<html xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<meta name="Generator" content="Microsoft Word 15 (filtered medium)">
<style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:"Calibri Light";
panose-1:2 15 3 2 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Calibri",sans-serif;}
h1
{mso-style-priority:9;
mso-style-link:"Heading 1 Char";
margin-top:12.0pt;
margin-right:0in;
margin-bottom:0in;
margin-left:0in;
margin-bottom:.0001pt;
page-break-after:avoid;
font-size:16.0pt;
font-family:"Calibri Light",sans-serif;
color:#2F5496;
font-weight:normal;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:#0563C1;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:#954F72;
text-decoration:underline;}
p.msonormal0, li.msonormal0, div.msonormal0
{mso-style-name:msonormal;
mso-margin-top-alt:auto;
margin-right:0in;
mso-margin-bottom-alt:auto;
margin-left:0in;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}
span.Heading1Char
{mso-style-name:"Heading 1 Char";
mso-style-priority:9;
mso-style-link:"Heading 1";
font-family:"Calibri Light",sans-serif;
color:#2F5496;}
span.EmailStyle19
{mso-style-type:personal;
font-family:"Calibri",sans-serif;
color:windowtext;}
span.EmailStyle20
{mso-style-type:personal;
font-family:"Calibri",sans-serif;
color:windowtext;}
span.EmailStyle21
{mso-style-type:personal;
font-family:"Calibri",sans-serif;
color:windowtext;}
span.EmailStyle22
{mso-style-type:personal;
font-family:"Calibri",sans-serif;
color:windowtext;}
span.EmailStyle23
{mso-style-type:personal;
font-family:"Calibri",sans-serif;
color:windowtext;}
span.EmailStyle24
{mso-style-type:personal;
font-family:"Calibri",sans-serif;
color:windowtext;}
span.EmailStyle25
{mso-style-type:personal;
font-family:"Calibri",sans-serif;
color:windowtext;}
span.EmailStyle26
{mso-style-type:personal;
font-family:"Calibri",sans-serif;
color:windowtext;}
span.EmailStyle27
{mso-style-type:personal;
font-family:"Calibri",sans-serif;
color:windowtext;}
span.EmailStyle28
{mso-style-type:personal;
font-family:"Calibri",sans-serif;
color:windowtext;}
span.EmailStyle29
{mso-style-type:personal;
font-family:"Calibri",sans-serif;
color:windowtext;}
span.EmailStyle30
{mso-style-type:personal;
font-family:"Calibri",sans-serif;
color:windowtext;}
span.EmailStyle31
{mso-style-type:personal;
font-family:"Calibri",sans-serif;
color:windowtext;}
span.EmailStyle32
{mso-style-type:personal;
font-family:"Calibri",sans-serif;
color:windowtext;}
span.EmailStyle33
{mso-style-type:personal;
font-family:"Calibri",sans-serif;
color:windowtext;}
span.EmailStyle34
{mso-style-type:personal;
font-family:"Calibri",sans-serif;
color:windowtext;}
span.apple-converted-space
{mso-style-name:apple-converted-space;}
span.EmailStyle36
{mso-style-type:personal;
font-family:"Calibri",sans-serif;
color:windowtext;}
span.EmailStyle37
{mso-style-type:personal;
font-family:"Calibri",sans-serif;
color:windowtext;}
span.EmailStyle38
{mso-style-type:personal-reply;
font-family:"Calibri",sans-serif;
color:windowtext;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
--></style>
</head>
<body lang="EN-US" link="#0563C1" vlink="#954F72">
<div class="WordSection1">
<p class="MsoNormal"><span style="font-size:14.0pt">There will be a Modern Optics and Spectroscopy Seminar held tomorrow,<b> December 4 at 12pm
</b>in <b><span style="color:red">56-154</span></b></span><o:p></o:p></p>
<p class="MsoNormal"><b><span style="font-size:14.0pt;color:red"> </span></b><o:p></o:p></p>
<p class="MsoNormal"><b><span style="font-size:14.0pt;color:red">**Please note location**</span></b><o:p></o:p></p>
<p class="MsoNormal"><b><span style="font-size:14.0pt"> </span></b><o:p></o:p></p>
<p class="MsoNormal"><b><span style="font-size:16.0pt">Andrew H. Marcus</span></b><o:p></o:p></p>
<p class="MsoNormal"><i><span style="font-size:16.0pt">University of Oregon</span></i><i><span style="font-size:14.0pt"><br>
<br>
</span></i><b><i><span style="font-size:16.0pt;color:black">“Spectroscopic studies of exciton-coupled cyanine dimers in model DNA fork constructs”</span></i></b><o:p></o:p></p>
<p class="MsoNormal"><i><span style="font-size:16.0pt;color:black"> </span></i><o:p></o:p></p>
<p class="MsoNormal"><i><span style="font-size:14.0pt;color:black">Understanding the properties of electronically interacting molecular chromophores, which involve internally coupled electronic-vibrational motions, is important to the spectroscopy of many biologically
relevant systems. We apply linear absorption, circular dichroism (CD), and two-dimensional fluorescence spectroscopy (2DFS) to study the polarized collective excitations of coupled cyanine dimers (composed of Cy3), which are rigidly positioned within the opposing
sugar-phosphate backbones near the junctions of double-stranded (ds) – single-stranded (ss) DNA fork construct. We show that the exciton-coupling strength of the (Cy3)2-DNA construct can be systematically varied with temperature below the ds – ss DNA denaturation
transition. We interpret spectroscopic measurements in terms of the Holstein-Frenkel vibronic dimer model, from which we obtain information about the local conformation of the (Cy3)2 dimer, as well as the degree of static disorder experienced by the cyanine
monomer and dimer probes locally within their respective DNA fork junction environments. The properties of these cyanine labeled DNA constructs that we have determined suggest that these systems may be employed as useful models to test fundamental concepts
of protein-DNA interactions, and the role of electronic-vibrational coherence in electronic energy migration within exciton-coupled bio-molecular arrays.</span></i><o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal">Refreshments will be served immediately following the seminar<o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> </span><o:p></o:p></p>
<p class="MsoNormal"><b><span style="font-size:11.0pt">Christine Brooks</span></b><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Administrative Assistant</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Massachusetts Institute of Technology</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Department of Chemistry</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt">77 Massachusetts Ave, 6-333</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Cambridge, MA 02139</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt">p: 617.253.7239</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt">e: <a href="mailto:cbrooks@mit.edu">cbrooks@mit.edu</a></span><o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
</div>
</body>
</html>