Due to their heteropolyhedral 3D open framework with cation exchange possibilities, pharmacosiderite supergroup arsenates play an essential role in the retention, mobility, and fate of various trace elements in the environment. However, the geochemical interaction with extremely toxic thallium (Tl) remains understudied. The formation of the compounds in the Tl(I)–M(III)–As(V)–H₂O (M(III) = Al, Fe) system results in the occurrence of poorly-crystalline thalliumpharmacosiderite, which was reported in the mining-impacted areas as well as in corresponding sediments and soils. Unfortunately, due to its low crystallinity, just a partial understanding of its key structural and compositional properties exists. Therefore, using hydrothermal synthesis (stainless steel autoclaves, autogenous pressure, T_max = 170 °C), we have synthesized good-quality synthetic analogue of thalliumpharmacosiderite (Tpsd), Tl_2.5Fe₄[(AsO₄)₃(OH)₄](OH)_1.5·3H₂O, and still-not discovered “thalliumpharmacoalumite” (Tpal), Tl_1.25Al₄[(AsO₄)₃(OH)₄](OH)_0.25·4H₂O single crystals. They were characterized using single-crystal X-ray diffraction (SC-XRD), powder X-ray diffraction (PXRD), Raman spectroscopy, scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM), providing more details on their chemical composition and crystal structure, thus bringing us one step further in better understanding of their structural and chemical properties and how they may relate to their formation in nature. Furthermore, Tl₃AsO₄ was resynthesized and its crystal structure and Raman spectrum were discussed, since it has a potential to be found in natural environments. Additionally, chemical characterization and Raman spectrum of a novel Tl-Fe-arsenate (Tl:Fe:As = 1:1:1) was mentioned. Consequently, the present research delivers useful insights on the role of pharmacosiderite supergroup arsenates in the environmental cycle of Tl.

由于其具有阳离子交换可能性的杂多面体 3D 开放框架，菱铁矿超群砷酸盐在环境中各种微量元素的保留、流动性和归宿方面起着至关重要的作用。然而，与剧毒铊 (Tl) 的地球化学相互作用仍未得到充分研究。Tl(I)– M (III)–As(V)–H ₂ O ( M(III) = Al, Fe) 体系导致结晶不良的铊毒菱铁矿的出现，据报道在受采矿影响的地区以及相应的沉积物和土壤中。不幸的是，由于其低结晶度，对其关键结构和组成特性的了解只有部分。因此，利用水热合成（不锈钢高压釜，自生压力，T _max  = 170 °C），我们合成了优质的铊铁矿类似物（Tpsd），Tl _2.5 Fe ₄ [(AsO ₄ ) ₃ (OH) ₄ ] (OH) _1.5 ·3H ₂ O，以及尚未发现的“铊药铝石”(Tpal)，Tl _1.25Al ₄ [(AsO ₄ ) ₃ (OH) ₄ ](OH) _0.25 ·4H ₂ O单晶。它们使用单​​晶 X 射线衍射 (SC-XRD)、粉末 X 射线衍射 (PXRD)、拉曼光谱、扫描电子显微镜 (SEM)、能量色散光谱 (EDS) 和透射电子显微镜 (TEM) 进行表征，提供有关它们的化学成分和晶体结构的更多详细信息，从而使我们更进一步地更好地了解它们的结构和化学性质以及它们如何与它们在自然界中的形成有关。此外，Tl ₃ AsO ₄被重新合成并讨论了它的晶体结构和拉曼光谱，因为它有可能在自然环境中被发现。此外，还提到了新型 Tl-Fe-砷酸盐 (Tl:Fe:As = 1:1:1) 的化学特性和拉曼光谱。因此，本研究提供了关于铁铁矿超群砷酸盐在 Tl 环境循环中的作用的有用见解。