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.

Filter by
Sorted by
Tagged with
-2
votes
1answer
329 views

Polarity of symmetric Lewis structure [closed]

Why is $\ce{CF2Cl2}$ polar? The Lewis dot structure shows the molecule as being symmetric. Wouldn't that make it nonpolar?
7
votes
1answer
1k views

Calculating dipole moments from atomic partial charges

How can I calculate dipole moment of a complex molecule where the partial charges are available from density functional theory? I have the coordinates of each atom from atomistic simulations of an ...
0
votes
0answers
106 views

Why is the molecular dipole the main determinant of whether a substance dissolves in another substance?

Consider a covalent molecule such as carbon tetrafluoride. In $\ce{CF4}$, each $\ce{C-F}$ bond is polar covalent. However, this substance is considered overall non-polar because each bond dipole ...
12
votes
2answers
7k views

Does the dipole moment increase or decrease by increasing the bond length?

It is established the dipole moment is a result of multiplication of the magnitude of charges (Q) and the distance between them (r). What I understand is that when an electron and a proton get closer (...
4
votes
2answers
5k views

Why does acetone have a greater dipole moment than dimethyl ether?

Below are the lewis structures for dimethyl ether and acetone. My chemistry textbook indicates that acetone has a larger dipole moment than dimethyl ether. I am familiar with dipole moments and the ...
5
votes
0answers
76 views

Program to compute multipoles of water at CCSD(T)-F12 accuracy

I want to compute traceless cartesian electrostatic multipole moment tensors up to fourth order (hexadecapole), at CCSD(T)-F12 accuracy using a large basis set. I'd like to be able to choose the ...
4
votes
1answer
4k views

Why does p-dichlorobenzene have zero dipole moment while hydroquinone does not?

At first I thought that both the OH groups would cancel out their dipole moments in hydroquinone. On reading further, I realized that because of the two different planar structures possible, it has a ...
1
vote
0answers
101 views

Closed shell structure & intrinsic molecular (electric) dipole moment

Does the closed shell structure of a molecule imply that it has an intrinsic (electric) molecular dipole moment? If so, why is that? I came across this in paper [1], which seems to suggest that this ...
4
votes
1answer
695 views

Why bond energy of acetone is more though it is more polar than formaldehyde?

I was going through the general properties of carbonyl compounds and then found this (in the pic) data, where it says that dipole moment of acetone (if we assume $\ce{R = -CH3}$) is more than ...
14
votes
2answers
1k views

Why are dipoles “permanent/induced dipole permanent/induced dipole” and not just “permanent/induced dipole” once?

My teacher would always say "induced dipole induced dipole" and while it annoyed my slightly (as you were saying the same word twice) it didn't really bother me, ...
6
votes
1answer
198 views

How do atoms lose their induced dipole?

There exists the basic chemistry lesson with induced dipoles where the electron density of one atom changes causing a dipole to form and causing a cascading effect where other atoms adjacent to that ...
3
votes
1answer
937 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 ...
2
votes
0answers
476 views

What is the need for dipole moment if electronegativity already exists?

Say we have an HCl molecule. The difference in electronegativities of the H and Cl atoms tells us how polar the HCl molecule is. The dipole moment is also a measure of the degree of polarity in ...
5
votes
2answers
1k views

Dipole moment of borazine

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.
2
votes
2answers
10k views

Dipole moment of CH2Cl2 and CHCl3 [duplicate]

Why does $\ce{CH2Cl2}$ have a higher dipole moment than $\ce{CHCl3}$? My argument being that the $\ce{CCl3-}$ ion being rather stable, can generate a good amount of polarity in the bond, moreover, ...
13
votes
4answers
1k views

What is the exact reason that compounds such as carbon dioxide cannot interact with other compounds through dipole-dipole interactions?

Whilst I understand that $\ce{CO2}$ has a linear structure, resulting in a vector sum of the dipoles of 0, I do not understand why the dipoles formed at the two oxygen atoms as a result of their ...
13
votes
1answer
2k views

Why is the dipole moment of chloromethane larger than the dipole moment of fluoromethane?

