Preparation and Luminescence of Naphthylated Metalloles Kristopher Fecteau Summer 2007 SURF research project

Research Objectives Synthesize naphthylated metalloles that are candidates for biological probes (DNA intercalating agents) Synthesize naphthylated metalloles that are candidates for biological probes (DNA intercalating agents) Compile spectral data of new compounds and their intermediates Compile spectral data of new compounds and their intermediates Gain a better understanding of what is involved in organic synthesis Gain a better understanding of what is involved in organic synthesis

What is a metallole? A metallole is a five membered carbon ring (pentadiene ring) containing one metallic atom (silicon is shown) A metallole is a five membered carbon ring (pentadiene ring) containing one metallic atom (silicon is shown) Each carbon atom (arrows) represents an opportunity for substitution, creating different metalloles, as do each of the –R groups bonded to the metallic atom Each carbon atom (arrows) represents an opportunity for substitution, creating different metalloles, as do each of the –R groups bonded to the metallic atom

Luminescence of Metalloles Unlike most compounds, metalloles are luminescent, meaning that they emit visible light when excited by ultraviolet light (photoluminescence) or an electric current (electroluminescence) Luminescence occurs in rigid molecules having extended pi electron systems, which exist in the pentadiene ring of the metalloles

Luminescence under normal light under ultraviolet light

The Naphthyl Group The naphthyl group is a 10-carbon ring The group’s planar structure and wide area allow it to intercalate into DNA (insert itself between two base pairs) The group’s planar structure and wide area allow it to intercalate into DNA (insert itself between two base pairs) NaphthaleneThe naphthyl group (hydrogens not shown)

Naphthylated Metalloles Naphthylated metalloles are substituted with naphthyl groups on the pentadiene ring 2,5-naphthyl substituted (previously synthesized) 3,4-naphthyl substituted (never before synthesized)

Luminescence some crystals of the 2,5-naphthyl substituted silole under UV light

Metallole Synthesis One way of synthesizing metalloles is through a ring-closure reaction of a diynyl intermediate:

Current Work Synthesis of the 2,5-naphthyl substituted silole where R=methyl (CH 3 ) (known compound) Synthesis of 2,5-naphthyl substituted siloles with different R-groups (e.g. phenyl, C 6 H 5 ) which are novel compounds Complete spectral analysis of these compounds including measuring their luminescent properties

Spectroscopy Nuclear Magnetic Resonance (NMR)- 13 C and 1 H spectra Infrared (IR) spectra Mass spectra Ultraviolet spectra All of these forms of spectroscopy provide data that, used together, allow us to identify and characterize the compounds being synthesized.

1 H-NMR Spectrum

IR Spectrum

Future Work Synthesis and characterization of 3,4- naphthyl substituted siloles, which are novel compounds, as well as characterizing their diynyl intermediates, which have also never been made before Synthesis of naphthylated germoles

Future Work We will need to synthesize one of the starting acetylenes for the 3,4-naphthyl substituted metalloles: The corresponding silicon diyne will be made from this acetylene just as before, which will be used to make the novel metalloles

Acknowledgments Professor Hank Tracy, USM Dept. of Chemistry – 2007 SURF Advisor Trevor Bozeman, 2006 SURF participant Thanks also to Professor James Ford, USM, and Professor Nick Benfaremo, Saint Joseph’s College