All Questions
Tagged with molecular-orbital-theory coordination-compounds
41 questions
2
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1
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64
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Symmetry and angular momentum in the Jahn-Teller paper
In the original paper of Jahn et Teller (https://royalsocietypublishing.org/doi/pdf/10.1098/rspa.1937.0142, section I-Two Examples) are described two examples: a linear molecule and one with square ...
- 177
3
votes
1
answer
180
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How to make the energy level diagram of dichlorodiammineplatinum(II)?
The oxidation state of platinum in $\ce{[PtCl2(NH3)2]}$ complex is $+2,$ so its configuration will be $\ce{5d^8 6s^0 6p^0}$ and the shape will be square planar.
But this complex has two strong field ...
- 43
6
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0
answers
476
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How to explain oxidizing power from Molecular Orbital Theory
I am trying to explain the oxidizing property of $\ce{Fe^3+}$ in $\ce{H2O}$ and $\ce{CN^-}$ which is $\ce{[Fe(H2O)6]^3+}$ and $\ce{[Fe(CN)6]^3-}$.
The electrochemical reactions along with their ...
- 651
0
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0
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160
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Jahn-Teller Distortion: How to compare magnitudes (in Cu2+ complexes)?
Octahedral complex of copper(II) undergo structural distortion (Jahn-Teller). Which one of the given copper(II) complexes will who the maximum structural distortion? (en - ethylenediamine)
(A) $[Cu(...
1
vote
1
answer
687
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Which is better ligand, PH3 or PF3?
It confuses me that many researches pointed out different results about phosphine ligands properties (σ-donor and π-acceptor). Since both phosphine $\ce{PH3}$ and phosphorus trifluoride $\ce{PF3}$ ...
- 651
6
votes
1
answer
796
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What is the correct molecular orbital diagram for the d orbitals in platinum for the tetraammineplatinum(II) complex?
I am trying to construct the diagram of $\mathrm{d}$ orbitals in the tetraammineplatinum(II) complex. According to the angular overlap model, $\mathrm{d}$ orbitals are going to look like those in the ...
5
votes
0
answers
654
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Explanation of the trans-effect (thermodynamic and kinetic) for octahedral transition metal complexes
The thermodynamic trans effect refers to the ground state weakening of the metal-ligand bond in a complex by a ligand trans to it. The kinetic trans effect is the lablisation of a ligand in a complex ...
- 5,735
7
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2
answers
625
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Explanation of the orbital energies resulting from Jahn-Teller distortion of octahedral complex using MO theory
I am confused about the energies of the orbitals after Jahn-Teller distortion of an octahedral complex. Take elongation for example.
To my understanding, since the ligands on the $z$ axis move away, ...
- 460
1
vote
0
answers
938
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Comparison between Molecular Orbital Theory and Valence Bond Theory
I have been reading about introductory Molecular Orbital Theory lately. Till now, I have used Valence Bond Theory to evaluate bonding. I have a few questions about it:-
In VBT, we used the idea that ...
- 169
0
votes
1
answer
185
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Jahn Teller Effect on Metal Complexes
I've been learning how the Jahn Teller Distortion effects the orbitals in Metal complexes and how the splitting of eg and t2g orbitals happens.
But the book mentions that the effect is strong for ...
- 748
5
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1
answer
465
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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 ...
7
votes
1
answer
2k
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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 ...
- 807
9
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2
answers
2k
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Why does the binding of DMSO to metal via the S atom (k-S) strengthen the S=O bond?
So, DMSO (dimethyl sulfoxide) can form metal complexes in both $\ce{\kappa-O}$ and $\ce{\kappa-S}$ mode i.e. binding with the oxygen or the sulfur respectively. The general explanation given is that ...
- 5,735
4
votes
1
answer
3k
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Geometry of Ni(acac)2
The complex $\ce{Ni(acac)2}$ is paramagnetic as expected , i.e it has two unpaired electrons giving rise to a magnetic moment of $ \sqrt{8}$ BM but doesn't have the tetrahedral geometry consistent ...
