Publications

Metallocenium incorporated charge-enhanced thiourea catalysts

Blechschmidt, R. D.; Mergendahl, C.; Kass, S. R. Org. Biomol. Chem., 2024, Advanced Article.

https://doi.org/10.1039/D3OB02007J

Anion-Activated Bases and Nucleophiles Characterized by Photoelectron Spectroscopy

Dempsey, S.; Cao, W.; Wang, X.; Kass, S. R. J. Chem. Phys. A. 2023, 127, 42, 8828-8833.

https://doi.org/10.1021/acs.jpca.3c04479

How generic is iodide-tagging photoelectron spectroscopy: An extended investigation on the Gly·X− (Gly = glycine, X = Cl or Br) complexes

 Cao, W.; Yuan, Q.; Zhang, H.; Zhou, X.; Kass, S. R.; Wang, X.  J. Chem. Phys. 2023, 159, 034305.

https://doi.org/10.1063/5.0159326

Electrostatically Enhanced 3- and 4-Pyridyl Borate Salt Nucleophiles and Bases

 Dempsey, S.; Lovstedt, A.; Kass, S. R.  J. Org. Chem. 2023, 88, 15, 10525-10538.

https://doi.org/10.1021/acs.joc.3c00523

Structure determination of a bis[4-di-n-butylamino)phenyl](pyridin-3-yl)borane tetramer highlighting a unique geometric conformation of the core 16-membered ring

Lovstedt, A.; Dempsey, S. H.; Kass, S. R.  Acta Cryst, 2023, C79, 170-176.

https://doi.org/10.1107/S2053229623002619

Metallocenium Lewis Acid Catalysts for Use in Friedel-Crafts Alkylation and Diels-Alder Reactions

Blechschmidt, R. D.; Lovstedt, A.; Kass, S. R.  Organometallics, 2022, 41, 2648-2655.

https://pubs.acs.org/doi/10.1021/acs.organomet.2c00408

Liberating the Anion: Evaluating Weakly Coordinating Cations

Dempsey, H. S.; Kass, S. R.  J. Org. Chem., 2022, 87, 22, 15466-15482.

https://pubs.acs.org/doi/10.1021/acs.joc.2c02001

Charge-activated TADDOLs: Recyclable organocatalysts for asymmetric (hetero-)Diels-Alder reactions

Riegel, G. F.; Takashige, K.; Lovstedt, A.; Kass, S. R.  J. Phys Org Chem., 2022, 3, 9, e4355.

https://onlinelibrary.wiley.com/doi/10.1002/poc.4355

Effects of Brønsted acid cocatalysts on the activities and selectivities of charge-enhanced thiourea organocatalysts in Friedel–Crafts and oxa-Pictet–Spengler reactions

Riegel, G. F.; Payne, C.; Kass, S. R.  J. Phys Org Chem., 2022, e4321.

www.dx.doi.org/10.1002/poc.4321

Observation and Exploitation of Spin-Orbit Excited Dipole-Bound States in Ion-Molecule Clusters

Cao, W.; Zhang, H.; Yuan, Q.; Zhou, X.; Kass, S. R.; Wang, X.  J. Phys. Chem. Lett., 2021, 12, 45, 11022-11028.

https://pubs.acs.org/doi/10.1021/acs.jpclett.1c03309

Observation of Conformational Simplification upon N-Methylation on Amino Acid Iodide Clusters

Cao, W.; Zhang, H.; Yuan, Q.; Zhou, X.; Kass, S. R.; Wang, X.  J. Phys. Chem. Lett., 2021, 12, 11, 2780–2787.

https://pubs.acs.org/doi/10.1021/acs.jpclett.1c00125

Cryogenic "Iodide-Tagging" Photoelectron Spectroscopy: A Sensitive Probe for Specific Binding Sites of Amino Acids

Zhang, H.; Cao, W.; Yuan, Q.; Zhou, X.; Valiev, M.; Kass, S. R.; Wang, X.  J. Phys. Chem. Lett., 2020, 11, 11, 4346–4352.

https://pubs.acs.org/doi/10.1021/acs.jpclett.0c01099

N-Vinyl and N-Aryl Hydroxypyridinium Ions: Charge-Activated Catalysts with Electron Withdrawing Groups

Riegel, G. F.; Kass, S. R.  J. Org. Chem., 2020, 85, 6017–6026.

www.dx.doi.org/10.1021/acs.joc.0c00498

Structural Considerations for Charge-Enhanced Brønsted Acid Catalysts

Payne, C.; Kass, S. R.  J. Phys. Org. Chem., 2020, e4069. 

www.dx.doi.org/10.1002/poc.4069

How Reliable Are Enantiomeric Excess Measurements Obtained by Chiral HPLC?

Payne, C.; Kass, S. R.  ChemistrySelect, 2020, 5, 1810–1817.

www.dx.doi.org/10.1002/slct.202000166

Electrostatically Enhanced Phosphoric Acids and Their Applications in Asymmetric Friedel−Crafts Alkylations

Ma, J.; Kass, S. R.  J. Org. Chem. 2019, 84, 11125–11134.

www.dx.doi.org/10.1021/acs.joc.9b01741

Ferrocene Acidity and C−H Bond Dissociation Energy via Experiment and Theory

Speetzen, B.; Kass, S. R.  J. Phys. Chem. A, 2019, 123, 6016–6021.

www.dx.doi.org/10.1021/acs.jpca.9b04382

Synthesis of Cyclic Organic Carbonates Using Atmospheric Pressure CO2 and Charge-Containing Thiourea Catalysts

Fan, Y.; Tiffner, M.; Schörgenhumer, J.; Robiette, R.; Waser, M.; Kass, S. R. J. Org. Chem., 2018, 83 (17), 9991–10000. 

