One-pot synthesis of Mo(0) dinitrogen complexes possessing monodentate and multidentate phosphine ligands

Mo(0) dinitrogen complexes bearing electron-rich mono- and bidentate phosphines can be synthesized in good yields from inexpensive and readily accessible MoCl(5) via a one-step mild reduction with Mg metal. trans-[(N(2))(2)Mo(PMePh(2))(PPh(CH(2)CH(2)PPh(2))(2))] can also be obtained via this strategy. However, in the presence of tri- and tetradentate ligands that are sterically restrictive, the analogous reduction leads to either (η(6)-arene) formation or [Mo(multidentate phosphine)(m)](n) oligomer complexes that have no dinitrogen ligands. One such η(6)-arene complex, where the Mo(0) center is ligated by 1,1,1-tris(diphenylphosphinomethyl)ethane, was isolated and characterized via X-ray crystallography.     

Preparation and reactivity of a monomeric octahedral platinum(IV) amido complex

Synthesis and isolation of the monomeric octahedral platinum(IV) amido complex (NCN)PtMe2NHPh have been accomplished upon deprotonation of the amine complex [(NCN)PtMe2(NH2Ph)][OTf]. The preliminary reactivity of the amido ligand has been explored.     

Synthesis,characterization, and reactivity of monomeric,arylpalladium halide complexes with a hindered phosphine as the only dative ligand

We report the isolation and structural characterization of several monomeric arylpalladium(II) halide complexes containing tri-tert-butyl phosphine, 1-adamantyl-di-tert-butylphosphine, or 2-adamantyl-di-tert-butylphosphine. X-ray diffraction, IR spectroscopy, and theoretical studies indicated that the complexes may be stabilized by agostic interactions. For example, the distance from the closest hydrogen atom to the palladium metal center in the X-ray structure of the 1-adamantyl-phenylpalladium bromide complex 1 was 2.26(3) A. The calculated Pd-H distance of 2.28 A and harmonic vibrational frequencies were in agreement with the measured distance, but Wiberg bond indices indicated only weak M-H-C interactions. Addition of 2-adamantyl-di-tert-butyl phosphine to 1 led to ligand exchange and formation of 2-adamantyl-di-tert-butyl phosphine complex 2. Addition of P(t-Bu)(3) generated free aryl bromide and Pd[P(t-Bu)(3)](2). Reactivity of complex 1 with nucleophiles provided evidence of the intermediacy of these complexes in palladium-catalyzed cross-coupling reactions. Complex 1 reacted with amine and base to form the corresponding arylamine, with tert-butoxide to form the corresponding ether, with boronic acid and fluoride to form the corresponding biaryl, and with styrene to form stilbene. This complex also catalyzed the reaction of bromobenzene with diphenylamine in the presence of base to produce 94% of the amination product in 45 min at room temperature. This rate is comparable to the reaction rate of in situ generated catalysts.     

Luminescence of ruthenium halide complexes containing a hemilabile phosphine pyrenyl ether ligand

A series of Ru(II) complexes, tcc-RuX2(POC4Pyr-P,O)2 (X = Cl (3), Br (4), I (5)), containing the hemilabile phosphine pyrenyl ether ligand 4-{2-(diphenylphosphino)phenoxy}butylpyrene (POC4Pyr (1)) are reported. The synthesis and spectroscopic properties of both the ligand, POC4pyr (1), and ligand oxide, P(=O)OC4pyr 2, and the solid-state structure of 1 are reported. Complexes 3-5 react rapidly with CO to give complexes ttt-RuX2(CO)2(POC4pyr-P)2 (X = Cl (6), Br (7), I (8)). No pyrene excimer emission is detected from 3-5; however, different intensities of excimer emission are observed for 6-8. The intensity of excimer emission decreases through the series, with 6 showing the most intense response. The emission is solely due to intramolecular pyrene excimers at low concentrations (< or =10(-4) M). Comparison of the UV-vis and steady-state fluorescence spectra shows overlap between the low energy d-d absorption of 7 and 8 with excimer emission (480 nm), suggesting nonradiative energy transfer may be occurring. Once excess CO is removed, complexes 6-8 isomerize to cis-dicarbonyl complexes cct-RuX2(CO)2(POC4Pyr-P)2 (X = Cl (9), Br (10), I (11)). The intensity of excimer emission from 9-11 increases with respect to the excimer emission observed for 6-8, with 9 showing a significant increase in excimer intensity.     

