Synthesis and Characterization of Triazenide and Triazene Complexes of Ruthenium and Osmium

Abstract

Triazenide [M(eta2-1,3-ArNNNAr)P4]BPh4 [M = Ru, Os; Ar = Ph, p-tolyl; P = P(OMe)3, P(OEt)3, PPh(OEt)2] complexes were prepared by allowing triflate [M(kappa2-OTf)P4]OTf species to react first with 1,3-ArN=NN(H)Ar triazene and then with an excess of triethylamine. Alternatively, ruthenium triazenide [Ru(eta2-1,3-ArNNNAr)P4]BPh4 derivatives were obtained by reacting hydride [RuH(eta2-H2)P4]+ and RuH(kappa1-OTf)P4 compounds with 1,3-diaryltriazene. The complexes were characterized by spectroscopy and X-ray crystallography of the [Ru(eta2-1,3-PhNNNPh){P(OEt)3}4]BPh4 derivative. Hydride triazene [OsH(eta1-1,3-ArN=NN(H)Ar)P4]BPh4 [P = P(OEt)3, PPh(OEt)2; Ar = Ph, p-tolyl] and [RuH{eta1-1,3-p-tolyl-N=NN(H)-p-tolyl}{PPh(OEt)2}4]BPh4 derivatives were prepared by allowing kappa1-triflate MH(kappa1-OTf)P4 to react with 1,3-diaryltriazene. The [Os(kappa1-OTf){eta1-1,3-PhN=NN(H)Ph}{P(OEt)3}4]BPh4 intermediate was also obtained. Variable-temperature NMR studies were carried out using 15N-labeled triazene complexes prepared from the 1,3-Ph15N=N15N(H)Ph ligand. Osmium dihydrogen [OsH(eta2-H2)P4]BPh4 complexes [P = P(OEt)3, PPh(OEt)2] react with 1,3-ArN=NN(H)Ar triazene to give the hydride-diazene [OsH(ArN=NH)P4]BPh4 derivatives. The X-ray crystal structure determination of the [OsH(PhN=NH){PPh(OEt)2}4]BPh4 complex is reported. A reaction path to explain the formation of the diazene complexes is also reported.

Preparation and reactivity of p-cymene complexes of ruthenium and osmium incorporating 1,3-triazenide ligands

“…1 H NMR (CD 2 Cl 2 , 25 C) d: 7.39e6.89 (m, 30H, Ph), 5.81, 5.44 (d, 4H, Ph p-cym), 2.66 (m, 1H, CH), 2.14 (s, 3H, CH 3 pcym), 1.28 (s, 9H, CH 3 Bu t ), 1.23 (d, 6H, CH 3 Pr i ) ppm. 13 (13,14) [Ar ¼ Ph (13), p-tolyl (14)] and OsCl(h 2 -1,3-p-tolyl-NNN-p-tolyl)(h 6 -p-cymene) (15) In a 25-mL three-necked round-bottomed flask were placed solid samples of the appropriate dimeric complex [MCl 2 (h 6 -pcymene)] 2 (M ¼ Ru, Os) (0.3 mmol), a slight excess of 1,3-diaryltriazene (0.7 mmol) and 10 mL of toluene. An excess of triethylamine (3 mmol, 0.42 mL) was added to the resulting solution, which was stirred for 24 h. The solvent was removed under reduced pressure to give an oil which was triturated with n-hexane.…”

“…We previously reported [13] the synthesis and reactivity of triazene and triazenide complexes of Ru and Os of the type [M(h 2 -1,3-ArNNNAr)L 4 ]BPh 4 and [MH{h 1 -1,3-ArN]NN(H)Ar}L 4 ]BPh 4 (M ¼ Ru, Os; L ¼ phosphite) and have now extended these studies to include half-sandwich h 6 -arene complexes, with the aim of testing whether triazenide ligands can be introduced into the chemistry of arene complexes and how they can modify their chemical and catalytic properties. The results of these studies, which allowed the synthesis and some reactivity of unprecedented h 6 -p-cymene complexes of Ru and Os incorporating either triazenide and phosphite or triazenide and isocyanide mixed ligands, are reported here.…”

Design, synthesis and properties of a trinuclear copper(I) cluster with a triazenide ligand

“…The use of different bridging and well-designed polydentate ligands has afforded an impressive array of nuclear coordination complexes with new architectures. Among them, the triazenide ligands have attracted our attention, as these compounds can serve as a monodentate (a) [1,2], a bidentate chelating (b) [3][4][5][6][7], and a bridging ligands (c) [8][9][10][11][12] (Scheme 1).…”

A hexanuclear Ni(II) complex of 1-[(2-carboxymethyl)benzene]-3-[2-pyridine] triazene

“…The study of metal complexes containing triazenido [RN = N-NR'] − ligands has increased greatly during the past two decades, as these compounds have remarkable bridging ability (Scheme 1a) to afford multinuclear complexes possessing potentially useful for the development of new materials and catalysts [1][2][3][4][5][6]. Although complexes with 1,3-(aryl) triazines are well known [7][8][9][10][11][12], relatively few other triazenide complexes have been developed [13,14].…”

“…1 H resonances were found in the range of 8.6-7.1 ppm for the aromatic protons, 3.97 ppm for the methyl group. The reaction of HL and Ni(Ac) 2 ⋅ 4H 2 O gave a hexanuclear nickel(II) complex {Ni 6 L 2 L′ 2 (μ 3 -OH) 2 …”