Efficiently red emitting cycloplatinated(II) complexes supported by N^O and N^P benzimidazole ancillary ligands

•Pt(II) complexes (piq)Pt(N^O) (1–4) and (piq)Pt(N^P) (5–8) have been synthesized.•All complexes display distorted square-planar geometries around pt(II) center.•The complexes show good monomeric emissions with the PLQYs up to 23% in DCM at 298 K.•he complexes exhibit different emission colors by changing the ancillary ligands.