Strong π-Interactions Between Tantalum and Apical Ligands in Square Pyramidal Complexes Supported by a Rigid Tetradentate Spectator Ligand; R. S. Morris and G. G. Lavoie Inorg. Chim. Acta 2015, 435, 1–6 (DOI: 10.1016/j.ica.2015.06.005)

​

Abstract. The synthesis of new tantalum(V) square pyramidal complexes supported by the tert-butyl-substituted (ethenediylidene)tetraphenoxide spectator ligand (TPO) and their reactivity are herein described. The tantalum ethoxide (TPO)Ta(OCH2CH3) (1) and dimethylamide (TPO)Ta(NMe2) (2) complexes were prepared and structurally characterised, giving valuable insight into -interactions between the metal centre and the apical ligand. The solid-state structures confirmed the geometry of both complexes, with TPO forming the base of the square pyramidal structure and the ethoxide and dimethylamide ligands occupying the apical position. Bond lengths and angles from the structures indicate significant double bond character between the metal and the apical ligand with very short metal–oxygen and metal–nitrogen bonds in 1 and 2, respectively, which results from donation of π-electron density from the heteroatom into empty metal d-orbitals. Reaction of (TPO)Ta(OCH2CH3) (1) and (TPO)Ta(NMe2) (2) with trimethylaluminum gave the methyl complex (TPO)Ta(CH3) (3). Complexes 1 and 2 were cleanly regenerated by addition of ethanol and dimethylamine to complex 3. Addition of strong Brønsted acids to these complexes gave mixtures of compounds that could not be characterised, possibly due to competing protonation of the spectator TPO ligand or formation of oligomeric species.

​

​

​

​

​

​

​

​

​

​

​

​

​

​​

 

​

​

Density Functional Theory Study of Bis(Imino) N-Heterocyclic Carbene Iron(II) Complexes; J. Al Thagfi and G. G. Lavoie Can. J. Chem. 2014, 92(10), 925–931 (DOI: 10.1139/cjc-2014-0022)

 

⭐︎ invited contribution in honour of Prof. Barry Lever’s contribution to the field of inorganic chemistry ⭐︎

​

Abstract. Density functional theory calculations at the B3LYP/DGDZVP and UB3LYP/TZVP levels were performed on 1,3-bis[1-(2,6-dimethylphenyl-imino)ethyl]imidazolium and on the corresponding imidazol-2-ylidene iron(II) dichloride complex, respectively. The resulting geometrical parameters of the optimized structures were in good agreement with previously reported X-ray structures. The ground state for the high-spin (quintet multiplicity) iron complex is 82.4 kJ/mol lower in energy compared to the low-spin (triplet) configuration, in agreement with magnetic susceptibility measurements. Further calculations were carried out on related benzimidazol-2-ylidene and pyrimidin-2-ylidene ligands, and on the corresponding iron complexes to gain insight into their electronic properties and reactivities. The energy of the highest occupied and lowest unoccupied molecular orbitals of all three carbenes suggests that the pyrimidin-2-ylidene and the benzimidazol-2-ylidene are the best σ-donor and best π-acceptor, respectively. Using those results, the metal center in the pyrimidin-2-ylidene iron dichloride complex was predicted to bear the highest electron density. This was supported by the high relative energy of its HOMO, compared to that of the corresponding imidazol-2-ylidene and benzimidazol-2-ylidene iron complexes. The electrostatic potential maps of all three metal complexes furthermore indicated a marked decrease in electron density for the coordinated imine group, supporting a greater reactivity towards nucleophiles.

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

Reactivity Study of Low-Coordinate Phosphaalkene IMes=PPh with Grubbs first-generation ruthenium benzylidene complexes; T. G. Larocque and G. G. Lavoie New J. Chem. 2014, 37, 499–502. (DOI: 10.1039/c3nj01416a)

​

Abstract. Reaction of IMes=PPh with RuCl2L2(CHPh) (L = PPh3 and PCy3) gave complexes with selectivity that is dependent on the metal precursor used. RuCl2(IMes=PPh)(PPh3)(CHPh), which adopts the rare cis chloride configuration, was inactive in ring-opening metathesis of diallyl sulfide. In contrast, the PCy3 analogue could not be isolated, and in fact led to an unusual decomposition product with two C–H activations.

​

​

​

​

​

​

​

​

​

 

​
 

 

Formation of a Dicationic Ruthenium Benzyl Complex by Halide Abstraction from a Grubbs-type Second-Generation Benzylidene; T. G. Larocque, A. C. Badaj and G. G. Lavoie Dalton Trans. 2013, 42, 14955–14958. (DOI: 10.1039/c3dt52357h)

​

Abstract. A new ruthenium benzylidene complex with a neutral bidentate N-heterocyclic carbene was prepared and evaluated in ring-closing metathesis of diallyl substrates. Addition of silver hexafluorophosphate caused degradation of the ruthenium complex through a new pathway to give an inactive benzyl complex. This degradation likely results from nucleophilic attack of the NHC ligand on the benzylidene carbon rendered more electrophilic through less 𝜋-backdonation from the cationic metal center. Minimizing formation of electron-poor alkylidene could be thus critical in future efforts to improve the lifetime of Grubbs-type second-generation catalysts.

