02036nas a2200289 4500008004100000022001400041245013000055210006900185260000800254300001400262490000700276520106100283653002601344653003101370653001201401653001401413653001701427100002501444700001701469700002401486700002101510700002701531700002401558700002101582700002401603856011901627 2020 eng d a2192-650600aPalladium-catalyzed insertion of ethylene and 1,1-disubstituted difunctional olefins: an experimental and computational study0 aPalladiumcatalyzed insertion of ethylene and 11disubstituted dif cJUN a1200-12090 v853 a

Insertion or coordination copolymerization of ethylene with di-substituted olefins is challenging and the choice of di-substituted mono-functional olefin versus di-substituted di-functional olefin (DDO) appears to be decisive. Here we show that DDO-inserted species are amenable to ethylene insertion and polymerization. DDOs such as 2-acetamidoacrylic acid (AAA), methyl 2-acetamidoacrylate (MAAA), and ethyl 2-cyanoacrylate (ECA) were treated with palladium complex [{P perpendicular to O}PdMe(L)] (P perpendicular to O=kappa(2)-P,O-Ar2PC6H4SO2O with Ar=2-MeOC6H4; L=C2H6OS) and the existence of respective insertion intermediates in moderate yield (up to 37 %) was established. These intermediates were exposed to ethylene and corresponding ethylene-inserted products were isolated and characterized. A careful comparison with three model compounds confirmed ethylene insertion and polymerization. Thus, the combined experimental and computational investigations show that DDO-inserted species can undergo ethylene insertion and polymerization.

10aHomogeneous catalysis10ainsertion copolymerization10aOlefins10aPalladium10aPolyethylene1 aGaikwad, Shahaji, R.1 aPatel, Ketan1 aDeshmukh, Satej, S.1 aMote, Nilesh, R.1 aBirajdar, Rajkumar, S.1 aPandole, Satish, P.1 aChugh, Jeetender1 aChikkali, Samir, H. uhttp://library.ncl.res.in/content/palladium-catalyzed-insertion-ethylene-and-11-disubstituted-difunctional-olefins02235nas a2200253 4500008004100000022001400041245008000055210006900135260000900204300001200213490000700225520142200232653001001654653002201664653002901686653001701715653001701732100002401749700002501773700002401798700002401822700002401846856011101870 2020 eng d a1861-472800aPd-iminocarboxylate complexes and their behavior in ethylene polymerization0 aPdiminocarboxylate complexes and their behavior in ethylene poly cFEB  a398-4050 v153 a

Designing co-catalyst-free late transition metal complexes for ethylene polymerization is a challenging task at the interface of organometallic and polymer chemistry. Herein, a set of new, co-catalyst-free, single-component catalytic systems for ethylene polymerization have been unraveled. Treatment of anthranilic acid with various aldehydes produced four iminocarboxylate ligands (L1-L4) in very good to excellent yield (75-92 %). The existence of 2-((2-methoxybenzylidene)amino) benzoic acid (L1) has been unambiguously demonstrated using NMR spectroscopy, MS and single-crystal X-ray diffraction. A neutral Pd-iminocarboxylate complex [{N O}PdMe(L1)] (N O=kappa(2)-N,O-ArCHNC6H4CO2 with Ar=2-MeOC6H4) C1 was prepared by treating stoichiometric amount of L1.Na with palladium precursor. The identity of C1 was confirmed by 1-2D NMR spectroscopy and single-crystal X-ray diffraction studies. Along the same lines, palladium complexes C2-C4 were prepared from ligands L2-L4 respectively. In-situ high-pressure NMR investigations revealed that these Pd complexes are amenable to ethylene insertion and undergo facile beta-H elimination to produce propylene. These palladium complexes were then evaluated in ethylene polymerization reaction and various reaction parameters were screened. When C1-C4 were exposed to ethylene pressures of 10-50 bar, formation of low-molecular-weight polyethylene was observed.

