A5066908956- Organometallic Complex Synthesis and Catalysis
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Fluorine in Organic Chemistry
- Synthetic Organic Chemistry Methods
- Organoboron and organosilicon chemistry
- Synthesis and characterization of novel inorganic/organometallic compounds
- Coordination Chemistry and Organometallics
- Cyclopropane Reaction Mechanisms
- Crystallography and molecular interactions
- Ferrocene Chemistry and Applications
- Asymmetric Synthesis and Catalysis
- Metal complexes synthesis and properties
- Inorganic Fluorides and Related Compounds
- Molecular Junctions and Nanostructures
- Advanced Cellulose Research Studies
- History and advancements in chemistry
- Chemical Synthesis and Reactions
- Oxidative Organic Chemistry Reactions
- Chemical Reactions and Mechanisms
- Photochemistry and Electron Transfer Studies
- biodegradable polymer synthesis and properties
- CO2 Reduction Techniques and Catalysts
- Catalysis and Hydrodesulfurization Studies
- Advanced NMR Techniques and Applications
Virginia Tech
2003-2023
University of Windsor
2010
Louisiana State University
2000-2001
Roanoke College
1999
Northwestern University
1995-1998
Dow Chemical (India)
1995
U.S. National Science Foundation
1992
Hope College
1990
Solid-electrolyte interphases (SEIs) in advanced rechargeable batteries ensure reversible electrode reactions at extreme potentials beyond the thermodynamic stability limits of electrolytes by insulating electrons while allowing transport working ions. Such selective ion occurs naturally biological cell membranes as a ubiquitous prerequisite many life processes and foundation biodiversity. In addition, can selectively open close channels response to external stimuli (e.g., electrical,...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTConstrained-Geometry Titanium(II) Diene Complexes. Structural Diversity and Olefin Polymerization ActivityDavid D. Devore, Francis J. Timmers, Dennis L. Hasha, Robert K. Rosen, Tobin Marks, Paul A. Deck, Charlotte SternCite this: Organometallics 1995, 14, 7, 3132–3134Publication Date (Print):July 1, 1995Publication History Published online1 May 2002Published inissue 1 July 1995https://doi.org/10.1021/om00007a005Request reuse permissionsArticle...
Reaction enthalpies of group 4 metallocenes having the general formula L2M(CH3)2 (L = Cp, 1,2-Me2Cp, Me5Cp; L2 Me2Si(Me4Cp)(tBuN); M Ti, Zr, and Hf) with strong organo-Lewis acid B(C6F5)3 were measured using batch titration calorimetry in toluene. Methide abstraction to form corresponding L2MCH3+CH3B(C6F5)3- contact ion pairs is highly exothermic all cases. Exothermicity increases increasing Cp methyl substitution: for ΔH −23.1(3), −24.3(4), −36.7(5) kcal mol-1 L Me2Cp, Me5Cp, respectively....
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCationic Metallocene Olefin Polymerization Catalysts. Thermodynamic and Kinetic Parameters for Ion Pair Formation, Dissociation, ReorganizationPaul A. Deck Tobin J. MarksCite this: Am. Chem. Soc. 1995, 117, 22, 6128–6129Publication Date (Print):June 1, 1995Publication History Published online1 May 2002Published inissue 1 June 1995https://pubs.acs.org/doi/10.1021/ja00127a029https://doi.org/10.1021/ja00127a029research-articleACS PublicationsRequest...
The reaction of CpNa (Cp = C5H5) with C6F6 (diglyme, 110 °C, 14 h) afforded a mixture products, from which two new triarylated cyclopentadienes, 1,2,4-Ar3C5H3 (3) and 1,2,3-Ar3C5H3 (4), were separated by silica gel chromatography (Ar C6F5). dienes 3 4 readily converted (NaH, THF) to the corresponding sodium cyclopentadienides, (1,2,4-Ar3C5H2)Na (7) (1,2,3-Ar3C5H2)Na (8). Reactions ligands 7 8 FeBr2 ferrocenes (1,2,4-Ar3C5H2)2Fe (11) (1,2,3-Ar3C5H2)2Fe (12), respectively. cobaltocenes...
1,1'-Dilithioferrocene, or (CpLi)2Fe (1), reacts with excess C6F6 in THF to afford mostly (C6F5Cp)2Fe (2), accompanied by the diiron complex (C6F5Cp)FeCp(1,4-C6F4)CpFe(CpC6F5) (3). The reaction of 1 1.0 equiv affords a mixture sparingly soluble step-growth oligomers assigned [−FeCp(1,4-C6F4)−]n (4). [1-Li-2-RNCp]FeCp (6, RN = CH2NMe2) [1-(C6F5)-2-RNCp]FeCp (7). Complex 6 0.5 CpFe[2-RNCp](1,4-C6F4)[2-RNCp]FeCp as two diastereomers (meso-8, major and dl-8, minor). relative stereochemistry...
