Titanium(II) chloride
{{chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 477000010
| ImageFile=Kristallstruktur Cadmiumiodid.png
| IUPACName=
| OtherNames=
|Section1={{Chembox Identifiers
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 8466246
| InChI = 1/2ClH.Ti/h2*1H;/q;;+2/p-2
| InChIKey = ZWYDDDAMNQQZHD-NUQVWONBAH
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/2ClH.Ti/h2*1H;/q;;+2/p-2
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = ZWYDDDAMNQQZHD-UHFFFAOYSA-L
| CASNo_Ref = {{cascite|changed|??}}
| CASNo=10049-06-6
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII =BK26WI342Q
| PubChem=66228
| SMILES = [Ti+2].[Cl-].[Cl-]
| EINECS = 233-164-9
}}
|Section2={{Chembox Properties
| Ti=1 | Cl=2
| Appearance=black hexagonal crystals
| Density=3.13 g/cm3
| MeltingPtC=1035
| BoilingPtC=1500
| Solubility=
| MagSus = +570.0·10−6 cm3/mol
}}
|Section3={{Chembox Hazards
| MainHazards = pyrophoric
| GHSPictograms = {{GHS02}}{{GHS05}}
| GHSSignalWord = Danger
| HPhrases = {{H-phrases|250|314}}
| PPhrases = {{P-phrases|210|222|260|264|280|301+330+331|302+334|303+361+353|304+340|305+351+338|310|363|370+378|405|422}}
| ExternalSDS = [http://msds.chem.ox.ac.uk/TI/titanium_II_chloride.html External MSDS]
| FlashPt=
| AutoignitionPt =
}}
}}
Titanium(II) chloride is the chemical compound with the formula TiCl2. The black solid has been studied only moderately, probably because of its high reactivity.Holleman, A. F.; Wiberg, E. Inorganic Chemistry Academic Press: San Diego, 2001. {{ISBN|0-12-352651-5}}. Ti(II) is a strong reducing agent: it has a high affinity for oxygen and reacts irreversibly with water to produce H2. The usual preparation is the thermal disproportionation of TiCl3 at 500 °C. The reaction is driven by the loss of volatile TiCl4:
::2 TiCl3 → TiCl2 + TiCl4
The method is similar to that for the conversion of VCl3 into VCl2 and VCl4.
TiCl2 crystallizes as the layered CdI2 structure. Thus, the Ti(II) centers are octahedrally coordinated to six chloride ligands.{{cite journal |author1=Gal'perin, E. L. |author2=Sandler, R. A. | title = TiCI2 | journal = Kristallografiya | year = 1962 | volume = 7 | pages = 217–19}}{{cite journal |author1=Baenziger, N. C. |author2=Rundle, R. E. | title = TiCI2 | journal = Acta Crystallogr. | year = 1948 | volume = 1 | pages = 274 | doi = 10.1107/S0365110X48000740 | issue = 5| doi-access = }}
Derivatives
Molecular complexes are known such as TiCl2(chel)2, where chel is DMPE (CH3)2PCH2CH2P(CH3)2 and TMEDA ((CH3)2NCH2CH2N(CH3)2).{{cite journal | author = Girolami, G. S.; Wilkinson, G.; Galas, A. M. R.; Thornton-Pett, M.; Hursthouse, M. B. | title = Synthesis and properties of the divalent 1,2-bis(dimethylphosphino)ethane (dmpe) complexes MCl2(dmpe)2 and MMe2(dmpe)2 (M = Ti, V, Cr, Mn, or Fe). X-Ray crystal structures of MCl2(dmpe)2 (M = Ti, V, or Cr), MnBr2(dmpe)2, TiMe1.3Cl0.7(dmpe)2, and CrMe2(dmpe)2 | journal = J. Chem. Soc., Dalton Trans. |issue = 7| year = 1985 | pages = 1339–1348|doi = 10.1039/dt9850001339}} Such species are prepared by reduction of related Ti(III) and Ti(IV) complexes.
Unusual electronic effects have been observed in these species: TiCl2[(CH3)2PCH2CH2P(CH3)2]2 is paramagnetic with a triplet ground state, but Ti(CH3)2[(CH3)2PCH2CH2P(CH3)2]2 is diamagnetic.{{cite journal |author1=Jensen, J. A. |author2=Wilson, S. R. |author3=Schultz, A. J. |author4=Girolami, G. S. | title = Divalent Titanium Chemistry. Synthesis, Reactivity, and X-ray and Neutron Diffraction Studies of Ti(BH4)2(dmpe)2 and Ti(CH3)2(dmpe)2 | journal = J. Am. Chem. Soc. | year = 1987 | volume = 109 | pages = 8094–5 | doi = 10.1021/ja00260a029 | issue = 26}}
A solid-state derivative of TiCl2 is Na2TiCl4, which has been prepared by the reaction of Ti metal with TiCl3 in a NaCl flux.{{cite journal |author1=Hinz, D. J. |author2=Dedecke, T. |author3=Urland, W. |author4=Meyer, G. | title = Synthese, Kristallstruktur und Magnetismus von Natriumtetrachlorotitanat(lI), Na2TiCI4 | journal = Zeitschrift für Anorganische und Allgemeine Chemie | volume = 620 |issue=5 | pages = 801–804|doi=10.1002/zaac.19946200507 |year=1994 }} This species adopts a linear chain structure wherein again the Ti(II) centers are octahedral with terminal, axial halides.{{cite journal |author1=Jongen, L. |author2=Gloger, T. |author3=Beekhuizen, J. |author4=Meyer, G. |name-list-style=amp | title = Divalent titanium: The halides ATiX3 (A = K, Rb, Cs; X = Cl, Br, I) | journal = Zeitschrift für Anorganische und Allgemeine Chemie | year = 2005 | volume = 631 | pages = 582–586 | doi = 10.1002/zaac.200400464 | issue = 2–3}}
References
{{reflist}}
{{Titanium compounds}}
{{Chlorides}}