Nickel(II) complexes containing bidentate amido phosphine ligands derived from alpha-iminophosphorus ylides: synthesis and structural characterization

The reactions of prop-2-ynyltriphenylphosphonium bromide with a series of primary aromatic or aliphatic amines in refluxing acetonitrile generated the corresponding 2-hydrocarbylaminoprop-1-enyltriphenylphosphonium bromide [RNHC(Me)=CHPPh(3)]+Br- (R = 2,6-C(6)H(3)iPr(2) (1a), 2,6-C(6)H(3)Me(2) (1b), Ph (1c), t-Bu (1d)) as crystalline solids. Deprotonation of 1a-d with NaH in THF at -35 degrees C afforded the alpha-iminophosphorus ylides RN=C(Me)CH=PPh(3) (2a-d) in high yield. Spectroscopic and crystallographic data of 2 suggest a strong intramolecular interaction between the imino nitrogen and the phosphorus atom. In contrast to N-arylated 2a-c, the N-tert-butyl-derived 2d is extremely moisture-sensitive. Hydrolysis of 2d led to elimination of benzene and generated concomitantly the phosphine oxide 3d that contains an ene-amine functionality. The reactions of 2a-c with Ni(COD)(2) in the presence of an excess amount of pyridine in toluene produced the divalent nickel complexes of the type [kappa(2)-RNC(Me)=CHPPh(2)]Ni(Ph)(Py) (4a-c). The solution and solid-state structures of these new compounds are presented.     

Preparation, characterization and structure of ruthenium phosphine complexes containing non-innocent ligands

Phosphine ruthenate complexes containing the non-innocent ligands 4-chloro-1,2-phenylenediamine (opda-Cl) and 3,3′,4,4′-tetraamminebiphenyl (diopda) were synthesized and characterized by means of X-ray diffraction, electrochemistry, ³¹P{¹H} NMR and electronic spectroscopies. Crystals of cis-[RuCl₂(dppb)(bqdi-Cl)] complex were isolated as a mixture of two conformational isomers due to different positions of the chlorine atoms of the o-phenylene ligand in relation to the P1 atom of the phosphine moiety.     

Synthesis and reactivity of the monomeric late-transition-metal parent amido complex [Ir(Cp*)(PMe3)(Ph)(NH2)

The late-transition-metal parent amido compound [Ir(Cp*)(PMe3)(Ph)(NH2)] (2) has been synthesized by deprotonation of the corresponding ammine complex [Ir(Cp*)(PMe3)(Ph)(NH3)][OTf] (6) with KN(SiMe3)2. An X-ray structure determination has ascertained its monomeric nature. Proton-transfer studies indicate that 2 can successfully deprotonate p-nitrophenylacetonitrile, aniline, and phenol. Crystallographic analysis has revealed that the ion pair [Ir(Cp*)(PMe3)(Ph)(NH3)][OPh] (8) exists as a hydrogen-bonded dimer in the solid state. Reactions of 2 with isocyanates and carbodiimides lead to overall insertion of the heterocumulenes into the N--H bond of the Ir-bonded amido group, demonstrating the ability of 2 to act as an efficient nucleophile. Intriguing reactivity is observed when amide 2 reacts with CO or 2,6-dimethylphenyl isocyanide. eta4-Tetramethylfulvene complexes [Ir(eta4-C5Me4CH2)(PMe3)(Ph)(L)] (L=CO (15), CNC6H3-2,6-(CH3)2 (16)) are formed in solution through displacement of the amido group by the incoming ligand followed by deprotonation of a methyl group on the Cp* ring and liberation of ammonia. Conclusive evidence for the presence of the Ir-bonded eta4-tetramethylfulvene moiety in the solid state has been provided by an X-ray diffraction study of complex 16.     

