Geometrical isomerization and acceptorless dehydrogenative alcohol oxidation based on pyrrole-based Ru(Ⅱ) complexes

•Geometrical ruthenium isomers containing pyridylpyrrole ligands were synthesized by controlling the reaction temperature.•Neutral hydrido-ruthenium complex with pyridylpyrrole ligand displays efficient catalysis for acceptorless dehydrogenative alcohol oxidation.•The ruthenium complexes containing pyridylpyrrole ligand were fully characterized by NMR, IR, X-ray diffraction analysis etc.