NEW MATERIAL: A compd. represented by formula (wherein Z1 and Z2 are each H, hydrocarbyl, acyl, alloyl, alkylimino, acylimino, metallocene-CO or metallocene-CH2-, R1 and R2 are H, hydrocarbyl, acyl, aroyl, nitro, amino, OH, carbonyl or carboxyl and Z3 is hydrocarbyl or a metallocene residue and at least one of Z1-Z3 is a metallocene residue, Z3 is a metal complex of a heterocyclic group and metals of Z1-Z3 are a transition metal).

USE: This new material is used for an electron moving medium, chemical sensor design, a redox catalyst and a second harmonic generator material.

PROCESS: Resorcinol and carboxaldehyde are reacted to obtain a reaction product which is, in turn, reacted with a carboxylic acid (derivative) under a condition converting all of hydroxyl groups of the product to ester groups.