Bis(2-pyridyl)ditellane as a Precursor for [HgTe]-Based Clusters and Zwitterionic Compounds

Metal chalcogenide cluster compounds are interesting substances by virtue of their intrinsic electronic and optical properties and their potential usage as single-source precursors for semiconductor materials. Herein, the synthesis and structural characterization of six new [HgTe]-based cluster compounds derived from bis(2-pyridyl)ditellane ((Py2Te2)-Py-o), and different mercury salts are described: four neutral clusters of the composition [Hg-4(PPh3)(2)(mu-(PyTe)-Py-o)(6)Cl-2] (1), [Hg-4(PPh3)(2)(mu-(PyTe)-Py-o)(6)Br-2] (2), [Hg-4(PPh3)(2)(mu-(PyTe)-Py-o)(6)I-2].DMF (3) and ([Hg-8(mu-(PyTe)-Py-o)(12)SCl2].5.25DMF (4), and the two zwitterionic clusters [Hg-8(mu-(HPyTe)-Py-o)(0.93)(mu-(PyTe)-Py-o)(11.07)SBr2.93]).7.62DMF (5) and [Hg-8(mu-(HPyTe)-Py-o)(0.83)(mu-(PyTe)-Py-o)(11.17)SI2.83]).7.25DMF (6) (Py-o = 2-pyridyl). The compounds were studied by single-crystal X-ray diffraction, FT-IR spectroscopy, and confocal Raman microspectroscopy. Furthermore, the optical energy gaps of the compounds were estimated by solid-state UV-Vis diffuse reflectance spectroscopy. The compounds with the smaller core structure (1-3) presented the larger E-g values, confirming small-particle optical properties' strong dependence on the core structure's size and composition.

Automated summary

This study investigated the synthesis and structural characterization of six new [HgTe]-based cluster compounds derived from bis(2-pyridyl)ditellane and different mercury salts. Various techniques, including single-crystal X-ray diffraction and FT-IR spectroscopy, were used to study the compounds, and their optical properties were evaluated by solid-state UV-Vis diffuse reflectance spectroscopy. The results showed a strong dependence of the optical properties on the core structure's size and composition, with smaller core structures presenting larger energy gap values.