,6)2], where M = Ti, V, Cr or Mo and [Mo(η6-NC5H3Me2-2,6)(η6-C6H5Me)] established that these sandwich compounds are electronically very similar to the bis(arene) analogues, and that 2,6-dimethylpyridine is a better δ acceptor than benzene.
TL;DR: In this article, a new class of combustion catalyst containing copper and chlorine was described, which has high activity for the total oxidation of chlorinated hydrocarbons such as CH2Cl2, CH2CLCH2Cl, CCl4 and 1,2-dichlorobenzene, in the presence of excess air at 300-500 °C.
Abstract: A new class of combustion catalyst containing copper and chlorine is described which has high activity for the total oxidation of chlorinated hydrocarbons such as CH2Cl2, CH2ClCH2Cl, CCl4 and 1,2-dichlorobenzene (1% of gas stream) into carbon oxides, HCl and Cl2, in the presence of excess air at 300–500 °C; no catalyst deactivation or loss of copper or chlorine is observed.
TL;DR: The crystal structures for the W(IV) compounds with P = H 2 PC 2 H 5 and PMe 3 were determined for the corresponding tungsten (V)_compounds [W((η-C 5 H 4 i Pr)Cl 4 (P)] by treatment with [Fe 2 (CO) 9 ].
TL;DR: The new compounds [W2(η-C5H4Pri)2Cl3(PR3)µ-Cl)(µ -C2Et2)] (PR3= PMe32a, PMe2Ph2b, PH2Ph 2c or PPh2H 2d) have been determined.
Abstract: The new compounds [W2(η-C5H4Pri)2Cl3(PR3)(µ-Cl)(µ-C2Et2)](PR3= PMe32a, PMe2Ph 2b, PH2Ph 2c or PPh2H 2d), [W2(η-C5H4Pri)2Cl3(PMe3)(µ-Cl)]3, [W2(η-C5H4Pri)2Cl2(PMe3)2(µ-C2Et2)]4, [W2(η-C5H4Pri)2Cl2(PMe3)(µ-C2Et2)]5, [W2(η-C5H4Pri)2Cl3(OEt)(µ-C2Et2)]6, [W2(η-C5H4Pri)2Cl3(SMe)(µ-C2Et2)]7 and [W2(η-C5H4Pri)2Cl2(µ-NR)(µ-C2Et2)](R = H 8a, Me 8b or Ph 8c) have been prepared. The crystal structures of compounds 2a and 8c have been determined. The compounds 8a–8c contain a three-centre, two-electron W–N–W ‘banana’π bond.
01 Jan 1995
TL;DR: In this article, the crystal structures of the new compounds M(η-C5R5) and Zr(C5H5) have been determined, where Zr acts as a co-catalyst for the polymerisation of ethylene and propene.
Abstract: The new compounds {M(η-C5R5)[η-CPh(NSiMe3)2]]Cl2} (where R = H, M = Ti, Zr, Hf or R = Me, M = Ti or Zr), are described. The crystal structures of {M(η-C5R5)([η-CPh(NSiMe3)2]Cl2} (R = H, M = Zr or Hf) have been determined. The compound {Zr(η-C5H5)[η-CPh(NSiMe3)2]Cl2} acts as a co-catalyst for the polymerisation of ethylene and propene.