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

Reactivity Study of Imino-N-Heterocyclic Carbene Palladium(II) Methyl Complexes; A. C. Badaj and G. G. Lavoie Organometallics 2013, 32, 4577–4590. (DOI: 10.1021/om400533d)

​

Abstract. Neutral and cationic palladium(II) complexes containing three different heteroditopic bis(aryl)-substituted imino-N-heterocyclic carbene ligands have been synthesized and structurally characterized. Modifications made to the substituent at the iminic carbon allow for independent tuning of the steric and electronic environment around the metal center. The nature of this substituent profoundly affects the thermal stability of the neutral palladium complexes. While the tert-butyl derivative decomposes at 60 °C over a period of 24 h to give the corresponding 1-mesityl-2-methyl-1H-imidazole and the corresponding imidoyl chloride as the major products, the phenyl and methyl analogues show no sign of decomposition. Likewise, the corresponding cationic complexes of all three carbene derivatives are stable under the same conditions, with no evidence of decomposition. While inactive for ethylene polymerization, these palladium methyl complexes react with CO and isocyanides to form a variety of products, including structurally-characterized simple adducts, and single and multiple insertion products.

​

​

​

​

​

​

​

​

​

​

Coordination and Reactivity Study of Titanium and Zirconium Complexes of the First Imidazol-2-imine Ethenolate Ligand; T. G. Larocque, S. Dastgir and G. G. Lavoie Organometallics 2013, 32, 4314–4320 (DOI: 10.1021/om4004708).

​

​Abstract. The synthesis and structural characterization of group 4 transition metal complexes bearing a novel imidazol-2-imine enolate ligand with different electronic properties are reported. X-ray crystallographic studies of a cyclopentadienyl zirconium complex confirmed the coordination motif of the ligand through the imine nitrogen and ethenolate oxygen atoms, yielding a new class of formally four-electron donor monoanionic bidentate ligands. The activity of the corresponding titanium(IV) and zirconium(IV) complexes in ethylene polymerization were assessed, resulting in activities up to 170 kg PE mol–1 h–1

​

​

 

 

 

 

 

 

 

 

 

 

 

​

Coordination and Reactivity Study of Group 4 and 10 Transition Metal Complexes of N-Imidazol-2-ylidene-N'-p-tolylureate and Thioureate Ligands; M. B. Harkness, E. Alvarado, A. C. Badaj, L. Fan and G. G. Lavoie Organometallics 2013, 32, 3309–3321. (DOI: 10.1021/om400220v)

​

Abstract. The synthesis and isolation of N-imidazol-2-ylidene-N'-p-tolylureate and thioureate proligands is described. Titanium(IV), nickel(II) and palladium(II) complexes containing one or two equivalents of the ligand were prepared by transmetalation of the ureate or thioureate salts. The X-ray structure of titanium complexes corroborated our prediction based on spectroscopic data and showed the ureate binds in a bidentate fashion through the oxygen and nitrogen atoms of the isocyanate building block, leaving the imidazol-2-imine fragment uncoordinated. Carbon–nitrogen bond lengths indicate substantial electron delocalization from the imidazole ring to the ureate group. In contrast, the ligand adopts a different coordination mode and binds to nickel and palladium through the Nimidazol-2-ylidene and Np-tolyl atoms. Surprisingly, despite the softer nature of sulfur, coordination of the thioureate was exclusively through the sulfur and nitrogen atoms of the isothiocyanate building block with all three metals studied. All complexes were tested for ethylene polymerization at ambient conditions using methylaluminoxane as cocatalyst. Titanium(IV) complexes were found to be the most active, with activities up to 60 kg PE mol–1 catalyst h–1.​

 

 

 

​

​

​

​

​

​

​

​

​

Preparation and Reactivity Study of 1,3-Bis(imino)benzimidazol-2-ylidene and 1,3-Bis(imino)pyrimidin-2-ylidene Chromium(III), Iron(II) and Cobalt(II) Complexes; J. Al Thagfi and G. G. Lavoie Organometallics 2012, 31, 7351–7358. (DOI: 10.1021/om300873k)

​

⭐︎ This manuscript was one of the Top 20 most downloaded articles from Organometallics in

October 2012 ⭐︎

​

Abstract. Chromium(III), iron(II) and cobalt(II) complexes of bis(imino)benzimidazol-2-ylidene and bis(imino)pyrimidin-2-ylidene were successfully prepared by reaction of either the benzimidazolium or pyrimidinium salts, or the corresponding copper complexes with the respective metal halide. X-ray diffraction analysis of the Cr(III) complex of the pyrimidin-2-ylidene ligand demonstrated, for the first time, the ability of bis(imino)carbene-type ligands to coordinate to metal centers in a tridentate fashion. The coordination mode of these ligands was surprisingly highly dependent on the nature of both the metal and the ligand itself. The activity of these complexes in ethylene polymerization was assessed at ambient conditions (room temperature and 1 atm C2H4) using methylaluminoxane as cocatalyst. In contrast to the iron and cobalt complexes, both chromium complexes were active in ethylene polymerization.​

