14100-30-2Relevant academic research and scientific papers
Gas-phase reactions of ClMn(H2O)+ with polar and nonpolar hydrocarbons in a mass spectrometer
Duan, Penggao,Fu, Mingkun,Pinkston, David S.,Habicht, Steven C.,Kenttaemaa, Hilkka I.
, p. 9266 - 9267 (2007)
The gas-phase reactions of ClMn(H2O)+ with a variety of volatile and nonvolatile, saturated and unsaturated hydrocarbons have been examined by using Fourier transform ion cyclotron resonance mass spectrometry (FT/ICR). The ClMn(H2O)+ ion reacts rapidly by exclusive H2O ligand displacement with all the hydrocarbons studied, including highly branched alkanes that usually fragment upon ionization. These observations are rationalized on the basis of the electronic structure of ClMn+. Collision-activated dissociation of the product ions provides structural information which promises to allow the distinction and structural characterization of isomeric hydrocarbons. These findings suggest that the ClMn(H2O)+ ion is a highly promising chemical ionization reagent for mass spectrometric characterization of hydrocarbons, including those that commonly exist in petroleum. Copyright
C-C Bond Elimination from High-Valent Mn Aryl Complexes
He, Yu-Tao,Karimata, Ayumu,Gladkovskaya, Olga,Khaskin, Eugene,Fayzullin, Robert R.,Sarbajna, Abir,Khusnutdinova, Julia R.
, p. 2320 - 2331 (2021)
Manganese complexes have been considered as a cheap and readily available alternative to commonly used precious metal catalysts in C-C bond coupling reactions. Although high-valent Mn aryl intermediates have been proposed in such reactions, a mechanistic understanding of possible organometallic intermediates in Mn-mediated C-C coupling is still lacking due to their high reactivity. We report the synthesis of stable, isolable Mn(III) aryl complexes obtained by oxidative addition of aryl bromide or aryl chloride. These complexes react with a range of organometallic alkylating or arylating reagents (alkyl and aryl Grignard reagents, MeLi, ZnMe2) to undergo C(sp2)-C(sp3) or C(sp2)-C(sp2) bond coupling, and a preliminary catalytic system could be demonstrated. The reagent scope and yield of the C(sp2)-C(sp3) coupled product can further be increased by addition of TEMPO as an oxidant, generating alkyl radicals.
Bismuth Compounds in Radical Catalysis: Transition Metal Bismuthanes Facilitate Thermally Induced Cycloisomerizations
Ramler, Jacqueline,Krummenacher, Ivo,Lichtenberg, Crispin
, p. 12924 - 12929 (2019/08/02)
The controlled radical chemistry of bismuth compounds is still in its infancy. Further developments are fueled by the properties of these complexes (e.g., low toxicity, high functional group tolerance, low homolytic bond dissociation energies, and reversible homolytic bond dissociations), which are highly attractive for applications in synthetic chemistry. Here we report the first catalytic application of transition metal bismuthanes (i.e. compounds with a Bi–TM bond; TM=transition metal). Using the catalyzed radical cyclo-isomerization of δ-iodo-olefins as a model reaction, characteristics complementary or superior to known B, Mn, Cu, Zn, Sn, and alkali metal reagents are demonstrated (including a different crucial intermediate), establishing transition metal bismuthanes as a new class of (pre-)catalysts for controlled radical reactions.
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
-
Page/Page column 10, (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.
A novel metal-chain extension reaction: Synthesis of (X)[Os(CO)3(CN-t-Bu)]nMn(CO)5 (X = Cl, Br, I; n = 1, 2, 3)
Jiang, Faming,Jenkins, Hilary A.,Green, David F.,Yap, Glenn P.A.,Pomeroy, Roland K.
, p. 281 - 291 (2007/10/03)
Complexes of formula (X)[Os(CO)3(CN-t-Bu)]nMn(CO)5 (X = Cl, Br, I; n = 1, 2, 3) have been prepared by the reaction of Os(CO)4(CN-t-Bu) with Mn(CO)5(X) in hexane at room temperature. The characterization of the complexes included the crystal structures of compounds with X = I, n = 1, 3 and X = Cl, Br, n = 2 (2ClA and 2BrB). The trinuclear products were isolated as two isomers. The major isomer (2XA) has an isocyanide ligand attached to each osmium atom, whereas the minor isomer (2XB) has both of these ligands bound to the terminal Os atom. The structures contain OsnMn chains with unbridged Os-Mn bonds (range of lengths are 2.870(1)-2.9245(8) A) and for compounds with n = 2 or 3 Os-Os bonds (range of lengths are 2.8812(4)-2.8928(5) A). The mechanism of formation is believed to involve replacement of a CO ligand with the 18e- ligand Os(CO)4(CN-t-Bu) at the metal with the coordinated halide, followed by a rearrangement in which the halide ligand migrates to the donor Os atom with concomitant migration in the reverse direction of a carbonyl ligand. The preparation of (OC)4(t-BuNC)OsMn(CO)4(Cl) with an Os-Mn dative bond is also reported along with the (OC)4(t-BuNC)OsRe(CO)4(X) analogues.
