Resume

• 2010

  Doctor of Philosophy (Ph.D.)

  Chemistry

  Vanderbilt University

• 2006

  Bachelor of Science (B.S.)

  Chemistry

• Pyrophoric material handling and disposal

  Nuclear Magnetic Resonance (NMR)

  Intert atmosphere chemical synthesis

  Research

  Lecturing

  Chemistry

  University Teaching

  Reaction environment and ligand lability in group 4 Cp2MXY (X

  Y = Cl

  OtBu) complexes

  William W. Brennessel

  Grant W. Steelman

  Eric J. Bierschenk

  Despite their usefulness in catalytic and materials chemistry

  the mixed cyclopentadienyl/alkoxide\ncomplexes of Ti

  Zr

  and Hf (Cp2M(OR)2) have few reliable synthetic routes available to them. We describe the use of mechanical ball milling to promote halide metathesis from Cp2MCl2

  and compare these results to those obtained in hexanes and THF. Even without solvent

  ring lability is extensive with titanium complexes

  and alkoxide compounds with 0–3 Cp rings are isolated. The ball milling reactions are much faster than those in solution

  but the distributions of products are similar to those obtained in hexanes

  although different from those in THF. The range of compounds obtained from Zr and Hf starting materials is more limited

  as Cp ring exchange does not occur.

  Reaction environment and ligand lability in group 4 Cp2MXY (X

  Y = Cl

  OtBu) complexes

  Arnold L. Rheingold

  Timothy P. Hanusa

  Mechanochemical Synthesis of [1

  3-(SiMe3)2C3H3]3(Al

  Sc)

  a Base-Free Tris(allyl)aluminum Complex and Its Scandium Analogue

  Abstract\nThe ball milling of beryllium chloride with two equivalents of the potassium salt of bis(1

  3-trimethylsilyl)allyl anion

  K[A′] (A′ = [1

  3-(SiMe3)2C3H3])

  produces the tris(allyl)beryllate K[BeA’3] (1) rather than the expected neutral BeA’2. The same product is obtained from reaction in hexanes; in contrast

  although a similar reaction conducted in Et2O was previously shown to produce the solvated species BeA’2(OEt2)

  it can produce 1 if the reaction time is extended (16 h). The tris(allyl)beryllate is fluxional in solution

  and displays the strongly downfield 9Be NMR shift expected for a three-coordinate Be center (δ22.8 ppm). A single crystal X-ray structure reveals that the three allyl ligands are bound to beryllium in an arrangement with approximate C3 symmetry (Be–C (avg) = 1.805(10) Å)

  with the potassium cation engaging in cation–π interactions with the double bonds of the allyl ligands. Similar structures have previously been found in complexes of zinc and tin

  i.e.

  M[M′A′3L] (M′ = Zn

  M = Li

  Na

  K; M′ = Sn

  M = K; L = thf). Density functional theory (DFT) calculations indicate that the observed C3-symmetric framework of the isolated anion ([BeA′3]−) is 20 kJ·mol−1 higher in energy than a C1 arrangement; the K+ counterion evidently plays a critical role in templating the final conformation

  Symmetric Assembly of a Sterically Encumbered Allyl Complex: Mechanochemical and Solution Synthesis of the Tris(allyl)beryllate

  K[BeA′3] (A′ = 1

  3-(SiMe3)2C3H3)

  Keith T. Quisenberry

  Balancing Adduct Formation and Ligand Coupling with the Bulky Allyl Complexes [1

  3-(SiMe3)2C3H3]2M (M = Fe

  Co

  Ni

  David L. Bruns

  William W. Brennessel

  The stereochemical outcomes of reactions conducted in solution and those under mechanochemical conditions need not be the same; this is a well-established observation in organic synthesis

  but few examples are known in organometallic systems. Halide metathesis is now shown to be a type of mechanochemical reaction that can produce different ratios of stereoisomers depending on whether the reagents are dissolved or ball-milled. Trihalides of As (X = I)

  Sb (X = Cl)

  and Bi (X = Cl) react with K[A′] (A′ = 1

  3-(SiMe3)2C3H3) (As

  Sb) or [AlA′3] (Bi) to generate the tris(allyl) complexes [EA′3]. All three complexes are found in two diastereomeric forms of C1 (R

  S

  S) and C3 (R

  R

  R) symmetry

  and mechanochemical synthesis increases the C1:C3 ratio relative to that produced in hexanes solution (up to 3.3× in the case of [AsA′3]). The stereoselectivity of the metathesis in the solid state can be correlated with the asymmetric environment found in the group 15 trihalides; mechanochemical induction provides a new tool for influencing this important class of synthetic reactions.