​

​

​

​

​

​

​

​

​

​

​

​

​

N-Heterocyclic Carbenes and Imidazole-2-Thiones as Ligands for The Gold(I) Catalysed Hydroamination of Phenylacetylene; E. Alvarado, A. C. Badaj, T. G. Larocque and G. G. Lavoie Chem. Eur. J. 2012, 18, 12112–12121. (DOI: 10.1002/chem.201201448)

​

Abstract. Gold(I) complexes of 1-(1-(2,6-dimethylphenylimino)-alkyl)-3-(mesityl)imidazol-2-ylidene (C^ImineR), 1,3-dimesitylimidazol-2-ylidene (IMes), and of the corresponding thione derivatives (S^ImineR and IMesS) were prepared and structurally characterised. The solid-state structure of the C^ImineR and S^ImineRgold(I) complexes showed monodentate coordination of the ligand with a dangling imine group that can possibly bind reversibly to the metal centre to stabilise otherwise unstable catalytic intermediates. Interestingly, reaction of C^IminetBu with AuCl(SMe2) led to the formation of (C^IminetBu)AuCl, which rearranges upon crystallisation to the unusual complex cation (C^IminetBu)2Au+, with AuCl2– as the counteranion. The activity of the gold complexes in the hydroamination of phenylacetylene with substituted anilines were tested and compared to other control catalyst systems. The best catalyst performance was obtained with (C^IminetBu)AuCl, with the exclusive formation of the Markovnikov addition product in excellent yield (>95%) regardless of the substituents on the aniline.​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

Titanium(IV) Imido Complexes of Imine Imidazole-2-Imine Ligands; S. Dastgir and G. G. Lavoie Dalton Trans. 2012, 41, 9651–9658. (DOI: 10.1039/c2dt31004j)

​

Abstract. Free imine imidazol-2-imine ligands with two different substitution patterns have been isolated for the first time and they were found to exist as an equilibrium mixture of geometric and mesomeric isomers. The relative ratios of these isomers are dependent on both the nature of the substituents and of the solvent. The synthesis of the titanium(IV) alkyl and arylimido complexes of these ligands was unexpectedly found to be very selective and was successfully achieved only with the lesser sterically-demanding 2,4,6-trimethylphenyl derivative IMesN^Imine. The solid-state structure of the alkylimido complex further confirms the zwitterionic character of the ligand. The isolated titanium imido complexes were found to be active catalysts for the polymerisation of ethylene.

​

​

 

 

 

 

 

 

 

 

 

 

 

 

​

Coordination and Reactivity Study of Titanium Phenoxo Complexes Containing a Bulky Bidentate Imino-N-Heterocyclic Carbene Ligand; T. G. Larocque and G. G. Lavoie J. Organometal. Chem. 2012, 715, 26–32. (DOI: 10.1016/j.jorganchem.2012.05.018)

​

Abstract. The synthesis and structural characterisation of early transition metal complexes containing the aryl-substituted acyclic imino-N-heterocyclic carbene ligand are reported. X-ray crystallographic studies of titanium phenoxo complexes confirmed that the NHC ligand coordinates through the carbenoid carbon and the imine nitrogen atoms to form an octahedral complex. NMR spectroscopic analyses revealed restricted rotation about the aryl bonds. Attempts to prepare the corresponding titanium imido complex repeatedly led to decomposition products, presumably due to the enhanced reactivity of the imine group resulting in its cleavage from the C^Imine ligand scaffold. The catalytic activities of the phenoxo complexes towards ethylene polymerisation were assessed.​

​

​

​

​

​

​

​

​

​

​

Synthesis, Characterization and Ethylene Polymerization Studies of Chromium, Iron, and Cobalt Complexes Containing 1,3-bis(Imino)-N-Heterocyclic Carbene Ligands; J. Al Thagfi and G. G. Lavoie Organometallics 2012, 31, 2463–2469. (DOI: 10.1021/om3001058)

​

⭐︎ This manuscript was one of the Top 20 most downloaded articles from Organometallics in March 2012 ⭐︎

​

Abstract. New chromium(III), iron(II) and cobalt(II) complexes of acyclic 1,3-bis[(2,6-dimethylphenylimino)ethyl and benzyl]imidazol-2-ylidene were prepared from the corresponding silver or copper adduct as transmetalating agent, or from in situ deprotonation of the parent imidazolium salt. The catalytic activities of all three complexes were evaluated for ethylene polymerization at atmospheric pressure and room temperature with activation by methylaluminoxane. The Cr(III) complexes were found to be the most active with a rate of 35 kg PE mol–1 Cr h–1. ​

​

​

​

​

​

​

​

​

​

​

​

​

Synthesis and Structural Characterization of Nickel(II) Complexes with Imino-N-Heterocyclic Carbene Heteroditopic Ligands; A. C. Badaj and G. G. Lavoie Organometallics 2012, 31, 1103–1111. (DOI: 10.1021/om2011485)

