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91.
Anderson KM Connelly NG Llamas-Rey E Orpen AG Paul RL 《Chemical communications (Cambridge, England)》2001,(18):1734-1735
Synthesis and characterisation of cyano-bridged complexes of the form [(eta-C5R4Me)L(ON)Mn(mu-XY)Mn(CO)2-L'(dppm)]z (X,Y = C,N; z = 1-3) shows that systematic variation of the orientation of the CN bridge and the nature and geometric arrangement of the ancillary ligands affords control of the direction and energy of metal-metal charge transfer in the mixed valence dications. 相似文献
92.
Dennett JN Knox SA Anderson KM Charmant JP Orpen AG 《Dalton transactions (Cambridge, England : 2003)》2005,(1):63-73
The synthesis, fluxionality and reactivity of the heterobimetallic complex [FeRu(CO)2(mu-CO)2(eta-C5H5)(eta-C5Me5)] are described. Complex exhibits enhanced photolytic reactivity towards alkynes compared to its homometallic analogues, forming the dimetallacyclopentenone complexes [FeRu(CO)(mu-CO){mu-eta]1:eta3-C(O)CR"CR'}eta]-C5H5)(eta-C5Me5)]( R'= R"= H; R'= R"= CO2Me; R'= H, R"= CMe2OH). Prolonged photolysis with diphenylethyne gives the dimetallatetrahedrane complex [FeRu(mu-CO)(mu-eta2:eta2-CPhCPh)(eta-C5H5)(eta-C5Me5)], which contains the first iron-ruthenium double bond. Complexes containing a number of organic fragments can be synthesised using , and . Heating a solution of gave the alkenylidene complex [FeRu(CO)2(mu-CO){mu-eta]1:eta2-C=C(CO2Me)2}(eta-C5H5)(eta-C5Me5)] through an unusual methylcarboxylate migration. Protonation and then addition of hydride to gives the ethylidene complex [FeRu(CO)2(mu-CO)(mu-CHCH3)(eta-C5H5)(eta-C5Me5)] via the ionic vinyl species [FeRu(CO)2(mu-CO)(mu-eta]1:eta2-CH=CH2)(eta-C5H5)(eta-C5Me5)][BF4]. Compound exhibits cis/trans isomerisation at room temperature. Protonation of dimetallacyclopentenone complexes gives the allenyl species [FeRu(CO)2(mu-CO)(mu-eta1:eta2-CH=C=CMe2)(eta-C5H5)(eta-C5Me5)][BF4]. Compound exist as three isomers, two cis and one trans. The two cis isomers are shown to be interconverting by sigma-pi isomerisation. The solid state structures of these compounds were established by X-ray crystallography and are discussed. 相似文献
93.
Lee J. Higham Ann J. Middleton Katie Heslop Paul G. Pringle Angharad Barber A. Guy Orpen 《Journal of organometallic chemistry》2004,689(19):2963-2968
The indan derived diphosphine, cis-1,3-(diphenylphosphino)indan (anphos) is synthesised by the addition of Ph2P(BH3)Li to cis-1,3-dibromoindan followed by deprotection with diethylamine. Anphos readily forms the bicyclic chelates [RhCl(CO)(anphos)], [PtCl2(anphos)], [PtCl(Me)(anphos)] and [FeCl2(anphos)]. The crystal structures of [FeCl2(anphos)] and the monoxide complex, [RhCl(CO)(anphosO)] have been determined. Reaction of the diphosphine with [Rh(acac)(CO)2] under moderate hydroformylation conditions catalysed the formation of 1-heptanal and branched aldehydes from 1-hexene in a ratio of 1.5:1. 相似文献
94.
David L. Davies Andrew F. Dyke Andreas Endesfelder Selby A.R. Knox Pamela J. Naish A. Guy Orpen Dietrich Plaas Graham E. Taylor 《Journal of organometallic chemistry》1980,198(2):C43-C49
The ethyne-derived demetallocycle [Ru2(CO) (μ-CO){μ-C(O)C2H2}(η-C5H5)2 isomerises in boiling toluene to yield the μ-vinylidene complex [Ru2(CO)2(μ-CO)(μ-CCH2) (η-C5H5)2], which on protonation with dry HBF4 provides the μ-carbyne complex [Ru2(CO)2(μ-CO)(μ-CCH3)(η-C5H5)2][BF4]; the structure of each product has been determined by X-ray diffraction. The μ-carbyne cation is attacked by hydride to produce the μ-methylcarbene complex [Ru2(CO)2(μ-CO)(μ-CHCH3)(η-C5H5)2]. 相似文献
95.
