“…The crystallographic asymmetric unit contains two equivalent molecules ( 3 -A and 3 -B; see Supporting Information), and molecule A is discussed. The Ti−N1 and Ti−N2 bond lengths (1.857(1) and 2.364(1) Å) are comparable to those of known η 2 -hydrazido titanium complexes, [(η 5 -C 5 H 5 )(η 2 -NHNMe 2 )]TiCl 2 (1.83 and 2.22 Å) and [(η 5 -C 5 H 5 )(η 2 -NPhNH 2 )]TiCl 2 (1.88 and 2.14 Å) . The hydrazide (−1) fragment can be best represented formally as a six-electron donor with a N1 Ti π-interaction and a N2 → Ti dative bond.…”
Section: Resultssupporting
confidence: 52%
“…The strong donor nature of the hydrazido moiety is expected to stabilize the catalytically active cationic species compared to the amido ligand, which may result in interesting polymerization characteristics. Two η 2 -hydrazido complexes, [(η 5 -C 5 H 5 )(η 2 -NHNMe 2 )]TiCl 2 and [(η 5 -C 5 H 5 )(η 2 -NPhNH 2 )]TiCl 2 , are the only known hydrazido titanium complexes before this work . However, Okuda and co-workers have reported structurally related tridentate CpA complexes, [(η 5 -C 5 Me 4 )SiMe 2 (NCH 2 CH 2 X)]MCl 2 (M = Zr, Hf), in which the two-electron-donor moiety (X = OMe or NMe 2 ) was found to act as a labile coordinating ligand for the electron-deficient metal center .…”
An η1-hydrazido bis(dimethylamido) complex, [(η5-C5Me4)SiMe2(η1-NNMe2)]Ti(NMe2)2 (2),
has been prepared from a neat reaction of (C5Me4H)SiMe2(NHNMe2) (1) with Ti(NMe2)4 at
130 °C via amine elimination. Treatment of 2 with Me3SiCl gives an η2-hydrazido dichloro
compound, [(η5-C5Me4)SiMe2(η2-NNMe2)]TiCl2 (3). The reaction of 2 with excess AlMe3 (ca.
5 equiv) affords an AlMe3 adduct, [(η5-C5Me4)SiMe2(η1-NNMe2AlMe3)]TiMe2 (4), which is
converted to a dimethyl complex, [(η5-C5Me4)SiMe2(η2-NNMe2)]TiMe2 (5), upon treatment
with NEt3. The reaction of 5 with B(C6F5)3 affords a methyl−triarylborate complex, [(η5-C5Me4)SiMe2(NNMe2)]TiMe(μ-Me)B(C6F5)3 (6). The reaction of 2 with H2O produces a tetrameric
organotitanoxane [(η5-C5Me4)(SiMe2NHNMe2)Ti]4O6 (7) with an adamantane-like cage
structure. However, the reaction of 2 with H2O in the presence of HCl affords a dimeric
complex [μ-(OSiMe2-η5-C5Me4)TiCl2]2 (8). Compounds 1−8 have been characterized by
spectroscopic and analytical data. Molecular structures of 2, 3, 4, 5, 7, and 8 have been
determined by single-crystal X-ray diffraction studies. Complexes 2−5 contain η1-hydrazido
(2 and 4) and η2-hydrazido (3 and 5) groups depending on the electronic nature of the titanium
center. Reversible interconversion between η1- and η2-hydrazido moieties has been observed
upon addition of either NEt3 (4 → 5) or AlMe3 (5 → 4). Complexes 2−5 exhibit moderate
catalytic activities for the polymerization of ethene in the presence of either methyaluminoxane (MAO) or AliBu3/Ph3C+B(C6F5)4
-.
