Questions tagged [crystal-field-theory]
For questions relating to the electronic structure of inorganic complexes, particularly the splitting of degenerate $d$ or $f$ orbitals by the symmetry of the surrounding ligands.
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Electronic configuration and symmetry labels of 3d$^7$ ions
In 3d$^7$ ions, e.g. Co$^{2+}$, the ground state is $^4$F, and it contains different levels due to the crystal field, such as $^4T_{1g}$, $^4T_{2g}$ and $^4A_{2g}$. Can anyone tell me what exactly ...
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Is concept of Weak and Strong Field Ligands applicable in Valence Bond Theory?
I am high school student studying Coordination- Chemistry. I have read about Valence bond theory and Crystal Field Theory as well.
My teacher taught me that Valence bond theory is based on ...
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Deriving population of $t_{2g}$ orbitals in transition metal oxides
I have recently studied ligand field theory but there is one thing I do not understand.
Consider an octaedral geometry of ligands around a transition metal with a $t_{2g}$ - $e_g$ splitting of atomic $...
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Color change in coordination compounds
When $\ce{FeCl3}$ is added in water it gives a pale yellow color, but on the addition of $\ce{KSCN}$ it changes to intense red color, so how would we explain the color change?
What I thought that the ...
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What's the reason of curvature in Tanabe-Sugano diagrams?
Analysing Tanabe-Sugano diagrams it's evident that some of the lines are pretty parallels to that of the ground field whilst others are inclinated or have some curvature.
I know what's the effect on ...
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Relative magnitude of the crystal field and spin-orbit coupling
In the EPR part of the book 'Physical methods in Inorganic Chemistry' by S. Drago i found that relative magnitudes of crystal field and spin-orbit coupling affect the g values.
I understand that the ...
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What is the shape of tetraamminenickel(II) complex?
I have basic knowledge of crystal field theory (CFT) and how to predict geometries in complexes with a coordination number of 4.
For $\ce{[Ni(NH3)4]^2+}$, we find that the metal center, $\ce{Ni^2+}$, ...
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Significance of Character tables in d orbital splitting
When we have a molecule say (Co(NH2)6) hypothetically any octahedral molecule it has the point group of Oh and the character table shows the quadratic function such as ($z^2,2z^2-x^2-y^2$) ($xy, xz, ...
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Energy of d(x²-y²) and d(xy) orbitals the same with respect to trigonal symmetry?
In the orbital splitting diagrams of trigonal planar and trigonal bipyramidal complexes the d$_{x² - y²}$ and d$_{xy}$ orbitals have the same energy. I have always assumed that this is because they ...
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Why is anhydrous trans-Bis(glycinato)copper(II) more stable than it's cis isomer?
As is shown in Ref.1, the trans isomer is much more stable, at least at molecular level.
Based on the crystal structural data from Ref.2 and atomic radii of O and N from wikipedia and some little ...
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Colour properties of nickel complexes
According to Crystal Field theory (CFT), complexes with stronger ligands must absorb light with higher frequency hence would transmit corresponding complementary colour.
The colour of $(\ce{[Ni(H2O)2(...
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Role of spin of electron in splitting of orbitals
What will happen if there are electrons with opposite spins present in the orbitals of ligand and metal atom during the splitting of orbitals in crystal field splitting?
Magnetic fields of two ...
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Why are electrons paired up in hexaaquacobalt(III)?
I know water is in the middle of the spectrochemical series generally being the differentiator between the weak field and strong field ligands.
I have generally seen water being a weak field ligand, ...
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Relationship between d group and $\Delta_O$ value found in Tanabe-Sugano diagram
So this question came up in class recently and got me thinking, is there any relationship between the metal d group and the $\Delta_O$ found for some allowed transition in Tanabe-Sugano diagram?
I ...
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Colour of diamagnetic compounds using Crystal Field Theory
I know that the colour in coordination compounds can be explained by CFT in terms of d-d transitions.
Are d-d transitions possible in diamagnetic complexes?
Why does $\ce{[Co(NH3)6]^3+}$ show colour?
...
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Why does low spin character predominate in hexafluoronickelate(IV)?
According to my book there are no unpaired electrons in $\ce{NiF6^2-}$. However, that should not be the case since fluoride is a weak field ligand. Why does hexafluoronickelate(IV) behave as a low ...
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Ionic radii of transition metal ions in the presence of weak field and strong field ligands
In the graph given in this image, I was told by my teacher that whenever we start filling the eg orbitals there is an increase in the radius because these orbitals face the ligand directly ...
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Why does energy of non-axial d-orbitals decrease in an octahedral complex?
In an octahedral complex, if we assume the metal ion to be inside a cube then ligands will approach from its faces. So the axial d orbitals will experience more electronic repulsion as compared to ...
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Do strong field ligands always give d2sp3 hybridisation and weak field ligands give sp3d2 for coordiantion number 6 [closed]
i am actually doing coordination compounds but get confused when it comes to hybridization so wanted to create a short of mine for the exam
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the ratio between high spin state and low spin state when they coexist
I am considering the spin state's effect on the charge carrier's lifetime, I was told that high spin and low spin state could coexist when the crystal field splitting energy and the pairing energy are ...
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molecular orbital theory and crystal field theory confusions
I am a high school student and I am very confused in Molecular orbital theory, it says that when two orbitals overlaps in the same phase, they form antibonding orbitals and when they overlap in ...
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What is electronic configuration of manganese in the manganate(VI) anion?
The electronic configuration of the central atom of $\ce{[MnO4]^2-}$ if given out to be $e^1\,t_2^0$
I want to know how to identify which one of the d-orbitals does this configuration utilizes because ...
