- A novel dimanganese complex linked by an unusually strong hydrogen bond. X-ray structure of the hydrogen-bonded complex and ab initio calculations
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In an attempt to prepare the fluoro complex (CO)3(dppe)MnF (3) by treating a CH2Cl2 solution of the aqua complex [(CO)3(dppe)Mn(OH2)]BF4 (1) with NaF(aq), we isolated instead, the dimanganese complex, [(CO)3(dppe)Mn(OH2)FMn(dppe)(CO)3]BF 4 (2). The two moieties, 1 and 3, are held together by an unusually strong O-HF hydrogen bond (OF=2.458(3) ?, HF=1.52 ?) between the aqua ligand on one manganese and the fluoro atom on the other manganese. Using as a simple model the interaction between +Li(H2O) and FLi, the hydrogen bonding distance O-HF was calculated to be; OF=2.443 ?. Authentic 3 was prepared in a homogeneous system using CH2Cl2-soluble [Et4N]F.
- Becker, Thomas M.,Bauer, Jeanette A. Krause,Bene, Janet E. Del,Orchin, Milton
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p. 165 - 170
(2007/10/03)
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- Phosphine, arsine and stibine complexes of manganese(I) carbonyl halides: Synthesis, multinuclear NMR spectroscopic studies, redox properties and crystal structures
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Reaction of [Mn(CO)5X] (X = Cl or Br) with L-L {L-L = dppm (Ph2PCH2PPh2), dppe (Ph2PCH2CH2PPh2), dppp (Ph2PCH2CH2CH2PPh2), C6H4(PPh2)2-o, C6H4(PH2)2-o, dpae (Ph2AsCH2CH2AsPh2), diars [C6H4(AsMe2)2-o], dpsp (Ph2SbCH2CH2CH2SbPh2) or dmsp (Me2SbCH2CH2CH2SbMe2)} or with two molar equivalents of L (= PPh2H, PCy2H or PPhH2) in refluxing CHCl3 yielded the neutral manganese(I) complexes [MnX(CO)3(L-L)] and [MnX(CO)3L2] as yellow or orange solids. Infrared spectroscopic studies confirmed the fac-tricarbonyl arrangement and 1H, 13C-{1H}, 31P-{1H} and 55Mn NMR spectroscopy have been used to probe the solution behaviour. For a given halide 55Mn NMR spectroscopic studies showed some dependence of δ(55Mn) on halide, chelate ring size, substituent and donor atom. X-Ray crystallographic analyses on [MnCl(CO)3{C6H4(PPh2) 2-o}], [MnBr(CO)3(dppe)] and the diprimary phosphine complex [MnCl(CO)3{C6H4(PH2) 2-o}]·CH2Cl2 confirmed a fac-tricarbonyl arrangement, with the ditertiary or diprimary phosphine chelating. The structure of [MnBr(CO)3-(PPhH2)2] also shows a fac-tricarbonyl arrangement with the primary phosphine ligands mutually cis.
- Pope, Simon J. A.,Reid, Gillian
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p. 1615 - 1621
(2007/10/03)
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- One-pot synthesis of fac-[Mn(CO)3(P-P)Cl] from Mn2(CO)10, [P-P] and chlorinated solvents: [P-P] = 1,2-bis(diethylphosphino)ethane (depe), 1,2-bis(diphenylphosphino)ethane (dppe) or 1,3-bis(diphenylphosphino)propane (dppp). The X-ray crystal structure of fac-[Mn(CO)3(depe)Cl]
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In a one-pot reaction, the three titled manganese chloride complexes were prepared by refluxing Mn2(CO)10 with (P-P) in 2-chloroethanol for two hours. The new compounds were characterized by IR, 1H NMR, mass spectra and microanalyses. The X-ray crystal structure of fac-Mn(CO)3(depe)Cl is also reported.
- Li, Guang Qing,Feldman, Julian,Krause, Jeanette A.,Orchin, Milton
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p. 2041 - 2045
(2008/10/09)
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- Conversion of a manganese-carbon-bonded complex to a manganese-oxygen-bonded complex, some reactions of manganese carbonato complexes
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Stirring a solution of the manganese carboxylate, (dppe)(CO)3Mn-C(O)OCH3, 1, in dichloromethane saturated with water converts it to the bridging carbonato complex, (dppe)(CO)3Mn-OC(O)O-Mn(CO)3(dppe), 2. This multi-step conversion involves the in-situ transformation of a Mn-C bonded complex to a Mn-O bonded one. When 2 is stirred with HCl, it is converted quantitatively to the covalent chloride (dppe)(CO)3Mn-Cl, 11, with evolution of carbon dioxide. Similar HCl treatment of the manganese carboxylate 1 gives three compounds: the same covalent chloride, 11; the ionic chloride, [(dppe)(CO)4Mn] + Cl-, 12, and the hydride, (dppe)(CO)3Mn-H, 5. Reasonable schemes for these conversions are suggested. Heating the ionic chloride complex to its melting point converts it to the covalent chloride complex; the same transformation is accomplished by refluxing the ionic chloride in acetonitrile.
