Germanium sulfide structure

The 2 2PTy2(t) Crystal Structure of Germanium Sulfide [GeS2]... 

Non-aqueous synthetic methods have recently been used to assemble mesoporous transition metal oxides and sulfides. This approach may afford greater control over the condensation-polymerization chemistry of precursor species and lead to enhanced surface area materials and well ordered structures [38, 39], For the first time, a rational synthesis of mesostructured metal germanium sulfides from the co-assembly of adamantanoid [Ge4S ()]4 cluster precursors was reported [38], Formamide was used as a solvent to co-assemble surfactant and adamantanoid clusters, while M2+/1+ transition metal ions were used to link the clusters (see Fig. 2.2). This produced exceptionally well-ordered mesostructured metal germanium sulfide materials, which could find application in detoxification of heavy metals, sensing of sulfurous vapors and the formation of semiconductor quantum anti-dot devices. 

The area of germanium sulfide cluster anions has been enriched by the publication of a number of new compounds. The structure of the quaternary germanium sulfide AgLasGeSg has been elucidated and shown to comprise La3GeS4 cubes linked through Ge—S bonds to form a three dimensional arrayIn contrast, the anion [CuGe2S5] comprises [Ge4Sio]" units. ... 

A bis(chelate) structure was found for the closely related germylene [MeC(NPr )2]2Ge, which was also made from GeCl2(dioxane) and 2 equivalents of the lithium amidinate (colorless crystals, 81%). The same synthetic approach was used to make bis(amidinato) metal dichlorides of silicon and germanium in high yields (83-95%). Rapid oxidative addition of chalcogen atom sources (styrene sulfide and elemental Se) to the germylene derivatives resulted in a series... 

In contrast to the sulfide of silicon (p. 187). the sulfides of tetravalent germanium (white) and tetravalent tin (yellow) are stable in water, but form complexes in the presence of excess sulfide ion. The sulfides of divalent tin and lead (both black) dissolve neither in strong base, in excess sulfide, nor in dilute acids. Note that PbS has the same structure as sodium chloride and is probably the most nearly covalent salt known having this structure, its color and metallic lustre setting it apart from the structurally similar ionic halides and oxides. 

Germanium(IV) sulfide exhibits two modifications, one with the chain structure illustrated in Figure 9, and the other, like the corresponding selenide, with a distorted CdL lattice. Tin(IV) sulfide and selenide both crystallize with the CdL lattice. " The mixed valence tin sulfide, Sn2S3, consists of infinite double rutile strands of corner and edge sharing [SnS6] octahedra connected by tin(ll) atoms in typical pyramidal coordination. - ... 

Sulfide Molecular Sieves. All crystalline molecular sieves and microporous crystals have so far been based on oxide frameworks. As discussed previously, the oxide-based molecular sieve family shows rich compositional and structural diversity, and the number of new species is still growing at a rapid rate. An important new direction for molecular sieves is provided by the recent discovery of sulfide-based molecular sieves. The first publication on these materials already described a whole family of sulfide molecular sieves containing germanium (Ge) and tin (Sn) or several other metals. The crystal structures are all new and include 12 unique framework structures. These materials may have potential applications using sulfur-containing feedstocks in which the sulfur present may stabilize the composition of the sulfide molecular sieve. 

Interestingly, zinc sulfide (p-ZnS) may also crystallize in a cubic lattice, which consists of a fee array of S , with Zn occupying 1/2 of the available tetrahedral sites. This structure is known as sphalerite or zincblende, and is shared with other compounds such as a-AgI, p-BN, CuBr, and p-CdS. When the same atom occupies both the fee and tetrahedral interstitials of the sphalerite structure, it is described as the diamond lattice, shared with elemental forms (allotropes) of silicon, germanium, and tin, as well as alloys thereof. Important semiconductors such as GaAs, p-SiC, and InSb also adopt the sphalerite crystal structure. 

---