​

Abstract. Two different heteroditopic bis(aryl)-substituted imino-N-heterocyclic carbene ligands were coordinated to nickel using new copper carbene dimers as transmetalating agents. The oxidative addition of an imidazolium salt precursor with Ni(COD)2 led to the unexpected bis(carbene)NiCl2 complex, presumably through a putative nickel hydride intermediate. All new complexes were isolated in good yield and were structurally characterized. The size of the iminic carbon substituent was found to have a profound impact on the bond angles and bond lengths about the metal center. All nickel complexes were tested for ethylene polymerization activity at standard temperature and pressure and were found to be inactive. ​

​

​

​

​

​

​

​

​

​

​

​

​

​

Synthesis of Vicinal Diamino-endo,cis-norbornene Derivatives; D. Hossain and G. G. Lavoie Synth. Commun. 2012, 42, 1200–1210. (DOI: 10.1080/00397911.2010.537426)

​

Abstract. The synthesis of 2,3-disubstituted-endo,cis-norborn-5-ene derivatives is described. Cyclic ureas and cis vicinal diamines substituted with p-tolyl and perfluorophenyl rings were prepared. The use of potassium carbonate as an innocuous CO source for the formation of a cyclic urea was demonstrated.​

​

​

​

​

​

​

​

​

New Stable Aryl-Substituted Acyclic Imino-N-Heterocyclic Carbene: Synthesis, Characterisation and Coordination to Early Transition Metals; T. G. Larocque, A. C. Badaj, S. Dastgir and G. G. Lavoie Dalton Trans. 2011, 40(47), 12705–12712. (DOI: 10.1039/c1dt11565k)

​

Abstract. The synthesis of the bulky 1-(1-aryl-2,2-dimethylpropyl)-3-(aryl)imidazolium salt from the corresponding imidazole and the activated imidoyl chloride is presented. The absence of acidic protons adjacent to the iminic carbon allowed for the first isolation of an imino-N-heterocyclic carbene of this ligand class. The free carbene was isolated, structurally characterised, and coordinated to titanium, zirconium, hafnium and chromium. The resulting metal halide complexes were fully characterised and were tested at room temperature and atmospheric pressure for their activity as ethylene polymerisation catalysts. The Zr(IV) complex was found to be the most active with a productivity of 140 kg PE · mol M–1 · h–1.​

​

​

 

 

 

​

​

​

​

Coordination Study of a New Class of Bidentate Imidazol-2-imine Imine Ligands to Titanium(IV) and Palladium(II); S. Dastgir and G. G. Lavoie Dalton Trans. 2010, 39, 6943–6946. (DOI: 10.1039/c0dt00498g)

​

Abstract. A new family of ligand precursors, N-(1-(2,6-dimethylphenylimino)ethyl)-1,3-bis(aryl)imidazol-2-imine hydrochloride, wherein aryl = 2,4,6-trimethylphenyl (3a) and 2,6-diisopropylphenyl (3b), was prepared and structurally characterised. Deprotonation of the salts yields molecules with delocalised-electrons, leading to zwitterionic mesomeric structures. Titanium(IV) (4a,b) and palladium(II) (5a,b) complexes were isolated and also structurally characterised. Two different coordination modes were observed where the ligand is either coordinated in a bidentate fashion as expected, or in a monodentate fashion through the more basic aryliminic nitrogen atom.​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

Synthesis and Structural Characterization of the First Copper(I) Complexes with bis(Imino)-N-Heterocyclic Carbene NCN Pincer Ligands; J. Al Thagfi, S. Dastgir, A. J. Lough, G. G. Lavoie Organometallics 2010, 29, 3133–3138. (DOI: 10.1021/om100321n) 

​

⭐︎ This manuscript was highlighted online by the editorial staff of Organometallics ⭐︎

​

Abstract. A new class of bis(acyclic imino)-N-heterocyclic carbene (NCN pincer) ligand precursors was synthesized and structurally characterized. In situ deprotonation using a basic metal precursor resulted in the corresponding copper(I) complexes in good yields. Monometallic and bimetallic structures were observed in the solid state depending on the ligand substitution pattern.​

​

​

​

​

​

​

​

​

​

​

First aryl-substituted acyclic imino-N-heterocyclic carbene ligand precursor: synthesis, characterization and coordination with silver(I) and copper(I); A. C. Badaj, S. Dastgir, A. J. Lough, G. G. Lavoie Dalton Trans. 2010, 39, 3361–3365. (DOI: 10.1039/c002234a)

​

Abstract. The first aryl-substituted imino-N-heterocyclic ligand precursor was prepared and structurally characterised, along with the corresponding silver(I) and copper(I) chloride complexes. An unusual T-shape coordination mode about the copper centre was observed.​

​

​

​

​

​

​

​

​

​

​

​

​

Formation of planar-chiral alkylphosphine- and aniline-substituted cyclopentadienyl metal complexes and their reactivity toward electrophiles; S. N. Paisner, G. G. Lavoie, R. G. Bergman Inorg. Chim. Acta 2002, 334, 253–275. (DOI: 10.1016/S0020-1693(02)00742-9)

