1.Unsymmetrical dirhenium complexes that contain [Re(2)](6+) and [Re(2)](5+) cores complexed by tridentate ligands with P(2)O and P(2)N donor sets.
Kuang SM1, Fanwick PE, Walton RA. Inorg Chem. 2002 Jan 28;41(2):405-12.
The quadruply bonded dirhenium(III) complex (n-Bu(4)N)(2)Re(2)Cl(8) reacts with tridentate ligands that contain essentially planar P,O,P donor sets to afford the complexes Re(2)Cl(6)(eta(3)-L(1)) (3) (L(1) = bis[2-(diphenylphosphino)phenyl]ether) and (n-Bu(4)N)[Re(2)Cl(7)(eta(1)-L(2))] (4) (L(2) = 4,6-bis(diphenylphosphino)dibenzofuran). Spectroscopic and electrochemical data support the unsymmetrical structure Cl(4)ReReCl(2)(eta(3)-L(1)) in the case of 3, while 4 contains monodentate P-bound L(2) both complexes contain Re---Re bonds. The synthon cis-Re(2)(mu-O(2)CCH(3))(2)Cl(4)(H(2)O)(2) reacts with ligands L(1), L(2), 2,6-bis(diphenylphosphinomethyl)pyridine (L(3)), bis[2-(diphenylphosphino)ethyl]amine (L(4)), and N,N-bis[2-(diphenylphosphino)ethyl]trimethylacetamide (L(5)) to give the paramagnetic complexes Re(2)(mu-O(2)CCH(3))Cl(4)(eta(3)-L(n)) (5-9) with Re bonds. The lability of the mu-acetato ligands in 5-9 has been demonstrated by the reactions of compounds 5 (n = 1) and 7 (n = 3) with 4-Ph(2)PC(6)H(4)CO(2)H, 2-Ph(2)PC(6)H(4)CO(2)H, and quinoline-4-carboxylic acid to give complexes 10-12 (from 5) and 13-15 (from 7), respectively.
2.Synthesis and structural characterisation of stable pyridine- and phosphine-functionalised N-heterocyclic carbenes.
Danopoulos AA1, Winston S, Gelbrich T, Hursthouse MB, Tooze RP. Chem Commun (Camb). 2002 Mar 7;(5):482-3.
Stable, uncoordinated (1-[2-(6-trimethylsilyl)pyridyl]-3-[(2,6- diisopropyl)phenyl]imidazol-2-ylidene), I, and (1-[beta-(diphenylphosphino)ethyl]-3-[(2,6-diisopropyl)phenyl]imidazol- 2-ylidene), II, have been synthesised; in the solid state they adopt a conformation with the lone pairs in a mutually anti arrangement.
3.Nickel complexes with new bidentate P,N phosphinitooxazoline and -pyridine ligands: application for the catalytic oligomerization of ethylene.
Speiser F1, Braunstein P, Saussine L, Welter R. Inorg Chem. 2004 Mar 8;43(5):1649-58.
The phosphinitooxazoline 4,4-dimethyl-2-[1-oxy(diphenylphosphine)-1-methylethyl]-4,5-dihydrooxazole (9), the corresponding phosphinitopyridine ligands 2-ethyl-[1'-methyl-1'-oxy(diphenylphosphino)]pyridine (11) and 2-ethyl-6-methyl-[1'-methyl-1'-oxy(diphenylphosphino)]pyridine (12), which have a one-carbon spacer between the phosphinite oxygen and the heterocycle, and the homologous ligand 2-propyl-[2'-methyl-2'-oxy(diphenylphosphino)]pyridine (13), with a two-carbon spacer, were prepared in good yields. The corresponding mononuclear [NiCl(2)(P,N)] complexes 14 (P,N = 9), 15 (P,N = 11), and 16 (P,N = 12) and the dinuclear [NiCl(micro-Cl)(P,N)](2) 17 (P,N = 13) Ni(II) complex were evaluated in the catalytic oligomerization of ethylene. These four complexes were characterized by single-crystal X-ray diffraction in the solid state and in solution with the help of the Evans method, which indicated differences between the coordination spheres in the solution and the solid state.
