Diorganotin Compounds Containing α‐Aminoacidato Schiff Base Ligands Derived from Functionalized 2‐Hydroxy‐5‐(aryldiazenyl)benzaldehyde. Syntheses, Structures and Sensing of Hydrogen Sulfide

Three novel bicycloazastannoxides, namely, [ n Bu 2 Sn(L 1 )] ( 1 ), [ n Bu 2 Sn(L 2 )] ( 2 ) and [Bz 2 Sn(L 3 )] ( 3 ) were synthesized in one pot procedures by reacting diorganotin(IV) precursors with a mixture composed of an α‐amino acid with either ( E )‐2‐hydroxy‐5‐((4‐nitrophenyl)diazenyl)benzaldehyde or ( E )‐2‐hydroxy‐5‐(phenyldiazenyl)benzaldehyde. Single‐crystal X‐ray diffraction analysis reveal that compound 1 is monomeric, compound 2 consists of both a monomer and a dimer, while compound 3 is a coordination polymer for which two modifications 3A and 3B were identified. The 119 Sn NMR chemical shifts measured in CDCl 3 solutions indicate five‐coordinate tin atoms for 1 – 3 . Further, compounds 1 and 2 were found to be highly selective for sensing hydrogen sulfide in UV/Vis channel in CH 3 CN/H 2 O (9:1) media. The development of orange red color is likely the results of a Brønsted‐type acid‐base reaction of H 2 S with compounds 1 and 2 , respectively, giving di‐ n ‐butyltin sulfide and the corresponding pro‐ligands H 2 L 1 and H 2 L 2 , respectively. Theoretical calculations accompany the experimental work.