1,4-Diaza-1,3-diene (DAD) complexes of early transition elements. Syntheses, structures and molecular dynamics of mono- and bis(η5-cyclopentadienyl)titanium-, zirconium- and hafnium(DAD) complexes. Crystal- and molecular structures of CpTi(DAD)CH2Ph, [CpTi(DAD)]2O, CpZr[(DAD)(N∩O)] and Cp2Hf(DAD) (original) (raw)
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Early Transition Metalα-Diazoalkane Complexes
Angewandte Chemie International Edition, 2000
The reaction of diazoalkanes with transition metals results either in coordination through the nitrogen atoms or in formation of a carbon ± metal bond. Many N-bonded substituted transition metal diazoalkanes have been studied, but only four series of C-bonded late transition metal compounds have been isolated. a-Metalated diazoalkanes L n MÀC(N 2 )R containing an early transition metal have not yet been reported. Treatment of zirconocene Zr IV complexes with diazoalkanes results in insertion into ZrÀC, [3] ZrÀH, [3c] ZrÀP, and zirconium ± metal bonds to give the corresponding hydrazonato ligands I [Eq. (1)].
Dalton transactions (Cambridge, England : 2003), 2014
We report here a number of dianionic 1,4-diaza-1,3-butadiene complexes of titanium and zirconium synthesised by a salt metathesis reaction. The reaction of either CpTiCl 3 or Cp 2 TiCl 2 with the dilithium salt of N,N'-bis(2,6-diisopropylphenyl)-1,4-diaza-1,3-butadiene [1; abbreviated (Dipp) 2 DADLi 2 ] afforded the monocyclopentadienyl titanium complex [η 5 -CpTi((Dipp) 2 DAD)Cl] (2) bearing a dianionic ene-diamide ligand, while the analogous reaction of zirconocene dichloride (Cp 2 ZrCl 2 ) with the dilithium salt 1 gave the bis-cyclopen- and [{(Dipp) 2 DADZrCl(μ-Cl)} 2 (κ 3 -Cl)(Li)(OEt 2 ) 2 ] (5) were obtained by the reaction of 1 and anhydrous metal tetrachloride in a 1 : 1 molar ratio in diethyl ether at room temperature. Meanwhile, the homoleptic titanium complex [Ti{((Dipp) 2 DAD)} 2 ] (6) was isolated in good yield by the treatment of 1 with TiCl 4 in a 1 : 2 molar ratio in diethyl ether. The complexes 2 and 5 were further reacted with neosilyl lithium to afford mono-and bisalkyl complexes of titanium [η 5 -CpTi{(Dipp) 2 DAD}(CH 2 SiMe 3 )] (7) and zirconium [Zr{(Dipp) 2 DAD}(CH 2 SiMe 3 ) 2 ] (8) respectively. Molecular structures of the complexes 2, 3, and 5-8 in the solid states were confirmed by single crystal X-ray diffraction analysis. The solid state structures of all the complexes reveal that the metal ions are chelated through the amido-nitrogen atoms and the olefinic carbons of the [(Dipp) 2 DAD] 2− moiety, satisfying the σ 2 ,π coordination mode. Compound 8 was used as a catalyst for the intermolecular hydrosilylation reaction of a number of olefins, and moderate activity of catalyst 8 was observed. † Electronic supplementary information (ESI) available: X-ray crystallographic files for 2, 3 and 5-8 in CIF format and . CCDC 1011649-1011654. For ESI and crystallographic data in CIF or other electronic format see
European Journal of Inorganic Chemistry, 2009
Reaction of 4,5-diazafluoren-9-one (dafone, 6) and zinc dichloride yields [(dafone)ZnCl 2 (H 2 O)] (11) in which the ZnCl 2 moiety is coordinated to a single nitrogen atom and also to a molecule of water. Hydrogen bonding, not only to the uncomplexed nitrogen atom of dafone but also to the ketonic oxygen atom of a neighbouring molecule, leads to a zigzag chain structure. In contrast, reaction with anhydrous zinc iodide forms cis-(dafone) 2 ZnI 2 (12) in which the metal-nitrogen distances -2.170(5) and 2.456(5) Å -are significantly different. Dafone, in the presence of dimethyl sulfoxide, reacts with K 2 PtCl 4 to produce square-planar (dafone)PtCl 2 (dmso) (13), whereas with K 2 PtBr 6 the octahedral complex (dafone)-PtBr 4 (14) is formed in which the ligand chelates in a symmet-
Journal of Organometallic Chemistry, 1999
Reaction of the bridged (dimethylsilanediyl)dicyclopentadienyl dilithium salt [(SiMe 2)(C 5 H 4) 2 Li 2 ] with MCl 4 , in toluene, gave the zirconium and hafnium complexes [M{(SiMe 2)(h 5-C 5 H 4) 2 }Cl 2 ] [M= Zr (1), Hf (2)]. Addition of two equivalents of M%R (M%= MgCl, R= CH 3 ; M%=Li, R=CH 2 CMe 2 Ph; M%= MgBz, R=CH 2 Ph) to toluene or diethyl ether solutions of [M{(SiMe 2)(h 5-C 5 H 4) 2 }Cl 2 ] afforded the dialkyl derivatives [M{(SiMe 2)(h 5-C 5 H 4) 2 }R 2 ] [R=CH 3 , M= Zr (3), Hf (4); R = CH 2 CMe 2 Ph, M =Zr (5), Hf (6); R =CH 2 Ph, M = Zr (7)]. Compound 1 reacted with LiMe and Mg(CH 2 Ph) 2 (THF) 2 in the presence of a stoichiometric amount of water to give the m-oxo derivatives [Zr{(SiMe 2)(h 5-C 5 H 4) 2 }R] 2 (m-O) [R = CH 3 (8), CH 2 Ph (9)]. The X-ray molecular structure of [Zr{(SiMe 2)(h 5-C 5 H 4) 2 }(CH 2 Ph)] 2 (m-O) (9) has been determined by diffraction methods. Its most remarkable feature is the planarity of the Bz Zr O Zr Bz and the linearity of the Zr O Zr systems.
