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.

Filter by
Sorted by
Tagged with
0
votes
0answers
22 views

Formation constant of Eriochrome Black T Complexed with Pb (II)

What is Eriochrome black t’s formation constant when complexed with Pb (II)? If Eriochrome was placed in solution with a metal ion complexed to NH3, would Eriochrome likely replace NH3 via ligand ...
-3
votes
0answers
36 views

Is [Co(H2O)6]3+ a low spin or high spin complex?

I had been taught that although $\ce{H2O}$ is normally a weak field ligand for 3d transition elements, $\ce{Co^{3+}}$ is an exception and forms a low spin complex with conventionally W.F.L. like $\ce{...
1
vote
0answers
49 views

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, ...
2
votes
1answer
199 views

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 ...
1
vote
0answers
97 views

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 ...
-1
votes
1answer
43 views

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 ...
0
votes
0answers
243 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
61 views

Why must there be degeneracy in the orbitals to have a Jahn-Teller effect? [closed]

Why is it the case that for Jahn-Teller effects to occur in transition metals there must be degeneracy in either the $\mathrm{t_{2g}}$ or $\mathrm{e_g}$ orbitals?
1
vote
0answers
55 views

What is the order of crystal field stabilisation energy for tris(ethylenediamine)chromium(III) chloride and hexaaquachromium(III) chloride?

In my book it is given that the crystal field stabilisation energy for $\ce{[Cr(en)3]Cl3}$ is more than that of the complex $\ce{[Cr(H2O)6]Cl3}.$ By what I have studied, the crystal field ...
3
votes
1answer
80 views

Sulfate and carbonate ions as ligands

The pentahydrate salt of copper (II) sulfate exists as a blue solid while the anhydrous and monohydrate salts appear as white solids. The structures of these salts are discussed here. The blue colour ...
0
votes
1answer
89 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 ...
1
vote
1answer
389 views

Magnetic nature of tetraamminedichlorocobalt(III) chloride

I know how to predict magnetic nature when the compound contains only strong field or only weak field ligands. But in $\ce{[Co(NH3)4Cl2]Cl},$ $\ce{NH3}$ is a strong ligand whereas $\ce{Cl-}$ is a weak ...
0
votes
1answer
1k views

What is the hybridization of chromium in chromate and dichromate ions?

I was recently reading about the transition metals and some important compounds of them. I came across a rather interesting diagram in my book... a tetrahedral structure for the chromate ion. The only ...
0
votes
0answers
176 views

Crystal field splitting energy of hexaaqua copper(II) and hexaaqua iron(II)

I am performing an experiment for the IB diploma program to determine the crystal field splitting energy of d-orbitals of different transition metal ions when they are complexed with ligands. In my ...
1
vote
0answers
59 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 ...
1
vote
2answers
78 views

Why is Libethenite (Cu2(OH)PO4) color green?

It is not a complex compound and the copper atom is not oxidized so I'm wondering how does its color change. The book mentioned that at favorable conditions, adding water in Copper phosphate, which is ...
2
votes
2answers
97 views

Colour of metal complexes with the same type and number of ligands

Crystal Field Theory says that because of d-orbital splitting caused by different ligands we have 2 different energy levels for d-orbitals. It also says that transition metals are coloured because ...
0
votes
0answers
127 views

Why are d(xy),d(yz) and d(xz) orbitals involved in d³s hybridisation?

Shouldn't d(x²-y²) dxy and dz² orbitals participate? Since this corressponds to the best case overlap? What factors decide the participating orbitals in hybridisation? P.S I am well versed with the ...
9
votes
2answers
2k 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?
4
votes
0answers
41 views

Changing of UV-Vis peak absorption after heating Ni(en)2(NO2)2

(c) The trans-isomer of $\ce{Ni(en)2(NO2)2}$ D is red $(λ_\mathrm{max} = \pu{500 nm}).$ It can be heated to give a new trans-isomer E, which is violet $(λ_\mathrm{max} = \pu{560 nm}).$ Assume that, ...
1
vote
0answers
134 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
468 views

Derivation of t2g eg splitting in octahedral field

I am trying to make the derivation of the d orbitals splitting under an octahedral field but I am kind of at a loss and don't know of any literature that can provide a more introductory level of this ...
0
votes
1answer
582 views

Magnetic moment from given CFSE value

Spin magnetic moment of a octahedral complex having CFSE = $– 0.8∆$ and surrounded by weak field ligands can be: A. $\sqrt{15} \space \mu_B$ B. $\sqrt{8} \space \mu_B$ C. (A) & (B) ...
1
vote
1answer
355 views

Why do some ions form tetrahedral complexes more readily than others? [closed]

Why does Co$^{2+}$ readily form tetrahedral complexes such as [CoCl$_4$]$^{2-}$, whereas Fe$^{2+}$ usually forms octahedral complexes?
2
votes
1answer
165 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{...
0
votes
0answers
660 views

Electronic configuration of d5-d-10 in terms of t2g and eg in an octahedral field when delta O is smaller than pairing energy?

As per the Crystal Field Theory, d4 splits into t2g3 and eg1 when delta 0 < Pairing energy. What about d5, d6 and so in the same case? Does the fifth, sixth... electrons enter the t2g or eg ...
1
vote
0answers
262 views

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 ...
5
votes
0answers
244 views

What is the magnetic moment of potassium hexacyanochromate(II)?