“…The crystallographic asymmetric unit contains two equivalent molecules ( 3 -A and 3 -B; see Supporting Information), and molecule A is discussed. The Ti−N1 and Ti−N2 bond lengths (1.857(1) and 2.364(1) Å) are comparable to those of known η 2 -hydrazido titanium complexes, [(η 5 -C 5 H 5 )(η 2 -NHNMe 2 )]TiCl 2 (1.83 and 2.22 Å) and [(η 5 -C 5 H 5 )(η 2 -NPhNH 2 )]TiCl 2 (1.88 and 2.14 Å) . The hydrazide (−1) fragment can be best represented formally as a six-electron donor with a N1 Ti π-interaction and a N2 → Ti dative bond.…”
Section: Resultssupporting
confidence: 52%
“…The strong donor nature of the hydrazido moiety is expected to stabilize the catalytically active cationic species compared to the amido ligand, which may result in interesting polymerization characteristics. Two η 2 -hydrazido complexes, [(η 5 -C 5 H 5 )(η 2 -NHNMe 2 )]TiCl 2 and [(η 5 -C 5 H 5 )(η 2 -NPhNH 2 )]TiCl 2 , are the only known hydrazido titanium complexes before this work . However, Okuda and co-workers have reported structurally related tridentate CpA complexes, [(η 5 -C 5 Me 4 )SiMe 2 (NCH 2 CH 2 X)]MCl 2 (M = Zr, Hf), in which the two-electron-donor moiety (X = OMe or NMe 2 ) was found to act as a labile coordinating ligand for the electron-deficient metal center .…”
An η1-hydrazido bis(dimethylamido) complex, [(η5-C5Me4)SiMe2(η1-NNMe2)]Ti(NMe2)2 (2),
has been prepared from a neat reaction of (C5Me4H)SiMe2(NHNMe2) (1) with Ti(NMe2)4 at
130 °C via amine elimination. Treatment of 2 with Me3SiCl gives an η2-hydrazido dichloro
compound, [(η5-C5Me4)SiMe2(η2-NNMe2)]TiCl2 (3). The reaction of 2 with excess AlMe3 (ca.
5 equiv) affords an AlMe3 adduct, [(η5-C5Me4)SiMe2(η1-NNMe2AlMe3)]TiMe2 (4), which is
converted to a dimethyl complex, [(η5-C5Me4)SiMe2(η2-NNMe2)]TiMe2 (5), upon treatment
with NEt3. The reaction of 5 with B(C6F5)3 affords a methyl−triarylborate complex, [(η5-C5Me4)SiMe2(NNMe2)]TiMe(μ-Me)B(C6F5)3 (6). The reaction of 2 with H2O produces a tetrameric
organotitanoxane [(η5-C5Me4)(SiMe2NHNMe2)Ti]4O6 (7) with an adamantane-like cage
structure. However, the reaction of 2 with H2O in the presence of HCl affords a dimeric
complex [μ-(OSiMe2-η5-C5Me4)TiCl2]2 (8). Compounds 1−8 have been characterized by
spectroscopic and analytical data. Molecular structures of 2, 3, 4, 5, 7, and 8 have been
determined by single-crystal X-ray diffraction studies. Complexes 2−5 contain η1-hydrazido
(2 and 4) and η2-hydrazido (3 and 5) groups depending on the electronic nature of the titanium
center. Reversible interconversion between η1- and η2-hydrazido moieties has been observed
upon addition of either NEt3 (4 → 5) or AlMe3 (5 → 4). Complexes 2−5 exhibit moderate
catalytic activities for the polymerization of ethene in the presence of either methyaluminoxane (MAO) or AliBu3/Ph3C+B(C6F5)4
-.
“…The Ru−NHNPh 2 distances (average 1.911(3) Å) and Ru−N−N angles (average 141.1(3)°) are similar to the Mo−NHNPh 2 distance (1.948(5) Å) and Mo−N−N angle (140.5(4)°) in [Mo VI (NHNPh 2 )(NNPh 2 )(acac)Cl 2 ], respectively. With regard to the hydrazido(1−) ligands in 2b (see Table ), the N5, N6, C49, and C55 atoms are basically coplanar, along with the N7, N8, C61, and C67 atoms; the N−N bonds (average 1.280(4) Å) are appreciably shorter than the corresponding bond in [Mo VI (NHNPh 2 )(NNPh 2 )(acac)Cl 2 ] (1.359(6) Å) 35 but fall in the range of 1.236(19) to 1.47(2) Å, found for such bonds in the reported hydrazido(1−) complexes. − 3 ORTEP drawing of [Ru IV (TTP)(NHNPh 2 ) 2 ] ( 2b ) with atomic numbering scheme (25% probability ellipsoids). Hydrogen atoms are omitted for clarity.…”
Section: Resultsmentioning
confidence: 98%
“…Currently, there are a good number of terminal hydrazido(1−) metal complexes known in the literature, all of which are monohydrazido(1−) species with metal centers spanning the groups IIIB (Sm), IVB (Ti, Zr), − VB (Ta), VIB (Mo, W), − VIIB (Tc, Re), − and VIIIB (Ir). , Strikingly, these complexes remain fully unknown for the entire subgroup of iron, ruthenium, and osmium. On the other hand, although complexes with terminal hydrazido(2−) ligands have been reported for both iron 47,48 and osmium, , respectively, none of these complexes have been isolated or even observed for ruthenium.…”
Bis(1,1-diphenylhydrazido(1-))ruthenium(IV) porphyrins, [Ru(IV)(Por)(NHNPh2)2] (Por = TPP, TTP, 4-Cl-TPP, 4-MeO-TPP), were prepared in approximately 60% yields through the reaction of dioxoruthenium(VI) porphyrins, [Ru(VI)(Por)O2], with 1,1-diphenylhydrazine in ethanol. This new type of ruthenium complex has been characterized by 1H NMR, IR, UV-vis, and FABMS with elemental analysis. The crystal structure of [Ru(IV)(TTP)(NHNPh2)2], which reveals an eta1-coordination mode for both hydrazido axial ligands, has been determined. The average Ru-NHNPh2 distance and Ru-N-N angle were found to be 1.911(3) A and 141.1(3) degrees, respectively. The porphyrin ring exhibits a ruffling distortion that is unprecedentedly large for ruthenium complexes with simple porphyrinato ligands (such as TTP). This is probably due to the steric effect of the axial hydrazido(1-) ligands.
