{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

l12 - CH 203 O R G A N I C C H E M I S T R Y I Optical...

Info icon This preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Optical activity © Bruno I. Rubio 1 CH 203 O R G A N I C C H E M I S T R Y I Optical activity The physical basis of optical activity A photon is associated with an electric vector and a magnetic vector that os- cillate in planes perpendicular to each other and perpendicular to the direc- tion of propagation of that photon, that is, if the photon is moving in the x direction, its electric vector oscillates in the y direction and its magnetic vector oscillates in the z direction. A beam of ordinary light propagating in the x direction consists of many photons whose electric vectors oscillate in planes that are random with respect to each other. The figure below shows photons of ordinary light propagating left to right and their associated os- cillating electric vectors: some electric vectors oscillate in the plane of the paper, whereas others at an angle to the plane of the paper. If the light passes through a polarizing filter (e.g., a sheet of Mylar plastic), only those photons whose electric vector oscillates in one specific plane emerge; the filter absorbs all other photons: polarizing filter The light that emerges from a polarizing filter is called plane-polarized or, simply, polarized light. If the plane of polarized light is rotated upon passing through a solution contained in a sample cell, the sample is said to be optically active: sample cell angle of rotation
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Optical activity © Bruno I. Rubio 2 When the experiment is performed under a set of standard conditions of tem- perature, solution concentration, sample-cell size, and nature of polarized light, the angle in degrees through which the plane of polarized light is ro- tated is denoted by the specific rotation [ ! ]. Some samples rotate the plane of polarized light in the clockwise direction: such samples are said to be dextrorotary and are denoted by the symbol (+). Some samples rotate the plane
Image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern