14516-54-2Relevant academic research and scientific papers
Preparation of a mixed-metal ketenylidene complex from Mn(CO)5(CX3) (X = Cl, Br)
Crespi, Ann M.,Shriver, Duward F.
, p. 1750 - 1752 (1986)
The reaction of Mn(CO)5(CBr3) and [PPN][Co(CO)4] yields the mixed-metal ketenylidene complex [PPN][MnCO2(CO)9(μ3-CCO)]. The structure of the ketenylidene complex was determined by X-ray crystallography.
Multi-step and multi-component organometallic synthesis in one pot using orthogonal mechanochemical reactions
Hernandez, Jose G.,Butler, Ian S.,Friscic, Tomislav
, p. 3576 - 3582 (2014/08/18)
We demonstrate that the mechanochemical strategies for oxidative addition and ligand substitution on organometallic centers can be mutually orthogonal, permitting the rational design of multi-component mechanochemical reaction procedures for assembling complex or solution-sensitive organometallic species from three, four or even five components in one pot. The herein established synthetic procedures represent a new level of complexity in mechanochemical reactions by milling and are the first to combine redox and ligand substitution reactions into mechanochemical strategies for either one-pot sequential ( telescoping ) or one-pot multi-component syntheses. This ability to combine mechanochemical transformations has enabled the solvent-free, room-temperature syntheses of relatively complex organometallics directly for simple zerovalent metal carbonyls as the simplest precursors. In particular, we demonstrate the efficiency of mechanochemical oxidative addition by targeting selected pentacarbonyl halides (fluoride, chloride, bromide, iodide) of rhenium(i) and manganese(i), and illustrate the potential of multi-step organometallic mechanochemistry in the syntheses of selected fac-tricarbonyl complexes of these metals.
Therapeutic delivery of carbon monoxide
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Page/Page column 9, (2010/05/13)
Compounds, pharmaceutical compositions and methods for the therapeutic delivery of carbon monoxide to humans and other mammals that employ Mn complexes having CO ligands, and additional halogen, monodentate and/or bidentate ligands, wherein the additional ligands do not occupy trans positions relative to each other.
Metal-metal bond cleavage of carbene complexes by halogens: The crystal and molecular structures of ax-[Mn2(CO)9{C(OEt)2-thienyl}], [Mn(CO)4(I){C(OEt)2-thienyl}] and eq-[Mn2(CO) 9{C(NH2)2-thienyl}]
Lotz, Simon,Landman, Marilé,Bezuidenhout, Daniela I.,Olivier, Andrew J.,Liles, David C.,Van Rooyen, Petrus H.
, p. 5929 - 5937 (2007/10/03)
The metal-metal bond in [M2(CO)9{C(OEt)R}] (M = Mn (1), Re (2), R = 2-thienyl (a), 2-bithienyl (b)) is readily cleaved with halogens to afford cis-[M(CO)4(X){C(OEt)R}] (M = Mn (3), X = I; M = Re (4), X = Br). In the binuclear manganese complex, the carbene ligand is found in an axial position due to steric reasons, whereas the electronically favoured equatorial position is found for the carbene ligands in the corresponding rhenium complexes and in [Mn2(CO)9{C(NH 2)thienyl}] (5a), containing a sterically less demanding NH 2-substituent.
Synthesis, characterization, and thermochemistry of (η1-C13H9)MN(CO)5 and (η5-C13H9)MN(CO)3
Decken, Andreas,MacKay, Andrew J.,Brown, Martin J.,Bottomley, Frank
, p. 2006 - 2009 (2008/10/08)
Reaction of LiC13H9 with Mn(CO)5Br at -78 °C gave (η1-C13H9)Mn(CO)5, 2. Thermal rearrangement of 2 yielded (η5-C13H9)Mn(CO)3, 1, 9, 9′
Photochemistry and Emission of the Dinuclear Complexes (CO)5MnRe(CO)3(L) (L = 2,2'-Bipyrimidine, 2,3-Bis(2-pyridyl)pyrazine) and Bridged Trinuclear Complexes (CO)5MnRe(CO)3(L)Re(Br)(CO)3 and (CO)5MnRe(CO)3(BPYM)W(CO)4: Effect of the Remote Metal Center on the Photodissociation of the ...
