Questions tagged [ligand-field-theory]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
-1
votes
0answers
11 views

I have a question about ligand field strength and how the field strength of a ligand can be changed by the addition of a substituent to it [closed]

For example, I am studying a half sandwich structure where the "table" is an Cp ligand. I am comparing the structure of the complex to that of its identical version except with an additional ...
1
vote
0answers
29 views

Tetrahedral complex and vibronic coupling or different rule for d-d transition?

I'm currently preparing a few slides for an upcoming talk in our group. I would like to mention some of the very basics regarding crystal field and ligand field theory as well, though this will not be ...
1
vote
0answers
59 views

Is Porphyrin Planar?

I have been looking at this diagram from quite some time, I know the 18 pi electron cycle that forms porphin(e) is definitely planar but what about the whole molecule?... The Nitrogen's act as a ...
1
vote
1answer
38 views

Understanding Scatchard Plots

Im having trouble understanding Scatchard plots. Y Axis = Bound/Free Ligand X Axis = Bound Ligand The graph has a negative slope. Why when there is almost no Bound (Y axis = 0) do we get a high ...
0
votes
1answer
34 views

Which of the following octahedral complexes absorbs the photon with the longest wavelength, λ?

I wonder which of the following absorbs photons with the longest wavelength, $\ce{[Cr(CN)6]^3-}$, $\ce{[Cr(SCN)6]^3-}$ and $\ce{[Cr(H2O)6]^3+}$. I know the one to absorb the highest wavelength should ...
5
votes
0answers
50 views

Molecular orbital diagram for carbene-metal and carbodiphosphorane-metal interaction

I am interested in understanding how carbenes and carbodiphosphoranes interact differently with a transition metals. I would like to use qualitative molecular orbital theory arguments (with an ...
3
votes
1answer
87 views

Is there an 'easy' way to determine if a ligand is a pi acceptor, donor or neutral?

First of all I am confused how something can be pi neutral? something either does or doesn't have filled p orbitals for example. given something I have never seen acting as a ligand before like ...
0
votes
1answer
106 views

Denticity of bridging ligands

How would we assign denticity to bridging ligands? For eg, consider $\ce{NH^-_2}$, it has 2 lone pairs and can hence act as a bridging ligand, making 2 metal-ligand bonds. So I thought it should be ...
2
votes
1answer
138 views

Intuitive Explanation for why more negative charge on ligand does not imply more splitting effect?

I have studied coordination chemistry as part of my school curriculum and we covered Crystal Field Theory as our final theory, and the book says that Ligand Field Theory and Molecular Orbital Theory ...
0
votes
1answer
112 views

Why does this ligand form 6-coordinate complexes with Transition elements and 8-coordinate complexes with Inner transition elements? [closed]

What change takes place in the denticity of this ligand if it is an inner-transition metal ion vs a common transition metal? Primarily, why does the ligand behaves differently with the two situations ...
5
votes
1answer
325 views

What is the shape of [Cr(NO)₄]?

I was learning about crystal field theory recently. I am quite confused about predicting the shape of $\ce{[Cr(NO)4]}$ complex because I am not able to conclude whether it will be square planar or ...
1
vote
0answers
372 views

Why is the crystal field splitting energy larger for square planar than octahedral complexes?

I recently came across a fact that for the same combination of metal and ligand, the crystal field splitting energy for square planar complexes is larger than that of the corresponding octahedral ...
0
votes
2answers
99 views

Why are chelating ligands often used to treat poisoning by heavy metals (e.g. mercury, lead)?

Why are chelating ligands such as EDTA often used to treat poisoning by heavy metals (e.g., mercury, lead)? I have a vibe that it has something to do with the lone pairs of electrons that are able to ...
0
votes
0answers
49 views

Reason behind more prioritising of normal spinels

According to my textbook: In normal spinels $\ce{A^{II}}$ should have occupied octahedral voids, but this factor is outweighed by greater lattice energy or smaller cation $\ce{B^{III}}$. Later, ...
2
votes
1answer
139 views

Effective Bohr Radius in Transition Metal Complexes?

I am playing around with a toy model of a transition metal complex where the HOMO are $d$-electron states of predominantly transition metal character. Let's say this is a $d^1$ (or $d^9$) system and ...
0
votes
0answers
1k views

Finding the wavelength of maximum absorption and Crystal Field Splitting of [Ni(H2O)6]2+

(I haven't been here for a long time, so tell me if my formatting is fine) Given The $\ce{[Ni(H2O)6]^2+}$ complex appears green in solution from the transmitted light. Estimate the wavelength of ...
0
votes
1answer
258 views

About Fe(III) and Fe(II) coordination complexes

Why does Fe(III) form octahedral coordination complexes if it has 5 electrons in its d-orbitals? I understand that Fe(II) has 6 electrons in its d-orbitals and 6 lone pairs from 6 ligands as the 12 ...
0
votes
1answer
79 views

What is the binding mode of the ligand in complexes with quadruple metal-metal bonds?

I'm wondering which atomic orbital is left in a complex with quadruple metal-metal bond to bind the steric ligand, since all d orbitals except the x2-y2 are used for the metal-metal bonds? or is it ...
2
votes
0answers
2k views

Why CO is a stronger and more common ligand than N2?

Both N2 and CO are considered sigma-donor and pi-acceptor. Their MO diagram is similar, so I wonder why CO binds generally more strongly and it is a more common ligand.
1
vote
0answers
75 views

Why does the hexachlorocopper(II) ion not form?

I am not entirely sure if this question has been answered before, but I was wondering why when copper forms a complex ion with chlorine there are only 4 chlorine ligands. I asked my teacher and he ...
10
votes
2answers
4k views

Why is Ni[(PPh₃)₂Cl₂] tetrahedral?

Since PPh₃ is strong field ligand and, the famous Wilkinson's catalyst, which also possess this ligand is square planar, then what makes the above complex tetrahedral?
1
vote
0answers
232 views

Applying Ligand Field Theory, How Can The Color Of Transition Complex Ions Be Explained/Represented?

1. To my understanding, Crystal Field Theory allows for an explanation for the colors of transition metal complex ions due to the d-d transitions which occur. This transition ∆o, is from the t2g ...
1
vote
0answers
41 views

Difference in properties of water as ligand vs 'in lattice'

I'm trying to understand the difference in properties between water in crystals in different positions in the lattice. In this wikipedia article It quotes: Both notations can be combined as for ...
2
votes
1answer
378 views

Spin state change during crystallisation for [NiCl2(PPh3)2]

$\ce{NiCl2(PPh3)2}$ is a complex that is borderline between tetrahedral(high spin) and square planar(no unpaired electron, high splitting parameter) because $\ce{Cl-}$ is a weak field ligand and $\ce{...
-1
votes
2answers
5k views

What is the number of unpaired electrons in (Fe(H2O)5NO)2+? [closed]

Given the fact that $\ce{NO+}$ is a strong field ligand and iron is in the +1 oxidation state, the valence orbitals of $\ce{Fe+}$ must undergo rearrangement from $\mathrm{3d^{6}4s^{1}}$ to $\mathrm{3d^...