Synthesis of different classes of five/six membered heterocyclic cyanine dyes: A review

Abstract

In this paper, synthesis of different classes of five/six membered heterocyclic cyanine dyes has been reviewed. In this paper review detailed synthesis steps were represented via equations. The synthesis covers, monomethine cyanine dyes (simple cyanine dyes), dimethine cyanine dyes, trimethine cyanine dyes (carbocyanine dyes), styryl cyanine dyes (hemicyanine dyes), aza-styryl cyanine dyes (aza-hemicyanine dyes and/or aza-cyanine dyes), merocyanine dyes (acyclic merocyanine dyes and cyclic merocyanine dyes) and apocyanine dyes. Besides, in the introduction section of this review paper some light is focused on the uses, applications and properties of cyanine dyes. This review paper is informative, useful and very readable for synthetic dye chemists, researchers and students who look for the different methods in the synthesis and preparation of various classes of five/six membered heterocyclic cyanine dyes with special emphasize in the field of heterocyclic and/or cyanine dyes chemistry. This specific type of collective review in the synthesis of different classes of only five/six membered heterocyclic cyanine dyes has been paid little attention and has great importance in the chemistry literature.