Water Stability Studies of Hybrid Iodoargentates Containing N‑Alkylated or N‑Protonated Structure Directing Agents: Exploring Noncentrosymmetric Hybrid Structures

In situ alkylation or protonation reactions on the thiazolyl-N donors of benzothiazole (btz) and its derivative 2-aminobenzothiazole (abtz) occurred to form four structure directing agents (SDAs), which feature different structure directing abilities and hydrophobicities. The thiazolyl-N alkylated and protonated btz cations direct to form an α-type (AgI₂)⁻ iodoargentate chain in (Etbtz)­(AgI₂) (1), (Prbtz)­(AgI₂) (2), and (Hbtz)­(AgI₂) (3), respectively, while the thiazolyl-N protonated abtz cation directs to form a new type of (Ag₂I₃)⁻ anionic chain in (Habtz)­(Ag₂I₃) (4). Compounds 1 and 4 represent the first noncentrosymmetric (NCS) hybrid iodoargentates with organic S-containing N-heterocycle derivative cations as SDAs. Further, 1 exhibits high water stability and is second harmonic generation (SHG) active with a response about twice that of KDP (KH₂PO₄). Importantly, the water stability studies indicate that hybrid iodoargentates with hydrophobic N-alkylated SDAs are more stable in water than those with relative hydrophilic N-protonated SDAs.