13939-06-5Relevant articles and documents
KOMPLEXKATALYSE. XVI. UEBER DIE REAKTION VON TRICHLORO-MONONITROSYL-MOLYBDAEN(II)- UND DICHLORO-DINITROSYL-MOLYBDAEN(0)-VERBINDUNGEN MIT EtAlCl2. NACHWEIS EINES Mo0Cl(NO)-KOMPLEXFRAGMENTS IN DEN KATALYSATORLOESUNGEN FUER DIE OLEFINMETATHESE
Seyferth, Karl,Taube, Rudolf
, p. 179 - 190 (1984)
The formation of an unstable Mo0Cl(NO)-containing complex in the reaction of trichloronitrosylmolybdenum(II) or dichlorodinitrosylmolybdenum(0) complexes MoCl3(NO)(OPPh3)2 or MoCl2(NO)2(PPh3)2 with EtAlCl2 has been proved by trapping experiment
UEBERGANGSMETALLKOMPLEXE MIT SCHWEFELLIGANDEN. XXIX. REDOXGEKOPPELTE SCHWEFELLIGAND-TRANSFERREAKTIONEN ZWISCHEN EISEN- UND MOLYBDAEN-ZENTREN: SYNTHESE, STRUKTUR UND REAKTIVITAET VON 2> * 2H2O UND 2>(2-) (dttd(2-) = 2,3,8,9-DIBENZO-1,4,7,10-TETRATHIADE...
Sellmann, Dieter,Binker, Gerhard,Schwarz, Joerg,Knoch, Falk,Boese, Roland,et al.
, p. 323 - 338 (1987)
The reaction of (dttd(2-) = 2,3,8,9-Dibenzo-1,4,7,10-tetrathiadecan(-2)) with (nor = norbornadiene) leads to the Mo(I) complex 2> by way of a redox coupled ligand transfer.The reaction proceeds by transferring the dttd(2-) ligand from to yielding 2>(2-) which is subsequently oxidized by Fe(II) to give 2>.Reduction of the latter by LiBEt3H/CO regenerates 2>(2-).In 2> both Mo centers are connected in three different ways viz., by a Mo-Mo bond, thiolato S atoms of dttd(2-) and the clamp of the SC2H4S bridge.The latter preserves the binuclearity when the closed 2> is reduced to the open 2>(2-).The reaction of Li22> with NOPF6 yields 2>.The structures of 2>, (NMe4)22> and (for the sake of comparison) of (NMe4) have been determined from X-ray diffraction studies.
Syntheses, Structures, and Molecular Orbital Analysis of Hydridotris(pyrazolyl)borate (Tp) Molybdenum Carbonyls: Paramagnetic TpMo(CO)3 and Triply Bonded Tp2Mo2(CO)4 (Mo Mo)
Curtis, M. David,Shiu, Kom-Bei,Butler, W. M.,Huffman, John C.
, p. 3335 - 3343 (1986)
Tris(pyrazolyl)borate ion, HB(C3N2H3)3- (Tp), reacts with Mo(CO)6 to give the anion, TpMo(CO)3-, which in turn is easily oxidized to the paramagnetic radical, TpMo(CO)3 (1), by a variety of mild oxidizing agents, e.g., Cp2Fe+.EHMO and 1H NMR studies of 1 show the odd electron occupies a doubly degenerate orbital and that the odd electron is delocalized onto the pyrazolyl rings of the Tp ligand by ?-bonding.The bonding of Tp and Cp ligands is compared in light of the EHMO results.Decarbonylation of 1 gives the triply bonded complex, Tp2Mo2(CO)4 (Mo Mo) (2).Compound 2 is largely unreactive toward nucleophiles, and the MoMo triple bond is cleaved in reaction with Br2, S8, etc.Several attempts to prepare mixed ligand dimers of the type TpCpMo2(CO)n are described.Compound 1 crystallizes in the trigonal system: space group , Z = 2, a = b = 11.359 (4) Angstroem, c = 8.161 (2) Angstroem, V = 911.9 (3) Angstroem3.The refinement converged with R1, R2 = 0.0383, 0.0435 based on 440 reflections with I > 2.33?(I).The molecule has strict C3 symmetry with Mo-N = 2.207 (7) Angstroem, Mo-C = 2.013 (11) Angstroem, C-O = 1.126 (11) Angstroem, C-Mo-N = 94.8 (3) deg, C-Mo-C = 87.8 (4) deg, and N-Mo-N = 82.5 (3) deg.The structure of 2 was determined on a solvate, 2*CHCl3, which crystallized in the orthorombic system, space group Pbca, Z = 8, a,b,c = 12.995 (2), 16.974 (4), 29.396 (6) Angstroem, V = 6485 (2) Angstroem3.The refinement, based on 2957 reflections with I > 3?(I), converged with R1,R2 = 0.055, 0.063.The molecule has approximate C2 symmetry.The N-donor atoms are in two general locations, one trans to the MoMo bond (Mo-N = 2.21 Angstroem) and one cis to the MoMo bond and trans to the carbonyls (Mo-N = 2.23 Angstroem).The carbonyls are also divided into two sets, one semibridging (Mo-C = 1.93 Angstroem, Mo-Mo-C = 70.5 deg) and one terminal (Mo-C = 1.96 Angstroem, Mo-Mo-C = 83.4 deg).The MoMo bond length is 2.507 (1) Angstroem.
