Reaction of [L
OEtRu(N)CI
2] (1) (L
OEt- = [CpCo{P(O)(OEt)
2}
3]
- , where Cp = η
5-C
5H
5) with Et
3SiH, 4,4,5,5-tetramethyl-1,3,2-dioxaborolane (pinacolborane) or
nBu
3SnH afforded the Ru(III) ammine complex [L
OEtRu(NH
3)CI
2] (2). Treatment of 1 with [L
OEtRuH(CO)(PPh
3)] (3) afforded a dinuclear Ru(IV)/Ru(II) μ-imido complex [L
OEtRuCI
2(μ-NH)Ru(CO)(PPh
3)L
OEt] (4). The reaction between 1 and 3 in toluene was found to follow the rate law: rate = k
2[1][3]. At 298 K, k
2 was determined to be (7.2 ± 0.4) × 10
-5 M
-1⋅s
-1. The activation parameters ΔH
‡ and ΔS
‡ were found to be (8.8 ± 1.6) kcal⋅mol
-1 and -(43.3 ± 11.1) e.u., suggesting that the formation of 4 involved a concerted pathway of the nucleophilic attack of the nitride by the Ru
II hydride. Reaction of 1 with 5 atm H
2 in the presence of 6 and Et
3N...[
Read more ]
Reaction of [L
OEtRu(N)CI
2] (1) (L
OEt- = [CpCo{P(O)(OEt)
2}
3]
- , where Cp = η
5-C
5H
5) with Et
3SiH, 4,4,5,5-tetramethyl-1,3,2-dioxaborolane (pinacolborane) or
nBu
3SnH afforded the Ru(III) ammine complex [L
OEtRu(NH
3)CI
2] (2). Treatment of 1 with [L
OEtRuH(CO)(PPh
3)] (3) afforded a dinuclear Ru(IV)/Ru(II) μ-imido complex [L
OEtRuCI
2(μ-NH)Ru(CO)(PPh
3)L
OEt] (4). The reaction between 1 and 3 in toluene was found to follow the rate law: rate = k
2[1][3]. At 298 K, k
2 was determined to be (7.2 ± 0.4) × 10
-5 M
-1⋅s
-1. The activation parameters ΔH
‡ and ΔS
‡ were found to be (8.8 ± 1.6) kcal⋅mol
-1 and -(43.3 ± 11.1) e.u., suggesting that the formation of 4 involved a concerted pathway of the nucleophilic attack of the nitride by the Ru
II hydride. Reaction of 1 with 5 atm H
2 in the presence of 6 and Et
3N afforded 4 and [L
OEtRu(OH)(CO)(PPh
3)][BF
4] in 10 and 15 % yield, respectively.
Reaction of 1 with [(PCy
3)
2RuHCl(CO)] gave the dinuclear μ-nitrido complex [L
OEtRuCl
2(μ-N)RuHCl(CO)(PCy
3)
2] (8) (Cy = cyclohexyl). A X-ray diffraction study suggested that 8 should be formulated as a Ru
VI≡N–Ru
II complex.
Refluxing 1 in CCl
4 afforded the mixed valence Ru(IV)/Ru(V) μ-nitrido complex [L
OEtRuCl
2]
2(μ-N) (9), presumably via the N ⋅ ⋅ N coupling of Ru(VI) nitride and subsequent coupling of the Ru(III) intermediate with the Ru(VI) nitride. Reduction of 9 in air gave the Ru(IV)/Ru(IV) complex [H(H
2O)
3][L
OEtRuCl
2]
2(μ-N) (10) that contains a symmetrical Ru
IV=N=Ru
IV bridge. 10 exhibited reversible Ru(IV,V)/Ru(IV,IV) and Ru(V,V)/Ru(IV,V) couples at 0.186 V and 1.132 V vs Cp
2Fe
+/0, respectively.
Homo- and heterobimetallic Ru μ-nitrido complexes have been synthesized by reaction of Ru(VI) nitrides with low valent organometallic complexes. Heating 1 with [Ru(p-cymene)Cl
2]
2 in benzene afforded a tetranuclear Ru(IV) μ-nitrido cluster [L
OEtRuCl
2(μ-N)RuCl
2(H
2O)]
2 (12) that contains a symmetrical Ru
IV=N=Ru
IV bridge. Reaction of [Ru(ppy)(MeCN)
4][PF
6] (Hppy = 2-phenylpyridine) with 1 afforded [L
OEtRuCl
2(μ-N)Ru(ppy)(MeCN)
3][PF
6] (13). Reaction of [Ru(ppy)(MeCN)
4][PF
6] with mer-[Ru(N)Cl
3(AsPh
3)
2] and [Ru(N)Cl
4]
- afforded [RuCl
3(AsPh
3)
2(μ-N)-Ru(ppy)(MeCN)
3][PF
6] (14) and [RuCl
4(μ-N)Ru(ppy)(MeCN)
3] (15), respectively.