Photochemical bond homolysis in a novel series of metal-metal bonded complexes Ru(E)(E′)(CO)2(iPr-DAB)
Aarnts, Maxim P.,Stufkens, Derk J.,Vlcek Jr., Antonin
, p. 37 - 46 (2008/10/08)
Photochemistry of the complexes trans,cis-Ru(E)(E′)(CO)2(iPr-DAB) (E = Cl, SnPh3, PbPh3, Mn(CO)5, Re(CO)5, Me; E′ (depending on E) = SnPh3, PbPh3, GePh3, Mn(CO)5, Re(CO)5) was found to be strongly dependent on the combination and characters of the axial ligands E and E′. Except for Ru(Cl)(SnPh3)(CO)2(iPr-DAB) and Ru(Cl)(PbPh3)(CO)2(iPr-DAB) which are nearly unreactive, one of the Ru-E/E′ bonds is split homolytically upon irradiation into the lowest-energy absorption band of the complex. For Ru(SnPh3)2(CO)2(iPr-DAB), this reaction occurs from a thermally equilibrated 3σπ* excited state with a rate constant of 2.3 × 105 s-1 and a temperature-dependent quantum yield (Ea = 1450 cm-1). The unselective Ru-Ge (60%) and Ru-Sn (40%) bond homolysis of Ru(SnPh3)(GePh3)(CO)2-(iPr-DAB) follows the same mechanism. On the other hand, bond homolysis is much faster (?108 s-1) for complexes which contain Ru-Me, Ru-Mn or Ru-Re bonds. Bond homolysis in these species is highly selective, since only Ru-Me, Ru-Mn and Ru-Re bond splitting was observed for Ru(Me)(SnPh3)(CO)2(iPr-DAB), Ru(SnPh3)(Mn(CO)5)(CO)2(iPr-DAB) and Ru(SnPh3)(Re(CO)5)(CO)2(iPr-DAB), respectively. The photoproduced [Ru(E)(CO)2(iPr-DAB)]· radicals were detected by time resolved UV-Vis spectroscopy on a timescale 10 ns-100 μs. The [Ru(SnPh3)(CO)2(iPr-DAB)]· radical was also characterised by EPR in the form of its adduct with PPh3. Depending on the solvent used, they either dimerise or abstract a chlorine atom from the solvent to produce Ru(Cl)(E)(CO)2(iPr-DAB).
New mixed carbonyl-nitro and -nitrito complexes of manganese and rhenium
Sieker, Anke,Blake, Alexander J.,Johnson, Brian F. G.
, p. 1419 - 1428 (2007/10/03)
Treatment of with Me3NO in CH2Cl2 in the presence of gave the anion cis-- which, on further reaction, yielded the new dianionic trimer 2- containing both bridging nitro- and nitrito-groups.Reactions of , cis--, - or 2- with also produce the same final product.The crystal and molecular structure of the + salt has been established by X-ray diffraction analysis.The molecule 2 crystallises in the triclinic space group P1-.Addition of to in CH2Cl2 yielded a series of mixed carbonyl-nitro/nitrito isomers, which have been characterised in solution.The unusual complex salt 3Cl has been characterised in the solid state by single-crystal X-ray diffraction methods.The molecule crystallises in the monoclinic space group P21/a.
Properties and dynamics of the σ(M′-Re) π* excited state of photoreactive dinuclear LnM′-Re(CO) 3 (α-diimine) (LnM′ = Ph3Sn, (CO)5Mn, (CO)5Re; α-diimine = bpy′, iPr-PyCa, iPr-DAB) complexes studied by time-resolved emission and absorption spectroscopies
Rossenaar, Brenda D.,Lindsay, Elspeth,Stufkens, Derk J.,Vl?ek Jr., Antonín
, p. 5 - 14 (2008/10/08)
The photophysics and photochemistry of the metal-metal bonded complexes LnM′Re(CO)3(α-diimine) (LnM′ = Ph3Sn, (CO)5Re, (CO)5Mn; α-diimine = bpy′, iPr-PyCa, iPr-DAB) have been studied. According to the time-resolved emission (80 K) and absorption (room temperature) spectra, the lowest excited state has a 3σ (M′-Re) π* character. It is a bound state, which can only be populated by surface crossing from optically excited MLCT states. Homolysis of the metal-metal bond from the σπ* state is promoted by nucleophilic and chlorinated solvents. Exceptional in this respect is the complex Ph3SnRe(CO)3(bpy′), which is nearly photostable in non-chlorinated solvents. The lifetime of the 3σπ* state decreases in the order α-diimine = bpy′ > iPr-PyCa > iPr-DAB > pAn-DAB. This trend is mainly determined by the energy gap law. The LnM′ dependence is more complicated because of an additional deactivating effect of an excited state distortion which depends on LnM′. At 80 K, the lifetime is determined by the weak coupling to the ground state; at room temperature by dissociation of M′-Re (with the exception of Sn-Re).
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.
