Thérèse Arliguie

Synthesis and crystal structure of [K(C12H24O6)][U(η-C7H7)2], the first cycloheptatrienyl sandwich compound

The title compound was prepared by treating a mixture of UCI4 and K with C7H8 or by reacting UCl4 with KC7H9; the crystal structure shows that the two C7H7 ligands are planar, parallel and perpendicular to the linear axis defined by the uranium atom and the ring centroids.

Inverse cycloheptatrienyl sandwich complexes. Crystal structure of [U(BH4)2(OC4H8)5][(BH4)3U(µ-η7,η7-C7H7)U(BH4)3]

The anions [X3U(µ-η7,η7-C7H7)UX3]–(X = NEt2 or BH4) have been obtained by treatment of UX4 with K[C7H9]; the cation [U(BH4)2(thf)5]+ was formed by protonation of [U(BH4)3(thf)3] with [NHEt3][BPh4] in tetrahydrofuran (thf).

Homoleptic 2-Mercapto Benzothiazolate Uranium and Lanthanide Complexes

Treatment of [Ln(BH 4) 3(THF) 3] (Ln = Ce, Nd) with 3 and 4 mol equiv of KSBT in tetrahydrofuran (THF) led to the formation of [Ln(SBT) 3(THF)] and [K(THF)Ln(SBT) 4], respectively. The uranium(IV) compound [U(SBT) 4(THF) 2] was obtained from U(BH 4) 4 and was reversibly reduced by sodium amalgam into the corresponding anionic uranium(III) complex. The crystal structures of [Ln(SBT) 3(THF) 2] (Ln = Ce, Nd), [K(15-crown-5) 2][Nd(SBT) 4], [U(SBT) 4(THF)], and [K(15-crown-5) 2][U(SBT) 4(py)] show the bidentate coordination mode and the thionate character of the SBT ligand.

Monocyclooctatetraene uranium thiolate complexes. Crystal structure of [{U(η-C8H8)(µ-SPri)2}2]

The monocyclooctatetraene uranium bis(thiolate) complexes [U(cot)(SR)2](cot =η-C8H8, R = Bun or Pri) were prepared by treating [U(cot)(BH4)2]1 with the corresponding thiol or NaSR reagent. The isopropane thiolate derivative is a dimer in the crystalline form, with four bridging SPri ligands, and this structure is retained in solution. Reaction of 1 with NaSBut afforded the anion [U(cot)(SBut)3]– which adopts a three-legged piano-stool configuration.

A new class of dihydrogen complexes containing oxygen donor ligands. Preparation of RuH(η2-H2)(OCOCF3)[P(C6H11)3]2 and of the equilibrated mixture RuH2(OCOCF3)2[P(C6H11)3]2/Ru(η2-H2)(OCOCF3)2[P(C6H11)3]2

The protonation of RuH2(H2)2(PCy3)2(1)(Cy = cyclohexyl) with CF3CO2H in acetone leads to the hydrido dihydrogen derivative RuH(H2)(OCOCF3)(PCy3)2(2), which reacts further in hexane to yield a very reactive RuIV dihydride, RuH2(OCOCF3)2(PCy3)2(3), a species which at room temperature is in equilibrium with the dihydrogen complex Ru(η2-H2)(OCOCF3)2(PCy3)2(4); (3)[or (4)] loses H2 in solution and reacts with cyclo-octene to give {Ru(C6H9PCy2)(OCOCF3)}2(µ-O)(µ-OCOCF3)2(6).

Unexpected dehydrogenation of a cyclohexyl group at low temperature through protonation of RuH3(η5-C5Me5)(PCy3)(Cy = cyclohexyl). X-Ray structure of [(η5-C5Me5)Ru{(C6H9)P(C6H11)}2]BF4

Low temperature protonation of RuH3(η5-C5Me5)(PR3)(R = Pri, Ph, cyclohexyl) leads either to decomposition (R = Pri), to a mixture of cis- and trans-[RuH2(η5-C5Me5)(PR3)2]BF4(R = Ph), or to dehydrogenation of a cyclohexyl group to afford the complex [Ru(η5-C5Me5){(C6H9)P(C6H11)2}]BF4 which shows a strong agostic interaction between a C–H bond of the cyclohexenyl group and the metal; a possible application of the later observation is proposed for the dehydrogenation of alkanes.

Inverse cycloheptatrienyl sandwich complexes of uranium and neodymium

Reaction of UX 4 (X = NEt 2 or BH 4 ) with K[C 7 H 9 ] afforded the anionic complexes K[X 3 U(µ-η 7 ∶η 7 -C 7 H 7 )UX 3 ] whereas treatment of [Nd(BH 4 ) 3 (thf) 2 ] (thf = tetrahydrofuran) with K[C 7 H 9 ] gave the neutral compound [(thf)(BH 4 ) 2 Nd(µ-η 7 ∶η 7 -C 7 H 7 )Nd(BH 4 )(thf) 2 ]. The formation of the cycloheptatrienyl ligand resulted from the disproportionation reaction 3 C 7 H 9 - → C 7 H 7 3- + 2 C 7 H 10 . The crystal structure of [(thf)(BH 4 ) 2 Nd(µ-η 7 ∶η 7 -C 7 H 7 )Nd(BH 4 )(thf) 3 ], the first cycloheptatrienyl compound of a 4f element, has been determined.

SYNTHESIS AND X-RAY CRYSTAL STRUCTURE OF NA(18-CROWN-6)U(CP*)2(SBUT))(S), THE FIRST F-ELEMENT COMPOUND CONTAINING A METAL-SULFUR DOUBLE BOND

The C–S bond cleavage of a thiolate ligand of [U(Cp*)2(SBut)2] was induced by treatment with Na(Hg) and the title compound was isolated after addition of 18-crown-6; the crystal structure exhibited the unsupported U–S–Na linkage of the molecular complex, with a U–S bond distance of 2.462(2) A.

RuH2[P(C6H5)2(p-C6H4CH3)]3: An unexpectedly stable and unreactive 16-electron ruthenium dihydride

Abstract The title complex is obtained either by daylight exposure in benzene or dissolution in acetone of RuH 2 ( n 2 -H 2 )(PPh 2 tol) 3 [PPh 2 tol = P(C 6 H 5 ) 2 ( P -C 6 H 5 CH 3 )] or by sodium borohydride reduction of RuCl 2 (PPh 2 tol) 3 after evaporation to dryness. It is fluxional and does not react with hydrogen to give the initial RuH 2 ( n 2 -H 2 )(PPh 2 tol) 3 .

Reactivity of ruthenium polyhydrides: reactions of RuH6[P(C6H11)3]2 with C5-cyclic hydrocarbons. Preparation of new ruthenium(IV) trihydrides RuH3(C5Me5)L [L = PMe3, PPh3, PPri3, or P(C6H11)3]

The hydrides RuH2(C5H6)(Pcy3)2(2) and RuH(C5H5)(Pcy3)2(3)(cy = cyclohexyl) are formed in the reaction of RuH6(Pcy3)2(1) with cyclopentene, although in the presence of 3,3-dimethylbut-1-ene only (3) is formed quantitatively, but treatment of (1) with C5Me5H gives no C5Me5 complex (although in C6D6 active H–D exchange with the phosphine protons is observed); however [Ru(C5Me5)Cl2]n when treated with phosphine (L = PMe3, PPh3, PPri3, or Pcy3) gives the paramagnetic complexes RuCl2(C5Me5)L, which on treatment with LiBHEt3 in tetrahydrofuran yields the new trihydrides RuH3(C5Me5)L.