Homo- and heterometallic iodobismuthates(III) with 1,3,5-trimethylpyridinium cation: Preparation and features of optical behavior

[SMe3]2[Bi2Ag2I10], a silver iodido bismuthate with an unusually small band gap

“…We used the trimethyl sulfonium cation [SMe 3 ] + , which has been shown to template halogenido metalates with unusual anion motifs, like [SMe 3 ][SbCl 4 ], the singular example of a halogenido pentelate with a three-dimensional anion structure, 27 and useful properties, like [SMe 3 ][PbI 3 ], an air-stable hexagonal perovskite 28 and [SMe 3 ] 4 [Pb 3 Br 10 ], a layered bromido plumbate with a broad red emission. 29 The anion motif in 1 is deceptively similar to the ones found in [NEt 4 ] 2 [Bi 2 Ag 2 I 10 ] by Chen 23 and [1,3,5-Me 3 py] 2 [Bi 2 Ag 2 I 10 ] by Adonin, 26 however 1 features a band gap of 1.82 eV, much smaller than those found in these previously reported chain-like silver iodido bismuthates. We have also newly prepared the simple iodido pentelates [SMe] 3 [E 2 I 9 ] (E = Bi, Sb; 2 , 3 ), which serve as a point of comparison.…”

“…43 1 on the other hand has an optical band gap of 1.82 eV, which is similar to those found in 2D elpasolites, such as [(3AMPY) 2 AgBiI 8 •H 2 O] (3AMPY = 3-(aminomethyl) pyridinium) 21 and (4FPEA) 4 AgBiI 8 (4FPEA = 4-fluorophenethylammonium) 44 with optical band gaps of 1.86 eV and 1.84 eV, respectively. Importantly, the band gap is significantly smaller than the 2.05 eV and 1.92 eV reported for the aforementioned and structurally very similar [NEt 4 ] 2 [Bi 2 Ag 2 I 10 ] 23 and [1,3,5-Me 3 py] 2 [Bi 2 Ag 2 I 10 ], 26 respectively. Generally, structureproperty relationships in halogenido pentelates and copper and silver halogenido pentelates are an area of ongoing investigations.…”

“…Fig. 3 Comparison of the anionic motifs of 1 (top), [NEt 4 ] 2 [Bi 2 Ag 2 I 10 ] by Chen and co-workers (center) 23 and [1,3,5-Me 3 py] 2 [Bi 2 Ag 2 I 10 ] by Adonin and co-workers (bottom, only for the leftmost of the repeating units all silver positions are shown) 26. …”

Copper- and Silver-Containing Heterometallic Iodobismuthates: Features of Thermochromic Behavior

“…We previously reported on three compounds ( 2 , 8 , and 9 ) [ 41 , 42 ]; all others were synthesized using a similar approach (see below) and characterized via XRD methods. The addition of EtOH to a 1:1 acetone/CH 3 CN mixture leads to the formation of Bi/Cu heterometallic coordination polymers.…”

“…Recently, we investigated the thermochromic behavior of a series of Te(IV) mononuclear halometallates [ 40 ] with varying substituted pyridinium-type cations, introducing a more advanced approach to such work, which involved multi-temperature spectra measurements. Continuing our work with heterometallic iodobismuthates templated by functionalized Py-based cations [ 41 , 42 ] and drawing on our experience with thermochromic bromotellurates [ 40 ], we decided to systematically study the potential thermochromic properties of the entire series of compounds.…”