[text only]
Brian A. O'Brien
 

Brian A. O'Brien homepages.gac.edu/~bobrien

    We have a number of projects in synthetic chemistry that are suitable, at various stages, for students of any standing from beginning freshmen to seniors. Brief descriptions of some of the projects that are available follow. Much more detail on some of the phosporus chemistry projects can be found in current proposals that can be accessed (on-campus access only) by clicking here.

    We are currently working on a diverse group of projects, some of which are described below. I will be glad to personally discuss the research with you in more detail if you so desire. If you're interested, you may stop by my office (Nobel 303A) for discussion of the possibilities. A call or e-mail ahead to make sure that I will be available is a good idea; my office telephone number is 933-7310; my e-mail address is bobrien@gustavus.edu or bobrien@gac.edu.

    Beginning students will usually be assigned to work on organic synthesis projects that aim to produce intermediate compounds for more advanced projects. Such projects serve not only to further the research effort - they also constitute an excellent method for learning of spectroscopy [nuclear magnetic resonance (NMR), infrared (IR)], methods for handling sensitive materials with exclusion of atmospheric moisture and oxygen (glove box and Schlenk apparatus), and mechanistic and structural organic chemistry.

    Inorganic synthesis projects are also available - for instance, the preparation of transition metal coordination compounds for further use in the more advanced projects. A good example of this is the preparation of ethylene(bis-triphenylphosphine) platinum(0) [formula: (Ph3P)2Pt(C2H4)] by a five-step sequence that begins with metallic platinum.

    Another aspect of synthesis in which we have an interest is in development of new experiments for the Organic and Inorganic courses. One such experiment, titled "Simple Preparation and NMR Analysis of mer and fac Isomers of Tris(1,1,1-trifluoro-2,4-pentanedionato)cobalt(III): An Experiment for the Inorganic Chemistry Laboratory," appeared in the July 2001 issue of the Journal of Chemical Education. Much of the research on development of this experiment was done by Ashley Jensen, a current Gustavus senior and coauthor of the paper. There is at present a need for student researchers to work on experiments on synthesis of chiral coordination complexes, chemistry of n-butylferrocene, and isolation and NMR and IR analysis of natural products.

    An alternative view of the nature of our research projects can be heard if you discuss them with the students who are currently working on them. Current research students' names are listed under each subheading.

    A poster presentation on recent developments in our acylphosphine chemistry, given on November 6, 1999 by Ryan Nelson at the National Meeting of Sigma Xi, the Scientific Research Society, is on display outside of Nobel 304.

    A presentation on further research on acylphosphine chemistry was given at the 219th American Chemical Society meeting in San Francisco, March 26- 30, by Ryan Nelson and
    Jeffrey Johnson. For the presentation abstract, click on the highlighted link: our paper was #112 .
    A paper on this work has been published in Organometallics this year.

    Philip Sass will be making a research presentation at the 222nd American Chemical Society meeting in Chicago in August 2001. The title is "Preparation of Primary Alkylphosphines by a Phospha-Gabriel Route". Coauthors on the paper are Jeffrey Johnson, Ryan Nelson, and Brian O'Brien.

    To view a list of projects in addition to those described on this page, click here.

    Phosphorus Chemistry
    [Philip Sass (Spring & Summer 2001), Ryan Nelson (June 2000 graduate),
    Jeffrey Johnson
    (June 2000 graduate)]

    Investigations in one main general area in which we are working encompass three areas of phosphorus chemistry. The first two sub-areas are related: we are investigating two different methods for construction of organic phosphorus-containing molecules in such a way as to electronically tune the back-bonding ability (i.e. cause the d orbitals of the phosphorus atom to interact with appropriate metal orbitals). The third area deals with compounds in which phosphorus is connected to other atoms through double or triple bonds; compounds of this nature are recent discoveries, so much of their chemistry is unexplored.  n the general area of phosphorus chemistry are of interest because metal-phosphorus compounds are important as tools for the synthesis of organic molecules which have both biological and industrial importance; in addition, main-group compounds of phosphorus are of current interest in the development of new syntheses of semiconducting and photovoltaic materials.

    Students who do research in the phosphorus chemistry projects learn laboratory techniques to which they might not otherwise be exposed, such as vacuum-line manipulation of gases, work at low temperatures, and work under oxygen-free conditions (glove box or Schlenk line operations) with compounds which are highly air-sensitive.  Extensive use of multinuclear NMR spectroscopy (so far including 31P, 19F, 1H, 13C, and 119Sn NMR) is also necessary for the analysis of the compounds with which we work.  A considerable amount of organic synthesis is also required  for construction of the organic backbones of the phosphorus-containing molecules. 

    Osmium, Rhenium, and Ruthenium Chemistry [no current students]

    Students in our group have prepared and characterized a unique compound in which osmium is bound simultaneously to four nitrogen atoms and an oxygen atom. Current work is focused on a new and improved method for preparation of the diamine that is used in the synthesis, and investigation of further coordination chemistry of the diamine and ligands prepared from it.  The chemistry associated with this project is of importance in the understanding of the reactions of Os(VIII) compounds with organic compounds, which, in turn, is of practical importance in organic synthesis. A project to expand this chemistry to include other high-valent transition metal comounds will be initiated in the near future.

    tert-Alkylation of Aromatic Substrates through Friedel-Crafts Chemistry
    [Christopher Krug (June 2001 graduate); Donald Berkholz (Spring 2001 & Fall 2001)]

    This project is an exploration of the effects on the regioselectivity of alkylation of acenaphthene, catalyzed by various Lewis acids. Solvent effects are also under study. The ultimate goal of the project is preparation of variously substituted naphthalic anhydrides by oxidation of t-alkylated acenaphthenes.

    Preparation of 4-(2-aminoethoxy)phenytoin  [no current students]

    We hope to design a synthesis of this analog of phenytoin, a drug for the treatment of Parkinson's-Disease, for use in affinity chromatography. This is a collaborative project with John Lammert and his students in the Gustavus Adolphus Biology department.

    Friedel-Crafts Cyclialkyaltion of Phenol [no current students]

    We are preparing cyclialkylated products of phenol so as to elucidate the structures of the products that are formed under conditions of catalytic oxidation.

    Chemistry of Buckminsterfullerene [John Zupancich]

    One of the most spectacular and intriguing chemical discoveries ever made is the very recent discovery of a new allotrope of carbon. The two previously known allotropes are diamond, which is a covalent network solid, and graphite, which has a layer structure. The new, third allotrope contains 60 carbon atoms bonded into a spherical shape which has the same geometry as that of a soccer ball. The new allotrope, called buckminsterfullerene due to its resemblance to a geodesic dome, can be made simply by striking an electric arc between graphite electrodes in an atmosphere of helium.

    C60 has been found to be much more reactive than either diamond or graphite; our plan is to react it with strong electrophiles in an attempt to attach new types of functional groups to the C60 framework.



[home][up]

© 1998 Gustavus Adolphus College. All Rights Reserved.
Last modified: June 2001
by Brian A. O'Brien (bobrien@gustavus.edu)