Synthesis, characterization and reactivity of tetranuclear ruthenium hydrido clusters containing chiral phosphine ligands

The chiral clusters [H(4)Ru(4)(CO)(12-n)(L)(n)] (n = 1, 2; L = NMDPP), 1,1-[H(4)Ru(4)(CO)(10)(L-L)] (L-L = DUPHOS, DIPAMP), 1,2-[H(4)Ru(4)(CO)(10)(DIOP)] and [{H(4)Ru(4)(CO)(10)(DIOP)}(2)] have been synthesized by derivatizing the parent carbonyl cluster [H(4)Ru(4)(CO)(12)] with the appropriate mono- or didentate chiral phosphine ligand. The phosphine-substituted clusters were found to be able to catalyze the (asymmetric) hydrogenation of tiglic acid albeit with relatively low selectivity (enantiomeric excesses varying from 0 to 23%). It was found that the stability of the chiral ruthenium hydride clusters and the product distribution obtained in the catalytic reactions are dependent on the nature of the chiral phosphine. The crystal structures of [H(4)Ru(4)(CO)(12-n)(L)(n)] (n = 1, 2; L = NMDPP), 1,1-[H(4)Ru(4)(CO)(10)(L-L)] (L-L = DUPHOS, O-DUPHOS (partially oxygenated ligand), DIPAMP), 1,2-[H(4)Ru(4)(CO)(10)(DIOP)] and [{H(4)Ru(4)(CO)(10)(DIOP)}(2)] are presented.     

Syntheses,characterization, and structures of three ruthenium complexes containing two monodentate dppm ligands

Three cis-Ru(dppm)₂XY complexes (XY?=?C₂O₄, 1; X?=?Cl, Y?=?N₃, 2; X?=?Y?=?N₃, 3) were prepared by reactions of cis-Ru(dppm)₂Cl₂ with (NH₄)₂C₂O₄, a mixture of NaN₃ and NaPF₆, and only NaN₃, respectively, while 3 could also be obtained from further reaction of 2 with NaN₃ undergoing a facile chloride abstraction. All complexes have been characterized by IR, NMR, UV–vis, and luminescence spectroscopic analyses as well as X-ray diffraction studies. Of these structures, 1 shows oxalate coordinates to Ru as a chelating ligand, while 2 displays Ru and azide linear, and 3 gives two azide groups cis to each other, which are different from two substituting ligands commonly lying in trans positions in Ru(P–P)₂ complexes by using cis-Ru(dppm)₂Cl₂ as a precursor.     

A terminal nickel(II) anilide complex featuring an unsymmetrically substituted amido pincer ligand: synthesis and reactivity

This work describes preparation and reaction chemistry of a terminal nickel(II) anilide complex supported by an unsymmetrically substituted diarylamido diphosphine ligand, [N(o-C(6)H(4)PPh(2))(o-C(6)H(4)P(i)Pr(2))](-) ([Ph-PNP-(i)Pr](-)). Treatment of NiCl(2)(DME) with H[Ph-PNP-(i)Pr] in THF at room temperature produced [Ph-PNP-(i)Pr]NiCl as green crystals in 82% yield. Salt metathesis of [Ph-PNP-(i)Pr]NiCl with LiNHPh(THF) in THF at -35 °C generated cleanly [Ph-PNP-(i)Pr]NiNHPh as a greenish blue solid. The anilide complex deprotonates protic (e.g., PhOH and PhSH) and aprotic (e.g., trimethylsilylacetylene, phenylacetylene, and acetonitrile) acids in benzene at room temperature to give quantitatively [Ph-PNP-(i)Pr]NiX (X = OPh, SPh, C≡CSiMe(3), C≡CPh, CH(2)CN). In addition, [Ph-PNP-(i)Pr]NiNHPh also behaves as a nucleophile to react with acetyl chloride to yield [Ph-PNP-(i)Pr]NiCl and N-phenylacetamide quantitatively. Carbonylation of [Ph-PNP-(i)Pr]NiNHPh with carbon monoxide affords cleanly the carbamoyl derivative [Ph-PNP-(i)Pr]Ni[C(O)NHPh]. The relative bond strengths of Ni-E in [Ph-PNP-(i)Pr]NiEPh (E = NH, O, S, C≡C) are assessed and discussed.     