www.dx.doi.org/10.1021/acs.joc.8b01374

Quantification of Catalytic Activity for Electrostatically Enhanced Thioureas via Reaction Kinetics and UV–vis Spectroscopic Measurement

Fan, Y.; Payne, C.; Kass, S. R. J. Org. Chem., 2018, 83 (18), 10855–10863. 

www.dx.doi.org/10.1021/acs.joc.8b01552

Asymmetric Arylation of 2,2,2-Trifluoroacetophenones Catalyzed by Chiral Electrostatically-Enhanced Phosphoric Acids

Ma, J.; Kass, S. R. Org. Lett., 2018, 20 (9), 2689–2692. 

www.dx.doi.org/10.1021/acs.orglett.8b00900

Enantioselective Friedel-Crafts Alkylation between Nitroalkenes and Indoles Catalyzed by Charge Activated Thiourea Organocatalysts

Fan, Y.; Kass, S. R.  J. Org. Chem., 2017, 82 (24), 13288–13296.

www.dx.doi.org/10.1021/acs.joc.7b02411

Electrostatically Enhanced Phosphoric Acids: A Tool in Brønsted Acid Catalysis

Ma, J.; Kass, S. R. Org. Lett. 2016, 18 (22), 5812-5815.  

www.dx.doi.org/10.1021/acs.orglett.6b02750

Chiral Separations of 3,3'-Substituted BINOLs and Protected Analogues

Payne, C., Kass, S.; Chiral Separations of 3,3'-Substituted BINOLs and Protected Analogues, 2016

www.registech.com

Electrostatically Enhanced Thioureas

Fan, Y.; Kass, S. R., Org. Lett. 2016, 14, 188-191.

www.dx.doi.org/10.1021/acs.orglett.5b03213

Selective Binding and Extraction of Aqueous Dihydrogen Phosphate Solutions via Three-armed Thiourea Receptors

Beletskiy, E. V.; Kass, S. R. Org. Biomol. Chem. 2015, 13, 9844-9849.

www.dx.doi.org/10.1039/C5OB01450F

Preorganized Hydrogen Bond Donor Catalysts: Acidities and Reactivities

Samet, M.; Kass, S. R., J. Org. Chem., 2015, 80, 7727-7731.

www.dx.doi.org/10.1021/acs.joc.5b01475

Charge-Enhanced Acidity and Catalyst Activation

Samet, M.; Buhle, J.; Zhou, Y.; Kass, S. R.  J. Am. Chem. Soc., 2015, 137, 4678–4680. 

www.dx.doi.org/10.1021/jacs.5b01805

Stereoelectronic effects: A simple yet powerful tool to manipulate anion affinity

Samet, M.; Fattahi, A.; Kass, S. R.  Org. Biomol. Chem., 2015, 13, 2170–2176. 

www.dx.doi.org/10.1039/C4OB02470B

Synthesis and Properties of the Strained Alkene Perfluorobicyclo[2.2.0]hex-1(4)-ene

Junk, C.; He, Y.; Zhang, Y.; Smith, J.; Gleiter, R.; Kass, S.; Jasinski, J; Lemal, D. J. Org. Chem., 2015, 80, 1523-1532.

www.dx.doi.org/10.1021/jo502456h

Power of a Remote Hydrogen Bond Donor: Anion Recognition and Structural Consequences Revealed by IR Spectroscopy

Samet, M.; Danesh-Yazdi, M.; Fattahi, A.; Kass, S. R. J. Org. Chem., 2015, 80, 1130-1135

www.dx.doi.org/10.1021/jo502652z

OLDER PUBLICATIONS

132. Tian, Z.; Reed, D. R.; Kass, S. R. “H/D Exchange Pathways: Flip-flop and Relay Processes”, Int. J. Mass Spectrom. 2015, 377, 130-138 (invited contribution).


131. Wang, X.-B.; Kass, S. R. “Anion A– • HX Clusters with Reduced Electron Binding Energies: Proton vs Hydrogen Atom Relocation Upon Electron Detachment”, J. Am. Chem. Soc., 2014, 136, 17332-17336.


130. Samet, M.; Wang, X.-B.; Kass, S. R. “A Preorganized Hydrogen Bond Network and Its Effect on Anion Stability”, J. Phys. Chem. A, 2014, 118. 5989-5993.


129. Fattahi, A.; Liebman, J. F.; Miranda, M. S.;Morais, V. M. F.; Matos, M. A. R.; Lis, L.; Kass, S. R. “Indenone and Cyclopentadienone Energetics via Mass Spectrometry and Computations: Are These Species Antiaromatic or "Merely" Nonaromatic?”, Int. J. Mass Spectrom. 2014, 369, 87-91 (and 2015, 378, 175-179, invited contribution)


128. Shokri, A.; Deng, S. H. M.; Wang, X.; Kass, S. R. “Molecular Recognition: Preparation and Characterization of Two Tripodal Anion Receptors”, Org. Chem. Frontiers 2014, 1, 54-61.


127. DeBlase, A. F.; Kass, S. R.; Johnson, M. A. “On the character of the cyclic ionic H-bond in cryogenically coooled deprotonated cysteine”, Phys. Chem. Chem. Phys. 2014, 16, 4569- 4575.


126. Tian, Z.; Lis, L.; Kass, S. R. “Carbon–Hydrogen BDEs: The Curious Case of Cyclopropene”, J. Org. Chem. 2013, 78, 12650-12653.


125. Shokri, A.; Kass, S. R. “Solvent Effects on the Molecular Recognition of Anions”, Chem. Comm. 2013, 49, 11674-11676.