On the Pauling electronegativity scale, fluorine and chlorine are 3.98 and 3.16, respectively. Since the dipole moment is dependent on electronegativity, why is the dipole moment of chloromethane ...
4
votes
2answers
219 views

Potential wells and symmetry in absorption spectroscopy

In a course I am following, we are analyzing the potential wells in molecular absorption spectroscopy. For molecules with more than one normal mode, we can study the potential wells involved in ...
12
votes
1answer
465 views

Why do post-Hartree-Fock methods fail to predict the direction of the dipole moment of carbon monoxide?

In carbon monoxide the dipole moment (negative to positive) points towards the oxygen, as I explained it in How can the dipole moment of carbon monoxide be rationalised by molecular orbital theory? A ...
14
votes
1answer
440 views

Dipole-quadrupole polarizability term for induced dipole

For describing an induced dipole, I have usually seen the following equation, $$ P_{i} = \alpha_{ij}E_{j} + \frac{1}{2}\beta_{ijk}E_{j}E_{k} $$ where $P_{i}$ is the $i^{\text{th}}$ component of the ...
9
votes
1answer
536 views

What is the dipole moment direction in the nitrosonium ion?

In the recent question about the molecular orbitals of $\ce{NO^{$x$}};\ x\in\{-1,0,+1\}$ the follow-up title question arose: Just a random side-question: What’s the dipole moment’s negative and ...
5
votes
3answers
6k 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 $\...
2
votes
2answers
410 views

How does one apply the knowledge of the direction of a molecular dipole moment?

I was watching Khan academy's video about molecular dipole moments, which explained what they are and how they can be calculated. I also read this article. Both sources explain the concept similar ...
1
vote
1answer
5k views

What is the difference between an ion-induced dipole attraction and just an ion-dipole attraction?

By what I've read, an ion-induced dipole attraction is a weak attraction that results when the approach of an ion creates a dipole in a non-polar atom or in a non-polar molecule by disturbing the ...
2
votes
2answers
6k views

Polarity index vs. Dipole moment

I'm looking to find whether water or methanol is more polar, and I'm getting conflicting answers. My textbook says "the polarity of a bond is quantified by the size of its dipole moment." According ...
1
vote
2answers
2k 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. The question is to find out which has greater dipole moment $\ce{...
2
votes
1answer
3k 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} \text{Compound}& \text{boiling point}\\\hline \ce{H2Te} &...
6
votes
1answer
305 views

Chemical bonding and dipole moment

We know that ammonia undergoes amine inversion. Why doesn't the dipole moment decrease in ammonia, since the direction of the dipole changes to the opposite direction every time there's inversion? ...
4
votes
1answer
811 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 ...
3
votes
1answer
122 views

What is the potential to use for non-dispersion interactions?

Although liquid argon’s intermolecular potential can be described using a Lennard-Jones (LJ) potential, which takes into account dispersion forces (induced dipole-induced dipole interactions), what ...
10
votes
2answers
750 views

Does 1-bromo-4-chlorobenzene have a permanent dipole moment?

My first thought was there would be a dipole moment as chlorine and bromine are unequal in electronegativity. I have since looked up the electronegativity of both chlorine and bromine through the ...
3
votes
1answer
785 views

Calculating the ionic polarizability from the Clausius-Mossoti relation

The concentration of atoms in a crystal is $N_d = \pu{2.24e28 m-3}$, and the relative dielectric constant is $\varepsilon_{r} = 5.62$. The crystal has a refractive index of $n = 1.5$. Using the ...
6
votes
1answer
4k views

How do you calculate the dipole moment of larger molecules?

I know that the dipole moment is obtained by: $$ \vec{\mu} = Q \cdot \vec{d} $$ with the condition that charges of a pair of atoms are equal and opposite, i.e. $\ce{NaCl}$. But, in order to obtain ...
-2
votes
1answer
170 views

Dipole-dipole interaction

So, dipole-dipole interaction exists between two polar molecules? A polar molecule consists of two ions and different charges (one is higher)?
2
votes
1answer
2k views

Why are naturally occuring liquids more rare than solids and gasses on Earth? [closed]

There are only a few naturally occurring liquids I can think of on earth, such as water, mercury and animal oils. Why are naturally occuring liquids more rare than solids and gasses on Earth? To be ...
2
votes
0answers
3k views

Lone pair and dipole moment of ozone

(This is a question similar to this and this, but none of the answers to those two questions answer my question.) I've seen many places explain the dipole moment of ozone from the formal charges of ...
2
votes
1answer
3k views

How to determine what organic molecule has the highest boiling point?