Unsymmetrical tren-based ligands: synthesis and reactivity of rhenium complexes

Reaction of bis(2-aminoethyl)(3-aminopropyl)amine with C(6)F(6) and K(2)CO(3) in DMSO yields unsymmetrical [(C(6)F(5))HNCH(2)CH(2)](2)NCH(2)CH(2)CH(2)NH(C(6)F(5)) ([N(3)N]H(3)). The tetraamine acts as a tridentate ligand in complexes of the type H[N(3)N]Re(O)X (X = Cl 1, Br 2) prepared by reacting Re(O)X(3)(PPh(3))(2) with [N(3)N]H(3) and an excess of NEt(3) in THF. Addition of 1 equiv of TaCH(CMe(2)Ph)Br(3)(THF)(2) to 1 gives the dimeric compound H[N(3)N]ClReOReBrCl[N(3)N]H (3) in quantitative yield that contains a Re(V)[double bond]O[bond]Re(IV) core with uncoordinated aminopropyl groups in each ligand. Addition of 2 equiv of TaCH(CMe(2)Ph)Cl(3)(THF)(2) to 1 leads to the chloro complex [N(3)N]ReCl (4) with all three amido groups coordinated to the metal, whereas by addition of 2 equiv of TaCH(CMe(2)Ph)Br(3)(THF)(2) to 2 the dibromo species H[N(3)N]ReBr(2) (5) with one uncoordinated amino group is isolated. Reduction of 4 under an atmosphere of dinitrogen with sodium amalgam gives the dinitrogen complex [N(3)N]Re(N(2)) (6). Single-crystal X-ray structure determinations have been carried out on complexes 1, 3, 5, and 6.     

Synthesis and activity of ruthenium alkylidene complexes coordinated with phosphine and N-heterocyclic carbene ligands

This paper reports the synthesis and characterization of a variety of ruthenium complexes coordinated with phosphine and N-heterocyclic carbene (NHC) ligands. These complexes include several alkylidene derivatives of the general formula (NHC)(PR(3))(Cl)(2)Ru=CHR', which are highly active olefin metathesis catalysts. Although these catalysts can be prepared adequately by the reaction of bis(phosphine) ruthenium alkylidene precursors with free NHCs, we have developed an alternative route that employs NHC-alcohol or -chloroform adducts as "protected" forms of the NHC ligands. This route is advantageous because NHC adducts are easier to handle than their free carbene counterparts. We also demonstrate that sterically bulky bis(NHC) complexes can be made by reaction of the pyridine-coordinated precursor (NHC)(py)(2)(Cl)(2)Ru=CHPh with free NHCs or NHC adducts. Two crystal structures are presented, one of the mixed bis(NHC) derivative (H(2)IMes)(IMes)(Cl)(2)Ru=CHPh, and the other of (PCy(3))(Cl)(CO)Ru[eta(2)-(CH(2)-C(6)H(2)Me(2))(N(2)C(3)H(4))(C(6)H(2)Me(3))], the product of ortho methyl C-H bond activation. Other side reactions encountered during the synthesis of new ruthenium alkylidene complexes include the formation of hydrido-carbonyl-chloride derivatives in the presence of primary alcohols and the deprotonation of ruthenium vinylcarbene ligands by KOBu(t). We also evaluate the olefin metathesis activity of NHC-coordinated complexes in representative RCM and ROMP reactions.     

Synthesis and reactivity of ruthenium complexes with 1,1′-dithiolate ligands

Reactions of [Ru(PPh₃)₃Cl₂] with ROCS₂K in THF at room temperature and at reflux gave the kinetic products trans-[Ru(PPh₃)₂(S₂COR)₂] (R = ⁿPr 1, ⁱPr 2) and the thermodynamic products cis-[Ru(PPh₃)₂(S₂COR)₂] (R = ⁿPr 3, ⁱPr 4), respectively. Treatment of [RuHCl(CO)(PPh₃)₃] with ROCS₂K in THF afforded [RuH(CO)-(S₂COR)(PPh₃)₂] (R = ⁿPr 5, ⁱPr 6) as the sole isolable products. Reaction of [RuCl₂(PPh₃)₃] with tetramethylthiuram disulfide [Me₂NCS₂]₂ gave a Ru(III) dithiocarbamate complex, [Ru(PPh₃)₂(S₂CNMe₂)Cl₂] (7). This reaction involved oxidation of ruthenium(II) to ruthenium(III) by the disulfide group in [Me₂NCS₂]₂. Treatment of 7 with 1 equiv. of [M(MeCN)₄][ClO₄] (M = Cu, Ag) gave the stable cationic ruthenium(III)-alkyl complexes [Ru{C(NMe₂)QC(NMe₂)S}(S₂CNMe₂)(PPh₃)₂][ClO₄] (Q = O 8, S 9) with ruthenium-carbon bonds. The crystal structures of complexes 1, 2, 4·CH₂Cl₂, 6, 7·2CH₂Cl₂, 8, and 9·2CH₂Cl₂ have been determined by single-crystal X-ray diffraction. The ruthenium atom in each of the above complexes adopts a pseudo-octahedral geometry in an electron-rich sulfur coordination environment. The 1,1′-dithiolate ligands bind to ruthenium with bite S-Ru-S angles in the range of 70.14(4)-71.62(4)°. In 4·CH₂Cl₂, the P-Ru-P angle for the mutually cis PPh₃ ligands is 103.13(3)°, the P-Ru-P angles for other complexes with mutually trans PPh₃ ligands are in the range of 169.41(4)-180.00(6)°. The alkylcarbamate [C(NMe₂)QC(NMe₂)S]⁻ (Q = O, S) ligands in 8 and 9 are planar and bind to the ruthenium centers via the sulfur and carbon atoms from the CS and NC double bonds, respectively. The Ru-C bond lengths are 1.975(5) and 2.018(3) Å for 8 and 9·2CH₂Cl₂, respectively, which are typical for ruthenium(III)-alkyl complexes. Spectroscopic properties along with electrochemistry of all complexes are also reported in the paper.     