124. Shokri, A.; Wang, X.; O'Doherty, G. A.; Kass, S. R. “Hydrogen Bond Networks: Strengths of Different Types of Hydrogen Bonds and An Alternative to the Low Barrier Hydrogen Bond Proposal”, J. Am. Chem. 2013, 113, 17919-17924.


123. Shokri, A.; Ramezani, M.; Fattahi, A.; Kass, S. R. “Electrostatically Defying Cation– Cation Clusters: Can Likes Attract In A Low Polarity Environment?”, J. Phys. Chem. 2013, 117, 9252-9255.


122. Tian, Z.; Kass, S. R. “Carbanions in the Gas Phase”, Chem. Rev. 2013, 113, 6986-7010 (invited contribution).


121. Kass, S. R. “Cyclopropenyl Anion: An Energetically Nonaromatic Ion”, J. Org. Chem. 2013, 78, 7370-7372.


120. Shokri, A.; Wang, X. B.; Kass, S. R. “Electron-Withdrawing Trifluoromethyl Groups in Combination with Hydrogen Bonds in Polyols: Brønsted Acids, Hydrogen-Bond Catalysts, and Anion Receptors”, J. Am. Chem. Soc. 2013, 135, 9525-9530.


119. Schmidt, J.; Kass, S. R. “Zwitterion vs Neutral Structures of Amino Acids Stabilized by a Negatively Charged Site: Infrared Photodissociation and Computations of Proline-Chloride Anion”, J. Phys. Chem. 2013, 117, 4863-4869.


118. Beletskiy, E. V.; Schmidt, J.; Wang, X. B.; Kass, S. R. “Three Hydrogen Bond Donor Catalysts: Oxyanion Hole Mimics and Transition State Analogues”, J. Am. Chem. Soc. 2012, 134. 18534-18537.


117. Shokri, A.; Schmidt, J.; Wang, X. B.; Kass, S. R. “Characterization of a Saturated and Flexible Aliphatic Polyol Anion Receptor”, J. Am. Chem. Soc. 2012, 134, 16944-16947.


116. Shokri, A.; Abedin, A.; Fattahi, A.; Kass, S. R. “Effect of Hydrogen Bonds on pKa Values: Importance of Networking”, J. Am. Chem. Soc. 2012, 134, 10646-10650.


115. Fattahi, A.; Lis, L.; Tehrani, Z. A.; Marimanikkuppam, S. S.; Kass, S. R. “Experimental and Computational Bridgehead C–H Bond Dissociation Enthalpies”, J. Org. Chem. 2012, 77, 1909-1914.


114. Shokri, A.; Schmidt, J.; Wang, X. B.; Kass, S. R. “Hydrogen Bonded Arrays: The Power of Multiple Hydrogen Bonds”, J. Am. Chem. Soc. 2012, 134, 2094-2099.


113. Schmidt, J.; Meyer, M. M.; Spector, I.; Kass, S. R. “Infrared Multiphoton Dissociation Spectroscopy Study of Protonated p-Aminobenzoic Acid: Does Electrospray Ionization Afford the Amino- or Carboxy-Protonated Ion? “, J. Phys. Chem. A 2011, 115, 7625-7632.


112. Meyer, M. M.; Kass, S. R. “Enolates in 3–D: An Experimental and Computational Study of Deprotonated 2-Adamantanone”, J. Org. Chem.,2010, 75, 4274-4279.


111. Meyer, M. M.; Chan, B.; Radom, L. Kass, S. R. “Gas-Phase Synthesis and Reactivity of Lithium Acetylide Anion, Li C≡C–”, Angew. Chem. Int. Ed. Eng. 2010, 49, 5161-5164 (highlighted in Chem. Aust. 2010, 77 (10), 10).


110. Meyer, M. M.; Kass, S. R. “Experimental and Theoretical Gas-Phase Acidities, Bond Dissociation Energies, and Heats of Formation of HClOx, x = 1 – 4”, J. Phys. Chem. A 2010, 114, 4086-4092.


109. Meyer, M. M.; Wang, X. B.; Reed, C. A.; Wang, L. S.; Kass, S. R. “Investigating the Weak to Evaluate the Strong: An Experimental Determination of the Electron Binding Energy of Carborane Anions and the Gas Phase Acidity of Carborane Acids”, J. Am. Chem. Soc. 2009, 131, 18050-18051.


108. Tian, Z.; Fattahi, A.; Lis, L.; Kass, S. R. “Single-Centered Hydrogen-Bonded Enhanced Acidity (SHEA) Acids: A New Class of Brønsted Acids”, J. Am. Chem. Soc. 2009, 131, 16984-16988.


107. Radom, L.; Mintz, B.; Chan, B.; Sullivan, M.; Buesgen, T.; Scott, A.; Kass, S. R.; Wilson, A. “Structures and Thermochemistry of the Alkali Metal Monoxide Anions (MO–), Monoxide Radicals (MO•) and Hydroxides (MOH)”, J. Phys. Chem. 2009, 113, 9501-9510.


106. Tian, Z.; Fattahi, A.; Lis, L.; Kass, S. R. “Neutral Intramolecular Hydrogen-Bonded Bases”, Croat. Chem. Acta 2009, 82, 41-45 (invited contribution).


105. Meyer, M. M.; Khairallah, G. N.; O’Hair, R. A. J.; Kass, S. R. “Gas-Phase Synthesis and Reactivity of Lithium Acetate Enolate Anion, –CH2CO2Li”, Angew. Chem. Int. Ed. Eng. 2009, 48, 2934-2936 (highlighted in Org. Mass Spectrom. 2010, 58, 280)


104. Tian, Z.; Kass, S. R. “Gas- vs. Liquid-Phase Structures via Electrospray Ionization Mass Spectrometry”, Angew. Chem, Int. Ed. Engl. 2009, 48, 1321-1323.