10aimine10aImine-carboxylate10aInsertion polymerization10aPd complexes10aPolyethylene1 aDeshmukh, Satej, S.1 aGaikwad, Shahaji, R.1 aGonnade, Rajesh, G.1 aPandole, Satish, P.1 aChikkali, Samir, H. uhttp://library.ncl.res.in/content/pd-iminocarboxylate-complexes-and-their-behavior-ethylene-polymerization02147nas a2200265 4500008004100000022001400041245010600055210006900161260000900230300001100239490000800250520122800258653002901486653003101515653002401546653001701570653001001587100002601597700002201623700002401645700002401669700003301693700002401726856013101750 2020 eng d a0014-305700aRenewing polyethylene: insertion copolymerization of sugar derived hydrophilic monomers with ethylene0 aRenewing polyethylene insertion copolymerization of sugar derive cJUL  a1097750 v1343 a

Although highly desirable, insertion copolymerization of renewable resource derived functional olefins with ethylene has been rarely investigated. Herein, we report insertion copolymerization of challenging sugar derived isohexide mono-enes with ethylene in the presence of Pd-phosphinesulfonate acetonitrile catalyst (C1). Thus, copolymerization of ethylene with isomannide mono-ene (2a), isosorbide mono-ene (2b'), isoidide mono-ene (2c) and methacryl-2,3,4,6-tetra-O-acetyl-D glucopyranoside (2d) afforded corresponding functionalized polyethylene (P2a-1 to P2d-1). High temperature proton NMR investigations revealed enchainment of 2a-2c in polyethylene backbone and the highest incorporation of 1.45% was observed for 2c. The high temperature proton NMR results were further corroborated by solid state C-13 NMR and IR spectroscopy. Gel permeation chromatography analysis displayed weight average molecular weight in the range of 13.0-27.2 x 10(3) g/mol. The thus prepared copolymers revealed melting temperature in the range of 117-126 degrees C. Relatively reduced melting temperature compared to neat polyethylene may suggest an irregular arrangement of pendant functional group on polyethylene main chain.

10aHydrophilic polyethylene10ainsertion copolymerization10aIsohexide mono-enes10aPolyethylene10aSugar1 aRajput, Bhausaheb, S.1 aPawal, Sandip, B.1 aBodkhe, Dnyaneshwar1 aRao, Nagamalleswara1 aSainath, Annadanam, V. Sesha1 aChikkali, Samir, H. uhttp://library.ncl.res.in/content/renewing-polyethylene-insertion-copolymerization-sugar-derived-hydrophilic-monomers-ethylene03063nas a2200229 4500008004100000022001400041245006500055210006300120260000900183300001100192490000800203520233200211653001302543653002802556653002702584653002902611653003102640653001702671100002702688700002402715856009402739 2021 eng d a0014-305700aInsertion copolymerization of functional olefins: Quo Vadis?0 aInsertion copolymerization of functional olefins Quo Vadis cJAN  a1101830 v1433 a

Functional polyethylene is a specialty polymer with unique set of properties and caters to a niche market. Currently, it is manufactured using high-pressure, high-temperature radical polymerization, or post-reactor (indirect) modification methods. Insertion copolymerization of functional olefins with ethylene provides a low pressure, direct route to prepare functional polyethylenes. However, insertion copolymerization of functional olefins with ethylene poses several impediments and requires special considerations. This review presents the current strategies, examines the progress, and attempts to gauge the commercial potential of direct synthesis of functional polyethylene. The performance of late transition metal catalysts derived from a-diimine, imine-phenolate, phosphine-sulfonate, bis-phosphine-mono-oxide, carbene-phenolate, phosphine-phenolate and their derivatives in the insertion copolymerization of functional olefins with ethylene is evaluated. While catalyst designing is crucial, incorporation of polar olefins that can serve an additional purpose is equally important. Therefore, we have organized the review in the following sections, polar alkenes with- acrylates, acrylic acids, acetates, nitriles, ethers, halides, two functional groups, cross-linking groups, dynamic interactions/self-healing properties, additional function/purpose, renewable functional olefins, and examine the progress. Among these, acrylates have been most intensively investigated and have been successfully incorporated in the polyethylene main-chain. Ethylene, methyl acrylate copolymers prepared by direct copolymerization reveal comparable melting temperature to that of LLDPE (at similar co-monomer content) and unfold the commercial potential of these materials. Recent developments on the insertion copolymerization of renewable functional olefins and di-functional olefins have elicited significant interest. This strategy is being viewed as a means of reducing environmental impact and enabling high functional group density at the same extent of incorporation. The overview thus offers a succinct account of insertion copolymerization of functional olefins, sheds light on the copolymer microstructure/material properties, and initiates a discussion on the commercial potential of functional polyethylene.