​

​Abstract. A wide range of transition metal complexes containing aniline- and alkylphosphine-substituted cyclopentadi-enyl ligands have been synthesized: CpPIr(CH3)2 (5), CpPIr(H)(Li) (11a,b), CpPIr(H)(Sn(C6H5)3) (13a,b) (CpP =1-(2-dimethylphosphino-1,1-dimethylethyl)-3-tert-butylcyclo-pentadienyl), CpNIr(C2H4)2 (7), CpNIrI2 (8), CpNIr(O3SCF3)2 (9), CpN(P(CH3)3)IrI2 (10), CpN(P(CH3)3)IrH2 (2), CpN(P(CH3)3)Ir(H)(Li) (15a,b), CpN(P(CH3)3)Ir(H)(Sn(C6H5) (16a,b) (CpN =1-(2-dimethylamino)phenyl-3-tert-butylcyclopentadienyl), CpPZrCl3 (18), CpPZr(CH2Ph)3 (23), CpPZr(CH2Ph)2Cl (20), [(CpP)TiCl3]2 (22), CpNCp’ZrCl2 (Cp’ = Cp (23), Cp* (24)), and CpPCp’ZrCl2 (Cp’ = Cp (25), Cp* (26). The presence of the planar-chiral CpP and CpN ligands dramatically changes the reactivity at the metal center in comparison to that of the analogous unchelated and achiral pentamethylcyclopentadienyl (Cp*) complexes. Lithium salts 11 and 15 were obtained by deprotonation of dihydride 2 and the earlier prepared dihydride CpPIrH2 (1) with tert-butyllithium; these reactive species show diastereoselectivity in their reactions with Ph3SnCl to form 13a,b and 16a,b, respectively. One enantiomer of diiodide 3 was found to react selectively with (R)-binaphthol to form (R,R)-CpPIr(binaphtholate) (17a) leaving (S)-3 unreacted. Attempts to separate the enantiomers of 3 and 17a were unsuccessful, however, due to the lack of difference in their solubility. DFT calculations carried out on the two possible diastereomers 17a and 17b correctly predict the exclusive formation of 17a. The zirconium and titanium complexes catalyze the polymerization of ethylene to polyethylene and propylene to isotactic polypropylene in the presence of MAO co-catalyst. Compounds 24 and 26 can be methylated to form Cp’Cp*Zr(CH3)2 (Cp’ = CpN (27), CpP (28)).

​

​

​

​

​

​

​

​

​

​

​

​

​

​

Synthesis of Novel Group 4 Complexes Bearing the Tropidinyl Ligand: Investigations of Dynamic Behavior, Reactivity, and Catalytic Olefin Polymerization; S. J. Skoog, C. Mateo, G. G. Lavoie, F. J. Hollander, R. G. Bergman Organometallics 2000, 19(7), 1406–1421. (DOI: 10.1021/om000038k)

​

Abstract. A new class of group 4 complexes bearing the tropidinyl (Trop) ligand were synthesized. This novel anionic ligand, easily derived from the natural product tropine, is regarded as an analogue of the well-studied Cp ligand (Cp ) cyclopentadienyl) and features a bicyclic ring system in which an allyl function donates 4π electrons and an amine function donates 2σ electrons to the metal center. The synthesis of the group 4 complexes involved transmetalation of a stannylated allyl functionality with a group 4 metal halide with concomitant elimination of Me3SnCl. Reaction of endo-stannylated tropidine (1) and ZrCl4, CpZrCl3, or CpTiCl3 afforded the complexes (Trop)2ZrCl2 (2), (Cp)(Trop)ZrCl2 (3), and (Cp)- (Trop)TiCl2 (4), respectively. These dihalide complexes were alkylated using methyllithium to generate (Trop)2ZrMe2 (5), (Cp)(Trop)ZrMe2 (6), (Cp)(Trop)TiMe2 (7), or benzylmagnesium chloride to give (Trop)2ZrBn2 (8) and (Cp)(Trop)ZrBn2 (9). Complexes 2, 3, 5, and 8 were characterized by X-ray crystallography. Complexes 5 and 6 were observed to undergo protonolysis with various acids (HA) to give mixed [Zr]MeA complexes. Reaction of complex 6 with isonitriles (ArNC) gave the η2-iminoacyl complex (Cp)(Trop)ZrMe[N(Ar)CMe] (13), whose structure was confirmed by X-ray crystallography. All the complexes displayed dynamic behavior, and the various exchange processes were investigated by variable-temperature NMR spectroscopy. The dihalide complexes 2, 3, and 4 in the presence of modified methylaluminoxane (MMAO) were active catalysts for the polymerization of ethylene. The catalyst system 3/MMAO displayed a very high ethylene polymerization activity and was similar to that observed for Cp2ZrCl2/MMAO. High molecular weight polypropylene was generated using 4/MMAO, and polypropylene oligomer was obtained using 3/MMAO. The cationic complex [(Cp)(Trop)ZrMe][MeB(C6F5)3] (14) was formed upon reaction of the dimethyl complex 6 with B(C6F5)3 and was shown to be an active ethylene polymerization catalyst.​