103. Tian, Z.; Wang, X. B.; Wang, L. S.; Kass, S. R. “Are Carboxyl Groups the Most Acidic Sites in Amino Acids? Gas-Phase Acidity, Photoelectron Spectra, and Computations on Tyrosine, p-Hydroxybenzoic Acid and Their Conjugate Bases”, J. Am. Chem. Soc. 2009, 131, 1174-1181.


102. Tian, Z.; Kass, S. R. “Does Electrospray Ionization Produce Gas-Phase or Liquid-Phase Structures?” J. Am. Chem. Soc. 2008, 130, 10842-10843 (Also see: Chem. Eng. News 2008, 86 (32), 38).


101. Tian, Z.; Radom, L.; Sullivan, M. B.; Chan, B.; Kass, S. R. “Lithium Monoxide Anion: A Ground-State Triplet With Record-Breaking Basicity”, Proc. Natl. Acad. Sci. 2008, 105, 7647-7651 (Also see: Chem. Eng. News 2008, 86 (23), 23 and Chem. Aust. 2008, 75 (9), 38).


100. Tian, Z.; Lis, L.; Kass, S. R. “Hydrogen-Deuterium Exchange and Selective Labeling of Deprotonated Amino Acids and Peptides in the Gas Phase” J. Am. Chem. Soc. 2008, 130, 8- 9.


99. Tian, Z.; Kass, S. R. “A Redetermination of the Heats of Formation of Chloro- and Dichlorocarbene and the Deprotonation of Methyl Cation, A Spin Forbidden Process?*” Int. J. Mass Spectrom. 2007, 267, 288-294 (invited contribution).


98. Tian, Z.; Poutsma, J. C.; Pawlow, A.; Kass, S. R. “Are Carboxyl Groups the Most Acidic Sites in Amino Acids? Gas Phase Acidity, H/D Exchange Experiments, and Computations on Cysteine and Its Conjugate Base” J. Am. Chem. Soc. 2007, 129, 5403-5407.


97. Pratt, L. M.; Truhlar, D. G.; Cramer, C. J.; Kass, S. R.; Thompson, J. D.; Xidos, J. D. “Aggregation of Alkyllithiums in Tetrahydrofuran” J. Org. Chem. 2007, 72, 2962-2966.


96. Tian, Z.; Fattahi, A.; Lis, L.; Kass, S. R. “Cycloalkane and Cycloalkene C–H Bond Dissociation Energies” J. Am. Chem. Soc. 2006, 128, 17087-17092.


95. Tian, Z.; Kass, S. R. “Organic gas-phase ion chemistry” Annu. Rep. Prog. Chem. Sect. B: Org. Chem. 2006, 102, 290-324 (invited contribution).


94. Fattahi, A.; Lis, L.; Tian, Z.; Kass, S. R. “The Heat of Formation of Cyclobutadiene” Angew. Chem. Int. Ed. Engl. 2006, 45, 4984-4988 (Highlighted article, see: Sci. 2006, 313, 275 and Bally, T. Angew. Chem. Int. Ed. Engl. 2006, 45, 6616-6619).


93. Kass, S. R. “Zwitterion-Dianion Complexes and Anion-Anion Clusters with Negative Dissociation Energies” J. Am. Chem. Soc. 2005, 127, 13098-13099.


92. Fattahi, A.; Lis, L.; Kass, S. R. “Experimental Determination of the Heat of Hydrogenation of Phenylcyclobutadiene” J. Am. Chem. Soc. 2005, 127, 13065-13069.


91. Fattahi, A.; Kass, S. R.; Liebman, J. F.; Matos, M. A. R.; Miranda, M. S.; Morais, V. M. F. “The Enthalpies of Formation of o-, m-, and p-Benzoquinone: Gas-Phase Ion Energetics, Combustion Calorimetry, and Quantum Chemical Computations Combined” J. Am. Chem. Soc. 2005, 127, 6116-6122.


90. Fattahi, A.; Kass, S. R. “Correlating Acidities, Electron Affinities, and Bond Dissociation Energies. Measure One, Get All Three!” J. Org. Chem. 2004, 69, 9176-9183.


89. Pratt, L. M.; Fattahi, A.; Kass, S. R. “Tetrafluorobenzyne Thermochemistry: Experiment and Theory” Eur. J. Mass Spectrom. 2004, 10, 813-818 (invited contribution).


88. Kass, S. R. “Anion-Induced Elimination Reactions” Encyclopedia of Mass Spectrometry 2004, 4, 567-574 (invited contribution).


87. Kass, S. R. “Stereoselective Carbanion Reactions” Encyclopedia of Mass Spectrometry 2004, 4, 491-495 (invited contribution).


86. Pratt, L. M.; Kass, S. R. “ Lithiated Hydrocarbons, Their Conjugate Bases and Corresponding Radicals: A Computational Study of RLi (R = CH3, CH3CH2, CH2=CH, and HC≡C)” J. Org. Chem. 2004, 69, 2123-2127.


85. Fattahi, A.; McCarthy, R. E.; Ahmad, M. R.; Kass, S. R. “Why Does Cyclopropene Have The Acidity of An Acetylene but the Bond Energy of Methane?” J. Am. Chem. Soc. 2003, 125, 11746-11750.


84. Kass, S. “Unimolecular Rearrangements of Carbanions” Encyclopedia of Mass Spectrometry 2003, 1, 633-641 (invited contribution).


83. Kass, S. “Strained Ring and Highly Basic Carbanions” Encyclopedia of Mass Spectrometry 2003, 1, 658-664 (invited contribution).