Norman DW Carraz CA Hyett DJ Pringle PG Sweeney JB Orpen AG Phetmung H Wingad RL 《Journal of the American Chemical Society》2008,130(21):6840-6847
C 1-Symmetric phosphino/phosphonite ligands are prepared by the reactions of Ph 2P(CH 2) 2P(NMe 2) 2 with ( S)-1,1'-bi-2-naphthol (to give L A ) or ( S)-10,10'-bi-9-phenanthrol (to give L B ). Racemic 10,10'-bi-9-phenanthrol is synthesized in three steps from phenanthrene in 44% overall yield. The complexes [PdCl 2( L A,B )] ( 1a, b), [PtCl 2( L A,B )] ( 2a, b), [Rh(cod)( L A,B )]BF 4 ( 3a, b) and [Rh( L A,B ) 2]BF 4 ( 4a, b) are reported and the crystal structure of 1a has been determined. A (31)P NMR study shows that M, a 1:1 mixture of the monodentates, PMePh 2 and methyl monophosphonite L 1a (based on ( S)-1,1 '-bi-2-naphthol), reacts with 1 equiv of [Rh(cod) 2]BF 4 to give the heteroligand complex [Rh(cod)(PMePh 2)( L 1a )]BF 4 ( 5) and homoligand complexes [Rh(cod)(PMePh 2) 2]BF 4 ( 6) and [Rh(cod)( L 1a ) 2]BF 4 ( 7) in the ratio 2:1:1. The same mixture of 5- 7 is obtained upon mixing the isolated homoligand complexes 6 and 7 although the equilibrium is only established rapidly in the presence of an excess of PMePh 2. The predominant species 5 is a monodentate ligand complex analogue of the chelate 3a. When the mixture of 5- 7 is exposed to 5 atm H 2 for 1 h (the conditions used for catalyst preactivation in the asymmetric hydrogenation studies), the products are identified as the solvento species [Rh(PMePh 2)( L 1a )(S) 2]BF 4 ( 5'), [Rh(S) 2(PMePh 2) 2]BF 4 ( 6') and [Rh(S) 2( L 1a ) 2]BF 4 ( 7') and are formed in the same 2:1:1 ratio. The reaction of M with 0.5 equiv of [Rh(cod) 2]BF 4 gives exclusively the heteroligand complex cis-[Rh(PMePh 2) 2( L 1a ) 2]BF 4 ( 8), an analogue of 4a. The asymmetric hydrogenation of dehydroamino acid derivatives catalyzed by 3a, b is reported, and the enantioselectivities are compared with those obtained with (a) chelate catalysts derived from analogous diphosphonite ligands L 2a and L 2b , (b) catalysts based on methyl monophosphonites L 1a and L 1b , and (c) catalysts derived from mixture M. For the cinnamate and acrylate substrates studied, the catalysts derived from the phosphino/phosphonite bidentates L A,B generally give superior enantioselectivities to the analogous diphosphonites L 2a and L 2b ; these results are rationalized in terms of delta/lambda-chelate conformations and allosteric effects of the substrates. The rate of hydrogenation of acrylate substrate A with heterochelate 3a is significantly faster than with the homochelate analogues [Rh( L 2a )(cod)]BF 4 and [Rh(dppe)(cod)]BF 4. A synergic effect on the rate is also observed with the monodentate analogues: the rate of hydrogenation with the mixture containing predominantly heteroligand complex 5 is faster than with the monophosphine complex 6 or monophosphonite complex 7. Thus the hydrogenation catalysis carried out with M and [Rh(cod) 2]BF 4 is controlled by the dominant and most efficient heteroligand complex 5. In this study, the heterodiphos chelate 3a is shown to be more efficient and gives the opposite sense of optical induction to the heteromonophos analogue 5. 相似文献
96.
97.
Piotr Jankowski Claire L. McMullin Ilya D. Gridnev A. Guy Orpen Paul G. Pringle 《Tetrahedron: Asymmetry》2010,21(9-10):1206-1209
The enantioselective hydrogenation catalyst [Rh(α-CgPH)2(cod)]BF4, (CgPH = 6-phospha-2,4,8-trioxa-adamantane) exists in solution as a mixture of two slowly interconverting rotamers, one with C2- and the other with C1-symmetry. 相似文献
98.
Jonathan P. H. Charmant Juan Fornis Julio Gmez Elena Lalinde M. Teresa Moreno A. Guy Orpen Santiago Solano 《Angewandte Chemie (International ed. in English)》1999,38(20):3058-3061
Enhanced reactivity is shown by uncoordinated C≡C bonds in the proximity of a metal in phosphanylacetylene complexes. cis-[Pt(C6F5)2(thf)2] reacts with [M(C6F5)2(PPh2C≡CPh)2] (M=Pt, Pd) to form binuclear complexes containing the novel 2,3-bis(diphenylphosphanyl)-1,3-butadien-1-yl bridging ligand. Substitution of the solvent ligands with, for example, PPh2H (see picture) provides species that could be characterized by X-ray crystallography. 相似文献
99.
Sin C. James Yvonne G. Lawson Nicholas C. Norman A. Guy Orpen Michael J. Quayle 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(4):427-429
Two pentahalo(N‐donor)bismuthate(III) salts, bis[hydrogen bis(4‐picoline)(1+)] pentabromo(4‐picoline‐N)bismuthate(III), (C12H15N2)2[BiBr5(C6H7N)], (I), and bis(pyridinium) pentachloro(pyridine‐N)bismuthate(III), (C5H6N)2[BiCl5(C5H5N)], (II), are described which show modest deviations from octahedral geometry at bismuth. In (I), the cations comprise two 4‐picoline molecules sharing a proton and in (II), pyridinium cations are present. The anion in (I) has twofold and that in (II) has mirror crystallographic symmetry. Both structures show a layered packing formed by the anions with the cations between the layers. Ring–ring interactions seem important in (I), whilst in (II), N/C—H?Cl—Bi hydrogen bonding is abundant. 相似文献
100.