Preparation and Preparation and Luminescence of Luminescence of

Naphthylated MetallolesNaphthylated Metalloles

Kristopher Fecteau

Summer 2007 SURF research project

Research ObjectivesResearch Objectives

Synthesize naphthylated metalloles that Synthesize naphthylated metalloles that are candidates for biological probes (DNA are candidates for biological probes (DNA intercalating agents)intercalating agents)

Compile spectral data of new compounds Compile spectral data of new compounds and their intermediatesand their intermediates

Gain a better understanding of what is Gain a better understanding of what is involved in organic synthesisinvolved in organic synthesis

What is a metallole?What is a metallole? A metallole is a five A metallole is a five membered carbon ring membered carbon ring (pentadiene ring) (pentadiene ring) containing one metallic containing one metallic atom (silicon is shown)atom (silicon is shown)

Each carbon atom Each carbon atom (arrows) represents an (arrows) represents an opportunity for opportunity for substitution, creating substitution, creating different metalloles, as different metalloles, as do each of the –R do each of the –R groups bonded to the groups bonded to the metallic atommetallic atom

Si

R R

1

2

34

5

Luminescence of MetallolesLuminescence of Metalloles

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

LuminescenceLuminescence

under normal light under ultraviolet light

The Naphthyl GroupThe Naphthyl Group

The naphthyl group is a 10-carbon ringThe naphthyl group is a 10-carbon ring

The group’s planar structure and wide area allow The group’s planar structure and wide area allow it to intercalate into DNA (insert itself between it to intercalate into DNA (insert itself between two base pairs)two base pairs)

H

H H

H

H

HH

H

Naphthalene The naphthyl group(hydrogens not shown)

Naphthylated MetallolesNaphthylated Metalloles

Naphthylated metalloles are substituted Naphthylated metalloles are substituted with naphthyl groups on the pentadiene with naphthyl groups on the pentadiene ringring

Si

CH3CH3 SiCH3

CH3

2,5-naphthyl substituted(previously synthesized) 3,4-naphthyl substituted

(never before synthesized)

LuminescenceLuminescence

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

Metallole SynthesisMetallole Synthesis

CHLi

R 2 S iC l222 n B u L i

2

Si

R

R

L iN a p h

Si

R R

LiLi

1 )Z n ( tm e n )C l2

2 )P d (P P h 3 ) 2 C l2

I

+2Si

RR

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

Current WorkCurrent Work

Synthesis of the 2,5-naphthyl substituted Synthesis of the 2,5-naphthyl substituted silole where R=methyl (CHsilole where R=methyl (CH33) (known ) (known compound)compound)Synthesis of 2,5-naphthyl substituted Synthesis of 2,5-naphthyl substituted siloles with different R-groups (e.g. phenyl, siloles with different R-groups (e.g. phenyl, CC66HH55) which are novel compounds) which are novel compounds

Complete spectral analysis of these Complete spectral analysis of these compounds including measuring their compounds including measuring their luminescent propertiesluminescent properties

SpectroscopySpectroscopy

Nuclear Magnetic Resonance (NMR)- Nuclear Magnetic Resonance (NMR)- 1313C C and and 11H spectraH spectra

Infrared (IR) spectraInfrared (IR) spectra

Mass spectraMass spectra

Ultraviolet spectraUltraviolet spectra

All of these forms of spectroscopy provide data that,used together, allow us to identify and characterize the compounds being synthesized.

11H-NMR SpectrumH-NMR Spectrum

IR SpectrumIR Spectrum

Future WorkFuture Work

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

Synthesis of naphthylated germolesSynthesis of naphthylated germoles

Future WorkFuture Work

We will need to synthesize one of the We will need to synthesize one of the starting acetylenes for the 3,4-naphthyl starting acetylenes for the 3,4-naphthyl substituted metalloles:substituted metalloles:

CH Si

CH3

CH3

CH3 +Br

Si

CH3

CH3

CH3

CH

The corresponding silicon diyne will be made from thisacetylene just as before, which will be used to make thenovel metalloles

AcknowledgmentsAcknowledgments

Professor Hank Tracy, USM Dept. of ChemistryProfessor Hank Tracy, USM Dept. of Chemistry – – 2007 SURF Advisor2007 SURF Advisor

Trevor Bozeman, 2006 SURF participantTrevor Bozeman, 2006 SURF participant

Thanks also to Professor James Ford, USM, and Thanks also to Professor James Ford, USM, and Professor Nick Benfaremo, Saint Joseph’s Professor Nick Benfaremo, Saint Joseph’s CollegeCollege