82. Ahmad, M. R.; Kass, S. R. “Unimolecular Rearrangements and Fragmentations in the Gas Phase: [1,3] Sigmatropic Isomerizations and [2 + 2] Cycloreversions” Aust. J. Chem. 2003, 56, 453-458 (invited contribution).


81. Wang, X. -B.; Dacres, J. E.; Yang, X.; Lis, L.; Bedell, V. M.; Wang, L. -S.; Kass, S. R. “Photodetachment of Zwitterions: Probing Intramolecular Coulomb Repulsion and Attraction in the Gas Phase Using Mono Decarboxylated Pyridinium Dicarboxylates. Implications on the Mechanism of Orotidine 5'-Monophosphate Decarboxylase” J. Am. Chem. Soc. 2003, 125, 6814-6826.


80. Reed, D. R.; Hare, M. C.; Chung, G.; Fattahi, A.; Gordon, M. S.; Kass, S. R. “o-, m-, and p- Dehydrophenol Radical Anions: Formation, Reactivity, and Energetics Leading To The Heats of Formation of o-, m-, and p-Oxocyclohexadienylidene” J. Am. Chem. Soc. 2003, 125, 4643-4651.


79. Wang, X. -B.; Dacres, J. E.; Yang, X.; Broadus, K. M.; Lis, L.; Wang, L. -S.; Kass, S. R. “Photodetachment of Zwitterions: Probing Intramolecular Coulomb Repulsion and Attraction in the Gas Phase Using Pyridinium Dicarboxylate Anions” J. Am. Chem. Soc. 2003, 125, 296-304.


78. Antol, I.; Glasovac, Z.; Hare, M. C.; Eckert-Maksic, M.; Kass, S. R. “On the Acidity of Cyclopropanaphthalenes. Gas Phase and Computational Studies” Int. J. Mass Spectrom., 2003, 222, 11-26 (invited contribution).


77. Broadus, K. M.; Kass, S. R. “Reactive Intermediates via Fourier Transform Mass Spectrometry” J. Phys. Org. Chem. 2002, 15, 461-468 (invited contribution).


76. Glasovac, Z.; Eckert-Maksic, M.; Dacres, J. E.; Kass, S. R. “Gas phase formation of 1- phenylcyclobuten-3-yl and 1-phenylallyl anions and a determination of the allylic C–H acidities and bond dissociation energies of 1-phenylcyclobutene and trans-1- phenylpropene” J. Chem. Soc. Perkin Trans 2, 2002, 410-415.


75. Reed, D. R.; Kass, S. R.; Mondanaro, K. R.; Dailey, W. P. “Formation of a 1- Bicyclo[1.1.1]pentyl Anion and an Experimental Determination of the Acidity and C-H Bond Dissociation Energy of 3-tert-Butylbicyclo[1.1.1]pentane” J. Am. Chem. Soc. 2002, 124, 2790-2795.


74. Lis, L.; Koltun, E.; Liu, H-w.; Kass, S. R. “Ring Scission Of Diastereomeric 4- Butylspiropentylcarbinyl Radicals As A Chemical Model For Identifying Enzyme- Catalyzed FAD Adducts Resulting From Spiropentylacetyl-CoA” J. Am. Chem. Soc. 2002, 124, 1276-1287.


73. Reed, D. R.; Kass, S. R. “Hydrogen-Deuterium Exchange at Non-Labile Sites: A New Reaction Facet With Broad Implications for Structural and Dynamic Determinations” J. Am. Soc. Mass Spectrom. 2001, 12, 1163-1168 (Highlighted article, see: Anal. Chem. 2001, 73, 584A).


72. Hare, M. C.; Marimanikkuppam, S. S.; Kass, S. R. “Acetamide enolate: Formation, reactivity, and proton affinity” Int. J. Mass Spectrom. 2001, 210/211, 153-163.


71. Broadus, K. M.; Kass, S. R. “The Electron as a Protecting Group. 3. Generation of Acenaphthyne Radical Anion and an Experimental Determination of the Heat of Formation of a Strained Cycloalkyne” J. Am. Chem. Soc. 2001, 123, 4189-4196.


70. Broadus, K. M.; Han, S.; Kass, S. R. “Rearrangements of Aryl Substituted Cyclopropenyl Anions and the Gas-Phase Acidity of a Simple Aryl Cyclopropene” J. Org. Chem. 2001, 66, 99-106.


69. Chung, G.; Pak, M. V.; Reed, D. R.; Kass, S. R.; Gordon, M. S. “Theoretical Study of Oxocyclohexadienylidene Isomers: Electronic Structures and Molecular Properties”, J. Phys. Chem. Soc. A 2000, 104, 11822-11828.


68. Broadus, K. M.; Kass, S. R.; Osswald, T.; Prinzbach, H. “Dodecahedryl Anion Formation and an Experimental Determination of the Acidity and C-H Bond Dissociation Energy of Dodecahedrane” J. Am. Chem. Soc. 2000, 122, 10964-10968.


67. Broadus, K. M.; Kass, S. R. “The Electron as a Protecting Group. 2. Generation of Benzocyclobutadiene Radical Anion in the Gas Phase and an Experimental Determination of the Heat of Formation of Benzocyclobutadiene” J. Am. Chem. Soc. 2000, 122, 10697- 10703.


66. Reed, D. R.; Hare, M. C.; Kass, S. R. “Formation of Gas-Phase Dianions and Distonic Ions As A General Method for the Synthesis of Protected Reactive Intermediates. Energetics of 2,3- and 2,6-Dehydronaphthalene” J. Am. Chem. Soc. 2000, 122, 10689-10696.


