Iron tethered carbon nitride has been developed and utilized as a recoverable heterogeneous catalyst for the construction of bis (hetero/homoarylidene)cycloalkanones in water, an environmentally nonthreatening medium at ambient temperature.

Iron integrated graphitic carbon nitride (GCN) was synthesized by adopting co-precipitation method. No appreciable change in XRD main peak of both GCN and Fe(III)-GCN indicates the lattice structure remains the same and there is no bulk doping of Fe(III). More sharp IR bands of Fe(III)-GCN between 1000 and 1750 cm⁻¹ compared with GCN reflect ordered packing of tri-s-triazine units in the nanosheets. Scanning electron microscopy (SEM) analysis reveals less thin and large two dimensional sheets have formed from bulk GCN during catalyst preparation. The absence of bright spots in transmission electron microscopy (TEM) indicates that there is no crystalline metal oxide phase confirming that iron(III) is present as ions. Fe(III)-GCN was then exploited as an efficient heterogeneous catalyst for the synthesis of bis (hetero/homoarylidene)cycloalkanones from heteroaromatic/homoaromatic carbaldehydes and cycloalkanone through carbon–carbon double bond construction. The reaction effected well in water, a green solvent as a reaction medium at ambient temperature. The catalytic competency exposed good performance towards reusability. Added advantages include easy preparation and inexpensiveness.