In vitro antitumor activity of water-soluble copper(I) complexes with diimine and monodentate phosphine ligands

Copper(I) complexes including diimine ligands of the bicinchoninic acid (BCA) and bathocuproinedisulfonic acid (BCS) families and water-soluble phosphines have been synthetized, characterized and investigated for their in vitro anticancer potential against human tumor cell lines representing examples of lung, breast, pancreatic and colon cancers and melanoma. All copper complexes exhibited moderate to high cytotoxic activity and the ability to overcome cisplatin resistance. Remarkably, growth-inhibitory effects evaluated in human non-transformed cells revealed a preferential cytotoxicity versus neoplastic cells. The remarkable cytotoxic effect towards BxPC3 pancreatic cancer cells, notoriously poor sensitive to cisplatin, was not related to a DNA or proteasome damage.     

Molybdenum amido complexes with single Mo-N bonds: synthesis,structure, and reactivity

Reactions of the complex [MoCl(eta(3)-C(3)H(4)-Me-2)(CO)(2)(phen)] (1) (phen=1,10-phenanthroline) with potassium arylamides were used to synthesize the amido complexes [Mo(N(R)Ar)(eta(3)-C(3)H(4)-Me-2)(CO)(2)(phen)] (R=H, Ar=Ph, 2 a; R=H, Ar=p-tolyl, 2 b; R=Me, Ar=Ph; 2 c). For 2 b the Mo-N(amido) bond length (2.105(4) A) is consistent with it being a single bond, with which the metal attains an 18-electron configuration. The reaction of 2 b with HOTf affords the amino complex [Mo(eta(3)-C(3)H(4)-Me-2)(NH(2)(p-tol))(CO)(2)(phen)]OTf (3-OTf). Treatment of 3-OTf with nBuLi or KN(SiMe(3))(2) regenerates 2 b. The new amido complexes react with CS(2), arylisothiocyanates and maleic anhydride. A single product corresponding to the formal insertion of the electrophile into the Mo-N(amido) bond is obtained in each case. For maleic anhydride, ring opening accompanied the formation of the insertion product. The reaction of 2 b with maleimide affords [Mo(eta(3)-C(3)H(4)-Me-2)[NC(O)CH=CHC(O)](CO)(2)(phen)] (7), which results from simple acid-base metathesis. The reaction of 2 b with (p-tol)NCO affords [[Mo(eta(3)-C(3)H(4)-Me-2)(CO)(2)(phen)](2)(eta(2)-MoO(4))] (8), which corresponds to oxidation of one third of the metal atoms to Mo(VI). Complex 8 was also obtained in the reactions of 2 b with CO(2) or the lactide 3,6-dimethyl-1,4-dioxane-2,5-dione. The structures of the compounds 2 b, 3-OTf, [Mo(eta(3)-C(3)H(4)-Me-2)[SC(S)(N(H)Ph)](CO)(2)(phen)] (4), [Mo(eta(3)-C(3)H(4)-Me-2)[SC(N(p-tol))(NH(p-tol))](CO)(2)(phen)] (5 a), and [Mo(eta(3)-C(3)H(4)-Me-2)[OC(O)CH=CHC(O)(NH(p-tol))](CO)(2)(phen)] (6), 7, and 8 (both the free complex and its N,N'-di(p-tolyl)urea adduct) were determined by X-ray diffraction.     