65. Broadus, K. M.; Kass, S. R. “Benzocyclobutadienyl Anion: Formation and Energetics of an Antiaromatic Molecule” J. Org. Chem. 2000, 65, 6566-6571.


64. Broadus, K. M.; Kass, S. R. “Probing Electrostatic Effects: Formation and Characterization of Zwitterionic Ions and Their “Neutral” Counterparts in the Gas Phase” J. Am. Chem. Soc. 2000, 122, 9014-9018.


63. Wang, X.-B.; Broadus, K. M.; Wang, L.-S.; Kass, S. R. “Photodetachment of the First Zwitterionic Anions in the Gas Phase: Probing Intramolecular Coulomb Repulsion and Attraction” J. Am. Chem. Soc. 2000, 122, 8305-8306 (Also see: Chem. Eng. News 2000, 78, 32).


62. Koltun, E. S.; Kass, S. R. “Synthesis of 3,5-Cyclooctadienol and 3,5-Cyclooctadienone. SeO2/O2 Oxidation of Dienes” Synthesis. 2000, 10, 1366-1368.


61. Han, S.; Hare, M. C.; Kass, S. R. “The gas-phase acidity of cyclopropene and simple alkyl derivatives: Can they be measured?” Int. J. Mass Spectrom. Ion Proc. 2000, 201, 101-108 (invited contribution).


60. Koltun, E. S.; Kass, S. R. “Synthesis and Reactivity of trans-Tricyclo[4.2.0.01,3]oct-4-ene” J. Org. Chem. 2000, 65, 3530-3537.


59. Koltun, E. S.; Kass, S. R. “Rearrangement of the trans-Tricyclo[4.2.0.01,3]oct-4-enyl Skeleton”, Tetrahedron 2000, 56, 2591-2594.


58. Reed, D. R.; Kass, S. R. “An Experimental Determination of the α and β C-H Bond Dissociation Energies in Naphthalene” J. Mass Spectrom. 2000, 35, 534-539.


57. Glasovac, Z.; Eckert-Maksic, M.; Broadus, K. M.; Hare, M. C.; Kass, S. R. “Benzocyclo- butene: The Impact of Fusing a Strained Ring on to Benzene” J. Org. Chem. 2000, 65, 1818-1824.


56. Baschky, M. C.; Kass, S. R. “Temperature and Pressure Effects on the Elimination Reactions of Diethyl Ether” Int. J. Mass Spectrom. Ion Proc. 2000, 195/196, 411-418 (invited contribution).


55. Broadus, K. M.; Kass, S. R. “Benzocyclobutenone Enolate: An Anion With An Antiaromatic Resonance Structure” J. Chem. Soc. Perkin Trans 2 1999, 2389-2396 (invited contribution).


54. Han, S.; Arrowood, T. L.; Young, Jr., V. G.; Kass, S. R. “The Structure and Thermal Stability of 1,2-Dimethoxycarbonyl-3,3-dimethylcyclopropene” Structural Chemistry, 1999, 10, 349-354.


53. Merrill, G. N.; Zoller, U.; Reed, D. R.; Kass, S. R. “The Formation and Characterization of Three-Membered Ring Carbanions in the Gas Phase: An Experimental and Theoretical Investigation of the Conjugate Bases of Thiirane, Thiirane-S-oxide, and Thiirane-S,S- dioxide” J. Org. Chem. 1999, 64, 7395-7406.


52. Arrowood, T. L.; Kass, S. R. “Formation of Transient and Long-Lived Cyclopropenyl Anions” J. Am. Chem. Soc. 1999, 121, 7272-7273 (Also see: Chem. Eng. News 1999, 77, 27).


51. Han, S.; Kass, S. R. “Synthesis of 3-Aryl-3-trimethylsilylcyclopropenes and Their Dibenzoyl Derivatives. Possible Cyclopropenyl Anion Precursors?” J. Chem. Soc. Perkin Trans 1 1999, 1553-1558.


50. Arrowood, T. L.; Kass, S. R. “Synthesis and Thermolysis of 3-Substituted 3- Trimethylsilylcyclopropenes” Tetrahedron 1999, 55, 6739-6748.


49. Broadus, K.; Kass, S. R. “The Conjugate Base of an Alicyclic Hydrazine: Formation and Energetics of N-Diaziridyl Anion” Int. J. of Mass Spectrom. Ion Proc. 1999, 185/186/187, 179-187 (invited contribution).


48. Bachrach, S. M.; Hare, M.; Kass, S. R. “Alkali Metal Salts of Dianions: A Theoretical and Experimental Study of (C6H4)–2 M+, M = Li and Na” J. Am. Chem. Soc. 1998, 120, 12646- 12649.


47. Clifford, E. P.; Wenthold, P. G.; Lineberger, W. C.; Petersson, G. A.; Broadus, K. M.; Kass, S. R.; Kato, S.; DePuy, C. H.; Bierbaum, V. M.; Ellison, G. B. “The Properties of Diazocarbene [CNN] and the Diazomethyl Radical [HCNN] via Ion Chemistry and Spectroscopy” J. Phys. Chem. 1998, 102, 7100-7112.


46. Merrill, G. N.; Kass, S. R. “A High-Level Ab Initio and Density Functional Investigation of Cyclopropenyl Anion and Its Mono-, Di-, and Trisubstituted Derivatives” J. Am. Chem. Soc. 1997, 119, 12322-12337.


45. Gronert, S.; Kass, S. R. “Theoretical Studies of Eliminations 6. The Regiochemistry and Stereochemistry of the Gas-Phase Reactions of 3-Halocyclohexenes with Fluoride. An Ab Initio Study” J. Org. Chem. 1997, 62, 7991-8000.


