Two [Co(bipy)₃]³⁺-Templated Silver Halobismuthate Hybrids: Syntheses, Structures, Photocurrent Responses, and Theoretical Studies

Abstract

Employing in situ-generated metal complexes as structural decorating agents, we, for the first time, isolated two [Co(bipy) 3 ] 3+ -templated silver halobismuthate hybrids, namely [Co(bipy) 3 ] 2 Ag 4 Bi 2 X 16 (X = Br (1), I (2); bipy = 2,2′-bipyridine). Compounds 1 and 2 belong to the isomorphic phrases and exhibit the nonperovskite structures characteristic of the discrete [Ag 4 Bi 2 X 16 ] 6− anions. UV−vis absorption spectra analyses showed that the optical band gaps of compounds 1 and 2 are 2.40 and 1.95 eV, respectively, implying the visible light responding semiconductor properties. Moreover, under the alternate light illumination, the title compounds exhibited "on/off" photocurrent behaviors, with high photocurrent densities comparable to many metal halide hybrids. Presented in this work also involved the Hirshfeld surface analyses and X-ray photoelectron spectroscopy studies together with the theoretical band structures, density of states, and electron wave functions.

Two Silver Halobismuthate Hybrids Decorated by Photosensitive Metal Complexes: Syntheses, Structures, Photoelectric Properties, and Theoretical Studies

“…The Ag–Br distances in the [AgBr 4 ] tetrahedron range from 2.5272(15) to 2.8052(18) Å, and the lengths of Bi–Br in the [BiBr 6 ] octahedra fall in the range of 2.6961(13)–3.0799(11) Å. These values are normal and compare well with those of some documented silver bromobismuthates, such as Cs 2 AgBiBr 6 , [CH 3 NH 3 ] 2 AgBiBr 6 , [CH 3 (CH 2 ) 3 NH 3 ] 4 AgBiBr 8 , [Fe(bipy) 3 ]AgBiBr 6 , and [Co(bipy) 3 ] 2 Ag 4 Bi 2 Br 16 . ,,,, …”

“…It is worth noting that the sum of the abovementioned three interactions reached as high as 87.3% ( 1 ) and 78.1% ( 2 ). This is not surprising and often found in many hydrogen-rich metal halides, such as [Co(bipy) 3 ] 2 ­Ag 4 ­Bi 2 ­Br 16 , [Fe(bipy) 3 ]­AgBiBr 6 , [Zn(bipy) 3 ] 2 ­Ag 2 ­BiI 6 (I) 1.355 ­(I 3 ) 1.645 , [Pb(MCP) 2 I]­PbI 3 , [NH 4 ]­[Fe(bipy) 3 ] 2 ­Ag 6 ­Br 11 , [Fe(phen) 3 ] 2 ­Ag 3 ­Pb 2 I­ 11 , [Ni(phen) 3 ]­Ag 2 ­PbI 6 , and [NH 4 ]­[Ni(phen) 3 ]­BiI 6 . ,− ,− In addition, the C···Br/Br···C and C···I/I···C contacts are non-negligible (10.0% for 1 and 10.2% for 2 ), indicative of strong anion···π interactions. The contribution comparisons of multiple interactions demonstrated in 1 and 2 are summarized in Figure g,h, respectively.…”

“…The Ag + ion is tetrahedrally coordinated, while the Bi 3+ and Zn 2+ ions lie in an octahedral environment. The observed distances of Ag–I, Bi–I, and Zn–N are reasonable calling for no further comments. − For compound 2 , apart from the bridging and terminal halogens, it also contains the μ 3 styles.…”

“…Noticeably, the decomposition temperatures far exceeded those of some other Bi-containing halides, such as [Cu(CH 3 CN) 4 ] 2 Cu 2 Bi 2 I 10 , [La(DMSO) 8 ]Bi 2 I 9 , and [1,4-MePy] 3 Bi 2 I 9 •(I 2 ) 3 . 49−51 The optical properties of title compounds were evaluated using the UV−vis diffuse reflectance spectra, which are depicted in Figure 5c,d 16,21,22,31,32,46 Photocurrent Responses. The suitable optical band gaps spurred us to further examine the photoelectric converting abilities of compounds 1 and 2.…”

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

“…These compounds feature optical band gaps between 1.93 eV and 2.29 eV. 14,15,23–25 Fig. 1 gives an overview of their structural motifs.…”