Elemental organic compounds. Part XIV. Polymerization of diene with organotransition metals

Tsutsui, Minoru; Ariyoshi, Junji

doi:10.1002/pol.1965.100030506

Cited by 5 publications

(1 citation statement)

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“…Chromium compounds such as Cr(acetylacetonate) 3 , Cr(CNPh) 6 , Cr(CO) 6 and Cr(CO) 3 (pyridine) 3 in combination with alkylaluminium compounds were reported to catalyze the 1,2‐polymerization of BD 12–15. Alkylchromium compounds such as CrEt 3 and CrPh 3 ·3THF (where THF is tetrahydrofuran) were reported to produce a mixture of 1,2‐ and trans ‐1,4‐PBD 16. The π‐allyl complex of chromium Cr(MeCHCHCH 2 ) 3 produces trans ‐1,4‐ and 1,2‐PBD depending on the conditions 17.…”

Section: Introductionmentioning

confidence: 99%

Highly trans‐1,4‐specific polymerization of 1,3‐butadiene catalyzed by [2,6‐bis{(4S)‐ (−)‐isopropyl‐2‐oxazolin‐2‐yl}pyridine] chromium complex activated with modified methylaluminoxane

Nakayama

Sogo

Cai

et al. 2011

Polymer International

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Chromium complexes with N,N,N‐tridentate ligands, LCrCl3 (L = 2,6‐bis{(4S)‐(−)‐isopropyl‐2‐oxazolin‐2‐yl}pyridine (1), 2,2′:6′,2″‐terpyridine (2), and 4,4′,4″‐tri‐tert‐butyl‐2,2′:6′,2″‐terpyridine (3)), were prepared. The structures of 1 and 2 were determined by X‐ray crystallography. Upon activation with modified methylaluminoxane (MMAO), 1 catalyzed the polymerization of 1,3‐butadiene, while 2 and 3 was inactive. The obtained poly(1,3‐butadiene) obtained with 1‐MMAO was found to have completely trans‐1,4 structure. The 1‐MMAO system also showed catalytic activity for the polymerization of isoprene to give polyisoprene with trans‐1,4 (68%) and cis‐1,4 (32%) structure. Copyright © 2011 Society of Chemical Industry

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Section: Introductionmentioning

confidence: 99%

Highly trans‐1,4‐specific polymerization of 1,3‐butadiene catalyzed by [2,6‐bis{(4S)‐ (−)‐isopropyl‐2‐oxazolin‐2‐yl}pyridine] chromium complex activated with modified methylaluminoxane

Nakayama

Sogo

Cai

et al. 2011

Polymer International

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Elemental organic compounds. Part XX. Ethylene dimerization to butene‐1

Tsutsui

Koyano

1967

J. Polym. Sci. A‐1 Polym. Chem.

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The oligomeriratioii of ethylene to obtah various low molecular weight products has been investigated for a long time and includes the Alfene Process' for the production of a-olefins.Selective dimerization has been achieved with some success over BFo,z pure Ni,t Co~harcoal,~ nickel oxide-silica-alumina,6 --B aluminosilicate,9 trialkylaluminum-titanates, rn and trisllrylslumin~-zirconates, 11 triethylaluniinum-nickel acetylscetone,'* or ethylaluminum sesquichloride-nickel carbonyl-triphenylph~sphine.'~ However, in most of the cases, the catalysts are complex mixtures of several components or the selectivity for butene-1 production is not prominent.We report a novel unicomponent organometallic catalyst, dicyclopentadienylnickel (nickelocene) for the highly selective dimerization of ethylene to butene-1.A solution of nickelocene (1 g.) in n-heptane (50 ml.) was placed in a 300-ml. autoclave under nitrogen pressure.The autoclave was heated at 2oo°C. for 18 hr., during which period the pressure decreased from 2600 to 1500 psi, indicating a reaction. After cooling to room temperature, the autoclave was vented and the released gas was collected in B trap cooled by a Dry Ice-acetone bath. The colorless liquid thus obtained (5 ml.) was found, by gas chromatography, to consist of butane, butene-l, trans-butene-2 and cis-butene-2, in a ratio of 1: 1198:89:56 (89yo butene-l). The catalyst was decomposed, and some higher oligomers were also detected in the reacted solution. Due to isomerization, the butene-l content dropped to ca. 20% when the reaction was conducted at 300°C.Ethylene was charged at a pressure of 600 psi.A logical mechanism is presented in eqs.(1).High temp.

