1 research outputs found
Two Thermochromic Layered Iodoargentate Hybrids Directed by 4- and 3‑Cyanopyridinium Cations
Two layered iodoargentates, [HCP]Â[Ag<sub>2</sub>I<sub>3</sub>]
(HCP<sup>+</sup> = NH-4-cyanopyridinium) (<b>1</b>) and [MCP]Â[Ag<sub>4</sub>I<sub>5</sub>] (MCP<sup>+</sup> = <i>N</i>-methyl-3-cyanopyridinium)
(<b>2</b>) have been solvothermally synthesized. For <b>1</b>, the inorganic layer is built up by 4-connected Ag<sub>4</sub>I<sub>8</sub> unit with cubane-type Ag<sub>4</sub>I<sub>4</sub> core via
sharing peripheral μ<sub>2</sub>-I in <i>ab</i> plane,
while the HCP<sup>+</sup> cations are located at the apertures and
interlayer space. For <b>2</b>, the inorganic layer is constructed
from [Ag<sub>6</sub>I<sub>6</sub>]<sub><i>n</i></sub> and
[AgI<sub>3</sub>]<sub><i>n</i></sub><sup>2<i>n</i>–</sup> chains via alternative corner- and edge-sharing modes
along the <i>b</i>-axis, while the MCP<sup>+</sup> cations
lie between neighboring layers. Compounds <b>1</b> and <b>2</b> exhibit reducing band gaps relative to the bulk β-AgI
and remarkable thermochromism, which are ascribed to the intermolecular
charge transfer (CT) and affected by electron affinity of pyridinium
cations