Talk:Titanium(IV) hydride

Derivatives??

What is a derivative? TiCl4 is not derived from the hydride. I can make that by direct chlorination. The tetraethyl titanium is made from TiCl4. It's conceivable that I could make it from the hydride and ethylene, but that is the stuff of Ziegler Natta catalyst intermediates. You are going to need to explain that.JSR (talk) 09:51, 1 October 2012 (UTC)

The term has already been replaced with structural analogues prior to the above post. Plasmic Physics (talk) 09:54, 1 October 2012 (UTC)

Dubious

I have marked the claim that this is the first transition metal to be characterised spectroscopically as dubious. Several others were studied based on their spectra, including FeH. Graeme Bartlett (talk) 10:48, 17 February 2013 (UTC)

Xiao, Z. L. (1991). "Reactions of vanadium and titanium with molecular hydrogen in krypton and argon matrixes at 12 K". The Journal of Physical Chemistry. 95 (7): 2696–2700. doi:10.1021/j100160a015. Retrieved 17 February 2013. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help); Unknown parameter |month= ignored (help)

...as cited in...

Thomas, J. Russell (30 January 1992). "The titane molecule (TiH₄): Equilibrium geometry, infrared and Raman spectra of the first spectroscopically characterized transition metal tetrahydride". The Journal of Chemical Physics. 96 (9): 6857–6862. doi:10.1063/1.462575. Retrieved 17 February 2013. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)

Plasmic Physics (talk) 11:31, 17 February 2013 (UTC)

YOu will need to qualify it with tetrahydride then. Graeme Bartlett (talk) 11:36, 18 February 2013 (UTC)

tri-μ-hydrido-pentahydrido-1κ³H,2κ²H-dititanium??!!

tri-μ-hydrido-pentahydrido-1κ³H,2κ²H-dititanium... Really?

1. First of all, this isn't the systematic name for titanium hydride, it's the systematic name for its dimer.
2. Secondly, no one is going to call the dimer anything other than a dimer. I expect most people wouldn't even know how to pronounce the systematic name.
3. Thirdly, and perhaps most importantly, this excessively elaborate elucidation is errant in its efficaciousness!

Can it please be removed? And while we're at it the page states that the dimer has never been observed before going on to say that TiH₄ is extremely prone to dimerisation. Bit of a puzzle that...Project Osprey (talk) 19:28, 7 June 2013 (UTC)

The dimer is the groundstate form of this substance, the article title does not constraint the topic to the monomer, the formal oxidation state in the dimer is still IV. The monomer is predicted to only be observable under special conditions such as matrix isolation, due to there being no energy barrier to dimerisation. Whereas, the dimer should be stable over a wider range of conditions. It is for me logical, to make the dimer the topic of the article. It's not about who is, or isn't going to call it this, it doesn't make it wrong to include it. It is not errant, it delivers information about the molecular structure in a concise way. I will fix the dimerisation sentence. Plasmic Physics (talk) 07:09, 8 June 2013 (UTC)

• I'm afraid that I am genuinely confused here. If the dimer is the ground state how does that fit in with the statement "dimeric, groundstate titanium(IV) hydride has not yet been identified"? — Preceding unsigned comment added by Project Osprey (talk • contribs) 09:56, 8 June 2013 (UTC)

Although not yet positively identified from experimental results, various computational studies calculates the dimer to be the groundstate. The molecule is predicted to be a fluxional molecule rapidly interconverting between the groundstate, and the low-lying, doubly-bridged isomer. Concentrated titanium(IV) hydride is also predicted to irreversibly polymerise into a covalent network solid, only stable at cryogenic temperatures, which is different from the titanium-hydrogen alloy. Coincidently, this covalent network solid is predicted to decompose into the alloy at STP conditions. Other than this, I'm not sure about what confuses you. Plasmic Physics (talk) 10:16, 8 June 2013 (UTC)

• Right, I think I understand now. I've done some editing to try and make things a bit clearer and thrown in some more refs. We should probably make a page for titanium(II) hydride at some point. You can actually buy that, so its probably worth mentioning. Project Osprey (talk) 22:33, 8 June 2013 (UTC)

Good work, perhaps if the dimer can be confirmed, we can make the article about that. Titanium (II) hydride as used in that context, is a misnomer - it is in fact, a specific titanium alloy (TiH
_~2). However, proper titanium(II) hydride has also been discovered as a covalent molecule, like titanium(IV) hydride. Plasmic Physics (talk) 22:59, 8 June 2013 (UTC)

Dimeric TiH₄ structure section and bonding sections

The reference quoted ( Webb, Simon P.; Gordon, Mark S. (1 July 1995). "The Dimerization of TiH4". Journal of the American Chemical Society 117 (27): 7195–7201. doi:10.1021/ja00132a020) does not in my opinion support the claim that TiH₄ is prone to dimerisation. What the paper actually says is "ab initio analysis ...show that dimerisation is thermodynamically and kinetically very favourable." and goes on to say that calculated IR frequencies are reported. This is a computational paper predicting properties of an unobserved species. This whole structure section as it stands is well informed speculation. Unless there is now physical evidence for the dimer this article needs a rewrite.

The bonding section claims sd³ hybridisation and quotes this paper ( Jonas, V.; Boehme, C.; Frenking, G. (1996). "Bent's Rule and the Structure of Transition Metal Compounds". Inorg. Chem. 35 (7): 2097–2099. doi:10.1021/ic951397o) the abstract details calculations on Cl₂MMe₂ molecules (M = variety of metals inc. Ti) can someone with access to this paper check that somewhere in the paper TiH₄ is mentioned and the reference is appropriate. Axiosaurus (talk) 15:36, 24 September 2013 (UTC)

The first query is answered with a new reference. Plasmic Physics (talk) 22:02, 24 September 2013 (UTC)