​

​

​

​

​

​

​

​

​

​

​

​

Synthesis, Structural Characterization, and Reactivity of Novel Zirconium(IV) Complexes Containing the Tropidinyl Ligand; G. G. Lavoie, R. G. Bergman Angew. Chem., Int. Ed. Engl. 1997, 36(22), 2450–2452. (DOI: 10.1002/anie.199724501)

​

​⭐︎ This manuscript made the front cover of the Communications section of Angew. Chem., Int. Ed. Engl. ⭐︎

​

Abstract. The tropidinyl (trop) group is a novel ligand that is isoelectronic with cyclopentadienyl (Cp), and is derived from a readily available natural product. It can be used to synthesize zirconium complexes that are analogous to metallocenes. When activated with methylaluminoxanes, they function as catalysts for ethylene polymerization. More about the synthesis and properties of this new class of complexes is reported.

​

​

​

​

​

​

​

​

​

​

​

​

Electroluminescence from New Polynorbornenes that Contain Blue-Light-Emitting and Charge-Transport Side Chains; T. J. Boyd, Y. Geerts, J.-K. Lee, D. E. Fogg, G. G. Lavoie, R. R. Schrock, M. F. Rubner Macromolecules 1997, 30(12), 3553–3559. (DOI: 10.1021/ma961613s) 

​

Abstract. A blue-light-emitting electroluminescent polymer was prepared by ring-opening metathesis polymerization (ROMP) of a norbornene monomer that contains a diphenylanthracene chromophore as a side chain (λmax,em ) 450 nm). Norbornene monomers also were synthesized that contain an oxadiazole (for electron transport) or a tertiary arylamine (for hole transport). Oligomers (25mers or 50mers) of homo- and copolymers (Mw/Mn ) 1.02–1.08) were prepared in toluene in 95–98% yield, employing Mo(N-2,6-C6H3-i-Pr2)(CHMe2Ph)(O-t-Bu)2 as the initiator. Electroluminescent devices made with a single layer of substituted polynorbornene, an ITO anode, and an Al cathode were prepared first. Two-layer devices were then constructed in which the substituted polynorbornene was spin cast onto a 25-bilayer poly(phenylenevinylene) (PPV) heterostructure. The two-layer device performed best in terms of efficiency, light output, and threshold voltage.​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

 

​

Ring-Opening Metathesis Polymerizations with Binaphtholate or Biphenolate Complexes of Molybdenum; K. M. Totland, T. J. Boyd, G. G. Lavoie, W. M. Davis, R. R. Schrock, Macromolecules 1996, 29(19), 6114–6125. (DOI: 10.1021/ma960351r)

​

​Abstract. Several racemic or enantiomerically pure complexes of the general type Mo(CHR)(NR′)(O2R") that contain binaphtholate or biphenolate (O2R") ligands have been prepared and employed to ring open several achiral, racemic, or enantiomerically pure norbornenes and norbornadienes. A bimodal molecular weight distribution sometimes results from polymerization of an enantiomerically pure monomer with a racemic initiator as a consequence of a different rate of chain growth from enantiomeric metal centers. The analogous polymerization of an enantiomerically pure monomer with an enantiomerically pure initiator yields only a single polymer chain, as expected. Evaluation of the cis content of the resulting polymers suggests that cis polymer results from polymerization via syn alkylidene propagating species and that accessibility of the anti rotamer on the polymerization time scale is determined by a subtle combination of steric bulk in the biphenoxide and imido ligands. All cis polymers were found to be highly isotactic. The X-ray structures of two catalytically active species are also described. One is a THF adduct of 3,3′-diphenyl-2,2′-diolate-1,1′-dinaphthyl (anti rotamer) while the other is a base-free syn species that contains the 6,6′-dimethyl-3,3′,5,5′-tetra-tert-butyl-1,1′-biphenyl-2,2′-diolate ligand.

 

​

​

​

​

​

​

​

​

​

​

​

​

​​

Optimized Liquid-Phase Oxidation; A. G. Wonders, G. G. Lavoie, C. E. Sumner, Jr., B. W. Davenport, M. de Vreede, B. A. Tennant US 7,608,732 B2, 69 pp. October 27, 2009.

​

Optimized Liquid-Phase Oxidation; A. G. Wonders, G. G. Lavoie, C. E. Sumner, Jr. US 7,582,793 B2, 67 pp. September 1, 2009.

​

Processes for Producing Aromatic Dicarboxylic Acids; G. G. Lavoie, R. T. Hembre, C. E. Sumner, Jr., J. N. Bays, D. B. Compton, B. A. Tennant, B. W. Davenport, D. Lange, T. R. Floyd US 7,550,627 B2, 11 pp. June 23, 2009.