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Using symmetry and group theory arguments to explain iron(II) in a tetrahedral crystal field
I am trying to figure out how to explain $1s \rightarrow 3d$ spectroscopic transitions for $\ce{Fe^{2+}}$ in $T_\mathrm{d}$ symmetry. These transitions make up the pre-edge region in K edge X-ray ...
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Do "weak-field" and "high spin" complexes refer to the same thing?
I will keep it brief; I know that there are weak field, "moderate" field, and strong field ligands and that these might contribute to a complex being high or low spin overall. My question is,...
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Why is tetrachlorocuprate (II) yellow if it is high-spin?
From my knowledge of transition metal complexes, tetrahedral complexes generally have less splitting (compared to octahedral complexes) because they only involve four ligands are they aren't placed ...
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Strength of Pi Donor and Acceptors as Ligands
The spectrochemical series is usually known as the "strength" of the ligands. It makes sense on a basic level as the more willing a ligand is to donating its electrons (via a $\sigma$-bond), ...
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Is acac- a weak field ligand?
From the chemical structure of acac- compared to NH3 and en, is acac- a stronger or weaker ligand strength? How and why do we know this?
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Tanabe-Sugano diagram x-axis question
While reading up on Tanabe-Sugano diagrams I noticed that many diagrams spread over the internet that all seem to come from this Wikipedia article: https://en.wikipedia.org/wiki/Tanabe–Sugano_diagram. ...
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Why is the pairing energy not considered when calculating the crystal field splitting energy?
Consider the low-spin octahedral crystal field splitting diagram for a d4 system.
When we calculate the crystal field splitting energy we simply observe the absorbed color of light and calculate the ...
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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 ...
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Understanding the Jahn–Teller elongation and compression for octahedral complexes (stabilisation/destabilisation of d orbitals)
I am currently learning about Jahn–Teller effect. For elongation I wondered why the d orbitals with $z$ component are stabilised when the metal–ligand bonds are getting longer? I thought a longer bond ...
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Visualizing the e_g and t_2g orbitals in case of tetrahedral crystal field splitting
I am reading about the crystal field theory (CFT) for the case of tetrahedral coordination entities. I understand that the $\mathrm{t_{2g}}$ orbital is nearer to the ligand than the $\mathrm{e_g}$ ...
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Has a low spin tetrahedral Ni(II) complex been synthesised?
How can $\ce{Ni(II)}$ form a low spin tetrahedral compound? I was not able to find such compounds.
$\ce{Ni(II)}$ will have $\mathrm {4s^03d^8}$ and tetrahedral needs $\mathrm{sp^3}$. So $2$ electrons ...
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The quartic electronic state of octahedral Fe(III): How make crystal field splitting diagram?
Using simple arguments from crystal field theory, how do I rationalize the quartic state of octahedral Fe(III)? I am not able to in a logical way distribute the 5 d electrons in such a a way as to end ...
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Parallel between polarisability of donor atom and CFS strength
Observing the strength of crystal field splitting by different ligands, can the following be considered?:
Most of the members in the series are ligands where the donor atom is nitrogen, oxygen or ...
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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 ...
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What is the magnetic moment of tris(oxalato)nickelate(IV)?
I'm really struggling with finding the magnetic moment of this complex:
In the solutions, it says that it is 2.83 BM (which corresponds to 2 unpaired electrons). However, in drawing out the d orbital ...
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Determination of spinel structure by CFSE
$\ce{CuFe2O4}$ has inverse spinel structure, but $\ce{ZnFe2O4}$ has normal spinel structure. Explain.
I know that normal spinels have a structure like $\ce{(A^{II})^{tet}(B^{III})^{oct}_2O_4}$-like ...
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CFSE Calculation
I have $\ce{[ML6]}$ & $\ce{[MD6]}$ as two complexes. I know the $\Delta_0$ & hybridisation of each of them. How do I calculate the CFSE for $\ce{[ML4D2]}$ ?
This is my way of thinking :
I can ...
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Comparing $\ce{PPh3}$ and dppe
The ligands $\ce{PPh3}$ and dppe (dppe = 1,2-Bis(diphenylphosphino)ethane) are both strong field ligands, but is one obviously a stronger field ligand than the other or are they roughly equal?
The ...
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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 ...
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Octahedral Crystal Field Splitting Orbital Degeneracy
How are the $\mathrm{e_g}$ orbitals degenerate with each other?
Note: This isn't a homework question. After the semester ended (I don't go to MIT), I ended up on MIT open course-ware to watch some ...
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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 ...
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Octahedral Crystal Field Splitting Orbital Energy Levels [closed]
(image source)
In the above diagram, where do the 3/5 and 2/5 come from? Also, how are the $\ce{e_g}$ orbitals degenerate with each other?
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Crystal field splitting of other orbitals
According to crystal field theory (CFT), $\mathrm{d}$-orbitals of central metal atom splits due to non uniform repulsion of ligands around the metal atom. Why isn't $\mathrm{p}$-orbital splitting ...
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t2g and eg electronic configuration
I have been told that with the help of crystal field theory, we can decide the electronic configuration ($\mathrm{t_{{2g}}}$ $\mathrm{e_g}$ configuration) of the metal ion in a complex.
For example, ...
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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 ...
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Definition of t2g orbitals in CFT
My textbook defines $\mathrm{t_{2g}}$ orbitals as
$\mathrm{t_{2g}}$ stands for a set of three orbitals which are asymmetric with respect to $C_2$ axes, perpendicular to the highest $C_n$ axes, but ...
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Transition metals and their ability to form coloured ions [closed]
I understand that in solution. transition metals form coloured ions, but what about the transition metals in solid compounds that are coloured- is this also due to d-d transition?
can you give any ...
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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 ...
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