Heavy alkaline earth and heterobimetallic s-block “ate” complexes.

Functional polypropylenes (FPs) are regarded as versatile building blocks for next-generation materials; however, their development has been stymied due to current synthetic limitations. Here, we report a diverse range of functionalized prepared via two-step copolymerization−postmodification strategy. Solution-phase copolymerization propylene and 11-bromo-1-undecene using C2, C1, Cs-symmetric catalysts-afforded poly(propylene)-co-(11-bromo-1-undecene), with tunable comonomer incorporation...

We report the use of alkaline-earth (Ae) metal-catalyzed dehydrocoupling silanes and amines for synthesis ferrocene-containing polycarbosilazanes. The barium complex [Ba(N(SiMe3)2)2·(THF)2] catalyzed hydrosilane FeCp(CpSiPhH2) (1) with 1,4-(H2NCH2)2C6H4 under mild conditions to give a polycarbosilazane pendant ferrocene groups. polymer could be readily cross-linked by addition phenylsilane unquenched reaction mixture. Well-defined polycarbosilazanes in main chain were also obtained from...

Abstract The dehydrocoupling of silanes and alcohols mediated by heavier alkaline‐earth catalysts, [Ae{N(SiMe 3 ) 2 } ⋅(THF) ] ( I – III [Ae{CH(SiMe ], IV VI (Ae=Ca, Sr, Ba) is described. Primary, secondary, tertiary were coupled to phenylsilane or diphenylsilane, whereas are less tolerant towards bulky substrates. Some control over reaction selectivity mono‐, di‐, tri‐substituted silylether products was achieved through alteration stoichiometry, conditions, catalyst. ferrocenyl silylether,...

Bimetallic 1,8-bis(silylamido)naphthalene alkaline earth complexes [(R3L)Ae]2 ([R3L]2– = [1,8-{(R3Si)N}2C10H6)]2–, where R3 Ph2Me, Ae Ca (1), Sr (2), and Ba (3); Ph3, (4), (5), (6) were prepared via protonolysis reactions of the phenyl-substituted proligands Ph3LH2 Ph2MeLH2 with [AeN″2]2 (N″ [N(SiMe3)2]−) in benzene. X-ray crystallographic analysis showed that 1, 2, 4 crystallize as nitrogen-bridged dimers. Conversely, 5 6 display a naphthalene-bridged motif, while structure 3 is...

Phosphonate-modified polypropylenes (PPR; R = PPr, P(O)(OiPr)2; PPh, P(O)(OPh)2) have been prepared via a two-step synthesis and display enhanced thermal stability, offering potential as compatible single-component flame-retardant additives for PP systems. typically displays high flammability poor fire resistance, which consequently restricts applications. Solution-phase copolymerization of propylene 11-bromo-1-undecene using commercial rac-ethylenebis(indenyl)zirconium dichloride afforded...

Currently, there is considerable interest in introducing molecularly defined main group metal compounds as precursors and model complexes of homogeneous catalysts for various bond cleavage forming transformations. With a...

Abstract H 2 adds reversibly across the metal‐metal bond of [(BDI)Ga(H)−Zn(tmeda)(thf)][BAr 4 F ] (BDI=[HC{C(CH 3 )N(2,6‐ i Pr ‐C 6 )} − , TMEDA= N N′ ‐tetramethylethylenediamine, BAr F− =[B(C ‐3,5‐(CF ) ). Due to stabilising effect solvent coordination, hydrogenation products [(BDI)GaH and [(tmeda)ZnH(thf)][BAr are favoured in THF solution, but THF‐free mixtures [(tmeda)ZnH(OEt )][BAr predisposed towards entropically driven dehydrogenation [(BDI)Ga(H)−Zn(tmeda)][BAr fluorobenzene solution.

Thermally sensitive polymeric zinc dihydride [ZnH2]n can conveniently be prepared by the reaction of ZnEt2 with [AlH3(NEt3)]. When reacted CO2 (1 bar) in presence chelating N-donor ligands Ln = N,N,N',N'-tetramethylethylenediamine (TMEDA), N,N,N',N'-tetramethyl-1,3-propanediamine (TMPDA), N,N,N',N″,N''-pentamethyldiethylenetriamine (PMDTA), and 1,4,7,10-tetramethyl-1,4,7,10-tetraazacyclododecane (Me4TACD), insertion into Zn-H bond readily occurred. Depending on denticity n, formates...

A heterobimetallic dihydride cation with a covalent Al–Ga bond forms by formal oxidative addition of [AlH 2 ] + to Ga( i ). The reverse reaction is initiated coordination THF or NHC, but does not occur for the Al–Al bonded homobimetallic analogue.

In the presence of TMEDA (N,N,N',N'-tetramethylethylenediamine), partially deaggregated zinc dihydride as hydrocarbon suspensions react with gallium(I) compound [(BDI)Ga] (I, BDI={HC(C(CH

The β-diketiminato carboranyl complexes, [(BDI)Ae( o -C 2 B 10 H 11 )] (Ae = Mg or Ca), have been synthesised and [(BDI)Mg( reacted with NHC IPr MCl to provide M( ), rare C-bonded coinage metal derivatives of ( ) − .

Reaction of the dimeric calcium hydride, [(BDI)CaH]2 (1), with Ph3SnH ensues elimination H2 to provide [(BDI)Ca-μ2-H-(SnPh3)Ca(BDI)] (3) and [(BDI)Ca(SnPh3)]2 (4) alongside dismutation Ph4Sn, Sn(0). DFT analysis indicates that stannyl anion formation occurs through deprotonation retention dinuclear species throughout reactions.

