Polymethines are planar, conjugated compounds made up from an odd
number of methine groups (CH) linked together by alternating single and double bonds,
also known as cyanines. These highly conjugated compounds can absorb light at wide
range of wavelengths, ranging from ultraviolet to infra red, just depending on the
number of alternating double bonds present in their structure. Herein is presented a
conspectus on the field of cyanines, where emphasis is set on their preparation and
functionalization methods, along with more detailed examples on several promising
applications with 165 references provided. Some synthetic details on the preparation of
state-of-the-art compounds are given as well.
Keywords: Biolabeling, Cyanines, Infrared dyes, Near infrared dyes,
Polymethines, Ultra violet dyes.