- 497
1
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0
answers
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Energy diagram of copper iodide complex
We did an experiment where copper iodide 4-methylpyridine and copper iodide imidazole was formed and now we are asked what orbital the electron is excited from and to.
After much research we still ...
- 1,095
1
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0
answers
307
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How do we get the wave function of Ligand Group Orbitals with the same symmetry as that of the corresponding metal orbitals
In the book Principles of Structure and Reactivity by Huheey, Chapter 14, the author has taken linear combination of ligand orbitals to form ligand group orbitals and then further combination of LGOs(...
- 79
2
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0
answers
58
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Do species with more unpaired electrons attract magnets more strongly than those with fewer unpaired electrons?
My lecture notes state that you can distinguish between high spin and low spin complexes by their magnetic properties.
This thought came to me: consider two octahedral crystal fields with a d7 ...
- 1,098
4
votes
1
answer
2k
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C4v point group complexes and the group orbitals (MO Theory)
Out of curiosity, what would the group orbitals be like in a C4v complex (square planar complexes or octahedral complexes with 5 identical ligands and 1 other) look like? I get a irreducible ...
- 1,115
2
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0
answers
503
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Structure of (CH3COO)3Fe
I'm a grade 12 student trying to comprehend MOT & LFT in Co-ordination compounds.
For one of our salt analysis(practicals), the test for acetate ion includes the addition of Neutral Ferric ...
- 21
1
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0
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456
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How to understand MO diagrams for cationic octahedral transition metal complexes
I am having problems understanding the construction of MO diagrams in octahedral transition metal complexes within ligand field theory (LFT) when the metal center is asumed as an cation:
I am ...
1
vote
1
answer
198
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UV Absorption of iodine with some solvent
$I_2$ in solution is typically absorbing around $525 \; nm$ this is why it appear to be magenta, I recently learn that with some solvent :
Benzene
Toluene
$o$-Xylene
$p$-Xylene
The coordination ...
- 453
4
votes
0
answers
92
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Rhombohedral second-order Jahn–Teller effect in Au(II) complex?
I was recently listening to a talk about the following work[1] when the author mentioned that they explained the following. In this $\ce{Au(II)}$-porphyrin complex you observe two sets of $\ce{Au-N}$ ...
- 4,362
7
votes
1
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9k
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Why is CO ligand higher than CN- in the spectrochemical series?
I've drawn MO diagrams for both molecules and they are isoelectronic. The main difference is that $\ce{C}$ is closer in electronegativity to $\ce{N}$ than it is to $\ce{O}$ so there will be less ...
- 115
2
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1
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770
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ligand pi system irreducible representation for trigonal bipyramidal transition metal complex
I am considering a D$_{3h}$ trigonal bipyramidal transition metal complex MX$_5$. I have found that the irreducible representation for the ligand s and $\sigma$ systems is 2A$_1'$+A$_2''$+E$'$. I ...
- 353
6
votes
1
answer
8k
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Why does [Co(NO2)6]4- ion have 3 unpaired electron as opposed to 1?
Why does $\ce{[Co(NO2)6]^4-}$ ion have 3 unpaired electron as opposed to 1?
The book says that it has 3 unpaired electrons. I thought $\ce{NO2-}$ was a strong field ligand, making $\ce{Co^2+}$ a $\ce{...
- 117
0
votes
0
answers
497
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Sigma and pi coordination in complexes (symmetry)
According to the Miessler Tarr and many molecular orbital diagrams for octahedral complexes on the internet will σ-donors/acceptors only influence the $e_g$-orbital, while π-donors/acceptors influence ...
- 4,362
1
vote
1
answer
539
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Bonding in MOF-5 [closed]
I came up with this problem today and I can't find the answer elsewhere:
How does the oxygen atom bond to the four zinc atoms? To be more specific, what would be the molecular orbital diagram for the ...
- 1,369
7
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1
answer
6k
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Coordination geometry: why is of Cu(acac)2 square planar?
Why is $\ce{Cu(acac)2}$ square planar, whereas $\ce{Al(acac)3}$ and $\ce{Fe(acac)3}$ form octahedral complexes? I see how a similar argument to $\ce{Pt}$ complexes would apply, i.e. with $\mathrm{d^9}$...
