Questions tagged [dipole]

For questions about the dipole moment of a bond or a molecule; its calculation, comparison with other bonds or molecules, affect on molecular properties, etc.

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Why does AsH3 have a higher boiling point than HBr?

Aside from the general trend of the boiling points of the hydrides, I noticed how the group 15 hydrides somehow "overtook" the group 17 ones in boiling point, which felt weird. Notably, H-...
4 votes
1 answer
213 views

Why would the chlorine atom be assigned a positive partial charge in chloroform and carbon tetrachloride?

Looking at electronegativity tables, chlorine consistently has a higher electronegativity than carbon. However, when I use simple algorithms (molcalc, acc2), I get a positive partial charge on the ...
12 votes
4 answers
12k views

Why does chloromethane have a larger dipole moment than chloroform?

Why does $\ce{CH3Cl}$, methyl chloride, have a larger dipole moment than $\ce{CHCl3}$, chloroform? Let us consider $\ce{C-Cl}$ bond moment to be $x$ and that of $\ce{C-H}$ bond to be $y$. In $\...
4 votes
1 answer
2k views

Is dipole moment a vector?

Isn't it a misconception to assume that dipole moments are similar to vectors in their behavior? My reasons are as follows: Let us take an example: Methane ($\ce{CH4}$) Clearly, the hydrogen atoms ...
20 votes
3 answers
6k views

How to calculate molecular dipole moment from a known wavefunction?

Say I have a molecular wavefunction as a set of molecular orbitals and want to calculate the molecule's dipole moment, but don't know how! I searched a lot but couldn't find any practical example. $$\...
25 votes
0 answers
2k views

How to calculate transition dipole moment from two known wavefunctions

I am interested in calculating the transition dipole moment (TDM) from the information from two wavefunctions of different states. This is somewhat similar to calculating the molecular dipole moment ...
4 votes
1 answer
80 views

Polyatomic molecule vibrational spectra - Molecular dipole expansion in Taylor series

To give some context: I am studying the molecular spectra in the context of an introductory course to atomic and molecular physics. My professor is using the transition rate expression from an initial ...
-2 votes
1 answer
142 views

Dipole Moment in P4O8 molecule

So from the structure, which seems to be quite symmetrical, according to me the dipole moment should be zero.
4 votes
6 answers
1k views

Does an ionic bond have a dipole?

Is an ionic compound like NaCl considered a dipole? It has a positive side (Na+) and a negative side (Cl-). Or is it true that an ionic bond does not have a dipole because a dipole is, by definition, ...
3 votes
1 answer
125 views

Dipole moments of trans and cis nitrous acid

I have a paper due about the isomers of nitrous acid, using various calculations methods to find molecular properties like their dipole moment. I've found the dipole moment of trans isomer to be 1.987 ...
-4 votes
2 answers
200 views

Why is the dipole moment of Anisole less than that of Phenol? [closed]

According to Wikidata, anisole has a dipole moment of 1.38D and according to this page on Researchgate, phenol has a dipole moment of 1.70D. Resonance in anisole: Resonance in phenol: According to my ...
1 vote
1 answer
536 views

Why is the inductive effect possible?

Firstly, I must preface that I am a Biology student. To elaborate my question, I was looking for the reason why carboxylic acids are more acidic than alcohols, despite both compounds containing —OH ...
9 votes
2 answers
93k views

Why don't polar and non-polar compounds dissolve each other?

Dipoles can also be induced in polar and non polar compounds, then why don't they dissolve?
23 votes
3 answers
14k views

Is Hydrogen Bonding a Type of Dipole Dipole Interaction?

I understand that dipole dipole forces is due to the attraction of the different partials charges of atoms in different molecules due to their different electro-negativities. For hydrogen bonding, ...
5 votes
1 answer
2k views

Dipole Moment of Normal Water vs Heavy Water

The question is in the title itself. My guess: Higher for Normal water. My Reasoning: Internet told me Deuterium is more electronegative than Protium. So, there should be less difference between ...
0 votes
3 answers
20k views

Does the distance increase as the polarity increases?

According to the dipole moment's definition, as polarity increases, the distance between the centres of positive and negative charges increases. In the ionic bond, as the polarity is maximum, the ...
3 votes
0 answers
45 views

Can the charges at the ends of a dipole in a polar molecule exceed unit electronic charge?

