Zur Darstellung und Kristallstruktur PbZn(NCS)₄ / Synthesis and Crystal Structure of PbZn(NCS)₄

Abstract

<jats:title>Abstract</jats:title><jats:p> PbZn(NCS)<jats:sub>4</jats:sub> is obtained from the binary compounds Pb(SCN)<jats:sub>2</jats:sub> and Zn(NCS)<jats:sub>2</jats:sub> with traces of water in an ultra-sound bath. The space group of the complex is Pn2<jats:sub>1</jats:sub>a (standard: Pna2<jats:sub>1</jats:sub>) with Z = 4. The structure consists of cis-connected octahedra <jats:sup>2</jats:sup><jats:sub>∞</jats:sub>[PbS<jats:sub>2</jats:sub>S<jats:sub>4/2</jats:sub>] forming two-dimensional layers. All SCN-groups are bound to Zn<jats:sup>2+</jats:sup> via their N atoms. The resulting ZnN<jats:sub>4</jats:sub> tetrahedra are arranged in the cavities formed by the PbS<jats:sub>6</jats:sub> octahedra.</jats:p>

Inorganic Metal Thiocyanates

“…31 Pb[Zn(NCS) 4 ] comprises Pb(SCN) 6 octahedra and Zn(NCS) 4 tetrahedra, both significantly distorted and connected into neutral layers. 18 Unlike the other discussed ternaries thus far, there are direct Pb−S−Pb connections in this structure and the PbS 2 substructure thus resembles a 2D perovskite with {110} type layers, e.g. the MnF 2 substructure in BaMnF 4 .…”

“…The large chemical differences between N and S do offer opportunities for ternary phases however, and this has been exploited in the synthesis of cation-ordered ternary frameworks (see Section 3). [16][17][18][19] The difference in bonding between termini can also be seen in the metal and thiocyanate bond angle: the experimental M-NCS angle distribution peaks at 180º and the M-SCN angle distribution centres on around 100º 16 , due to the shapes of the frontier orbitals. The bent M-SCN angle, together with the rod-like shape of thiocyanate means that the symmetries of metal thiocyanates are typically lower than of equivalent halides.…”

Inorganic Metal Thiocyanates

“…Structures of the layered ternary metal thiocyanates. (a) Postperovskite Cs­[Mn­(NCS) 3 ], , (b) Zn­[Pb­(SCN) 4 ] with its {110} block perovskite structures, (c) MnHg 2 (NCS) 6 with a complex, perovskite-related structure formed from MnN 6 octahedra and Hg 2 tetrahedral dimers, and (d) K­[Ag­(SCN) 2 ] formed from edge- and corner-sharing AgS 4 tetrahedra. , …”

“…Pb­[Zn­(NCS) 4 ] comprises Pb­(SCN) 6 octahedra and Zn­(NCS) 4 tetrahedra, both significantly distorted and connected into neutral layers . Unlike the other discussed ternaries thus far, this compound contains extended Pb–S–Pb connections forming an infinite chain along the b axis.…”

“…The large difference in hardness between the N and the S termini offers opportunities for ternary phases, however, and this has been exploited in the synthesis of cation-ordered ternary frameworks (see section ). − …”