Cyanine Dyes

Tue, 06/04/2013 - 15:58 -- sewm02

Cyanine Dyes


In this project you are required to

  1. perform the necessary calculations to prepare a dye solution with an absorbance between 0.5 and 1.0
  2. prepare a dye solution in methanol with the smallest possible amount of a given dye
  3. obtain an visible spectrum of the dye
  4. post your findings on this wiki page
  5. everybody is required to have seen and described in the notebook the solutions of all of the given dyes; this means you make them all by yourself or you share your solutions with your peers
  6. interpret the data meaningfully: talk to your laboratory instructor and refer to the "particle in a box" module in Physical Chemistry.
  7. prepare and submit a standard AIL laboratory report within one week after the completion of the PChem module.

Your plan of procedure needs to include:

  1. all necessary calculations for the preparation of the dye solutions.
  2. a detailed procedure how you will prepare the solutions.
  3. a back-up plan as to what you will do if your absorbance values don't fall withing the required range.

The Dyes

Below are the structures and the molecular weights of the dyes of interest. Your instructor will assign you one of these compounds. For your calculations you can assume that the extinction coefficients lie in the range of 1 x 105 to 1 x 106 L/(mol cm).

Image:Thiacyanine.gif Image:Carbocyanine.gif

Image:Dicarbocyanine.gif Image:Tricarbocyanine.gif


Your Data

Post your findings below.

Spring 2010

Larisa's Data

3,3'-diethylthiadicarbocyanine iodide

Molecular Weight: 518.48 gm/mol

lambda max: 650.00 nm

Absorbance (ave): 0.99

Concentration: 5.786 x 10-9 M


Mike's Data:

3,3'-diethylthiacyanine iodide

Molecular Weight: 466.4 gm/mol

lamba max: 423.00 nm

Absorbance (ave): 0.57

Concentration: 3.216 x 10-6 M

Sara's Data:

3,3’ diethylthiacyanine iodide

Molecular Weight: 466.4g/mol

Lambda max: 548.00nm

Absorbance: 3.792

Concentration: 2.573x10-5mol/L

Justin's Data:

3,3'-diethylthiatricarbocyanine iodide

Molecular Weight: 544.51 gm/mol

Lambda max: 758.00 nm

Absorbance: 2.136

Concentration: 7.346 x 10-6 M


Mark's data

3,3'-diethylthiatricarbocyanine iodide

Molecular Weight: 544.51 gm/mol

Lambda max: 757.00 nm

Absorbance: 3.615

Concentration: 1.836 X 10-7 M

Will's Data

1,1’-diethyl-2,2’-quinotricarbocyaninie iodide

Max wavelength: 743.00 nm

Absorbance: 1.334

Mwt: 532.46 g/mol

Concentration: 5.63*10^-5

Spring 2009

Your posts for Spring 2009 must include: the name of the dye, the concentration of the solution, lambda max, the extinction coefficient at lambda max, and the obtained spectrum. It is essential that your peak at lambda max has an absorbance value of 0.5 < A < 1.0 and that the spectrum has been scaled to the peak of interest.


Jana's data:

3,3'-diethylthiadicarbocyanine iodide

molecular weight = 518.48 ± 0.03 g/mol

Lamda max= 651. ± 3 nm

Absorbance = 0.729 ± 0.003

concentration = 7.29x10-6 M


3,3'-diethylthiacyanine iodide

molecular weight = 466.40 ± 0.03 g/mol


Lamda max= 423. ± 3 nm

Absorbance = 0.950 ± 0.003

concentration = 9.50x10-6 M

Tiffany's data:

3,3'- diethylthiatricarbocyanine iodide

Molecular weight: 544.51 ± 0.03

Lamda max= 758 ± 3nm

Absorbance= 0.746

COncentration= 7.46x10M

Greg's data:

3,3'-diethylthiacarbocyanine iodide

Lamda max = 557.0 nm

Absorbance = 0.765

Concentration = 7.65x10^-6 ±6.67x10^-7M

Data from Spring 2008:

3,3`-diethylthiacyanine iodide - Jordan Moran

Lambda max = 423.00 nm Absorbance = 0.360

3,3`-diethylthiatricarbocyanine iodide - Leslie Claypoole

Lambda max = 757.00 nm

Absorbance = 0.230

Megan Smith 3,3-diethylthiadicarbocyanine iodide Wavelength at 651 nm Absorbance of 0.988. Image:cyaninedyespectra.jpg

Amanda Tonkery 1,1-Diethyl-2,2 quinotricarbocyanine iodide Wavelength at 816nm Absorbance of 0.165


J.P. Johnson 1,1-Diethyl-2,2 quinotriaro cyanine iodido Wavelength at 820nm Absorbance of 0.2 Image:Cyaninedye3.jpg