Outersterp, J. W. M. van,Stufkens, D. J.,Vlcek, A. Jr.
, p. 5183 - 5194 (2008/10/08)
Photochemical and emission properties of the dinuclear (CO)5MnRe(CO)3(L) and trinuclear (CO)5MnRe(CO)3(L)Re(Br)(CO)3 and (CO)5MnRe(CO)3(BPYM)W(CO)4 complexes (L = 2,2'-bipyrimidine (BPYM), 2,3-bis(2-pyridyl)pyrazine(DPP)) are described. All these compounds undergo photochemical homolysis of the Mn-Re bond upon excitation into their MLCT absorption band(s) in the visible spectral region. Mn(Cl)(CO)5 and Re(Cl)(CO)3(L) or Re(Cl)(CO)3(L)Re(Br)(CO)3 are formed in chlorinated solvents (CH2Cl2, CCl4) from the former two types of complexes, respectively. In THF, photolysis produces Mn2(CO)10, together with [Re(CO)3(L)].bul., [Re(CO)3(L)Re(Br)(CO)3].bul., or [Re(CO)3(BPYM)W(CO)4].bul. radicals, respectively, which presumably contain also a coordinated THF molecule. Photoreactions of the dinuclear complexes occur with high quantum yields (0.36 for BPYM and 0.54 for DPP), which are independent of the temperature and of the excitation wavelength. The attachment of the Re(Br)(CO)3 group to the potentially bridging ligand L in (CO)5MnRe(CO)3(L) to form the L-bridged trinuclear species strongly influences the excited state dynamics involved in the photochemistry. Thus, the photochemical quantum yields of the trinuclear complexes are both temperature and excitation wavelength dependent. The apparent activation energy, together with the overall quantum yield, decreases upon changing the excitation from the high- to the low-energy MLCT absorption band. The Mn-Re bond homolysis is about 6 times more efficient for bridging DPP than for bridging BPYM. The dinuclear complexes exhibit, in a 2-MeTHF glass at 80 K, an emission from thermally unequilibrated states, whereas double emission, extending into the near-IR spectral region, was observed for (CO)5MnRe(CO)3(DPP)Re(Br)(CO)3. Its BPYM analogue is nonemissive. To account for this complex photobehavior, an excited state diagram and a qualitative dynamics model are proposed. The reaction is assumed to occur from a (3)σπ(*) state that is nonradiatively populated from the higher MLCT state(s). The main effects of the attachment of the Re(Br)(CO)3 group, which is responsible for the changed photochemical behavior, are the profound stabilization of the π(*) LUMO of the bridging ligand L and the introduction of another MLCT excited state into the trinuclear molecule.
Isomers of Re(CO)3(CNt-Bu)LX: synthetic strategies starting from MnRe(CO)8(CNt-Bu)L and Re(CO)4LX (X=halogen; L=Group 15 donor ligand)
Leins, Ann E.,Conville, Neil J.
, p. 183 - 190 (2007/10/02)
Reaction of Re(CO)4LX (L=PMePh2, PMe2Ph, PPh3, P(OMe)3, P(Oi-Pr)3, P(O-o-tol)3; X=Br, I) with t-BuNC in the presence of PdO catalyst gave the new complexes Re(CO)3(CNt-Bu)LX in high yield ( >60percent).The new complexes were shown by spectroscopic techniques (IR, 1H and 31P NMR) to comprise a mixture of mer and fac isomers.The mer/fac ratio decreased with reaction temperatures (e.g.L=P(OMe)3; 10 deg C, ratio=3; 45 deg C, ratio=0.25).At high temperatures (90 deg C) isomerization of the mer to the fac isomers (L=PMe2Ph, P(OMe)3) occurred, suggesting that the mer isomer was the kinetic product of the catalyzed reaction.Reactions induced by Me3NO gave similar effects.Halogen cleavage of MnRe(CO)8(CNt-Bu)L, prepared from MnRe(CO)9(CNt-Bu) and L in the presence of Me3NO, yielded either one or two isomers of Re(CO)3(CNt-Bu)(L)X (X=I, Br; 40percent yield).For large L (e.g.PPh3) a new mer isomer with L trans to X was synthesized, and characterized by IR and NMR spectroscopy.For small L (e.g.P(OMe)3) a mixture of the two different mer products was obtained.The product isomer ratio was determined predominantly by the position of L in the starting dimer. Key words: Rhenium; Carbonyl; Catalysis; Heterobimetallics; Substitution
Solid-liquid reactions of manganese and cobalt carbonyl anions with alkyl halides containing β-hydrogens or -halogens
Kovács, István,Ungváry, Ferenc,Garst, John F.
