50495-19-7Relevant academic research and scientific papers
Mo- and W-N2 and -CO complexes with novel mixed P/N ligands: Structural properties and implications to synthetic nitrogen fixation
Stephan, Gerald C.,N?ther, Christian,Sivasankar, Chinnappan,Tuczek, Felix
, p. 1008 - 1019 (2008/10/09)
Four new ligands containing a pyridine or thiazole group and one or more N-(diphenylphosphinomethyl)amine functions have been prepared and employed for the synthesis of Mo(0) and W(0) carbonyl and dinitrogen complexes. For comparison coordination of the literature-known ligand N,N-bis(diphenylphosphinomethyl)-methylamine (PNP, 1) to such systems has been investigated as well. Two new ligands are N,N-bis(diphenylphosphinomethyl)-2-aminopyridine (pyNP2, 2) and N,N′-bis(diphenylphosphinomethyl)-2,6-diaminopyridine (PpyP, 3). In a third new ligand, N-diphenylphosphinomethyl-2-aminothiazole (thiazNP, 4), the pyridine group is replaced by thiazol. Finally, the pentadentate ligand N,N,N′,N′-tetrakis(diphenylphosphinomethyl)-2,6-diaminopyridine (pyN2P4, 5) has been synthesized. Coordination of ligands 2, 3 and 4 to low-valent metal centers is investigated on the basis of the three molybdenum carbonyl complexes [Mo(CO)3(NCCH3)(pyNP2)] (6), [Mo(CO)4(PpyP)] (7) and [Mo(CO)4(thiazNP)] (8), respectively, all of which are structurally characterized. Moreover, employing ligands 1 and 2 the two dinitrogen complexes [W(N2)2(dppe)(PNP)] (9) and [Mo(N2)2(dppe)(pyNP2) (10), respectively, are prepared. Both systems are investigated by vibrational and NMR spectroscopy; in addition, complex 10 is structurally characterized.
Double deprotonation of coordinated ethylimide to CH3CN: Molecular mechanism and relevance to the chemistry of Mo and W organoimides
Sivasankar, Chinnappan,Tuczek, Felix
, p. 3396 - 3398 (2007/10/03)
Reaction of [MCl(NEt)(dppe)2]Cl (M = Mo, W) with n-BuLi in tert-butyl methyl ether under an N2 atmosphere yields the M(0) bis(dinitrogen) complexes [M(N2)2(dppe)2] and acetonitrile. A mechanism is proposed for this reaction which involves an anionic chloro-acetonitrile intermediate. The implications of these findings to the chemistry of Mo and W organoimides are discussed. The Royal Society of Chemistry 2006.
THE INFLUENCE OF THE STERIC PROPERTIES OF THE LIGANDS PR2Ph AND L ON THE FORMATION AND PROPERTIES OF THE COMPLEXES Mo(η6-PhPR2)(L)(PPh2CH2CH2PPh2), R = Et, L = PPhEt2 and R = Ph, L = PPh3, PR'3, CO, CNR, N2, H2
Frizzell, James J.,Luck, Rudy L.,Morris, Robert H.,Peng, Shane H.
, p. 243 - 256 (2007/10/02)
The reduction of MoCl4(DPPE) (DPPE = PPh2CH2CH2PPH2) with Mg or Na/Hg in the presence of 2 PPhR2 under Ar results in the formation of the new complexes Mo(η6-PhPR2)(PPhR2)(DPPE) when R is Ph(Ia) or Et(II).No η6-PhPR2 complex is obtained when R is Me because this small ligand forms strong Mo-P ?-bonds; nor is one obtained for R = Cy because of too much steric crowding.The limits for η6-complexation can be quantified in terms of cone angle sums.Complex Ia is very similar to Mo(η6-PhPMePh)(PMePh2)3 (IIIa) in that both react at similar rates with a variety of small ligands L = PMePh2, PMe2Ph, PMe3, P(OMe)3, N2, CO, CNBut and H2 via dissocation of a labile ?-bonded ligand.Several other less crowded η6-arylphosphinemolybdenum complexes including II do not have labile ligands at 25 degC.The new complexes Mo(η6-PhPPh2)(L)(DPPE) have been characterized by 31P and 1H NMR, IR and gas uptake measurements.Ia has a higher affinity for H2 than IIIa possibly because Mo(η6-PhPPh2)(H)2(DPPE) adopts a non-fluxional trans-configuration.The 31P chemical shift of the η6-bonded ligand in 8 derivatives of Ia and 12 of IIIa correlate with the sum of cone angles of the three ?-bonded ligands in each complex.
Modification of silicon and carbon electrodes with methacrylamide polymers containing covalently attached molybdenum dinitrogen complexes
DuBois, Daniel L.
, p. 2047 - 2052 (2008/10/08)
Methacrylamide polymers with pendant monodentate, bidentate, and tridentate phosphine ligands (poly-P1, poly-P2, and poly-P3, respectively) have been synthesized. These polymers react with Mo(N2)2(PPh2Me)4 to form polymers with bound molybdenum dinitrogen complexes. Similarly, MoCl3(THF)3 reacts with poly-P3 to form MoCl3(poly-P3). These polymers have been used to modify silicon and carbon electrodes. These electrodes have been characterized by cyclic voltammetry and FT-IR spectroscopy. The redox chemistry of electrodes modified with Mo(N2)2(poly-P3)PPh2Me and Mo(N2)2(poly-P2)2 on silicon and carbon electrodes closely parallels that observed for their solution counterparts. However, reduction of MoCl3(poly-P3) and MoCl3(poly-P2)2 on silicon and carbon electrodes does not lead to formation of polymer-bound molybdenum dinitrogen complexes.