- 1,696
2
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1
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2k
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Why is the iron(II) on the heme molecule depicted as having 6 electrons in its 5 d non- and anti-bonding orbitals?
Approximating the $\ce{Fe}$ complex as a square base pyramid ($D_\mathrm{4h}$ symmetry) with 5 $\ce{N}$ ligands, My electron count of the system gives me 16 electrons – 10 from the $2\times 5$ $\ce{N}$...
6
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1
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How can I build the molecular orbital diagram of the complex tetraammincopper(II) (square planar structure)?
I have to build the molecular orbital for the $\ce{[Cu(NH_3)_4]^{2+}}$ complex.
I know I have to use the characters table, the irreducible representations, the rule 5 and, somehow, determine the ...
13
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1
answer
4k
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IS DMSO-o a σ-donor, a π-donor, or both?
DMSO is an ambidentate ligand that can bind in a κO fashion via the oxygen lone pair and in a κS fashion via the sulfur lone pair.
I know that DMSO can behave as a π-acceptor when it ...
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4
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1
answer
1k
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Cyanide complexes in Molecular Orbital Theory
In molecular orbital theory, please explain why cyanide ion combines with metal from the carbon end and not from the nitrogen end?
- 123
4
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1
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2k
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Why do better π-acceptor ligands cause smaller Δ(T) d-orbital splitting?
Consider a formazanate ligand. Then imagine an electron-withdrawing group added to it. I expect a small σ-donating effect, and good π-accepting properties.
My supervisor tells me that an ...
3
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1
answer
13k
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Does crystal field splitting energy Δ increase going down a group of transition metals if the ligands are weak field?
Going down a group, the metal orbitals are more diffuse so there is greter
overlap between the metal and the ligand orbitals.
If there are no π-interactions, i.e. with σ-donor ligands like $\ce{NH3}$, ...
- 491
38
votes
1
answer
83k
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Why is [PdCl4]2- square planar whereas [NiCl4]2- is tetrahedral?
The molecule $\ce{[PdCl4]^2-}$ is diamagnetic, which indicates a square planar geometry as all eight d electrons are paired in the lower-energy orbitals.
However, $\ce{[NiCl4]^2-}$ is also $\mathrm{d^...
user22986
25
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1
answer
11k
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How can the intense color of potassium permanganate be explained with molecular orbital theory?
In the permanganate ion, manganese is in the $+7$ oxidation state, therefore it is a $\ce{d^0}$ ion. $\ce{d^0}$ and $\ce{d^1^0}$ ions don't absorb visible spectrum radiation because there are no ...
- 26.8k
14
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1
answer
4k
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Molecular orbital diagram of a complex including an oxido ligand
With highly oxidized metal centers, we expect that the hydroxido ligand's proton becomes acidic and will be lost to the surrounding media, creating an oxido ligand.
The oxo ligand is a $\pi$ basic ...
- 963
1
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1
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617
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MO scheme for coordination complexes (tetrahedral) - Heteroligand vs. homoligand
How is the MO diagram drawn for a tetrahedral complex with heteroligands (e.g. $\ce{[NiCl2(PPh3)2]}$) different from a tetrahedral complex with the same type of ligand? Do we consider the same "a1 and ...
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29
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1
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What are t2g and eg in CFT?
In the crystal field theory (CFT), when the splitting of the d-orbital occurs, it gets divided into two parts.
The upper part with higher energy is the $\mathrm{e_g}$ and the lower part with lower ...
- 1,693
1
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1
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877
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Which d-orbitals split according to CFT?
According to CFT, the degenerate d-orbitals split into $eg$ and $t_2 g$ groups. Are these the outermost nd orbitals which are vacant(4-d in case of 4th period) or the penultimate filled (n-1)d ...
- 400
6
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1
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5k
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MO-Scheme of SCN- and its bonding properties when used as a ligand
I tried to figure out the MO-scheme of the tetragonal-bipyramidal complex trans-$\ce{[Co(en)2(NCS)2]SCN}$ in which the isothiocyanate ligands are bound to the $\ce{Co^3+}$-Ion in $\eta^{1}$-mode (en = ...
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