Compare and answer which one has the highest boiling point: $\ce{CH3CH2CH2CH3}$ (butane) ... [$\pu{−1}$ to $\pu{1^\circ C};\ 30$ to $\pu{34^\circ F};\ 272$ to $274\ \pu K$] $\ce{CH3NH2}$ (...
1
vote
0answers
202 views

How is it possible to get an attractive charge-dipole interaction using the modified Coulomb law?

Vqµ = − qµ / (4π ε0εr r2) Say you had a negative charge, interacting with the positive end of a dipole then the charge would be -1.602 x 10-19 C and the dipole moment would always be a positive value....
3
votes
1answer
463 views

Dipole moment of molecule (isolated vs in solution)

Would you expect a dipole moment determined in solution to be different from that in an isolated molecule? If so, why?
4
votes
3answers
617 views

What are dipole moments in a molecule supposed to act upon?

In a $\ce{CO_2}$ molecule, a total of four electron pairs are shared between the carbon and oxygen atoms, such that 2 pairs are shared between the carbon atom and each oxygen atom. Oxygen has a ...
2
votes
1answer
3k views

Logical way to compare dipole moment

I have to find the decreasing order of dipole moment of $\ce{CHCl3}$, $\ce{CH3Cl}$, $\ce{CH2Cl2}$, and $\ce{CCl4}$. Now I know that in $\ce{CCl4}$ there will be no dipole moment. Now to compare the ...
15
votes
0answers
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
1answer
687 views

Is there an example of a closed shell molecule with a permanent ground state magnetic dipole?

It seems that molecules of point group C$_{n}$ and C$_{nh}$ can in principle support a permanent magnetic dipole moment (Barron, 2004). However, I cannot think of any closed shell molecules that ...
1
vote
0answers
1k views

Why is the oxidation state of carbon in carbon monoxide +2? Why does its dipole moment point from oxygen to carbon? [duplicate]

Shouldn't it be +3 since 3 of its electrons are being pulled away by the electronegative oxygen? Also, shouldn't the dipole moment point from the carbon to the oxygen since most of the electron ...
2
votes
0answers
1k views

Which has more ionic character, LiF or K2O?

After drawing the structures of both and considering dipole moment, doesn't it seems that all K2O should have more ionic character than LiF? My textbook says its LiF.
1
vote
1answer
4k views

Comparing the dipole moment of water and ethanol

Why is the dipole moment of water (1.85D) larger than ethanol (1.66D)? I thought the inductive effect from ethyl would develop more delta - charge on oxygen.. hence increasing the charge and the ...
2
votes
0answers
30 views

How does hot air remove guests from cyclodextrin?

Cyclodextrin, as I know, has a hydrophobic cavity. Therefore, it would absorb hydrophobic organic compounds. But the organic compound can also be removed with hot air since the interaction between the ...
4
votes
2answers
2k views

Zero dipole moment of p-dinitrobenzene

Why is $\mu=0$ for p-dinitrobenzene ? How can the dipole moments of the two Nitro groups exactly cancel each other ? Shouldn't it have a non-zero, albeit feeble, dipole moment ?
18
votes
4answers
2k views

What is the origin of the “positive-to-negative” convention concerning dipole moments in chemistry?

I'm a physics professor who often teaches students who have taken a lot of chemistry (read: pre-meds). In physics, the dipole moment of a charge configuration is defined as pointing from ...
2
votes
0answers
521 views

Boiling point and Intermolecular forces

After looking for proper reasons for boiling point orders, nobody could even explain why $\ce{CCl4}$ has a higher boiling point than $\ce{SiCl4}$, but after looking for patterns, in lots and cases of $...