​

Optimized Liquid-Phase Oxidation; A. G. Wonders, G. G. Lavoie, C. E. Sumner, Jr. US 7,361,784 B2, 67 pp. April 22, 2008.

​

Liquid Phase Oxidation of p-Xylene to Terephthalic Acid in the Presence of a Catalyst System Containing Nickel, Manganese and Bromine Atoms; G. G. Lavoie US 7,348,452 B2, 8 pp. March 25, 2008.

​

Catalysts Containing N-Pyrrolyl Substituted Nitrogen Donors; L. S. Moody, P. B. Mackenzie, C. M. Killian, G. G. Lavoie, J. A. Ponasik, Jr., A. G. M. Barrett, T. W. Smith, J. C. Pearson US 7,319,084 B2, 74 pp. Jan. 15, 2008.

​

Catalysts Containing per-ortho Aryl Substituted Aryl or Heteroaryl Substituted Nitrogen Donors; L. S. Moody, P. B. Mackenzie, C. M. Killian, G. G. Lavoie, J. A. Ponasik, Jr., T. W. Smith, J. C. Pearson, A. G. M. Barrett US 6,946,532 B2, 17 pp., 20 Sept. 2005.

​

Catalysts Containing per-ortho Aryl Substituted Aryl or Heteroaryl Substituted Nitrogen Donors; L. S. Moody, P. B. Mackenzie, C. M. Killian, G. G. Lavoie, J. A. Ponasik, Jr., T. W. Smith, J. C. Pearson, A. G. M. Barrett US 6,844,446 B2, 17 pp., 18 Jan. 2005.

​

Catalysts Containing N-Pyrrolyl Substituted Nitrogen Donors; L. S. Moody, P. B. Mackenzie, C. M. Killian, G. G. Lavoie, J. A. Ponasik, Jr., A. G. M. Barrett, T. W. Smith, J. C. Pearson, US 6,825,356 B2, 72 pp., 20 Nov. 2005.

​

Supported Group 8–10 Transition Metal Olefin Polymerization Catalysts; P. B. Mackenzie, L. S. Moody, C. M. Killian, G. G. Lavoie, US 6,822,062 B2, 39 pp., 23 Nov. 2004.

​

Supported Group 8–10 Transition Metal Olefin Polymerization Catalysts; P. B. Mackenzie, L. S. Moody, C. M. Killian, G. G. Lavoie, US 6,660,677 B1, 45 pp., 9 Dec. 2003.

​

Mixed Olefin Polymerization Catalysts Processes Employing such Catalysts, and Polymers Obtained Therefrom; C. M. Killian, P. B. Mackenzie, G. G. Lavoie, J. A. Ponasik, Jr., L. S. Moody US 6,620,896 B1, 11 pp., 16 Sept. 2003.

​

Olefin Polymerization Processes Using Supported Catalysts; G. G. Lavoie, P. B. Mackenzie, C. M. Moore, T. W. Smith US 6,605,677 B2, 18 pp., 12 Aug. 2003.

​

Catalysts Containing per-ortho Aryl Substituted Aryl or Heteroaryl Substituted Nitrogen Donors, L. S. Moody, P. B. Mackenzie, C. M. Killian, G. G. Lavoie, J. A. Ponasik, Jr., T. W. Smith, J. C. Pearson, A. G. M. Barrett US 6,579,823 B2, 19 pp., 17 June 2003.

​

Catalysts Containing N-Pyrrolyl Substituted Nitrogen Donors; L. S. Moody, P. B. Mackenzie, C. M. Killian, G. G. Lavoie, J. A. Ponasik, Jr., A. G. M. Barrett, T. W. Smith, J. C. Pearson, US 6,559,091 B1, 71 pp., 6 May 2003.

​

Catalysts Containing N-Pyrrolyl Substituted Nitrogen Donors; L. S. Moody, P. B. Mackenzie, C. M. Killian, G. G. Lavoie, J. A. Ponasik, Jr., T. W. Smith, J. C. Pearson, A. G. M. Barrett, G. W. Coates, US 6,545,108 B1, 82 pp., 8 April 2003.

​

Copolymerization of Norbornene and Functional Norbornene Monomers, C. M. Killian, P. B. Mackenzie, J. A. Hyatt, L. S. Moody, G. G. Lavoie, US 6,538,085 B2, 23 pp., 25 March 2003.

​

Copolymerization of Norbornene and Functional Norbornene Monomers, G. G. Lavoie, P. B. Mackenzie, US 6,512,065 B2, 13 pp., 28 Jan. 2003.

​

Copolymerization of Norbornene and Functional Norbornene Monomers, G. G. Lavoie, P. B. Mackenzie, US 6,395,851 B1, 8 pp., 28 May 2002.

​

Copolymerization of Norbornene and Functional Norbornene Monomers, C. M. Killian, P. B. Mackenzie, J. A. Hyatt, L. S. Moody, G. G. Lavoie, US 6,350,837 B1, 16 pp., 26 Feb. 2002.