(91)Zr (I = 5/2) solid-state NMR (SSNMR) spectra of the zirconocene compounds, Cp(2)ZrCl(2), Cp*(2)ZrCl(2) (1), Cp(2)ZrBr(2) (2), (Me(3)SiC(5)H(4))(2)ZrBr(2) (3), O(Me(2)SiC(5)H(4))(2)ZrBr(2) (4), (1,3-C(5)H(3))(SiMe(2)OSiMe(2))(2)(1,3-C(5)H(3))ZrBr(2) (5), Ind(2)ZrCl(2) (6), Cp(2)ZrMeCl (7), Cp(2)ZrMe(2) (8), and [Cp(2)ZrMe][MeB(C(6)F(5))(3)] (9) have been acquired. Static SSNMR acquired for all complexes at magnetic fields 9.4 21.1 T. Cp(2)ZrCl(2) 1 to 5 possess relatively narrow central...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTUnderstanding electronic effects in organometallic complexes. Electron donation by the trimethylsilyl groupPaul G. Gassman, Paul A. Deck, Charles H. Winter, Daniel Dobbs, and Danh CaoCite this: Organometallics 1992, 11, 2, 959–960Publication Date (Print):February 1, 1992Publication History Published online1 May 2002Published inissue 1 February 1992https://pubs.acs.org/doi/10.1021/om00038a069https://doi.org/10.1021/om00038a069research-articleACS...
The reaction of NaC5H5 (NaCp) and hexafluorobenzene (1:1 ratio) in THF at 25 °C for 15 h afforded, after hydrolysis, a mixture regioisomeric (pentafluorophenyl)cyclopentadienes. This was isolated as monoisomeric dimer 1-(pentafluorophenyl)cyclopentadiene. structure the determined crystallographically. Flash vacuum thermolytic cracking 200 regenerated (pentafluorophenyl)cyclopentadiene regioisomers. In contrast, NaCp, NaH, C6F6 (1:2:5 reflux 3 d affords,...
Reactions of either 3-(pentafluorophenyl)indene (1a) or (pentafluorophenyl)cyclopentadiene (1b) with Ti(NMe2)4 afford products in which one both the ortho fluorines C6F5 group are replaced a dimethylamino group. The selectivity suggests titanium-mediated, intramolecular nucleophilic aromatic substitution mechanism. organic 3-[2-(dimethylamino)tetrafluorophenyl]indene (4a), 3-[2,6-bis(dimethylamino)trifluorophenyl]indene (7a), and 1-[2,6-bis(dimethylamino)trifluorophenyl]cyclopentadiene (7b)...
ABSTRACT This study describes a novel method of forming nanocomposite comprising cellulose nanocrystals (CNCs) as the reinforcing filler and high‐density polyethylene (PE) matrix. The involves covalent attachment metallocene catalyst, 1,1′‐bis(bromodimethylsilyl)zirconocene dibromide 1 , to hydroxyl‐rich surfaces CNCs subsequent slurry polymerization with excess alumoxane (MMAO‐12) cocatalyst. Polymerization proceeds activities reaching 500 kg mol −1 atm h while are simultaneously dispersed...
The reaction of (η5-C5H4SiMe3)2Fe with excess BCl3 in CH2Cl2 at −78 °C affords a mixture metathesis product (η5-C5H4BCl2)2Fe and an isomer, [η5-1,3-C5H3(BCl2)2]Fe(η5-C5H5). In contrast, does not react appreciably trimethylsilyl-substituted group 4 metallocenes below 80 °C. When (η5-C5H4SiMe3)2MCl2 (M = Ti, Zr) is treated BBr3 for several days, one methyl selectively cleaved from each trimethylsilyl substituent to afford (η5-C5H4SiMe2Br)2MBr2 useful yields. Exposure crystalline samples these...
The reaction of NaCp (Cp = C5H5) with excess C6F6 and NaH in refluxing diglyme afforded a 57% yield 1,2,3,4-tetrakis(pentafluorophenyl)cyclopentadiene (1). Treatment 1 THF sodium tetrakis(pentafluorophenyl)cyclopentadienide (2) 89% yield. Reactions 2 M(CO)5Br (M Mn, Re) yielded [(C6F5)4C5H]M(CO)3 complexes (3, M 33%, 4, Re, 28%). various iron(II) salts CoBr2 however failed to afford the corresponding octaarylated metallocenes. Infrared spectroscopic analysis 3 4 revealed an increase 16(1)...
