A 2D coordination polymer of [Cd(TMA)(4-CNPy)(H2O)]n (H2TMA = 3-thiophenemalonic acid, 4-CNPy = 4-cyanopyridine) with impedimetric humidity sensing performance

•A new coordination polymer of [Cd(TMA)(4-CNPy)(H2O)]n (CdL) is obtained via precipitation.•The CdL is 2D planar networks with the Schläfli symbol (44) stacked in a stagger-peaked fashion.•The CdL exhibits typical impedimetric humidity sensing behavior.•The CdL shows high sensitivity, fast response-recovery, and narrow hysteresis loop to humidity.