Reaction of 14 with AgOTf (OTf
- = triflate) afforded [RuCl
2(AsPh
3)(H
2O)(μ-N) Ru(ppy)(MeCN)
3][PF
6][OTf] (16). Substitution of 14 with K[N(Ph
2PQ)
2] (Q = S, O) led to formation of [Ru{N(Ph
2PS)
2}
2Cl(μ-N)Ru(ppy)(MeCN)
3][PF
6] (17) and [Ru{N(Ph
2PO)
2}Cl
2(AsPh
3)(μ-N)Ru(ppy)(MeCN)
3][PF
6] (18), respectively. Treatment of 1 with [M(COD)Cl]
2 (M = Ir, Rh COD = 1,5-cyclooctadiene) afforded Ru(VI)/M(I) heterobimetallic μ-nitrido complexes [L
OEtRuCl
2(μ-N)M(COD)Cl] (M = Ir (19), Rh (20)). Treatment of 1 with [Cp*IrCl
2]
2 (Cp* = η
5-C
5Me
5), [Cp*Ir(ppy)(H
2O)][OTf] and [Ir(ppy)
2Cl]
2 afforded the Ru(VI)/Ir(III) μ-nitrido complexes [L
OEtRuCl
2(μ-N)IrCp*Cl
2] (21), [L
OEtRuCl
2(μ-N)IrCp*(ppy)][OTf] (22) and [L
OEtRuCl
2(μ-N)Ir(ppy)
2Cl] (23), respectively. X-ray diffraction studies revealed that complexes 13-20 are unsymmetrical μ-nitrido complexes containing the Ru
VI≡N–M’ bridges.
Treatment of [
nBu
4N][Ru(N)Cl
4] with K[N(R
2PS)
2] in tetrahydrofuran at -78℃ afforded the Ru(IV)/Ru(IV) bimetallic μ-nitrido complexes trans-[Ru
2{N(R
2PS)
2}
4Cl(μ-N)] (R = Ph (24), Pr
i(25)). Reaction of [
nBu
4N][Ru(N)Cl
4] with K[N(
tBu
2PS)
2] gave the Ru(II) thionitrosyl complex trans-[Ru(NS){N(
tBu
2PS)}
2Cl] (26), presumably via abstraction of the sulfur in [N(
tBu
2PS)
2]
- by a Ru(VI) nitride intermediate. Trans-[Ru(NS){N(R
2PS)}
2Cl] (R = Ph (29), Pr
i (30),
tBu (26)) could be conveniently prepared from mer-[Ru(NS)Cl(AsPh
3)
2] and K[N(R
2PS)
2]. Treatment of [Ru(PPh
3){N(Ph
2PS)
2}
2] with PhN
3 afforded [Ru{N(PhN)}
2{N(Ph
2PS)
2}
2] (32) containing a neutral tetrazene ligand, presumably via the [2+3] cycloadditon of a Ru(IV)=NPh intermediate with PhN
3.
A cationic Ru(VI) nitride complex containing a bulky bidentate Schiff base ligand, trans-[Ru(N)(H
2O)L
2][OTf] (34), was prepared from cis-[Ru(N)Cl(L)
2] (33) (HL = 2-[(2,6-diisopropylphenyl)imino]methyl-4,6-dibromophenol) and AgOTf. No N ⋅ ⋅ N coupling was found when 34 was reacted with pyridine in polar solvents. Treatment of 33 with Me
3NO and elemental sulfur gave cis-[Ru(NO)Cl(L)
2] (35) and cis-[Ru(NS)Cl(L)
2] (36), respectively. Irradiation of cis-[Ru(NO)Cl(L)
2] in CH
2Cl
2/MeCN with UV ligand afforded [Ru(MeCN)Cl(L)
2] (37) that could also be prepared by treatment of 33 with Me
3SiN
3.
Refluxing FeCl
2 with HL in methanol in the presence of Et
3N afforded [Fe(OMe)(L)
2] (38). Reaction of [Fe(OMe)(L)
2] with HCl and Me
3SiN
3 gave [FeCl(L)
2] (39) and [Fe(N
3)L
2] (40), respectively.
Post a Comment