Titanium trisulfide

Titanium trisulfide (TiS₃) is an inorganic chemical compound of titanium and sulfur. Its formula unit contains one Ti⁴⁺ cation, one S²⁻ anion and one S₂²⁻.

Titanium trisulfide

Names
Other names Titanium(IV) sulfide
Identifiers
CAS Number	12423-80-2 Y
3D model (JSmol)	covalent form: Interactive image ionic form: Interactive image
ChemSpider	50645119
InChI InChI=1S/3S.Ti Key: HOZYDKBKUUVYKD-UHFFFAOYSA-N InChI=1S/S2.S.Ti/c1-2;;/q2*-2;+4 Key: KVFIBOBJNNMQLV-UHFFFAOYSA-N
SMILES covalent form: [Ti]1(=S)SS1 ionic form: [S-][S-].[S-2].[Ti+4]
Properties
Chemical formula	TiS3
Molar mass	144.062 g/mol
Appearance	Black whiskers
Band gap	1 eV (indirect)[1][2]
Electron mobility	80 cm2/(V·s)[3]
Structure[1][2]
Crystal structure	Monoclinic, mP8
Space group	P21/m, No. 11
Lattice constant	a = 0.4973 nm, b = 0.3443 nm, c = 0.8714 nm α = 90°, β = 97.74°, γ = 90°
Formula units (Z)	2
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

TiS₃ has a layered crystal structure, where the layers are weakly bonded to each other and can be exfoliated with an adhesive tape. The exfoliated layers have potential applications in ultrathin field-effect transistors.^[2]

Synthesis

Millimeter-long crystalline whiskers of TiS₃ can be grown by chemical vapor transport at ca. 500 °C, using excess sulfur as the transporting gas.^[1][2]

Properties

Transmission electron micrograph of TiS₃ revealing its layered structure

TiS₃ is an n-type semiconductor with an indirect bandgap of about 1 eV.^[2] Its individual layers are made of TiS atomic chains; hence they are anisotropic and their properties depend on the in-plane orientation. For example, in the same sample, electron mobility can be 80 cm²/(V·s) along the b-axis and 40 cm²/(V·s) along the a-axis.^[3]