I calculated the magnetic moment of $\ce{K4[Cr(CN)6]}$? in the following way: $\ce{Cr^{+2}}$ has $4$ d electrons. And since $\ce{CN-}$ is a strong field ligand, the electrons will pair up in the $\...
3
votes
0answers
402 views

Fluoride anion as a strong field ligand

In the case of $\ce{[Fe(H_2O)_6]^{3+}}$ there are $5$ unpaired electrons as water acts as a weak field ligand. But instead of flouride acting as a weak field ion in the $\ce{[MnF_6]^4-}$ , why does it ...
5
votes
1answer
3k views

Bonding in Zeise's salt

I am not sure I completely understand the bonding in coordination compounds formed by donation of pi electron cloud by the ligands to the central atom. For example, consider Ziese's salt: I came ...
4
votes
1answer
2k views

Is cobalt(II) in the hexaamminecobalt(II) complex high spin or low spin?

I want to determine the electronic configuration of $\ce{Co}$ in $\ce{[Co(NH3)_6]Cl2}$ with Crystal Field Theory. I know that since the complex is octahedral, there would be degeneracy breaking and ...
2
votes
1answer
3k views

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 ...
6
votes
0answers
516 views

How does the Jahn-Teller distortion result in both elongation and compression?

Recently, I have been reading up on the Jahn-Teller effect and I have read articles and posts on it, such as What is the mathematical basis behind the Jahn-Teller effect?. However, many of these ...
-2
votes
1answer
889 views

Why do NON -Transition elements exhibit variable oxidation state?

I know transition elements exhibit variable oxidation states because valence electrons are in d block and s which are very close so they have similar energies ,thus with slightly different energies ...
2
votes
1answer
321 views

Jahn Teller distortion and magnetic moments.

It is relatively well known that the discrepancy between the observed and experimental magnetic moments in the first row transition metals is attributed to spin-orbit coupling when it comes to metal ...
3
votes
2answers
3k views

Why is a [Cu(SCN)2] complex black?

I've been creating various Copper(II) complexes using different ligands and predicting their relative hues using Crystal Field Theory by using the spectrochemical series to predict the extent of d ...
0
votes
1answer
696 views

Tetragonal (z-in/z-out) in tetrahedral complexes?

Is it possible to have tetragonal distortion in tetrahedral complexes? Because distortions in octahedral complexes take place along the C4 axis to reduce the symmetry to D4h, but there is no C4 ...
3
votes
0answers
282 views

Crystal Field Theory - Operator Equivalent Methods

I am a bit confused by some of the points of operator equivalent methods in crystal field theory. I would appreciate any help I could get with any of my questions. First, I am confused as to the ...
1
vote
0answers
1k views

How does the dx2-y2 orbital bond with four ligands in square planar metal-metal complexes

I understand that the complex [Re2Cl8]2- has a bond order of 4 between the ruthenium ions. The bond comprises of sigma interactions between Dz2 orbitals, two sets of pi interactions between dxz and d ...
2
votes
1answer
475 views

Crystal field splitting in complexes other than octahedral or tetrahedral [closed]

Is there a methodology to developing the crystal field splitting diagram for various crystal fields? I know the octahedral and tetrahedral diagrams, but if I'm asked to draw something like square ...
3
votes
0answers
59 views

Why does some compound as given in the image below change from low spin to high spin above a particular transition temperature?

Magnetic moment sudden increase at a particular temperature is explained by CFT. But why does it happen at all?
-1
votes
1answer
332 views

Ionic interaction in crystal field theory

How correct is the assumption of ionic interaction between the ligands and the central metal atom in cft when many ligands do not even possess charge over them? Besides, I also referred to the ...
2
votes
1answer
1k views

Identifying a Positive or Neutral Ligand Inside Coordination Sphere?

There are some coordination compounds like $\ce{Na2[Fe(CN)5NO]}$, where ligands like $\ce{NO}$ are used which exist as both $\ce{NO+}$ (nitrosonium ion) and $\ce{NO^.}$ (neutral nitrosyl). How to ...
3
votes
1answer
4k views

Why is hexafluoridocobaltate(III) the only common high-spin cobalt(III) complex?

Almost all $\ce{Co^3+} (\mathrm{d^6})$ complexes are low spin, including $\ce{[Co(H2O)6]^3+, [Co(ox)3]^3–, [Co(NH3)6]^3+}$ and $\ce{[Co(CN)6]^3–}$. The only common high-spin cobalt(III) complex is $\...
4
votes
1answer
1k views

What's the configuration of chromium(III) in aqueous medium according to crystal field theory?

It has $\mathrm{3d^3}$ configuration, but how will we decide if they enter $\mathrm{t_{2g}}$ or $\mathrm{e_g}$ orbitals since we don't know which complex will form?
2
votes
1answer
528 views

Energies of d orbitals relative to the barycentre

Rather than referring to the energy of an isolated metal atom, the weighted mean of these two sets of perturbed orbitals $(\mathrm d_{xy}, \mathrm d_{xz}, \mathrm d_{yz}$ and $\mathrm d_{x^2 - y^2}$, $...
3
votes
1answer
96 views

Color difference among oxovanadium species

Why dioxovanadium $\ce{[VO2]+}$ is pale yellow, whereas orthovanadate $\ce{[VO4]^3-}$ is colorless? Both of them should be colorless if we ignore charge transfer for a moment, because in both cases ...
2
votes
0answers
126 views

Why do compounds form if overall energy of free ion increases according to CFT

According to crystal field theory, a free ion has certain energy and its energy increases when it is symmetrically surrounded by ligands. Now the degenerate d orbitals split into two new set of ...
8
votes
2answers
1k views

In an octahedral complex, what happens to the electrons donated by the ligand?

I am trying to understand how complexes are coloured. After some reading, I found out this was due to the d-d splitting induced by the coordinate bonds of ligands to the central metal ion. The ...
4
votes
0answers
106 views

What will happen if ligand orientation is changed?

How we came to know ligand should approach from t2g orbitals in d5 configuration for tetrahedral complexes? What will be the difference in energy if ligand approach from eg? As far as I can think, ...