Synthesis, crystal structure, spectroscopic, and Hirshfeld surface study of a new functionalized α-hydroxyphosphonate complex of tin(IV) chloride

A new octahedral [SnCl₄L·H₂O] complex (L = γ-keto allyl phosphonate) (1) was prepared and characterized by multinuclear (¹H, ¹³C, ³¹P, and ¹¹⁹Sn) NMR spectroscopy, IR spectroscopy, and single-crystal X-ray diffraction. The NMR data show that, in solution, the complex exclusively exists in trans isomeric form. The solution structure was confirmed by ¹¹⁹Sn NMR spectrum, showing a single triplet corresponding to the trans isomer. The effect of distant substituent on the metal–ligand interaction was investigated and compared to closely related tin–phosphoryl complexes. The crystal structure is stabilized by strong O-H···Cl hydrogen bonds forming layers of dimers with absence of π–π interactions. The Hirshfeld surface analysis confirms the interactions involving hydrogen atoms in the complex by the higher percentage of H···H (41.1%) and Cl···H/H···Cl (40%) interactions.