Do alkyl groups on aromatic or aliphatic structure directing agents affect water stabilities and properties of hybrid iodoargentates?

Abstract

Two types of in situ formed structure directing agents (SDAs) including aromatic triphenylphosphine (PPh)- and aliphatic piperazine (Hpp)-derivative cations were used to synthesize five new hybrid iodoargentates, namely (EtPPh)AgI (1, Et = ethyl), (n-PrPPh)AgI (2, n-Pr = n-propyl), (i-PrPPh)AgI (3, i-Pr = isopropyl), (Mepp)AgI (4, Me = methyl), and (Happ)(AgI)·2I·2HO (5, app = N-aminoethylpiperazine). A comparative study of the two types of SDAs on the structures, stabilities and properties of hybrid iodoargentates was performed in detail. Structurally, except for (EtPPh) and (n-PrPPh), which both directly form (AgI) anionic chains in 1 and 2, three SDAs generate hybrid iodoargentates different from each other with inorganic anions ranging from a 0-D (AgI) dimer to 1-D α-type (AgI) and (AgI) chains. With regard to the electronic structures, aromatic PPh-derivative cations make noticeable contributions to the bottom of the conduction bands, while aliphatic pp-derivative cations make nearly no contribution to the frontier orbitals, clearly indicating their different ways to adjust the band gaps. With regard to stability, the decomposition temperatures of 1-3 in the range of 324-349 °C are noticeably higher than the values of 217 and 225 °C for 4 and 5. Furthermore, 1-4 exhibit good water stabilities, which is ascribed to the alkylation reactions precluding the formation of strong hydrogen bonds between alkylated SDAs and extraneous HO molecules. Contrarily, the presence of typical hydrophilic [double bond, length as m-dash]NH, [triple bond, length as m-dash]NH and -NH groups on the protonated (Happ) cation makes 5 sensitive to water and a hydrolysis reaction occurs to generate a cubic AgI phase. Finally, 1-3 exhibit high photocatalytic efficiencies for the degradation of rhodamine B (RhB) dye in wastewater under visible light. All conclusions obtained here will help a lot in the synthesis of stable functional metal halide-based hybrids.

Structure‐Dependent Photochromic Iodoargentate Hybrids Based on Photolytic Mechanism

“…Recently, matched with methylnicotinohydrazide, carbomethoxypyridinium and pyrazinium, several photochromic iodometallates have been recently reported by our group, which exhibit simultaneous intermolecular CT and unique photo‐induced intermolecular ET and are largely attributed to the introduction of moderately electron‐deficient acceptors. Taking into account the fact that semiconductive iodoargentates possess intrinsically structural diversity, tunable energy gaps and consequent photosensitivity, judicious selection of electron‐deficient organic moieties can be used as an effective route to modulate the electron behavior of iodoargentates from optically inert CT to photoactive ET and consequent photochromic behavior.…”

Synthesis, crystal structure, vibrational and optical properties of a new Pb(II) complex (2-hydroxyethyl)piperazine-1,4-diium tetrachloroplombate(II) C6H16N2OPbCl4

“…They are among the most important backbones in today's drug discovery industries. The piperazine scaffold is an important pharmacophore found in a large number of biologically active compounds [14][15][16][17][18]. Based on the above considerations, in the present work, we report the synthesis, structure, Hirshfeld surface, spectroscopic measurement, optical study and thermal analysis of a new hybrid material: (2-hydroxyethyl) piperazine-1,4-diium tetrachloroplombate(II), C 6 H 16 N 2 OPbCl 4.…”

Ionic Liquid Synthesis of (Et3S)[Ag4I5] – A Structure Containing Basket‐Like Silver‐Iodide Cages with Ag22+ Pairs

“…Since the iodoargentates tend to form anionic frameworks, the nature of the cations concerning both structure and intrinsic properties have been identified as useful tools to direct structure and properties of the compounds isolated. A few examples illustrating both different structural themes, as well as optoelectronic applications, involve metal‐organic framework‐like structures and supra‐molecular aggregation, [11,12] and control of the aggregation patterns of the inorganic, anionic structures [13,14] . Cationic transition metal complexes have been used as the counterions as another strategy to further tune physiochemical properties of the iodoargentate compounds [15–17] .…”