Tetraphenylarsonium tribromo(triphenylphosphine)nickelate(II)

Abstract

C24H20As +. C18H15Br3NiP-, [As(C6Hs)4I-[Ni(C6Hs)3PBr3], monoclinic, P2Jc, a = 15.798 (2), b = 9.975 (1), c = 25.142 (4)/k, fl = 93.46 (2) °, U = 3954.8 ,,~3, Z = 4, D e = 1.585 Mg m -3, g(Cu/(tO =

Aryl Grignard cross-coupling of aryl chlorides catalysed by new, highly active phosphine/imidazolium nickel(II) complexes

“…The Ni atom is tetrahedrally coordinated by the phosphorus atom of the phosphine group and by three bromine atoms. The Ni-P distance is comparable with the value found in [NiBr3(PPh3)] -(C24H20As) + (2.323(1) Å ) [27]. The Br atoms are rotationally staggered with respect to the phenyl and the imidazolium groups.…”

2-Carboxy-9-dihydroxymethyl-1,10-phenanthroline Complexes of Cobalt(II) and Copper(II)

“…The Co--N distances observed are either shorter or longer than Coll~Nphen distances of 2.11(1)-2.14(1)A (Youinou, Ziessel & Lehn, 1991;Boys, Escobar & Wittke, 1984) observed in highspin Co n complexes; the Co--N1 distance, however, is not as short as those observed in low-spin CoII-phen complexes (Faus, Julve, Lloret & Mufioz, 1993). The Co--O distances are within expected values (Youinou et al, 1991;Hanton & Raithby, 1980). The variation in the bond lengths is due to the coordination of the carboxyl O21 atom which causes the metal center to shift towards N1, effectively shortening the M--N1 bond while lengthening M--N10.…”

“…The variation in the bond lengths is due to the coordination of the carboxyl O21 atom which causes the metal center to shift towards N1, effectively shortening the M--N1 bond while lengthening M--N10. The N1--Co--N10 bond angles of 75 ° are smaller than those in bidentate phenanthroline species (Boys et al, 1984;Corwin, Fikar & Koch, 1987) but similar to those for phenanthroline-containing macrocycles (Hanton & Raithby, 1980). The total bite angle for the ligand is 150 °.…”

Electronic Structure of Four-Coordinate C3v Nickel(II) Scorpionate Complexes: Investigation by High-Frequency and -Field Electron Paramagnetic Resonance and Electronic Absorption Spectroscopies

“…We found bonding parameters for the chloride that did not greatly differ from those for Ni(PPh 3 ) 2 Cl 2 . For the bromide and iodide, bonding parameters larger than those previously reported (for [Ni(PPh 3 )X 3 ] -, X ) Br, I, 51 or for Ni(L N + )Br 3 , 46 see Table 4) are required, although the σ value does decrease in the order Cl > Br > I. These [LNiX 3 ] complexes, however, are not ideal analogues because of the presence of three halo ligands, and we further suggest that the electronic absorption data in the Tp*NiX series allows a more accurate determination of bonding parameters than was the case in those complexes.…”