0000000000184252
AUTHOR
Francisco Amor
Linked amido-indenyl complexes of titanium
Abstract Titanium complexes Ti( η 5 : η 1 -C 9 H 6 SiMe 2 NCMe 3 )X 2 (X = Cl, Me, CH 2 SiMe 3 , CH 2 Ph) containing the tert -amino-functionalized indenyl ligand C 9 H 6 SiMe 3 NCMe 3 have been synthesized by the reaction of the dilithium derivative Li 2 [C 9 H 6 SiMe 2 NCMe 3 ] with TiCl 3 (THF) 3 followed by oxidation or by the alkylation of the dichloro derivative. Unexpectedly, the reaction of C 9 H 6 (SiMe 3 )(SiMe 2 Cl) with TiCl 4 does not give Ti( η 5 -C 9 H 6 SiMe 2 Cl)Cl 3 .
Chelated η5-cyclopentadienyl-η-ethyl complexes of molybdenum and tungsten; molecular structure of W(η5-C5H4CH2-η-CH2)(CO)3
Abstract Molybdenum and tungsten complexes M(η5-C5H4CH2-η-CH2)(CO)3 (M=Mo, W) containing the bidentate ethyl-functionalized cyclopentadienyl ligand C5H4CH2CH2 have been synthesized by the reaction of spiro[2.4]hepta-4,6-diene with M(CO)3L3 (M=Mo; L3=1,3,5-C6H3Me3; M=W; L=NCMe). Reaction of the more stable tungsten complex with C6H5ICl2 and HBF4 gave complexes of the type W(η5-C5H4CH2CH2Cl)(CO)3Cl, W(η5-C5H4CH2CH3)(CO)3Cl and W(η5-C5H4CH2CH3)(CO)3(FBF3), respectively. The crystal structure of the tungsten tricarbonyl complex W(η5-C5H4CH2-η-CH2)(CO)3 has been determined by X-ray crystal diffraction on a single crystal and shows a four-legged piano stool structure.
Alkyl Complexes of Group 4 Metals Containing a Tridentate-Linked Amido−Cyclopentadienyl Ligand: Synthesis, Structure, and Reactivity Including Ethylene Polymerization Catalysis
A series of group 4 metal complexes M(η5:η1:η1-C5Me4SiMe2NCH2CH2X)R2 (M = Ti; R = Me, CH2Ph; M = Zr, Hf; R = Me, Et, nPr, nBu, CH2Ph, CH2SiMe3, Ph) containing the tridentate-linked amido−tetramethy...
Zirconium, hafnium and yttrium complexes containing two linked amido— tetramethylcyclopentadienyl ligands: Synthesis, reactivity and molecular structure of Hf(η5:η1−C5Me4SiMe2NiPr)2
Abstract Zirconium and hafnium complexes M(η5: η1−C5Me4SiMe2NR′)xCl(4−2x) (M = Zr, Hf; x = 1, 2; R′ = iPr, tBu) containing one or two linked amido-tetramethylcyclopentadienyl ligands C5Me4SiMe2NR′ have been synthesized by the reaction of the dilithium derivative Li2(C5Me4SiMe2NR′) with MCl4(THF)2. The crystal structure of the hafnium complex Hf(η5: η1−C5Me4SiMe2NiPr)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 π-donor ligands with Hf—N bond lengths of 2.115(2) A. The isoelectronic heterobimetallic yttrium complex Li[Y(η5: η1−C5Me4SiMe2NCH2CH2OMe)2] reacts with phenylacetylene to give …
Mono(cyclopentadienyl)titanium complexes containing a sulfide-bridged bis(phenolato) ligand. Molecular structure of Ti{2,2′-S(OC6H2-4-Me-6-tBu)2}(η5-C5H5)Cl
A series of titanium complexes containing a sulfur-bridged chelating bis(phenolato) ligand, Ti{2,2′-S(OC 6 H 2 -4-Me-6- t Bu) 2 }(η 5 -C 5 R 5 )Cl (R=H, Me; R 5 =1,3-(SiMe 3 ) 2 H 3 ), were prepared by the reaction of the dilithium derivative Li 2 [2,2′-S(OC 6 H 2 -4-Me-6- t Bu) 2 ] with Ti(η 5 -C 5 R 5 )Cl 3 . Alkylation of the chloro complexes gave complexes of the type Ti{2,2′-S(OC 6 H 2 -4-Me-6- t Bu) 2 }(η 5 -C 5 R 5 )R′ (R′=Me, CH 2 Ph). The crystal structure of the chloro complex Ti{2,2′-S(OC 6 H 2 -4-Me-6- t Bu) 2 }(η 5 -C 5 H 5 )Cl has been determined by X-ray diffraction and shows a monomeric four-legged piano-stool structure with the sulfur and chlorine atoms in trans positions. …
