Solve Mystery of Titanium Trichloride's Electron Structure

[Dual Op Amp]

Well, Mr. Chem tr, it's not going to be an anion, when it only covalently bonds, but this is a metal to non-metal, so it would be an ionic bond. But, the octec rule should only apply to atoms with no more than two shells. N = 2. But, it doesn't. In titanium, it tries to empty the 4S and the 3D. This doesn't make any sense, an atom is stable when the ENTIRE shell is filled. To do that, titanium would have to fill 3S, 3P, and 3D. But, it doesn't, that's where I'm stuck.

 

[Dual Op Amp]

Okay, I found an even better way to phrase it.
An atom is stable, when the entire valence shell is filled.
So, why would an atom with three shells be stable, when it still has it's D orbital to fill?
Example: Argon. 1S^2, 2S^2,2P^6,3S^2,3P^6
The D orbital is not filled, yet argon is stable!

 

[Gokul43201]

An atom is stable, when the entire valence shell is filled.

Where did you read this sentence ?

That statement is not correct.

It is commonly used because it applies to all atoms/ions up to [Ne], and these include many of the common elements like H, C, N, and O.

The correct statement is that an atom is most stable when it has 8 electrons (2 for atoms/ions with 2 electrons or less) in its outermost shell. This is known as the octet(/duet) rule... which I believe you're aware of. So how is it that you misquoted the rule ?

Additionally, keep in mind that stability is not a binary condition, and is always relative to something.

 

[Dual Op Amp]

Well, I've read it everywhere.

The association between stability and electronic structure is a general phenomenon. It is summarized by the filled shell rule: Atoms are most stable when they have a filled valence shell. The electron shell with a principal quantum number of 1 is filled when it contains 2 electrons. In this case the filled shell rule is sometimes called the duet rule. The only atom we will be concerned with in terms of the duet rule is hydrogen. When the principal quantum number equals 2, the filled valence shell contains eight electrons, and the filled shell rule is referred to as the octet rule. We will use the octet rule as a guideline when we consider valence bond theory. Bonding rules provides a summary of the implications of the filled shell rules on bonding in organic molecules.
Hmm...Okay, now I am confused.

 

[Gokul43201]

So basically, what you've quoted says that the "filled shell rule" works (only) for n=1, 2. Beyond that, you have to use the Octet Rule (which is identical to the FS Rule for n=2). And even this is not an absolute rule, but can definitely be used to judge relative stability.

 

[Astronuc]

Bonding rules provides a summary of the implications of the filled shell rules on bonding in organic molecules.

Caution - organic chemistry (based on carbon and group 2 elements) is different from inorganic chemistry, and particularly transition metal chemistry.

Carbon (Z=6) has a relatively simple structure compared to the transition metals.

One point about a full P-subshell - all the electrons are paired - which makes for stability. This is consistent with the observation that each of the noble gases has the highest ionization potential of its respective period.

Another observation - the elements of the second group of the periodic table never form compounds in which they have more than 8 electrons in their valence shell. But elements in the third group are not so restricted.

Regarding the octet rule - take a look at http://wine1.sb.fsu.edu/chm1045/notes/Bonding/Except/Bond08.htm

Regarding:

Example: Argon. 1S², 2S²,2P²,3S²,3P².
The D orbital is not filled, yet argon is stable!

There is no 2d orbital (quantum mechanics, and just like there is no 1p orbital) and the 3d orbitals start filling with the fourth period elements, not in the third period.

Also, I think Gokul43201 made an important point that must be kept in mind - stability is relative.

 

[Dual Op Amp]

Well, it's almost been a year. For two, maybe three years I searched for the COMPLETE answer to covelant bonding. Only to find it was in hybridization. I thought this was some stupid theory, and ignored it for the longest time. I've known the answer for about two to three months now, but am now remembering this forum.
I FINALLY found the answer here...
www.chemguide.co.uk/atoms/bonding/covalent.html#top