44. Dombrowski, G. W.; Gassman, P. G.; Kass, S. R. “Rearrangement Pathways of the Tricyclo[4.1.0.01,3]heptyl Skeleton” Tetrahedron Letts 1997, 38, 7819-7822.


43. Han, S.; Kass, S. R. “The Synthesis of Potential Cyclopropenyl Anion Precursors: 3- Methyl-3-trimethylsilylcyclopropene and Its Dibenzoyl Derivative” Tetrahedron Letts 1997, 38, 7503-7506.


42. Moore, L.; Lubinski, R.; Baschky, M. C.; Dahlke, G. D.; Hare, M.; Arrowood, T.; Glasovac, Z.; Eckert-Maksic, M.; Kass, S. R. “Benzocyclopropenyl Anion: A Stable 8π Electron Species” J. Org. Chem. 1997, 62, 7390-7396.


41. Hare, M.; Emrick, T.; Eaton, P.; Kass, S. R. “Cubyl Anion Formation and an Experimental Determination of the Acidity and C-H Bond Dissociation Energy of Cubane” J. Am. Chem. Soc. 1997, 119, 237-238 (Also see: Chem. Eng. News 1997, 75, 36-37).


40. Merrill, G. N.; Gronert, S.; Kass, S. R. “A Systematic Study of the Potential Energy Surface for the Base-Induced Elimination Reaction of Fluoride Ion With Ethyl Fluoride Using Density Functional Theory” J. Phys. Chem. A 1997, 101, 208-218.


39. Merrill, G. N.; Kass, S. R. “Calculated Gas Phase Acidities Using Density Functional Theory: Is It Reliable?” J. Phys. Chem. 1996, 100, 17465-17471.


38. Merrill, G. N.; Dahlke, G. D.; Kass, S. R. “β-Cyanoethyl Anion: lusus naturae” J. Am. Chem. Soc. 1996, 118, 4462-4468.


37. Ahmad, M. R.; Kass, S. R. “The Thio-Wittig Rearrangement of Deprotonated Allyl Methyl Sulfide. A Gas Phase Unimolecular Isomerization Probed With A Tandem Variable Temperature Flowing Afterglow-Triple Quadrupole Device” J. Am. Chem. Soc. 1996, 118, 1398-1407.


36. Baschky, M. C.; Sowa, Jr., J. R.; Gassman, P. G.; Kass, S. R. “The Gas-Phase Generation of Trifluoromethyl Cyclopentadienides” J. Chem. Soc., Perkins Trans. 2 1996, 213-215.


35. Torborg, C. J.; Rabasco, J. J.; Kass, S. R. “Nucleophilic Substitution Gone Awry: A Novel Cyclopropanation Reaction With A Surprising Stereochemical Outcome”, Tetrahedron Letts. 1995, 36, 6025-6028.


34. Gordon, M. S.; Kass, S. R. “CHN2-: A Biradical Anion and A Potentially New Type of Reactive Intermediate” J. Phys. Chem. 1995, 99, 6548-6550. Also see: J. Phys. Chem. A 1997, 101, 7922.


33. Gronert, S.; Merrill, G. N.; Kass, S. R. “The Fluoride-Induced Elimination of Ethyl Fluoride. The Importance of High-Level Optimizations in Ab Initio and DFT Studies” J. Org. Chem. 1995, 60, 488-489.


32. Baschky, M. C.; Peterson, K. C.; Kass, S. R. “Stereospecificity in the Gas Phase. Formation and Characterization of Configurationally Stable Cyclopropyl Anions” J. Am. Chem. Soc. 1994, 116, 7218-7224.


31. Staneke, P. O.; Ingemann, S.; Nibbering, N. N. M.; Eaton, P.; Kass, S. R. “Cubene: The Stability of a Nonplanar Olefin” J. Am. Chem. Soc. 1994, 116, 6445-6446.


30. Rabasco, J. J.; Gronert, S.; Kass, S. R. “Stereoselectivity in 1,2-Elimination Reactions: Surprising Results” J. Am. Chem. Soc. 1994, 116, 3133-3134.


29. Sachs, R. K.; Kass, S. R. “3-Carbomethoxycyclopropen-3-yl Anion. Formation and Characterization of an Antiaromatic Ion” J. Am. Chem. Soc. 1994, 116, 783-784. (Also see: Chem. Eng. News 1994, 72, 36-37).


28. Rabasco, J. J.; Kass, S. R. “Stereoselectivity in 1,4-Elimination Reactions. The Gas Phase Reactivity of Deuterium Labeled 3-Methoxycyclohexene and 4,4-Dimethyl-3- methoxycyclo-hexene” J. Org. Chem. 1993, 58, 2633-2636.


27. Rabasco, J. J.; Kass, S. R. “Regioselectivity in Gas-Phase Elimination Reactions: 1,2 vs 1,4 and Allenic Ion vs Dienide Formation” Tetrahedron Letts 1993, 34, 765-768.


26. Chou, P. K.; Dahlke, G. D.; Kass, S. R. “Unimolecular Rearrangements of Carbanions in the Gas Phase. II. Cyclopropyl Anions” J. Am. Chem. Soc. 1993, 115, 315-324.


25. Dahlke, G. D.; Kass, S. R. “The ortho-Dehydrophenoxy Anion: An Unusual Ion Formed From A Surprising Reaction” Int. J. Mass Spectrom. and Ion Processes, 1992, 117, 633- 645.


24. Guo, H.; Kass, S. R. “Vinylcyclopropyl Anion: Structure, Reactivity, Thermodynamic Properties, and an Unusual Rearrangement” J. Am. Chem. Soc. 1992, 114, 1244-1248.