  Mechanochemical Influence on the Stereoselectivity of Halide Metathesis: Synthesis of Group 15 Tris(allyl) Complexes

  Solvent-based syntheses have long been normative in all areas of chemistry

  although mechanochemical methods (specifically grinding and milling) have been used to good effect for decades in organic

  and to a lesser but growing extent

  inorganic coordination chemistry. Organometallic synthesis

  in contrast

  represents a relatively underdeveloped area for mechanochemical research

  and the potential benefits are considerable. From access to new classes of unsolvated complexes

  to control over stoichiometries that have not been observed in solution routes

  mechanochemical (or ‘M-chem’) approaches have much to offer the synthetic chemist. It has already become clear that removing the solvent from an organometallic reaction can change reaction pathways considerably

  so that prediction of the outcome is not always straightforward. This Perspective reviews recent developments in the field

  and describes equipment that can be used in organometallic synthesis. Synthetic chemists are encouraged to add mechanochemical methods to their repertoire in the search for new and highly reactive metal complexes and novel types of organometallic transformations

  Advances in organometallic synthesis with mechanochemical methods

  Nicholas

  Rightmire

  LOADMASTER LUBRICANTS

  University of Nevada

  Reno

  Vanderbilt University

  Bellarmine University

  Bellarmine University Department of Chemistry

  UC Irvine

  Louisville

  Kentucky Area

  •Academic year: Lead a weekly problem and tutoring session hosted by the department to supplement lectures and prepare students for exams\n\n•Summer 2009: Instructed two-hour review sessions four times a week to supplement summer chemistry course\n

  Chemistry Undergraduate TA

  Bellarmine University Department of Chemistry

  Bellarmine University

  LOADMASTER LUBRICANTS

  Hugo

  MN

  Research

  Development

  and Formulation Chemist

  Irvine

  CA

  Investigated the synthesis and properties of low-valent uranium and thorium compounds \n\nMentored graduate student researchers in common chemistry procedures

  safety practices

  and conducting research towards earning a degree

  Postdoctoral Research Fellow

  UC Irvine

  Greater Nashville Area

  TN

  Lead a Q&A panel of experienced TA’s and facilitated practice teaching exercises for new students as part of the yearly Teaching Assistant Orientation (TAO) for incoming and first year Chemistry graduate students.

  Practicee and Pedagogy Leader

  Vanderbilt University

  Reno

  Nevada Area

  Teaching centered postdoctoral position as instructor of record for two lectures a semester\n\nChem121A: First Semester of General Chemistry \n•\tSpring 2017: Two sections (~450 students)\n•\tFall 2017: One section (~250 students)\n•\tSpring 2018: One section (~250 students)\n\nChem122A: Second Semester of General Chemistry\n•\tSpring 2018: One section (~250 students)\n\nChem220A: Introductory Organic Chemistry for Nursing Majors\n•\tSummer 2017 (~50students)\n•\tFall 2017 (~250 students)\n\nNevadaFIT: five-day

  intensive academic boot camp designed to increase success for incoming College of Science freshmen\n•\tFall 2017\n

  Postdoctoral Teaching Scholar

  University of Nevada

  Reno

  Greater Nashville Area

  TN

  Developed new mechanochemical synthesis methods and facilitated honors research for an undergraduate chemistry major during the semester and summer months.

  Graduate Research Assistant

  Vanderbilt University

  Greater Nashville Area

  TN

  Instructed general chemistry laboratory as an independent course from lecture

  Graduate Teaching Assistant

  Vanderbilt University

  Greater Nashville Area

  TN

  Instructed five to six weekly discussion sessions of 20 to 30 students to supplement general chemistry lecture with problem sets and quizzes covering information from lecture

  Graduate Teaching Fellow

  Vanderbilt University