According to my current understanding, charges at the end of the dipole of a polar molecule are formed due to the shifting of the electron cloud towards the more electronegative atom. In my book it is ...
2 votes
1 answer
132 views

Best description of forces/ mechanisms that stabilize the interaction between a hydrophobic protein binding pocket and a hydrophobic ligand

This is a more theoretical or definition question that is related to the terms "hydrophobic effect", "hydrophilic interaction", and "van der Waals' forces" (and others I ...
3 votes
0 answers
53 views

Can we find dipole moment of water from a familiar property?

There are many videos on Youtube showing deflection of a stream of water by a charged rod. My question is whether we can do a rough calculation of the dipole moment of water molecules using this ...
5 votes
2 answers
954 views

Link between centrosymmetry, dipole moment and chirality

What is the relationship between the three concepts in the title? I know all centrosymmetric molecules are achiral, but not all achiral molecules are centrosymmetric. Thus, there are no molecules ...
0 votes
0 answers
66 views

Comparing dipole moments of hydrogen halides

How can we compare dipole moments of halide ions? As we go down the group, the induced charged hydrogen decreases as electronegativity difference between hydrogen and corresponding halogen decreases ...
0 votes
0 answers
95 views

How to convert from dipole derivative to atomic units?

I need to convert dipole derivative output by Gaussian into atomic units. The dipole derivative is given in Gaussian in the weird units $(\mathrm{km/mol})^{1/2}$. I know that $\pu{1 D^2/(Å^2amu)}$ = $\...
3 votes
2 answers
1k views

What does Partial charge means in Dipole Dipole forces [duplicate]

Dipole-dipole forces act between the molecules possessing permanent dipole. Ends of the dipoles possess “partial charges” and these charges are shown by Greek letter delta (δ). Partial charges are ...
0 votes
0 answers
45 views

Should there be a better explanation on Van Der Waals force? [duplicate]

The explanation on how Van der Waals force forms is this: Van der Waals forces consist of induced, temporary dipoles between neighbouring molecules. These are caused by constantly shifting electron ...
23 votes
2 answers
7k views

Non-zero dipole moment of hydroquinone

Why does hydroquinone possess a non-zero dipole moment? The $\ce{OH}$ groups present at para positions on the benzene ring should cancel the effect of each other... if there is a plane change then ...
0 votes
0 answers
107 views

Are spontaneous/induced dipoles the same as van der Waals forces?

I am puzzled by the names of dipoles. What is the difference among permanent dipoles, spontaneous dipoles, van der Waals forces, and intermolecular forces? Does "The intermolecular force" ...
1 vote
0 answers
84 views

Quantitatively Calculate Dipole Moment [duplicate]

Recently, I have been reading up on articles relating to the dipole moments of different molecules (specifically this). I see how they can get bond lengths and experimental dipole moments with ...
40 votes
3 answers
2k views

Is Hexafluorocyclohexane the "Most Polar" Small Molecule?

Earlier this year, there was a lot of attention when all-cis 1,2,3,4,5,6-hexafluorocyclohexane was synthesized*: Notably, C&E News quoted the lead author: This compound is remarkable for being ...
9 votes
3 answers
4k views

Dipole moment and polarity of borazine / borazole / inorganic benzene

What is the dipole moment of borazine? I tried googling it but can't find a reliable source. I searched in JD Lee too. It might have it but I could not find.
1 vote
1 answer
698 views

Using covalent or ionic radius when calculating dipole moment

When the ionic character of a bond is above 50% should I use ionic radius instead of covalent one when calculating the dipole moment? The formula I have for dipole moment is $\mu = \text{(% ionic ...
8 votes
2 answers
562 views

Differences between formulae for dipole–dipole interaction energy

I came across two formulae for dipole-dipole interaction energies on Chemistry LibreTexts — Dipole-Dipole Interactions: $$V=-\frac{2\mu_1 \mu_2}{4\pi\epsilon_0r^3}\tag{3}$$ and $$V=-\frac{2\mu^2_\...
4 votes
0 answers
4k views

How to explain the periodic trends in boiling points in groups?

Observing the trend of boiling points of the compounds listed, choose the appropriate terms to fit into the blanks: \begin{array}{lr} \hline \text{Compound} & \text{b.p.}/\pu{°C}\\ \hline \ce{H2Te}...
1 vote
2 answers
3k views

How are reactivity and dipole moment related?

Recently, I came across a question: which of the two compounds has a greater reactivity; $\ce{NH_{3}}$ or $\ce{NF_{3}}$? It is known that despite the same structure the dipole moment of $\ce{NH_{3}}$...
1 vote
2 answers
3k views

How to determine which of two similar compounds has the larger dipole moment?