Activation parameters in flash photolysis studies of Mo(CO)6
Kayran, Ceyhan,Richards, Margaret,Ford, Peter C.
, p. 143 - 148 (2004)
Reported is a combined time-resolved optical (TRO) and infrared (TRIR) spectroscopic investigation of the flash photolysis of Mo(CO)6 in cyclohexane solution. TRIR studies using 308 nm excitation led to transient bleaching of the strong νCO band at 1987 cm-1 of Mo(CO)6 and appearance of new bands at 1931 and 1964 cm-1 attributed to Mo(CO)5(Sol). Using a high pressure/variable temperature flow cell, the kinetics of back reaction with CO (kCO) to regenerate the hexacarbonyl was studied over the PCO range 1-20 atm and at five temperatures. These data gave kCO=4.6±0. 2×106 M-1 s-1 (298 K) and the activation parameters ΔHCO?=32.6±3 kJ/mol and ΔSCO?=-7.3±11 J mol-1 K-1 from which an interchange mechanism was proposed. The analogous species seen in the TRO experiment displayed a transient absorbance at 420 nm and analogous kinetics properties although at lower PCO self-trapping with Mo(CO)6 (to give Mo2(CO)11) is a competitive process. The Mo(CO)5(Sol) transient could also be trapped by nPrBr (kRBr=5.3??0.7×10 7 M-1 s-1).
Synthese und Reaktivitaet kohlenwasserstoffueberbrueckter Komplexe von Mangan, Rhenium, Molybdaen und Wolfram
Lindner, Ekkehard,Pabel, Michael,Fawzi, Riad,Mayer, Hermann A.,Wurst, Klaus
, p. 109 - 121 (1992)
The hydrocarbon-bridged complexes M(CH2)nM (M=MN(CO)5: n=5 (2b), 10 (2c); M=Re(CO)5: n=5 (3b), 10 (3c); M=(η5-C5H5)Mo(CO)3: n=5 (4b), 10 (4c); M=(η5-C5H5)W(CO)3: n=10 (5c)) are obtained by reaction of the bistriflates Y(CH2)nY (Y=F3CSO3, n=5 (1b), 10 (1c)) with the carbonyl metalates - (M=Mn (2), Re (3)) and 5-C5H5)M(CO)3>- (M=Mo (4), W (5)) in diethyl ether and THF, respectively.Depending on the solvent, the reaction of 1b with 2 also affords the cyclic carbene complex 2d.The action of SO2 and CO, respectively, on the complexes 2a-c and 4b,c results in the formation of the sulfinato-S complexes 5-C5H5)(OC)3MoSO2(CH2)nO2SMo(CO)3(η5-C5H5)> (n=5 (4b'), 10 (4c')) and the diacyl-bridged compounds (n=3 (2a'), 10 (2c')).According to an X-ray structural analysis, the monoacyl complex (2e) crystallizes in the orthorhombic space group Cmca with Z=4, the acyl function being disordered. 1H NMR spectroscopic investigations indicate a hindered rotation about the Cα-Cβ-? bond in 2b, c and 3b, c.