Synthesis and characterisation of nonclassical ruthenium hydride complexes containing chelating bidentate and tridentate phosphine ligands

The synthesis and characterisation of nonclassical ruthenium hydride complexes containing bidentate PP and tridentate PCP and PNP pincer-type ligands are described. The mononuclear and dinuclear ruthenium complexes presented have been synthesised in moderate to high yields by the direct hydrogenation route (one-pot synthesis) or in a two-step procedure. In both cases [Ru(cod)(metallyl)(2)] served as a readily available precursor. The influences of the coordination geometry and the ligand framework on the structure, binding, and chemical properties of the M--H(2) fragments were studied by X-ray crystal structure analysis, spectroscopic methods, and reactivity towards N(2), D(2), and deuterated solvents.     

Sterically variable dizinc complexes bearing bis(iminopyridyl)phenolate ligands: synthesis, structures and reactivity studies

A series of chiral dizinc complexes of the type [(2,6-{ArN=C(Me)C5H3N}2C6H3O)Zn2(micro-Cl)Cl2] [Ar=2,6-i-Pr2C6H3 (), 2,6-Me2C6H3 (), 2,4,6-Me3-C6H2 (), 2,4-Me2C6H3 ()] can be conveniently prepared in good yield by the template reaction of 2,6-{O=C(Me)C5H3N}2C6H3OH with an excess of the corresponding aniline and two equivalents of zinc dichloride in n-BuOH at elevated temperature. Alternatively, the pro-ligands, 2,6-{(ArN=C(Me)C5H3N}2C6H3OH [Ar=2,6-i-Pr2C6H3 (L1-H), 2,6-Me2C6H3 (L2-H), 2,4,6-Me3C6H2 (L3-H), 2,4-Me2C6H3 (L4-H)], can be isolated and then treated with two equivalents of zinc dichloride to afford . Interaction of with two equivalents of NaOAc in the presence of TlBF4 gives the diacetate-bridged salt [(L1)Zn2(micro-OAc)2](BF4) () while with Nadbm (dbm=dibenzoylmethanato) the bis(dbm)-chelated salt [(L1)Zn2(dbm)2](BF4) () is obtained. Hydrolysis occurs on reaction of with TlOEt to furnish [(L1)Zn2(micro-OH)Cl2] () as the only isolable product. Conversely, reaction of with Tlhp (hp=2-pyridonate) affords the neutral bis(pyridonate)-bridged trimetallic complex [(L1)Zn3(micro-hp)2Cl3] () as the major product along with as the minor one. Complex and mixtures of / act as modest activators for the ring-opening polymerisation of epsilon-caprolactone. Single crystal X-ray diffraction studies have been performed on , , , , and reveal Zn...Zn separations in the range: 3.069(4)-4.649(6) A.     

Ethylene polymerization of the new titanium complexes bearing a phosphine oxide‐bridged bisphenolato ligand

A series of novel titanium(IV) complexes combining a phosphine oxide‐bridged bisphenolato ligand TiCl₂{2,2′‐O?P‐R₃ (4‐R₂‐6‐R₁‐C₆H₂O)₂}(THF) ( 6a : R₁ = tBu, R₂ = H, R₃ = Ph; 6b : R₁ = Ph, R₂ = H, R₃ = Ph; 6c : R₁ = R₂ = tBu, R₃ = Ph; 6d : R₁ = R₂ = cumyl, R₃ = Ph; 6e : R₁ = tBu, R₂ = H, R₃ = PhF₅) were prepared by the reaction of corresponding bisphenolato ligands with TiCl₄ in THF. X‐ray analysis reveals that complex 6a adopts distorted octahedral geometry around the titanium center. These catalysts were performed for ethylene polymerization in the presence of modified methyaluminoxane (MMAO). The effects of reaction parameters on ethylene polymerization behaviors, such as cocatalyst concentration, polymerization temperature, and reaction time were studied in detail. In general, these new complexes exhibited high catalytic activity, good temperature tolerance, and long lifetime for ethylene polymerization. The resulting polymers possess high molecular weight, unimodal distribution, and linear structure. © Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7062–7073, 2008