​

Olefin Polymerization Catalysts Containing Group 8–10 Transition Metals, Processes Employing such Catalysts and Polymers Obtained Therefrom, P. B. Mackenzie, L. S. Moody, C. M. Killian, J. A. Ponasik, Jr., J. P. McDevitt, G. G. Lavoie, US 6,303,720 B1, 60 pp., 16 Oct. 2001.

​

Olefin Oligomerization and Polymerization Catalysts, G. G. Lavoie, J. A. Ponasik, Jr., C. M. Killian, L. S. Moody, P. B. Mackenzie, US 6,281,303 B1, 21 pp., 28 Aug. 2001.

​

Catalyst Composition for the Polymerization of Olefins, J. A. Ponasik, Jr., J. P. McDevitt, C. M. Killian, P. B. Mackenzie, L. S. Moody, G. G. Lavoie, US 6,200,925 B1, 30 pp., 13 March 2001.

​

Olefin Polymerization Catalysts Containing Group 8–10 Transition Metals, Processes Employing such Catalysts and Polymers Obtained Therefrom, P. B. Mackenzie, L. S. Moody, C. M. Killian, J. A. Ponasik, Jr., J. P. McDevitt, G. G. Lavoie, US 6,103,658, 52 pp., 15 Aug. 2000.

 

 

 

​

​

 

Prof. Lavoie is an inventor on over 16 PCT world patent applications. More than 24 US applications have published from the time the US Patent and Trademark Office (USPTO) started publishing applications in 2002. Recently published applications are listed below. The applications numbers of other ones are listed for convenience.

​

Catalysts Containing N-Pyrrolyl Substituted Nitrogen Donors, L. S. Moody, P. B. Mackenzie, C. M. Killian, G. G. Lavoie, J. A. Ponasik, Jr., A. G. M. Barrett, T. W. Smith, J. C. Pearson, US Appl. 2006/0178490 A1, 76 pp., filed March 21, 2006. (E.I. DuPont de Nemours)

​

Processes for Producing Aromatic Dicarboxylic Acids, G. G. Lavoie, R. T. Hembre, C. E. Sumner, Jr., J. N. Bays, D. B. Compton, B. W. Davenport, D. Lange, T. R. Floyd, PCT Int. Appl. 2006/096312 A1, 31 pp., filed February 21, 2006. (Eastman Chemical Company)

​

Processes for Producing Aromatic Dicarboxylic Acids, G. G. Lavoie, R. T. Hembre, C. E. Sumner, Jr., J. N. Bays, D. B. Compton, B. A. Tennant, B. W. Davenport, D. Lange, T. R. Floyd, S. A. Schunk, O. Busch, PCT Int. Appl. 2006/096313 A1, 27 pp., filed February 21, 2006. (Eastman Chemical Company)

​

Processes for Producing Terephthalic Acid, C. E. Sumner, Jr., R. T. Hembre, D. Lange, G. G. Lavoie, B. A. Tennant, T. R. Floyd, B. W. Davenport, D. B. Compton, J. N. Bays, PCT Int. Appl. 2006/096311 A1, 46 pp., filed February 21, 2006. (Eastman Chemical Company)

​

Optimized Liquid-Phase Oxidation, A. G. Wonders, G. G. Lavoie, C. E. Sumner, Jr., PCT Int. Appl. 2006/028874 A1, filed August 29, 2005. (Eastman Chemical Company)

​

Optimized Liquid-Phase Oxidation, A. G. Wonders, G. G. Lavoie, C. E. Sumner, Jr., PCT Int. Appl. 2006/028769 A2, 179 pp., filed August 29, 2005. (Eastman Chemical Company)

​

Optimized Liquid-Phase Oxidation, A. G. Wonders, G. G. Lavoie, C. E. Sumner, Jr., B. W. Davenport, PCT Int. Appl. 2006/028815 A2, 160 pp., filed August 29, 2005. (Eastman Chemical Company)

​

Optimized Liquid-Phase Oxidation, A. G. Wonders, G. G. Lavoie, C. E. Sumner, Jr., B. W. Davenport, M. de Vreede, B. A. Tennant, US Appl. 2006/0205976 A1, 69 pp., filed June 16, 2005. (Eastman Chemical Company)

​

Liquid Phase Oxidation of p-Xylene to Terephthalic Acid in the Presence of a Catalyst System Containing Nickel, Manganese, and Bromine Atoms, G. G. Lavoie, PCT Int. Appl. 2005/108340 A1, 25 pp., filed April 8, 2005. (Eastman Chemical Company)

 

World PCT Patent applications (16 total): WO 2011/156921 (York), 2006/028769, /028815, /028874, /096311, /096312, /096313, /138029, 2005/108340, 2002/022694, /036642, 2001/083571, /096406, 2000/050470, /050475, 1999/062968.

 

US Patent applications (2002–2010: 24 total): 20090259069, 20060205977, 20060205976, 20060205975, 20060205974, 20060178490, 20060047155, 20060047153, 20060047152, 200502440055, 20050090630, 20050090381, 20050054856, 20040029720, 20040228978, 20030225228, 20030195110, 20020111449, 20020091210, 20020058769, 20020058768, 20020049135.