The tin sulfates Sn(SO₄)₂ and Sn2(SO4)3: crystal structures, optical and thermal properties

Area of Science:

• Solid State Chemistry
• Inorganic Chemistry
• Crystallography

Background:

• Tin sulfates are compounds with limited structural and property data.
• Understanding tin sulfate structures is crucial for materials science applications.

Purpose of the Study:

• To determine and report the crystal structures of two tin(IV) sulfate polymorphs (Sn(SO4)2-I and Sn(SO4)2-II).
• To report the first heterovalent tin sulfate, Sn2(SO4)3.
• To revise and complement the known crystal structure of SnSO4.
• To investigate and compare the optical and thermal properties of these tin sulfates.

Main Methods:

• Single-crystal X-ray diffraction was used to determine the crystal structures.
• Fourier-transform infrared (FTIR) spectroscopy.
• UV-visible (UV-vis) spectroscopy.
• Luminescence spectroscopy.
• 119Sn Mössbauer spectroscopy.
• Thermogravimetric analysis (TGA).

Main Results:

• The crystal structures of Sn(SO4)2-I (space group P21/c) and Sn(SO4)2-II (space group P21/n) were elucidated.
• The novel heterovalent tin sulfate Sn2(SO4)3 adopting space group P1̄ was synthesized and characterized.
• The crystal structure of SnSO4 was revised, and its data were complemented.
• Optical and thermal properties were systematically investigated and compared across the studied tin sulfates.

Conclusions:

• This work significantly expands the structural knowledge of tin sulfates.
• The findings provide a comprehensive dataset for the optical and thermal properties of tin sulfates.
• The reported structures and properties lay the foundation for future research and applications of tin-based materials.