- Li, Guang Qing,Burns, Robert M.,Mandal, Santosh K.,Bauer, Jeanette Krause,Orchin, Milton
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- Reactions of ditertiary phosphines with η6-arenetricarbonylmanganese cations
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Ditertiaryphosphines PPh2(CH2)nPPh2 (n = 1-3) react at room temperature with the η6-arenetricarbonylmanganese cations 6-XYC6H4)Mn(CO)3>+ (Ia, X = Y = H; Ib, X = Me, Y = H) by monocarbonyl substitution an formation of 6-XYC6H4)Mn(CO)2(η1-PPh2(CH2)nPPh2)>+.Prolonged refluxing results in metal-ring bond breaking and formation of cis- and trans-2-PPh2CH2PPh2)2>+ and trans-2-PPh2(CH2)2PPh2)2>+.Activation of a carbonyl group in 6-XYC6H4Mn(CO)2(η1-PPh2(CH2)nPPh2)>+ by TMNO gives the series of chelate complexes 6-XYC6H4Mn(CO)(η2-PPh2(CH2)nPPh2)>+ (n = 1 - 3).The X-ray structure of the chelate with n = 3 is reported.In the case of 6-XYC6H4)Mn(CO)3>+ (Ic, X = Cl, Y = H); Id, X = Cl, Y= Me), formation of fac-Mn(CO)3(η2-PPh2(CH2)nPPh2Cl (n = 1, 2) occurs, in a reaction analogous to that with monophosphines, see D.A.Brown, W.K.Glass and K.M.Kreddan, J.Organomet.Chem., 413 (1991) 223, but there was no evidence for ring adducts as intermediates.
- Brown, David A.,Glass, W. Kenneth,Kreddan, Khaled M.,Cunningham, Desmond,McArdle, Patrick A.,Higgins, Tim
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- Nineteen-electron adducts in the photochemistry of Cp2Fe2(CO)4 (Cp = η5-C5H5)
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Cp2Fe2(CO)4 is apparently different from the other metal-metal-bonded carbonyl dimers in that irradiation of this dimer in the presence of ligands does not lead to disproportionation: Cp2Fe2(CO)4 + L + hv ? CpFe(CO)2- + CpFe(CO)3-nLn+. However, it was demonstrated that with most ligands the disproportionation reaction does occur but the back-reaction of the products is facile. The back-reaction can be prevented by reacting further one of the products. For example, in CH2Cl2 solution, CpFe(CO)2- reacts with the solvent to give CpFe(CO)2CH2Cl and the back-reaction is prevented. The mechanism of the disproportionation reaction is proposed to be a chain mechanism involving 19-electron adducts formed by the reaction of a 17-electron metal radical with a ligand, e.g. CpFe(CO)2 + L → CpFe(CO)2L. It is demonstrated that the 19-electron adducts are powerful reductants. The following organometallic, organic, and inorganic substrates were reduced by the 19-electron species, thereby demonstrating the versatility of these species as reducing agents: CpMo(CO)3Cl, Fe(CN)63-, Mn2(CO)10, Re2(CO)10, Ru3(CO)12, Fe(CO)5, N-n-butylpyridinium, and Cp2Co+. Experiments involving the reduction of Cp2Co+ demonstrated several mechanistic points concerning the reactivity of 19-electron species.
- Goldman, Alan S.,Tyler, David R.
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p. 253 - 258
(2008/10/08)
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- ?-Alkynyl Complexes of Manganese(I) as η2-Bonding Ligands for Group 1B Metal-Ligand Fragments. X-Ray Crystal Structure of t)2(CO)6(dppe)2>PF6*0.5CH2Cl2
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Several compounds of the types (n=1; M=Cu, Ag, or Au); R=CH2OMe, But, or Ph; dppe=Ph2PCH2CH2PPh2> and have been prepared from the alkynyl complexes fac- and the appropriate reagents to generate the metal-ligand fragments Ml.The salt has been characterized by X-ray diffraction. several equilibri in solution involving the cationic species with free ?-alkynyl complex and P(C6H4Me-2)3 have been observed and their reactions with Cl(1-) have been examined.
- Carriedo, Gabino A.,Miguel, Daniel,Riera, Victor,Solans, X.
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p. 2867 - 2874
(2007/10/02)
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