PMC

Carbon, hydrogen, nitrogen, tin and iodine atoms are shown in dark brown, light pink, gray, green and purple, respectively.

Unless stated otherwise, ‘A’ refers to the organic cations chosen for the preparation of the hybrid tin perovskite (20% PEA and 80% FA in the present work). Reaction 1: oxidation of perovskite by O₂ and SnI₄ formation; Reaction 2: solid-state formation of A₂SnI₆ from SnI₄ and AI, where A ≡ FA. Reaction 3: hydrolysis of SnI₄ by H₂O and HI formation; Reaction 4: oxidation of HI by O₂ and I₂ formation; Reaction 5: oxidation of perovskite by I₂ and SnI₄ formation.

Chemical strategies for syntheses of MRS2481 and analogs. (A) Preparation of analogues of variable spacer chain lengths and variable substitution of the pyridinium moiety. For the structure of R₁, refer to . Reagents: (a) benzyltrimethylammonium hydroxide, tetrabutylammonium iodide at r.t. for 2 days; (b) sodium iodide in acetone; (c) pyridine derivative in acetone at 50 °C for 3 days. (B) Preparation of compound 17, which contains a chemically reactive aryl amino group. Reagents: (a) tin, acetic acid, HCl at 100 °C for 1.5 h; (b) di-t-butyl-dicarbonate in methanol at 45 °C for 1 h; (c) benzyltrimethylammonium hydroxide, tetrabutylammonium iodide at r.t. for 2 days; (d) sodium iodide in acetone; (e) pyridine in acetone at 50 °C for 3 days; (f) trifuoroacetic acid. (C) Preparation of 4-substituted pyridinium salts 19 and 20 and non-pyridinium derivatives, including the symmetric diester 22. Reagents: (a) 1,8-dibromooctane, benzyltrimethylammonium hydroxide, tetrabutylammonium iodide at r.t. for 3 days; (b) N-methylmorpholine, tetrabutylammonium iodide in acetone at 50 °C for 2 days; (c) 4-propyl-pyridine, tetrabutylammonium iodide in acetone at 50 °C for 3 days; (d) 4-(2-hydroxyethyl)-pyridine, tetrabutylammonium iodide in acetone at 50 °C for 3 days.

Ball and stick representations (Mercury 3.9) of the conformation adopted by bromo(4-iodo-1,2,3,4-tetraphenyl-1,3-butadienyl)diphenyltin (SICSOM, bottom) and the network formed by tris(trimethylstannyl)ammonium iodide (RONDAZ, top). One layer of RONDAZ is presented, and hydrogen atoms have been omitted for clarity. TBs are depicted as black dotted lines; Nc values are shown close to the respective interactions. Color code: gray carbon, purple iodine, brown bromine, light blue nitrogen, dark teal tin