Inorganic‐Cored Photoactive Assemblies: Synthesis, Structure, and Photochemical Investigations on Stannoxane‐Supported Multifluorene Compounds

Abstract

Organostannoxanes were used as inert supports for the preparation of multichromophore assemblies. The synthesis involves a single-step procedure and allows the preparation of compounds in which the number of chromophore units can be varied from one to six. Thus, the reactions of LCOOH (1-fluorenecarboxylic acid) or L'COOH (9-fluorenecarboxylic acid) with various organostannoxane precursors afforded the fluorenyl derivatives [Ph(3)SnO(2)CL] (1), [Ph(3)SnO(2)CL'] (2), [{nBu(3)SnO(2)CL''}(n)] (3), [{nBu(3)SnO(2)CL'}(n)] (4), [{tBu(2)Sn(OH)O(2)CL}(2)] (5), [{tBu(2)Sn(OH)O(2)CL'}(2)] (6), [{[nBu(2)SnO(2)CL](2)O}(2)] (7) [{[nBu(2)SnO(2)CL'](2)O}(2)] (8), [{nBuSn(O)O(2)CL}(6)] (9), and [{nBuSn(O)O(2)CL'}(6)] (10). Interestingly, the formation of 3 is accompanied by an unusual oxo-transfer reaction. The ligand L is oxidized at the 9-position. Compounds 1, 3, 5, 7, and 8 were characterized by X-ray crystallography. The solid-state structures of these compounds reveal rich supramolecular structures owing to multiple intermolecular interactions between the various supramolecular synthons present in these molecules. The optical behavior of 1-10 is primarily dictated by the fluorenyl periphery. These compounds display strong blue fluorescent emission in solution and blue-green fluorescent emission in the solid state. Fluorescence lifetimes of all of these compounds are on the nanosecond timescale, and this suggests that the emission originates from the singlet excited state to the ground state. Intermolecular interactions in the solid state lead to considerable broadening of the emission bands.

Ambient Temperature Sn–C Bond Cleavage Reaction Involving the Sn‐n‐butyl Group. Weak F···F Interactions in the Solid State Structure of [{nBu2SnO2C–C6H4‐4‐CF3}2O]2

“…Compound 2 shows two resonances at δ = –254 and –272 ppm in its 119 Sn NMR spectrum indicating the presence of two types of tin atoms in its molecular structure. These values are comparable to the literature precedents 4c. The 19 F NMR spectrum of both 1 and 2 show singlets that resonate at δ = –69 and –67 ppm, respectively.…”

Synthesis, crystal structure and in vitro antitumor activity of a novel organotin(IV) complex with 9-hexyl-9H-carbazole-3-carboxylic acid

“…The geometry around the central tin atom can be described as capped tetrahedral. Two types of Sn-O bond lengths are found: Sn(1)-O(1) 2.085(2) and Sn(1)-O(2) 2.563(2) Å [16]. Adjacent molecules are interacted with each other through H bonds to form a 1D chain structure (Fig.…”

Morphological studies on Sn-O coordination driving self-assembly of well-defined organotin-containing block copolymers

“…In comparison, there are rare report about direct coordination with both metal and ligands in the polymer chain to drive the self-assembly of block copolymer. Meanwhile, the self-assembly of organotin carboxylate has brought out considerable structural diversity and topologies [31][32][33][34][35][36][37][38] , which is attributed to the various coordination geometries and coordination numbers of tin as well as the different binding modes with the carboxylate ligand in monodentate or bidentate.…”