Lead(II) compounds with neutral coordination of semicarbazones: synthesis and characterization

• 2-benzoylpyridine semicarbazide/4-phenyl semicarbazide derived ligands as hydrochloride salts react with Pb II ions in aqueous or organic media. • The Pb II coordination compounds contain the pre-ligands coordinated as neutral species. • Pb⋯N, Pb⋯O, π⋯π and hydrogen bond interactions dictate the solid state arrangements. 2-benzoylpyridine semicarbazide/4-phenylsemicarbazide derived ligands as hydrochloride salts, [H 2 L]Cl and [H 2 L Ph ]Cl·2H 2 O, react with Pb 2+ ions in aqueous and organic milieus. The compounds [Pb 2 (HL) 2 Cl 4 ]·2DMF ( 1a ), [Pb 2 (HL) 2 Cl 4 ]·5H 2 O ( 1b ), [Pb 2 (HL) 2 Cl 2 (NO 3 ) 2 ]·4H 2 O ( 2 ), [Pb 2 (HL) 2 (SCN) 4 ] ( 3 ), [Pb 4 (HL Ph ) 4 Cl 8 ] ( 4 ), [Pb(HL Ph ) 2 (NO 3 ) 2 ] ( 5 ) and [Pb(HL Ph ) 2 (SCN) 2 ] ( 6 ) were obtained and characterized by powder X-ray diffraction and by infrared and ultraviolet–visible spectroscopies. Compounds 1 – 5 were analyzed by single-crystal X-ray diffraction. Tetrel and hydrogen bonds dominate the solid-state arrangements. The aqueous synthetic approach makes the pre-ligands of this work promising for further studies in aqueous coordination chemistry with p -block metal ions. [H 2 L]Cl and [H 2 L Ph ]Cl·2H 2 O are suitable for coordination as neutral HL or HL Ph species.