, p. 389 - 396 (2008/10/08)
Heterogeneous reactions afforded the first detection (by IR and NMR spectroscopy) of a secondary (η1-allyl)manganese carbonyl complex, CH3CH=CHCH(CH3)Mn(CO)5, which results from the reaction of solid NaMn(CO)5 with 4-bromo-2-pentene in benzene or in saturated hydrocarbons at temperatures up to 5°C. The analogous reaction of NaCo(CO)4 gives CH3-CH=CHCH(CH3)C(O)Co(CO)4, the product of CO insertion into CH3CH=CHCH(CH3)Co-(CO)4, which constitutes approximately 10% (by IR spectroscopy) of the equilibrium mixture with CH3CH=CHCH(CH3)C(O)Co(CO)4 under CO at 1 atm and 5°C. Addition of PPh3 to this mixture leads to the formation of isolable CH3CH=CHCH(CH3)C(O)Co(CO)3PPh3. Similar reactions of 4-bromo-2-pentene with NaMn(CO)4PPh3 and NaCo(CO)3PPh3 do not give metal-carbon-bonded species, nor do room-temperature reactions of 4-bromo-2-pentene with NaMn-(CO)5 and NaCo(CO)4. Instead, the products include 2-pentenes, 1,3-pentadienes, 4,5-dimethyl-2,6-octadiene isomers, BrMn(CO)5, Mn2(CO)10, Co2(CO)8, and η3-(CH3CHCHCHCH3)Co(CO)3. Reactions of dimethyl chlorosuccinate, ethyl 2-bromopropionate, methyl 3-bromopropionate, and dimethyl dibromosuccinate with NaMn(CO)5 and NaCo(CO)4 give varying amounts of alkylmetal carbonyl compounds and products of β-elimination. The characteristics of these transformations suggest radical mechanisms initiated by single electron transfer (SET). Radical pairs formed by SET are implicated as intermediates in both substitutions and eliminations.
Reactivity of Main-Group-transition-metal bonds IX*. The kinetics of iodination of compounds containing two or more tin-transition-metal bonds
Chipperfield, John R.,Clark, Stephen,Webster, David E.,Yusof, Halimahton
, p. 205 - 213 (2007/10/02)
Rate coefficients are reported for the cleavage by halogens of tin-transition-metal bonds in compounds containing two or more such bonds.Bond reactivity with iodine is in the order Sn-Co ca.Sn-Fe above Sn-Mo ca.Sn-W above Sn-Mn.Rates of halogenation of compounds containing three tin-transition-metal bonds show that a subtle balance between steric and electronic effects determines bond reactivity.
The preparation and reactions of ω-bromoacylmanganese pentacarbonyls
Masters, Andrew P.,Sorensen, Ted S.
, p. 502 - 506 (2007/10/02)
The reaction of ω-bromoacyl chloride Br-CH2-(CH2)n-CoCl and Mn(CO)5(1-) is reported.In the case of n = 0, one obtains ketene, Mn(CO)5Br and chloride ion.In contrast, the corresponding chloro compound gives the known chloroacyl manganese complex.With n = 1, 2, or 3, one can isolate the corresponding ω-bromoacylmanganese complexes.On mild heating, the n = 1 complex produces only ethylene and Mn(CO)5Br.The n = 2 and 3 complexes are also relatively labile on heating in THF solution and produce the 1-alkene as the major organic product.In chloroform solution, the corresponding ω-bromoalkyl complex is produced initially on heating, but further heating again produces mainly the 1-alkene.However, the n = 2 complex also produces appreciable amounts of cyclopropane.
