Titanium(II) chloride is the
chemical compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...
with the
formula
In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship betwe ...
TiCl
2. The black solid has been studied only moderately, probably because of its high reactivity. Ti(II) is a strong reducing agent: it has a high affinity for oxygen and reacts irreversibly with water to produce H
2. The usual preparation is the thermal
disproportionation of
TiCl3 at 500 °C. The reaction is driven by the loss of volatile
TiCl4:
::2 TiCl
3 → TiCl
2 + TiCl
4
The method is similar to that for the conversion of
VCl3 into
VCl2 and
VCl4.
TiCl
2 crystallizes as the layered
CdI2 structure. Thus, the Ti(II) centers are octahedrally coordinated to six chloride ligands.
Derivatives
Molecular complexes are known such as TiCl
2(chel)
2, where chel is
DMPE (CH
3)
2PCH
2CH
2P(CH
3)
2 and
TMEDA
Tetramethylethylenediamine (TMEDA or TEMED) is a chemical compound with the formula (CH3)2NCH2CH2N(CH3)2. This species is derived from ethylenediamine by replacement of the four amine hydrogens with four methyl groups. It is a colorless liquid, ...
((CH
3)
2NCH
2CH
2N(CH
3)
2). Such species are prepared by reduction of related Ti(III) and Ti(IV) complexes.
Unusual
electronic effects have been observed in these species: TiCl
2 CH3)2PCH2CH2P(CH3)2sub>2 is paramagnetic with a triplet
ground state
The ground state of a quantum-mechanical system is its stationary state of lowest energy; the energy of the ground state is known as the zero-point energy of the system. An excited state is any state with energy greater than the ground state ...
, but Ti(CH
3)
2 CH3)2PCH2CH2P(CH3)2sub>2 is diamagnetic.
A solid-state derivative of TiCl
2 is Na
2TiCl
4, which has been prepared by the reaction of Ti metal with TiCl
3 in a NaCl
flux
Flux describes any effect that appears to pass or travel (whether it actually moves or not) through a surface or substance. Flux is a concept in applied mathematics and vector calculus which has many applications in physics. For transport phe ...
. This species adopts a linear chain structure wherein again the Ti(II) centers are octahedral with terminal, axial halides.
References
{{Chlorides
Titanium halides
Chlorides
Titanium(II) compounds