Rauchfuss ideas

# Small Molecule Transformations, some so-called "Grand Challenges"

-   Synthetic systems cannot simulate the O~2~ evolving reaction; the
    enzyme structure has recently been refined at high resolution.

-   Chemists have not (?) harnessed electron-hole separations in useful
    organic catalysis. This is key to molecular-level approaches to and
    understanding of photo-water splitting, which we know is in our
    future.

-   Fuel cell scientists are challenged by O~2~ reduction catalysis. The
    cofacial porphyrin approach did not pan out. What needs to be done,
    i.e. bi- or multi-metallic designs?

-   Replicate MMO: CH~4~ + O~2~  CH~3~OH or should we just give up?

-   We do not know the mechanism of methanogenesis (and its reverse),
    which is responsible for most of earth's combustable energy
    reserves.

# Clusters

-   Why do we see so little catalysis by multi-metallic complexes?
    Contrast: proven effectiveness of multi-metallic catalysis in
    Nature.

-   Why does Nature use M-S clusters and, with the exception of HDS, we
    don't: N~2~-ase, H~2~-ase, CO + H~2~O.

-   Roles of interstitial atoms in cluster tuning and gluing, e.g. in
    N~2~-ase and Corbett-like, e.g. Zr~6~(μ~6~-C)Cl~x~ clusters.

# Ligands

-   "In the beginning" all ligands did was just coordinate, next they
    conferred steric bulk (Tolman), chirality (Sharpless, Noyori, etc.),
    and special solubility (fluorous), but most ligands remain lightly
    functionalized.

-   Ligands could be designed to recognize specific substrates or sense
    their environment (e.g. pH). Would this be useful? One approach:
    hybrids of "organic catalysis" (e.g. proline catalysis) and
    organometallic catalysis.

-   Megaligands: Schrock's super tripod, buckyballs and fragments
    thereof, Feher's silsequioxane and beyond: advantages,
    breakthroughs, challenges?

-   High temperature ligands: Organometallic chemists are acclimated to
    0-120C, but industry and heterogeneous catalyzers work at higher
    temperatures. The Perriana/Goldman/Kaska chemistry points to absence
    of design rules underpinning more rugged ligands.

-   Classical ligands - amines/imines are increasingly popular because
    they have been lightly studied by organometallic chemists, despite
    100 years of Werner chemistry. What other "old-fashioned" ligands
    remain to be re-discovered?

-   Research based on porphyrins/cobalamin has been particularly
    fruitful, what other bio-motifs await exploitation? E.g.
    Mn~3~O~x~L~n~.

-   Cp, TACN, Tp have proven useful because they are manipulable. Other
    facial ligand classes?

-   The diimines are especially amenable to ligand tuning, related
    opportunities?

# Homogeneous-Heterogeneous interface themes

-   What are the prospects for designing multidentate ligands to allow
    well-defined surface coordination chemistry and catalysis? (esp.
    beyond Au)

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-   Potential advantages to tandem, one-pot heterogeneous-homogeneous
    catalysis (i.e. slurry of heterog. Catalyst in a soln of
    homogeneous). Combined one-pot tandem homogeneous catalysis (e.g.,
    Bazan work)

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-   What kinds of catalysis are sought by the sensor community?

-   Electrode-coupled organometallic catalysis: advantages,
    breakthroughs, challenges

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-   Oxides: What is Adams' catalyst, PtO~x~ and are there solution
    analogues? Solution analogues of AgO~x~ related to ethylene oxide
    synthesis.

-   Sulfides: What exactly is the active phase of Co-MoS~x~ HDS
    catalysts?

-   What are the active TiCl~x~ and VCl~x~ species in Ziegler-Natta,
    still a key family of catalysts. Or is this hopeless?

-   Bucky-tubes, both single and multiwalled as containers, supports.

-   Similarly for specially fabricated silicon.

# 

# Homogeneous themes

-   Relative advantages to heterolytic vs. homolytic H~2~ activation
    (Noyori vs. Wilkinson)? Should we be shifting to heterolytic
    hydrogenation, related processes for hydroformylation, etc?

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-   Odd electron catalysts, why isn't there more?

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-   Hyperelectrophilic complexes (e.g. are there olefin analogues to
    Ir(CO)~6~^3+^?

-   To what extent can main group catalysts supplant more expensive,
    more toxic TM catalysts, e.g. Al catalysis of alkene polymerization

# Hybrid bio-organometallics catalysis

-   Shape selectivity conferred by the protein and novel reactivity
    conferred by the organometallic center, or can proteins really
    support interesting, abiological catalysis.

-   What methods exist for connecting ("conjugating") organometallics
    with proteins? e.g. phosphine-substituted amino acids,
    biotin-ligands, etc.

-   Similarly: hybrids with lipids, nucleic acids, sugars

# Redox

-   For redox-coupled or redox-switchable catalysis

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-   Many metallo-enzymes are covalently linked to redox centers: what
    are the advantages to nature and why we don't we use this motif?
    E.g. prior work by Wrighton on Fc-PR~2~.

-   Oxyanionic ligands for atom transfer, c.f. bismuthate and tellurate
    in ammoxidation.

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-   Little literature exists on the redox properties of metal hydrides
    and dihydrogen complexes, although this knowledge underpins design
    rules relevant to H~2~ production and some fuel cell applications.

# 

# Reaction media

-   Novel solvents (e.g., *o*-C~6~H~4~F~2~) ionic liquids,
    super-critical solvents

-   Novel anions and cations that are even less interacting or
    interestingly interacting (second sphere effects)

**Practical tools many researchers seek**

-   In situ techniques have transformed the study of organometallic
    catalysis resealable NMR tubes, high pressure NMR, React-IR, HPLC,
    ESI-MS (analogous in-situ methods are key in heterogeneous
    catalysis).

-   Molecular modeling: how-to's, short-cuts, risks.

-   Strategies for screening catalysis: how-to's, short-cuts, risks

# DOE advantages

-   DOE can uniquely tap into actinide chemistry, what distinctive areas
    of catalysis could this expertise enable?

-   DOE can uniquely tap into isotopes for mechanistic studies -
    tritium, labeled metals. What is available and what distinctive
    opportunities exist?

-   Comment: In some ways, DOEs establishment of facilities (special
    reactors) and more specialized reagents would be more useful (to
    many chemistry users) than mega-facilities.