Copolymerization of ethene with styrene using different methylalumoxane activated half-sandwich complexes
Ethene was copolymerized with styrene using five different methylalumoxane (MAO) activated half-sandwich complexes of the general formula Me 2 Si(Cp)(N-R)MCl 2 , varying the substituents on the cyclopentadienyl ring and the substituent on the amide (Cp = tetramethylcyclopentadiene CBT, 1-indenyl IBT, 3-trimethylsilyl-1-indenyl SIBT, or fluorenyl FBZ, R = tert-butyl (complexes CBT,IBT, SIBT, FBZ ) or benzyl CAT), as well as the metal center ( M = Ti, except FBZ: M = Zr). Polymerization behavior was analyzed with respect to catalyst activity and polymerization kinetics, styrene incorporation, copolymer microstructure, and molecular weight. All complexes produced random poly(ethene-co-styrene)…
Remarkably Robust Group 4 Metal Half-Sandwich Complexes Containing Two Higher Alkyl Ligands: X-ray Structure and Reactivity of the Di-n-butyl Complex [Hf(η5:η1:η1-C5Me4SiMe2NCH2CH2OMe)nBu2]
The reaction of LiR with M(η5:η1:η1-C5Me4SiMe2NCH2CH2OMe)Cl2 (1, M = Zr (a), Hf (b)) gives the isolable, thermally stable complexes M(η5:η1:η1-C5Me4SiMe2NCH2CH2OMe)R2 (R = Et (2), nPr (3), nBu(4)), which contain two alkyl ligands with β-hydrogen atoms.
Zirconium and hafnium mono(alkyl) complexes containing a tridentate linked amido-tetramethylcyclopentadienyl ligand. Molecular structure of Hf(η5:η1:η1-C5Me4SiMe2NCH2CH2OCH3)Cl2
Abstract Zirconium and hafnium complexes M( η 5 : η 1 : η 1 -C 5 Me 4 SiMe 2 NCH 2 CH 2 OMe)Cl 2 (M=Zr, Hf) containing the tridentate 2-methoxyethylamido-functionalized tetramethylcyclopentadienyl ligand C 5 Me 4 SiMe 2 NCH 2 CH 2 OMe have been synthesized by the reaction of the dilithium derivative Li 2 [C 5 Me 4 SiMe 2 NCH 2 CH 2 OMe] with MCl 4 (THF) 2 . Selective monoalkylation of the dichloro complexes gave complexes of the type M( η 5 : η 1 : η 1 -C 5 Me 4 SiMe 2 NCH 2 CH 2 OMe)(R)Cl (R=CH 2 Ph, o -C 6 H 4 CH 2 NMe 2 ). The crystal structure of the hafnium dichloro complex Hf( η 5 : η 1 : η 1 -C 5 Me 4 SiMe 2 NCH 2 CH 2 OMe)Cl 2 has been determined by X-ray crystal diffraction and sho…
Substituted 1,4-Diaza-1,3-butadiene Monocyclopentadienyl Titanium Complexes. Crystal Structure of Ti(η5-C5Me5)(η4-iPrNCHCHNiPr)Me
We report the synthesis of 1,4-diaza-1,3-butadiene (dad) complexes Ti(η5-C5R5)(η4-R‘2-dad)Cl (R = H, Me; R‘ = iPr, tBu) by reaction of Ti(η5-C5R5)Cl3 (R = H, Me) with the dilithium salts of diisopropyl- and di-tert-butyl-substituted 1,4-diaza-1,3-butadienes (Li2[R‘2-dad]). Alkylation of the pentamethylcyclopentadienyl diisopropyl and di-tert-butyl derivatives with methylmagnesium chloride and methyllithium gave complexes Ti(η5-C5Me5)(η4-iPr2-dad)Me and Ti(η5-C5Me5)(η4-tBu2-dad)Me, respectively. Addition of excess water to di-tert-butyl chloro complexes gave the oxo-bridged complexes [{Ti(η5-C5R5)(η4-tBu2-dad)}2(μ-O)] (R = H, Me). The temperature-dependent spectroscopic behavior of Ti(η5-C5H…