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Elemental organic compounds. Part XXI. Polymerization of ethylene by dibenzenechromium

Tsutsui

Koyano

1967

J. Polym. Sci. A‐1 Polym. Chem.

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It has recently been reported that the polymerization of biitadiene takes place on surfaces of various transition metal atoms such a s Ti, Cr, Fe, Co, and Ni, each of which is formed by the decomposition of corresponding organic derivatives.The polymerization mechanism can be explained by the concept of catalysis at the atomic level which, when created, increases the activity of the transition metal towards addition polymerization by means of stimulatec. interaction of r-electrons of the monomer with the metal d orbitals. The oligomerization of butadiene by a zero-valent nickel atom has also been interpreted by essentially the same mechanism.2We have, however, been able to dimerize a monoolefin, ethylene, selectively on atomic nickel which was produced by the decomposition of nickelocene. 3 We have now found another example of this type of ethylene polymerization catalyst. A solution of dibenzenechromium (0), 1.1 g. in nitrogen-saturated n-heptane (50 d.), was placed in a 300-ml. autoclave under a nitrogen atmosphere. Ethylene was charged into the autoclave to 630 psi. The pressure did not change on prolonged heating a t 200°C. for 16 hr. However, a t 250OC. and 2800 psi, a rapid decrease to 1100 psi was observed after 7 hr. The white solid polyethylene formed was dissolved in hot xylene and boiled with hydrochloric acid three times to remove the catalyst and was reprecipitated several times with xylenemethanol.According to infrared analysis, it seems to have contained only an internal trans double bond (965 cm.-I) as the unsaturated bond.This value corresponds to 88% ~rystalliinity.~The intrinsic viscosity measured in tetralin at 130°C. was 0.99, from which the molecular weight calculated by Tung's equation was 34,000.6On the basis of these findings, it appears that the polymerization reaction may proceed through atomic level catalysis, since the reaction commences a t a temperature close to the decomposition poin t 6 of dibenzenechromium.The trans double bond in the polymer implies that the double bond was fixed to the catalyst during the propagation reaction and the chain grew from both sides independently. Thus, the mechanism of eqs. (1) is postulated.The catalyst was found decomposed in the cooled autoclave.The purified polymer weighed 3.7 g.The density was 0.966 g./cc. by the density-gradient tube method. JOURNAL OF POLYMER SCIENCE: PART A-I vor,. 5 (1967) Soon after metallic chromium is formed from the thermal decomposition of dibenaenechromium, the surrounding ethylene molecules start interacting with the vacant d orbitals of the metal to form n-bonding (I). Since the active chromium atoms shows a strong ability to dehydrogenate orgauic groups forming chromium hydride,' the ethylene ligands form a biradical olefiiiic chain (111).Each radical can add additional ethylene molecules assisted by the central metal which can interact with the ethylene *-system (111, IV). Thus, the successive radical propagation continues catalytically until hydrogen radicals from the decomposition of chromium hydride finally...

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Elemental organic compounds. Part XIV. Polymerization of diene with organotransition metals

Cited by 5 publications

References 8 publications

Highly trans‐1,4‐specific polymerization of 1,3‐butadiene catalyzed by [2,6‐bis{(4S)‐ (−)‐isopropyl‐2‐oxazolin‐2‐yl}pyridine] chromium complex activated with modified methylaluminoxane

Highly trans‐1,4‐specific polymerization of 1,3‐butadiene catalyzed by [2,6‐bis{(4S)‐ (−)‐isopropyl‐2‐oxazolin‐2‐yl}pyridine] chromium complex activated with modified methylaluminoxane

Elemental organic compounds. Part XX. Ethylene dimerization to butene‐1

Elemental organic compounds. Part XXI. Polymerization of ethylene by dibenzenechromium

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