European Journal of Inorganic Chemistry, 2003
Zr) under different conditions provided the monocyclopentadienyl complexes [M{η 5 -C 5 H 3 -[SiMe 2 (NHtBu)] 2 }(NMe 2 ) 3 ] [M = Ti (2), Zr (3)] and the single (η-amidosilyl)cyclopentadienyl compounds [M{η 5 -C 5 H 3 [Si-Me 2 (NHtBu)][SiMe 2 (η 1 -NtBu)]}(NMe 2 ) 2 ] [M = Ti (4), Zr (5)]. The related dibenzyl compounds [M{η 5 -C 5 H 3 [SiMe 2 -(NHtBu)][SiMe 2 (η 1 -NtBu)]}(CH 2 Ph) 2 ] [M = Ti (6), Zr ] resulted from treatment of 1 with M(CH 2 C 6 H 5 ) 4 (M = Ti, Zr). Further deprotonation of the amido complexes 4 and 5 and the benzyl complexes 6 and 7 by heating in toluene solution gave the bis(η-amidosilyl)cyclopentadienyl complexes [a]
Polyhedron, 1998
Copper(ll), nickel(ll), zinc(lI) and cobalt(Ill) complexes of C-meso-5,12-diethyl-7,14-dimethyltetra-azacyclotetradeca-4,11-diene (C-meso-Me2Et2[14ldieneN4)
Polyhedron, 1998
Zirconium and hafnium complexes M(qs:~/~-CsMe4SiMe2NR').,CI~4 z,) (M = Zr, Hf; x = 1, 2; R' = iPr, tBu) containing one or two linked amido-tetramethylcyclopentadienyl ligands CsMe4SiMe2N R' have been synthesized by the reaction of the dilithium derivative Li2(CsMe4SiMe2NR') with MCI4(THF)2. The crystal structure of the hafnium complex Hf(r/5 : qI-CsMeaSiMezNiPr)2 has been determined by a single-crystal X-ray diffraction study and shows a C2-symmetric helical metallocene, in which the amido ligands are bonded as n-donor ligands with Hf-N bond lengths of 2.115(2) A. The isoelectronic heterobimetallic yttrium complex Li[Y(q5 : ~/~-CsMe4SiMe2NCH2CH2OMe)2] reacts with phenylacetylene to give the bis(phenylacetylide) derivative Li[Y{qS-CsMe4SiMe2NH(CH2CH2OMe)}:(C=-CPh)2]. ~5
Journal of Organometallic Chemistry, 1978
The complexes trans-[PdCl{C(=NR)C(Me)=NR'} (PPh&] (R = C6Hll, p-C,H,OMe; RI = p-C6H40Me, Me) containing a o-bonded 1,4diaza-3-methylbutadiene-2-yl group with different substituents on the nitrogen atoms have been prepared by two routes. The first involves initial methylation of the mixed isonitrile complex [PdCl,(CNR)(CNR')] by HgMe*, followed by reaction with PPhj (Pd/PPh3 molar ratio l/2). The second method involves condensation of primary aliphatic amines with the carbonyl group of the 1-azabut-1-en-3-one-2yl moiety of the complex trans-]PdCl{C(=NR)C(Me) = 0 } (PPh&]. The 1,4diaza-3-methylbutadiene-2-yl derivatives act through their imino nitrogen atoms as chelating ligands towards anhydrous metal chlorides MCI? (M = Co, Ni, Cu, Zn). Magnetic moment measurements and the far-infrared and electronic spectra of these adducts indicate an essentially pseudo-tetrahedral configuration at M in the solid and in solution. With the ZnCl, adducts, the 'H NMR pat@n for the phenyl protons of the p-methoxyphenyl N-substituent depends upon the position of the substituent in the 1,4diazabutadiene chain. E Bock ar!d EL tom Dieck. Chem_ Ber.. 100 (1967) 228. & +m +eek and LW, se-Chem. Ber.. Id4 (1071) 92: &sew_ C&m_ Internat. Edit., 9 (19.70) 793. AT,T_ asie& and B.O. We+J_ O&anomehiChem., 78 (1974) C-40.