Molybdenum-Carbon Bond Dissoiation Energies in Mo(CO)6
Ganske, Jane A.,Rosenfeld, Robert N.
, p. 4315 - 4318 (1990)
The pressure dependence of the recombination rate constants for Mo(CO)n (n = 3, 4, and 5) with CO has been studied by time-resolved infrared laser absorption spectroscopy.These data, in conjuntion with an RRKM model for unimoleular decay of the activated
Synthesis and structure of the first η6-pyrazine complex 6-Me4pyrazine)2> and related studies
McGhee, William D.,Sella, Andrea,O'Hare, Dermot,Cloke, F. Geoffrey N.,Mehnert, Christian,Green, Malcolm L. H.
, p. 125 - 130 (1993)
The synthesis of vanadium and molybdenum complexes derived from nitrogen-containing heterocyclic aromatic ligands are described.The first η-pyrazine sandwich complex, 6-Me4pyrazine)2>, has been prepared by metal vapour synthesis and crystallographically characterized.The synthesis of 6-2,6-lutidine)2> has been substantially improved, and provides a convenient starting material for the preparation of the new half-sandwich compounds 6-2,6-lutidine)(PMe3)3> and 6-2,6-lutidine)(η3-allyl)Cl>2.
Further kinetics studies of intermediates formed by flash photolysis of Mo(CO)6
Diz, Enrique Lozano,Ford, Peter C.
, p. 3084 - 3088 (2008)
Kinetics studies of the behavior of Mo(CO)5(CH) in the presence of radical initiators were conducted in cyclohexane (CH) solution by laser flash photolysis with time-resolved infrared detection. Activation parameters were determined for reactio
Imido-titanium/molybdenum heterobimetallic systems. Switching from η6-arene to fischer-type aminocarbene complexes by tuning reactivity conditions
Lorber, Christian,Vendier, Laure
, p. 1127 - 1136 (2010)
Two types of bimetallic titanium/molybdenum systems are described: the first possesses unprecedented η6-arene-imido groups, while the second has Fischer-type aminocarbene ligands bridging the two metals. The (η6-arene)-Mo imido-Ti complex Ti[=N(η6-Ar)Mo(CO) 3]Cl2(NHMe2)2 (2; Ar = 2, 6-'Pr 2-C6H3) has been prepared through the reaction of (η6-ArNH2)Mo(CO)3 (3) and TiCl 2(NMe2)2. The alternative route from 2 and Ti(NMe2)4/Me3SiCl also afforded 1, but it was contaminated with a small amount of Ti(=NAr)Cl2(NHMe 2)2 (1). The reaction between the dimeric complexes {Ti(μ-NAr)(NMe2)2}2 and Mo(CO)6 gave complex mixtures of products, among which the Fischer-type aminocarbene complex [(CO)5Mo{=C(NMeCH2NMe2)O}Ti(=N 2,6-Pri2-C6H3)(NMe 2)(NHMe2)] (4) could be characterized. The formation of 4 resulted from the nucleophilic attack of the amido -NMe2 to the carbonyl that afforded the titanoxy aminocarbene linker between the Mo and the Ti centers, followed by a subsequent C-H activation of a methyl group of the aminocarbene and C,N coupling with an amido ligand on titanium. Treatment of Ti(NMe2)4 with 1 equiv of Mo(CO)6 produced the titanoxy aminocarbene [(CO)5Mo{=C(NMe2)O}Ti(NMe 2)3] (5), while in the presence of 1 equiv of ArNH 2 the imido complex [(CO)5Mo{=C(NMe2)O} Ti(=N-2, 6Pr'2-C6H3)(NMe2)(NHMe 2)2] (6) is formed. The molecular structures of 1-6 have been determined by X-ray diffraction.
Borylene transfer under thermal conditions for the synthesis of rhodium and iridium borylene complexes
Braunschweig, Holger,Forster, Melanie,Kupfer, Thomas,Seeler, Fabian
, p. 5981 - 5983 (2008)
(Chemical Equation Presented) Borylene transfer reactions to [(η5-C5R5)M(CO)2] (M = Rh, R = H; M = Ir, R = Me) using [(OC)5Mo=BN(SiMe3)2] as a borylene source proceed at room temperature and generate terminal rhodium and iridium borylene complexes (see scheme). Iridium complex 1 was characterized by X-ray crystallography.
