Synthesis, characterisation and thermal stability of 5‐ferrocenylidene‐(1, 3‐dimethylbarbituric acid) and 5‐ferrocenylidene‐(1, 3‐diethylthiobarbituric acid)

Purpose To discuss synthesis and evaluation of organo‐metallic dyes as second‐order nonlinear optical (SONLO) material. Design/methodology/approach New dyes have been synthesised via Knovoenagel reactions of ferrocene carboxyaldehyde and two active methylene compounds. Findings The ferrocenyl dyes prepared have shown bathochromic shift and thermal stability. Practical implications These compounds have UV‐Vis bathochromic shift, enabling them to be used as SONLO materials as well as dyes. Originality/value The paper provides further information on the thermal studies of these types of molecules.