Standard ligand-substitution reactions afforded moderate yields of (PhC5H4)2ZrCl2 (1), (1,3-Ph2C5H3)CpZrCl2 (2), [1,3,-(C6F5)2C5H3]CpZrCl2 (5), and [1,2,4-(C6F5)2C5H3]CpZrCl2 (6). Crystal structures 1, 2, 6, [(C6F5)C5H4]2HfMe2 (7) were obtained. Physicochemical studies (CV, IR) show that C6F5 groups are strongly electron-withdrawing compared to phenyl groups. In ethylene-1-hexene copolymerization using (C6F5C5H4)CpZrCl2 (3), (C6F5C5H4)2ZrCl2 (4), 5 (toluene solution, methylalumoxane...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTricarbonyl(.eta.6-hexachlorobenzene)chromium(0)Paul G. Gassman and Paul A. DeckCite this: Organometallics 1994, 13, 5, 1934–1939Publication Date (Print):May 1, 1994Publication History Published online1 May 2002Published inissue 1 1994https://pubs.acs.org/doi/10.1021/om00017a058https://doi.org/10.1021/om00017a058research-articleACS PublicationsRequest reuse permissionsArticle Views383Altmetric-Citations23LEARN ABOUT THESE METRICSArticle Views are...
The reaction of decafluorobiphenyl with 10 equiv sodium cyclopentadienide (NaCp) in THF (65 °C, 2 h) afforded 4,4'-bis(cyclopentadienyl)octafluorobiphenyl (1) as a mixture double-bond isomers 72% yield after workup and purification. Subsequent treatment hydride (25 6 disodium (2). Reaction NaCp, ligand 2, FeBr2 (21:1:10 mol ratio) mostly ferrocene well the diiron complex CpFe(η5-C5H4-4,4'-C6F4C6F4-η5-C5H4)FeCp (3), linear triiron Cp[Fe(η5-C5H4-4,4'-C6F4C6F4-η5-C5H4)]2FeCp (4), tetrairon...
Depending on ratios of starting materials and reaction conditions, treatment sodium indenide (NaInd) with C6F6 NaH in THF afforded 3-(pentafluorophenyl)indene (1) or 1,3-bis(pentafluorophenyl)indene (2) 65% 80% yields, respectively, after aqueous workup recrystallization from methanol. Both 1 2 reacted quantitatively to afford the corresponding mono- diarylated indenides (3 4), respectively. The monoarylated ligand (3) Re(CO)5Br at 65 °C for h...
The reaction of 5,5-bis(trimethylstannyl)cyclopentadiene with CpZrCl3 (Cp = eta 5-C5H5) affords the monostannylated metallocene complex (eta 5-Me3SnC5H4)CpZrCl2 (1), accompanied by variable amounts 5-ClMe2SnC5H4)CpZrCl2 (2). (1) reacts BCl3 or ICl to afford 2 (Sn-CH3 cleavage), but HCl, Cp2ZrCl2 is obtained instead (Sn-Cp cleavage). Depending on conditions, treatment either 1 BBr3 5-BrMe2SnC5H4)CpZrBr2 (3) 5-Br2MeSnC5H4)CpZrBr2 (4). excess I2 iodostannylated 5-IMe2SnC5H4)CpZrCl2 (5). Two...
The metallocenes (C6F5C5H4)CpZrMe2 (1, Cp = C5H5) and (C6F5C5H4)2MMe2 (2a, M Zr; 2b, Hf) were treated with B(C6F5)3 and, separately, commercial methylalumoxane (MAO, depleted of excess Me3Al). ensuing methide transfer reactions followed by 19F NMR. Spectra the "activated" species obtained using MAO strikingly similar, suggesting that similar "cation-like" are formed either organo-Lewis acid, MAO-activated tentatively formulated as (C6F5C5H4)CpZrMe+ Me[AlMeO]n- (C6F5C5H4)2MMe+ (M Zr, Hf)....
Abstract Mechanistic studies with 5‐ethyl‐3‐methyllumiflavinium (Fl + ) perchlorate, a biomimetic model for flavoenzyme monoamine oxidase B (MAO‐B) catalysis, and the tertiary, allyl amine 1‐methyl‐4‐(1‐methyl‐1 H ‐pyrrol‐2‐yl)‐1,2,3,6‐tetrahydropyridine (MMTP) reveal that proton‐coupled electron transfer (PCET) may be an important pathway MAO catalysis. The first step involves single‐electron (SET) leading to free radicals Fl . MMTP , latter produced by deprotonation of initially formed...