“…In the molecular structure of 10b the (NNPh 2 ) 2− and the (N(H)NPh 2 ) − ligand can easily be distinguished by the TiN double bond length of 1.7338(17) Å as a typical double bond (comparable to 1.757(1) Å in 9 , vide supra) in contrast to the Ti−N single bond length of 1.9575(18) Å for a slightly shortened single bond (comparable to 1.96 Å in 7a ). Both hydrazido ligands are bonded in a end-on coordination mode, in contrast to side-on hydrazido(2−) − and hydrazido(1−) − ,,, ligands. To the best of our knowledge, structurally characterized end-on coordinated titanium hydrazido(1−) complexes are unknown up to now.…”
Intramolecular catalytic hydroamination reactions of geminally disubstituted amino alkenes employing the bulky substituted bis(η 5 :η 1 -pentafulvene)titanium complexes 1a and 1b and the corresponding benzannelated derivative 2 as catalysts are presented. While all three complexes are competent hydroamination catalysts, best results are achieved with the bis(benzofulvene) derivative 2. In addition, a series of Ti-N-containing compounds became available by stoichiometric reactions of 1 with N-H acidic substrates. In such a way, using aniline derivates (H 2 N-Ar, Ar: p-tolyl, 1naphthyl) the bisamides (η 5 -C 5 H 4 -CHR 2 ) 2 Ti(NHAr) 2 (CHR 2 : adamantyl, Ar: p-tolyl 5a; R: p-tolyl, Ar: p-tolyl 5b; R: p-tolyl, Ar: 1-naphthyl 5c; CHR 2 : adamantyl, Ar: 1-naphthyl 5d) are prepared in high yields under mild conditions. In contrast to this, the employment of the catalytically relevant amine H 2 NCH 2 C(Ph) 2 CH 2 CHdCH 2 (3a) in a reaction with (η 5 :η 1 -C 5 H 4 dCR 2 ) 2 Ti (CR 2 : adamantylidene, 1a) leads to the titanium monoamide (η 5 :η 6), characterized by X-ray diffraction. In reaction of 1a and 1b with benzophenone imine the titanocene bis(enamides) (η 5 -C 5 H 4 -CHR 2 ) 2 Ti(NdCPh 2 ) 2 7a and 7b are formed. Titanium nitrogen double bonds are formed by treatment of 1a with 1,1-diphenylhydrazine. In that manner the hydrazido titanocene (η 5 -C 5 H 4 -CHR 2 ) 2 TidN-N(Ph) 2 (CHR 2 : adamantyl) was structurally characterized as the pyridine adduct 9. Three different Ti-N bonds are formed in one step by reaction of (η 5 :η 1 -C 5 H 4 dCR 2 ) 2 Ti (R: p-tolyl, 1b) with 1,1-diphenylhydrazine and pyridine (py), leading to (η 5 -C 5 H 4 -CHR 2 )Ti(dN-NPh 2 )(-N-NPh 2 )py 10b (dative Ti-N bond: Ti-py 2.211(2) A ˚, single Ti-N bond: Ti-NNPh 2 -1.968(2) A ˚, double Ti-N bond: Ti-NNPh 2 2-1.738(1) A ˚). The formation of 10b is accompanied by the liberation of one C 5 H 5 CHR 2 ligand. Generally, the bis(η 5 :η 1 -pentafulvene)titanium complexes 1 and 2 are valuable catalysts in hydroamination reactions and reagents in order to prepare Ti-N-containing metallocene-type derivatives.
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