SYNTHESIS AND CHARACTERIZATION OF

IRON-CARBONYL CLUSTERS

Energy Crisis!

Hydrogen: Fuel of the future

Figure from: Crabtree, G.W.; Dresselhaus, M.S. MRS Bull. 2008, 33, 421-428.

Figures from: S. K. Ritter, C&EN 2011, 89 (45), 26-29.

Electrolyzer

Proton Onsite′s Electrolyzer

Hydrogenase Enzymes

Science , 2013, 342, pp. 472-475 

Our Focus: Aromatic Thiolates

Enzymatic Model

Iron-clusters

S S

Fe Fe

COOCCOOC

OC CO

H2N

H2N

a

S S

Fe Fe

OCCOCOOC

OC CONH2H2NS S

Fe Fe

COOCCOOC

OC CO

b c

NH2H2N

S S

Fe Fe

COOCCOOC

OC CO

H2N

H2N

S S

Fe Fe

OCCOCOOC

OC COH2N

S S

Fe Fe

COOCCOOC

OC CO

NH2H2N

NH2HS

NH2

HS

NH2

SH

C

Fe

Fe Fe

COOC

COOC

OC CO

CO

COOC

O

O

OC H2N

Synthesis of Iron Clusters

Separation of Product via Column Chromatography

S S

Fe Fe

COOCCOOC

OC CO

H2N

H2N

S S

Fe Fe

OCCOCOOC

OC CONH2H2N S S

Fe Fe

COOCCOOC

OC CO

NH2H2N

Infrared Spectroscopy

Wavenumber cm-1 Wavenumber cm-1

Wavenumber cm-1

Intramolecular H----S bonding

S S

Fe Fe

OCCOCOOC

OC COH2N

NH

H

Ortho Positioned Amine Ligand

S S

Fe Fe

OCCOCOOC

OC CONH2H2N

S S

Fe Fe

COOCCOOC

OC CO

H2N

H2N

Ultraviolet Visible Spectroscopy

Wavelength (nm)

Abs

orba

nce

Conclusion

1. Successfully made and characterized two new iron-clusters

2. IR and UV-Visible spectra show evidence of intra-molecular H---S bonding in Ortho-compound.

3. Further studies: we will look at the influence of the H---S interaction on the electrocatalytic properties of the compounds.

S S

Fe Fe

OCCOCOOC

OC CONH2H2N

S S

Fe Fe

COOCCOOC

OC CO

H2N

H2N

Acknowledgements

• Funding from ATU Undergraduate Research Grant 2015• Dr. Charles Mebi• Donald McCormick