23. Rabasco, J. J.; Kass, S. R. “Reactions of Strong Bases With Vinyl Fluoride. Formation and Characterization of 1-Fluorovinyl Anion and The Fluoride-Acetylene Hydrogen Bonded Complex” J. Am. Soc. Mass. Spectrom. 1992, 3, 91-98.


22. Chou, P. K.; Kass, S. R. “Unimolecular Rearrangements in the Gas Phase. The Thermolysis of Bicyclobutyl and Phenylcyclopropyl Anion” Org. Mass. Spectrom. 1991, 26, 1039-1040.


21. Rabasco, J. J.; Kass, S. R. “The Gas-Phase Elimination Reaction of 3-Methoxycyclohexene: Regiochemistry” Tetrahedron Letts 1991, 32, 4077-4080.


20. Dahlke, G. D.; Kass, S. R. “Substituent Effects in the Gas Phase: 1-Substituted Allyl Anions” J. Am. Chem. Soc. 1991, 113, 5566-5573.


19. Kroeker, R. L.; Bachrach, S. M.; Kass, S. R., “Ab Initio Calculations on the Diazirinyl Anion. A Nonaromatic Species” J. Org. Chem. 1991, 56, 4062-4064.


18. Chou, P. K.; Kass, S. R. “(E) and (Z) Vinyl Anions. The Formation and Characterization of Regio- and Stereoisomers in the Gas Phase” J. Am. Chem. Soc. 1991, 113, 4357-4359.


17. Chou, P. K; Kass, S. R., “C4H4 Negative Ions: Formation of the Bicyclo[1.1.0]but-1(3)-ene Radical Anion and An Experiental Determination of the Heat of Formation of Bicyclo[1.1.0]but-1(3)-ene” J. Am. Chem. Soc. 1991, 113, 697-698.


16. Kroeker, R. L.; Kass, S. R, “Diazirinyl Anion: A Cyclic Four π-Electron System” J. Am. Chem. Soc. 1990, 112, 9024-9025.


15. Kass, S. R.; Guo, H.; Dahlke, G. D., “The Formation and Reactivity of the Thiomethyl Anion” J. Am. Soc. Mass Spectrom. 1990, 1, 366-371.


14. Kass, S. R., “Hydrocarbon Acidities Calculated with MINDO/3, MNDO, and AM1” J. Comput. Chem. 1990, 11, 94-104.


13. Anderson, K. K.; Kass, S. R., “Vinyl Anion Synthesis In the Gas Phase” Tetrahedron Letts 1989, 30, 3045-3048.


12. Kass, S. R.; Chou, P. K., “The Bicyclobutyl Anion: An Alkyl Carbanion” J. Am. Chem. Soc. 1988, 110, 7899-7900.


11. DePuy, C. H.; Van Doren, J. M.; Gronert, S.; Kass, S. R.; Motell, E. L.; Ellison, G. B.; Bierbaum, V., “Gas Phase Negative Ion Chemistry of Diazomethane” J. Org. Chem. 1989, 54, 1846-1850.


10. DePuy, C. H.; Kass, S. R.; Bean, G. P., “Formation and Reactions of Heteroaromatic Anions in the Gas Phase” J. Org. Chem. 1988, 53, 4427-4433.


9. Damrauer, R.; Kass, S. R.; DePuy, C. H. “Gas-Phase Acidities of Methylsilanes: C-H versus Si-H” Organometallics. 1988, 7, 637-640.


8 Shiner, C. S.; Vorndam, P. E.; Kass, S. R., “Gas-Phase Acidities and Heats of Formation of 2,4- and 2,5-Cyclohexadien-1-one, the Keto Tautomers of Phenol” J. Am. Chem. Soc. 1986, 108, 5699-5701.


7. Kass, S. R.; Filley, J.; Van Doren, J. M.; DePuy, C. H., “Nitrous Oxide in Gas Phase Ion- Molecule Chemistry: A Versatile Reagent for the Determination of Carbanion Structure” J. Am. Chem. Soc. 1986, 108, 2849-2852.


6. Kass, S. R.; DePuy, C. H., “Gas-Phase Ion Chemistry of Azides. The Generation of CH2=N- and CH2=NCH2-” J. Org. Chem. 1985, 50, 2874-2877.


5. Jones, M. E.; Kass, S. R.; Filley, J.; Barkley, R. M.; Ellison, G. B.,”Alkylation of Enolate Ions” J. Am. Chem. Soc. 1985, 107, 109-115.


4. Wiberg, K. B.; Kass, S. R.; de Meijere, A.; Bishop, K. C., “Electrophilic Cleavage of Cyclopropanes. Acetolysis of Bicyclic and Tricyclic Cyclopropanes” J. Am. Chem. Soc. 1985, 107, 1003-1007.


3. Wiberg, K. B.; Kass, S. R.; Bishop, K. C., “Electrophilic Cleavage of Cyclopropanes. Acetolysis of Bicyclo[2.1.0]pentane and Bicyclo[3.1.0]hexane” J. Am. Chem. Soc. 1985, 107, 996-1002.


2. Wiberg, K. B.; Kass, S. R., “Electrophilic Cleavage of Cyclopropanes Acetolysis of Alkylcyclopropanes” J. Am. Chem. Soc. 1985, 107, 988-995.


1. Wiberg, K. B.; Lupton, E. C., Jr.; Wasserman, D. J.; de Meijere, A.; Kass, S. R., “Enthalpies of Formation of cis- and trans-1,2-Diethylcyclopropane and cis- and trans-Bicyclo[6.1.0]- nonane. Structural Effects on Energies of Cyclopropane Rings” J. Am. Chem. Soc. 1984, 106, 1740-1744.