Synthesis, structure, and reactivity of diamidophosphine complexes of yttrium and the lanthanides

2001 ◽  
Vol 79 (7) ◽  
pp. 1194-1200 ◽  
Author(s):  
Michael D Fryzuk ◽  
Peihua Yu ◽  
Brian O Patrick
Keyword(s):  
Aluminum Hydride ◽  
Molecular Structures ◽  
Donor Ligands ◽  
Lithium Aluminum ◽  
X Ray Crystallography ◽  
Mononuclear Complexes ◽  
Alkyl Derivatives ◽  
Metal Derivative ◽  
Aluminum Lithium ◽  
Partial Success

The reaction of the dilithiodiamidophosphine ligand precursor PhP(CH2SiMe2NPh)2Li2(THF)2([NPN]Li2(THF)2) with LnCl3(THF)3 (Ln = Y, Sm, Ho, Yb, Lu; THF = tetrahydrofuran) in refluxing toluene generates the mononuclear complexes [NPN]LnCl(THF) in good yield. The molecular structures have been shown to be five-coordinate in the solid state and in solution. Attempts to prepare alkyl derivatives have only met with partial success; the reaction of MeMgCl with [NPN]YCl(THF) generates the partially characterized mixed-metal derivative [NPN]YMe2MgCl. The reaction with LiAlH4 results in complete ligand exchange and the formation of the tetranuclear lithium aluminum hydride derivative {[NPN]AlH2Li(THF)}2. Reduction of the lutetium derivative with KC8 and naphthalene generated the dinuclear naphthalene-bridged species {[NPN]Lu}2(µ-η4:η4-C10H8) wherein each Lu centre engages in η4-coordination to opposite sides of the arene moiety. X-ray crystallography was used to characterize the four complexes.Key words: lanthanides, yttrium, mixed-donor ligands, aluminum, lithium, naphthalene.

Photorearrangement of 2-cyanobicyclo[2.2.1]hept-2-ene. Observation of 1,2- and 1,3-sigmatropic shifts

1982 ◽  
Vol 60 (13) ◽  
pp. 1657-1663 ◽  
Author(s):  
Ikbal A. Akhtar ◽  
John J. McCullough ◽  
Susan Vaitekunas ◽  
Romolo Faggiani ◽  
Colin J. L. Lock
Keyword(s):  
Single Crystals ◽  
Lithium Aluminum Hydride ◽  
Aluminum Hydride ◽  
Major Product ◽  
Molecular Structures ◽  
Lithium Aluminum ◽  
Mercury Vapour ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Mercury Vapour Lamp

Irradiation of 2-cyanobicyclo[2.2.1]hept-2-ene (2-cyanonorbornene, 4) in hexane, with the full arc of a mercury vapour lamp, gives the rearrangement products 1-cyanobicyclo[4.1.0]hept-2-ene 5 and 7-cyanotricyclo[4.1.0.03.7]heptane 6 in the ratio 20:1. These products were separated by preparative vpc. The structure of the major product 5 was determined by single crystal X-ray analysis. Reduction of 5 with lithium aluminum hydride gave the corresponding primary amine, which was converted to the p-bromobenzenesulfonamide 9, mp 150–151 °C, which gave single crystals from ethanol–water. The crystal and molecular structures are described. The minor product 6 was hydrogenated to give 7-cyanobicyclo[2.2. 1]heptane. Formation of 5 and 6 may involve concerted σ2s + π2s and σ2a + π2a processes respectively, which are photochemically allowed.

scholarly journals Correlation between Slow Magnetic Relaxations and Molecular Structures of Dy(III) Complexes with N5O4 Nona-Coordination

2019 ◽  
Vol 5 (2) ◽  
pp. 27 ◽  
Author(s):  
Kaede Kobayashi ◽  
Yukina Harada ◽  
Kazuki Ikenaga ◽  
Yasutaka Kitagawa ◽  
Masayoshi Nakano ◽  
...  
Keyword(s):  
Magnetic Relaxation ◽  
Bias Field ◽  
Molecular Structures ◽  
Donor Ligands ◽  
Relaxation Phenomena ◽  
Zero Bias ◽  
Donor Ligand ◽  
Axial Ligands ◽  
Mononuclear Complexes ◽  
Slow Magnetic Relaxation

A series of Dy(III) mononuclear complexes [DyA2L]+ (L denotes Schiff base N5 ligand that occupies equatorial positions and A− denotes bidentate anionic O-donor ligands such as NO3− (1), AcO− (2), and acac− (3)) were synthesized to investigate the correlation between the slow magnetic relaxation phenomena and the coordination structures around Dy(III). The Dy(III) ion in each complex is in a nona-coordination with the anionic O-donor ligand occupying up- and down-side positions of the N5 equatorial plane. 2 and 3 show slow magnetic relaxation phenomena under a zero bias-field condition, and all complexes showed slow magnetic relaxation under the applied 1000-Oe bias-field conditions. Arrhenius analyses revealed that the ΔE/kB, the barrier height for magnetization flipping, increases in this order, with the values of 24.1(6), 85(3), and 140(15) K. The effects of the exchanging axial ligands on the magnetic anisotropy were discussed together with the DFT calculations.

Synthesis, structural characterization and catalytic activity of chlororuthenium(II) complexes with substituted Schiff base/phosphine ancillary ligands

2020 ◽  
Vol 75 (9-10) ◽  
pp. 851-857
Author(s):  
Chong Chen ◽  
Fule Wu ◽  
Jiao Ji ◽  
Ai-Quan Jia ◽  
Qian-Feng Zhang
Keyword(s):  
Schiff Base ◽  
Catalytic Activity ◽  
Structural Characterization ◽  
Room Temperature ◽  
Molecular Structures ◽  
Cationic Complex ◽  
Neutral Complex ◽  
Ancillary Ligands ◽  
X Ray ◽  
X Ray Crystallography

AbstractTreatment of [(η6-p-cymene)RuCl2]2 with one equivalent of chlorodiphenylphosphine in tetrahydrofuran at reflux afforded a neutral complex [(η6-p-cymene)RuCl2(κ1-P-PPh2OH)] (1). Similarly, the reaction of [Ru(bpy)2Cl2·2H2O] (bpy = 2,2′-bipyridine) and chlorodiphenylphosphine in methanol gave a cationic complex [Ru(bpy)2Cl(κ1-P-PPh2OCH3)](PF6) (2), while treatment of [RuCl2(PPh3)3] with [2-(C5H4N)CH=N(CH2)2N(CH3)2] (L1) in tetrahydrofuran at room temperature afforded a ruthenium(II) complex [Ru(PPh3)Cl2(κ3-N,N,N-L1)] (3). Interaction of the chloro-bridged complex [Ru(CO)2Cl2]n with one equivalent of [Ph2P(o-C6H4)CH=N(CH2)2N(CH3)2] (L2) led to the isolation of [Ru(CO)Cl2(κ3-P,N,N-L2)] (4). The molecular structures of the ruthenium(II) complexes 1–4 have been determined by single-crystal X-ray crystallography. The properties of the ruthenium(II) complex 4 as a hydrogenation catalyst for acetophenone were also tested.

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