10aCatalyst10aFunctional polyethylene10afunctional polyolefins10aHydrophilic polyethylene10ainsertion copolymerization10aPolyethylene1 aBirajdar, Rajkumar, S.1 aChikkali, Samir, H. uhttp://library.ncl.res.in/content/insertion-copolymerization-functional-olefins-quo-vadis01964nas a2200253 4500008004100000022001400041245011400055210006900169260000800238300001400246490000600260520113300266653001301399653000901412653001801421653001701439653001901456100001801475700002001493700002201513700002401535700002701559856012401586 2023 eng d a2637-610500aPolyethylene-grafted sheet-like silsesquioxane nanocomposites with unprecedented adhesion to polar substrates0 aPolyethylenegrafted sheetlike silsesquioxane nanocomposites with cJUL a5972-59830 v53 a

Polyethylene is a highly apolar polymer with very pooradhesionto most substrates, necessitating the use of tie layers. Therefore,the synthesis of functional polyethylene is a long-standing challengein catalytic ethylene polymerization. Here, we report the preparationof a nanocomposite comprising polyethylene covalently grafted ontosheet-like silsesquioxanes, with unprecedented adhesion to metal andglass. A norbornene-grafted, layered Mg-silsesquioxane is treatedwith Grubbs second-generation catalyst (G-II), and the identity ofcovalently tethered G-II is unambiguously ascertained. Covalentlytethered G-II catalyzes the ring opening metathesis polymerizationof cyclooctene to poly(cyclooctene). The resulting poly(cyclooctene)is catalytically hydrogenated to yield polyethylene. This polyethylenenanocomposite exhibited a bonding strength of the order of 100 MPaon stainless steel and aluminum, 10-fold higher than reported forengineered polyethylene copolymers. The nanocomposite exhibits anincrease in the polar component of surface energy, yet remains compatibleand cocrystallizes with a polyethylene matrix.

10aadhesion10aclay10aNanocomposite10aPolyethylene10asilsesquioxane1 aSharma, Vivek1 aPaulbudhe, Uday1 aBachhar, Nirmalya1 aChikkali, Samir, H.1 aKumaraswamy, Guruswamy uhttp://library.ncl.res.in/content/polyethylene-grafted-sheet-silsesquioxane-nanocomposites-unprecedented-adhesion-polar02487nas a2200277 4500008004100000022001400041245010000055210006900155260000800224520154900232653001701781653000801798653003001806653002701836653001701863100002401880700001901904700002101923700002101944700002801965700002201993700002502015700001702040700002402057856012802081 2024 eng d a1060-132500aDesigning of imine thiophene-ligated metal-complexes and implication in ethylene polymerization0 aDesigning of imine thiopheneligated metalcomplexes and implicati cSEP3 a

Polyethylene is the single largest volume polymer produced globally using Ziegler-type catalysts. Numerous modifications have been reported in search of a better catalyst that can control molecular weight, polydispersity, and branching. In our attempts to identify a suitable imine thiophene-ligated chromium complex, we examined 9 different titanium complexes computationally. The DFT investigations considered barriers for insertion, propagation, and termination by beta-H elimination or chain transfer, and identified N-(4-methoxyphenyl)-2-phenyl-1-(thiophen-2-yl)ethan-1-imine(L9) as the most suitable ligand. Subsequently, L9 was prepared in good yield (70%) by condensing 2-phenyl-1-(thiophen-2-yl)ethan-1-one with 4-methoxyaniline. Ligand L9 was treated with early transition metal precursors (Ti, Cr, Zr) to generate a homogenous catalyst. The identity of these catalysts was unambiguously ascertained using a combination of NMR, ICP, FT-IR, UV-Vis spectroscopy, and ESI-MS. The performance of L9-ligated titanium complex [Cat.1] was examined in ethylene polymerization using MMAO as a co-catalyst. Insertion of ethylene was tracked using high-pressure NMR experiments and Cat.1 was found to be active in the polymerization. Ethylene polymerization conditions were optimized to obtain high activity and molecular weight polyethylene. The chromium complex [Cat.2] outperformed the Ti and Zr-derived catalysts with the highest TOF of 6294 mol of PE/mol of Cr/h. Cat.2 produced high molecular weight, high-density polyethylene.

10aCr-complexes10aDFT10ahigh-density polyethylene10aImine thiophene ligand10aPolyethylene1 aShaikh, Maulali, H.1 aRamekar, Rohan1 aJawoor, Shailaja1 aDash, Soumya, R.1 aBirajadar, Rajkumar, S.1 aPawal, Sandip, B.1 aThenmani, Nandakumar1 aVanka, Kumar1 aChikkali, Samir, H. uhttp://library.ncl.res.in/content/designing-imine-thiophene-ligated-metal-complexes-and-implication-ethylene-polymerization