I am solving some problems involving the order of dipole moments of some compounds. I could solve most of them but the following: Which has greater dipole moment? $\ce{CH3F}, \ce{CH_3Cl}$ Since ...
2 votes
2 answers
28k views

How do I figure out the relative polarity of organic compounds?

It's a question on my quiz which I guessed right and couldn't do the reasoning: Based on the intermolecular forces, predict the boiling points of the following substances and list them in the order ...
5 votes
1 answer
2k views

What is the relationship between dipole moment and solubility?

I thought a large dipole moment meant the substance was polar, so I'm confused by the following statement (from Wikipedia) that "With a dipole moment of 3.92 D, acetonitrile dissolves a wide range of ...
2 votes
0 answers
96 views

Why is the intensity of the IR spectra of IBr higher than that of ICl?

Why is the intensity of the IR spectra of $\ce{IBr}$ higher than that of $\ce{ICl}$? I know that the IR spectra intensities are proportional to the derivative of the dipole moment with internuclear ...
6 votes
1 answer
4k views

Relationship between electric dipole moment and polarization?

$$\vec{p}_\text{ind} = \alpha \vec{E}$$ The induced dipole moment is the polarizability times the electric field vector. $$\vec{P}(\omega) \propto \chi^{(1)}(\omega) \vec{E}(\omega)$$ The polarization ...
14 votes
1 answer
6k views

Order of dipole moments

What is the order of dipole moments for $\ce{SO3, SiO2, P2O5,}$ and $\ce{Cl2O7}$? This question is from a book and the answer given is $\ce{Cl2O7 < SO3 < P2O5 < SiO2}$. Can someone explain ...
2 votes
2 answers
432 views

Net direction of dipole moment in oxygen difluoride

What is the net direction of dipole moment in $\ce{F2O}$ molecule? In the case of $\ce{NH3}$ and $\ce{NF3}$ molecules both have net dipole moment with direction reversed due to strong ...
1 vote
3 answers
2k views

Why hydrogen bonds are stronger than Van der Waals forces?

Why the hydrogen bonds are more intense than Van der Waals forces in the case where the molecules with the Van der Waals forces have a stronger dipolar moment than the molecules with the hydrogen bond?...
1 vote
0 answers
107 views

Dielectric polarization: how to identify what part of the total polarization (dipolar+electronic+ionic) I need (conceptual question, I use DFPT, VASP)

I am doing polarization calculations to get data for use in other calculations. To start with, I want to calculate the static dielectric constant. However, I'm a newbie to polarization and it is a ...
0 votes
0 answers
151 views

TD-DFT transition dipole moment vector does not align with experimental data

I have been modelling excited states of some molecules with similar stucture using TD-DFT theory, however, I have encountered an issue that sometimes transition dipole moment does not align with the ...
1 vote
1 answer
784 views

What is the direction of the net electric dipole moment in hydronium H3O+?

Assuming electric dipole moment points towards the negative charge, what would its direction be in hydronium? Although the bonding electron density is distorted towards the more electronegative oxygen,...
-1 votes
1 answer
126 views

How does this rotation minimize the dipole moment?

A paper I'm reading says: The low energy conformation of 3 minimizes the overall dipole moment of the compound and thus rotates the exocyclic amide 180° from desired conformation, as can been seen in ...
1 vote
4 answers
4k views

Why does ozone have a dipole moment different than 0 [duplicate]

First of all, I know that the reason for this is the bent structure of the molecule. However, we were taught in my class that the dipole moment of a molecule is equal to the vector sum of the dipole ...
0 votes
0 answers
290 views

When do lone pairs affect dipole moments?

My textbook says that NH3 has more dipole moment than NF3 despite F being more electronegative than H, because the dipole moment due to the lone pair on N points in the same direction as the ones due ...
4 votes
0 answers
644 views

Why do molecules showing a pure rotational spectra require a permanent dipole?

I understand that pure rotational spectra only exist for molecules which have a permanent dipole moment. The common explanation is "so that they can interact with the E-field of the incoming ...
-2 votes
1 answer
474 views

How is dipole moment of ammonia less than sulphur dioxide? [closed]

Sulphur dioxide has only two bonds at 180º so shouldn't the dipole moment of molecule be 0 and as ammonia has 1 lone pair so it's dipole can't be 0 so how Sulphur dioxide has more dipole moment than ...
7 votes
3 answers
882 views

Dipole moment of (1s,2s,3s)-1,2,3-trichlorocyclopropane

Which of the following compounds has a zero dipole moment? Only one of the options is correct According to me, it looks like both options (c) and (d) are right. Since the dipole moments of option (c) ...