Treatment of β-diketiminato (BDI = HC{C(CH3)Ndipp)}2 where dipp 2,6-iPr2C6H3) magnesium butyl [(BDI)MgBu] (I) and calcium hexamethyldisilazide [(BDI)Ca{N(SiMe3)2}] (II) complexes with equimolar quantities diphenylphosphine–borane, Ph2PH·BH3, results in the formation respective alkaline earth (Ae) phosphidoborane derivatives [(BDI)Mg(Ph2PBH3)]2 (6a) [(BDI)Ca(Ph2PBH3)] (7a). Although satisfactory single crystals 7a could not be obtained, 6a was crystallographically characterized both compounds...

Using a highly active supported permethylindenyl-phenoxy (PHENI*) titanium catalyst, high molecular weight ethylene-propylene (EPM) and ethylene-propylene-diene (EPDM) elastomers are prepared using slurry-phase catalysis. Final copolymer composition was found to reflect the monomer feed ratio in linear fashion, access continuum of material properties with single catalyst. Post-polymerisation crosslinking EPDM also demonstrated model sulfur vulcanisation system.

Abstract The electrocatalytic activity of La 1‐ x Ba MnO 3 nanoparticles towards the oxygen reduction reaction (ORR) is investigated as a function A‐site composition. Phase‐pure oxide with diameter in range 40 to 70 nm were prepared by using an ionic liquid route and deposited onto mesoporous carbon films. structure surface composition are probed XRD, TEM, EDX, XPS. Electrochemical studies carried out under alkaline conditions show strong correlation between effective number reducible Mn...

Reactions of B(C6F5)3 with the β-diketiminato (BDI) alkaline-earth phosphidoborane complexes, 1a [(BDI)Ca(H3B·PPh2)] and 1b [(BDI)Mg(H3B·PPh2)]2 (BDI = [HC{C(CH3)N(2,6-iPr-C6H3)}2]-) result in formation phosphinodiboronate complexes 4a [(BDI)Ca(η6-toluene){H3B·PPh2·B(C6F5)3}] 4b [(BDI)Mg{H3B·PPh2·B(C6F5)3}]. Calcium complex is stable aromatic solvents at room temperature does not display well-defined onward reactivity elevated temperatures. Magnesium undergoes a transformation to provide...

Using a highly active permethylindenyl-phenoxy (PHENI*) titanium catalyst, high to ultra-high molecular weight ethylene–linear-α-olefin copolymers are prepared in yields, with exceptional comonomer affinity, and predictable, tuneable composition.

A family of ansa-permethylindenyl-phenoxy (PHENI*) transition-metal chloride complexes has been synthesized and characterized (1–7; {(η5-C9Me6)Me(R″)Si(2-R-4-R′-C6H2O)}MCl2; R,R′ = Me, tBu, Cumyl (CMe2Ph); R″ nPr, Ph; M Ti, Zr, Hf). The ancillary ligands could readily be exchanged with halides, alkyls, alkoxides, aryloxides, or amides to form PHENI* [L]TiX2 (8–17; X Br, I, CH2SiMe3, CH2Ph, NMe2, OEt, ODipp). solid-state crystal structures these indicate that one two conformations may...

The dimeric calcium and magnesium hydrides, [(BDI)AeH]2 [BDI = HC{(Me)CNDipp}2, Dipp 2,6‐i‐Pr­2C6H3;­ Ae Mg or Ca] do not react with Ph3GeH in non‐coordinating solvent. Addition of THF, however, induces deprotonation access to monomeric Ae‐germanide complexes, [(BDI)Ae{GePh3}(THF)], both which have been structurally characterized. Although this process is facile when Ca, the analogous magnesium‐based reaction requires heating temperatures >100 °C, under conditions germanide formation...

Protonolysis of [Cp*M] (M=Ga, In, Tl) with [(Me4 TACD)H][BAr4Me ] (Me4 TACD=N,N',N'',N'''-tetramethyl-1,4,7,10-tetraazacyclododecane; [BAr4Me ]- =[B{C6 H3 -3,5-(CH3 )2 }4 ) provided monovalent salts TACD)M][BAr4Me ], whereas [Cp*Al]4 yielded trivalent TACD)AlH][BAr4Me ]2 . Protonation TACD)Ga][BAr4Me [Et3 NH][BAr4Me gave an unusually acidic (pKa (CH3 CN)=24.5) gallium(III) hydride dication TACD)GaH][BAr4Me Deprotonation IMe4 (1,3,4,5-tetramethyl-imidazol-ylidene) returned ]. These reversible...

The synthesis of heteroleptic complexes with calcium- and magnesium-tin bonds is described. dimeric β-diketiminato calcium hydride complex, [(BDI)Ca(μ-H)]2 (ICa) reacts Ph3Sn-SnPh3 to provide the previously reported μ2-H bridged stannanide dimer, [(BDI)2Ca2(SnPh3)(μ-H)] (3). Computational assessment this reaction supports a mechanism involving hypervalent stannate intermediate formed by nucleophilic attack on distannane. Monomeric stannanides, [(BDI)Ca(SnPh3)·OPPh3] (8·OPPh3)...

Density functional theory (DFT) calculations demonstrate that the previously reported reaction of [(BDI)Mg-n-Bu] (BDI = HC{(Me)CN-Dipp}2; Dipp 2,6-diisopropylphenyl) with silaborane Me2PhSi-Bpin provides magnesium silanide derivative [(BDI)MgSiMe2Ph], through intermediacy a short-lived silyl-pinacolato-organoborate species. The nucleophilic character resultant anion is assayed series reactions RN═C═NR (R i-Pr, Cy, t-Bu) and p-tolN═C═N-p-tol. When they are performed in strict 1:1...