Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 9: Problem 94

There are two compounds of the formula \(\mathrm{Pt}\left(\mathrm{NH}_{3}\right)_{2} \mathrm{Cl}_{2}:\) The compound on the right is called cisplatin, and the compound on the left is called transplatin. (a) Which compound has a nonzero dipole moment? (b) One of these compounds is an anticancer drug, and one is inactive. The anticancer drug works by its chloride ions undergoing a substitution reaction with nitrogen atoms in DNA that are close together, forming a \(\mathrm{N}-\mathrm{Pt}-\mathrm{N}\) angle of about \(90^{*} .\) Which compound would you predict to be the anticancer drug?

Short Answer

Expert verified
The short answer based on the given step-by-step solution: (a) Cisplatin has a nonzero dipole moment due to its asymmetric molecular geometry, with chlorine atoms on the same side of the Pt atom. (b) Cisplatin is predicted to be the anticancer drug, as its molecular geometry allows it to form a \(90^{\circ}\) N-Pt-N angle when interacting with DNA, unlike transplatin, where the Cl atoms are farther apart, making it difficult to form the optimal angle for anticancer activity.

Step by step solution

01

Draw the structures of cisplatin and transplatin

To help visualize the molecular geometry and compare the dipole moments of cisplatin and transplatin, draw the structures like so: Cisplatin: Cl-Pt-Cl | | NH3 NH3 Transplatin: Cl-Pt-NH3 | | NH3 Cl Note that in cisplatin, the chlorine atoms (Cl) are on the same side of the Pt atom, and in transplatin, the Cl atoms are on opposite sides of the Pt atom.
02

Determine the dipole moment

The dipole moment depends on the overall molecular geometry and polarity of the individual bonds. In both cisplatin and transplatin, the bonds between Pt and Cl are polar, as are the bonds between Pt and NH3. A nonzero dipole moment results from the presence of polar bonds and an asymmetric molecular geometry. In cisplatin, the Cl atoms are on the same side of the Pt atom, causing an uneven distribution of charge that leads to a nonzero dipole moment. In transplatin, the Cl atoms are on opposite sides of the Pt atom, causing the charge distribution to be balanced, leading to an overall dipole moment of zero. Answer (a): Cisplatin has a nonzero dipole moment.
03

Determine the anticancer drug

According to the problem statement, the anticancer drug works by its chloride ions undergoing a substitution reaction with nitrogen atoms in DNA, forming an N-Pt-N angle of about \(90^{\circ}\). Since the molecular geometries of cisplatin and transplatin differ, their interactions with DNA also vary. In cisplatin, the Cl atoms on the same side of Pt are closer together, allowing the compound to form a \(90^{\circ}\) N-Pt-N angle when interacting with DNA. In transplatin, the Cl atoms are farther apart, making it difficult to form the optimal \(90^{\circ}\) N-Pt-N angle for the anticancer activity. Answer (b): Cisplatin is predicted to be the anticancer drug.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

(a) Draw Lewis structures for chloromethane $\left(\mathrm{CH}_{3} \mathrm{Cl}\right),\( chloroethene \)\left(\mathrm{C}_{2} \mathrm{H}_{3} \mathrm{Cl}\right)\(, and chloroethyne \)\left(\mathrm{C}_{2} \mathrm{HCl}\right) .(\mathbf{b})$ What is the hybridization of the carbon atoms in each molecule? (c) Predict which molecules, if any, are planar. (d) How many \(\sigma\) and \(\pi\) bonds are there in each molecule?

Consider the Lewis structure for acetic acid, which is known as vinegar: CCC(=O)O (a) What are the approximate bond angles about each of the two carbon atoms, and what are the hybridizations of the orbitals on each of them? (b) What are the hybridizations of the orbitals on the two oxygen atoms, and what are the approximate bond angles at the oxygen that is connected to carbon and hydrogen? (c) What is the total number of \(\sigma\) bonds in the entire molecule, and what is the total number of \(\pi\) bonds?

(a) Using only the valence atomic orbitals of a hydrogen atom and a fluorine atom, and following the model of Figure 9.46 , how many MOs would you expect for the HF molecule? (b) How many of the MOs from part (a) would be occupied by electrons? (c) It turns out that the difference in energies between the valence atomic orbitals of \(\mathrm{H}\) and \(\mathrm{F}\) are sufficiently different that we can neglect the interaction of the 1 s orbital of hydrogen with the 2 s orbital of fluorine. The 1 s orbital of hydrogen will mix only with one \(2 p\) orbital of fluorine. Draw pictures showing the proper orientation of all three \(2 p\) orbitals on F interacting with a 1 sorbital on \(\mathrm{H}\). Which of the \(2 p\) orbitals can actually make a bond with a 1 s orbital, assuming that the atoms lie on the \(z\) -axis? (d) In the most accepted picture of HF, all the other atomic orbitals on fluorine move over at the same energy into the molecular orbital energy-level diagram for HE. These are called "nonbonding orbitals." Sketch the energy- level diagram for HF using this information and calculate the bond order. (Nonbonding electrons do not contribute to bond order.) \((\mathbf{e})\) Look at the Lewis structure for HE. Where are the nonbonding electrons?

Consider the molecule \(\mathrm{PF}_{4}\) Cl. (a) Draw a Lewis structure for the molecule, and predict its electron-domain geometry. (b) Which would you expect to take up more space, a \(\mathrm{P}-\mathrm{F}\) bond or a \(\mathrm{P}-\mathrm{Cl}\) bond? Explain. (c) Predict the molecular geometry of \(\mathrm{PF}_{4} \mathrm{Cl}\). How did your answer for part (b) influence your answer here in part (c)? (d) Would you expect the molecule to distort from its ideal electron-domain geometry? If so, how would it distort?

Consider the \(\mathrm{H}_{2}^{+}\) ion. (a) Sketch the molecular orbitals of the ion and draw its energy-level diagram. (b) How many electrons are there in the \(\mathrm{H}_{2}^{+}\) ion? (c) Write the electron configuration of the ion in terms of its MOs. (d) What is the bond order in \(\mathrm{H}_{2}^{+}\) ? (e) Suppose that the ion is excited by light so that an electron moves from a lower-energy to a higher- energy MO. Would you expect the excited-state \(\mathrm{H}_{2}^{+}\) ion to be stable or to fall apart? (f) Which of the following statements about part (e) is correct: (i) The light excites an electron from a bonding orbital to an antibonding orbital, (ii) The light excites an electron from an antibonding orbital to a bonding orbital, or (iii) In the excited state there are more bonding electrons than antibonding electrons?
See all solutions

Recommended explanations on Chemistry Textbooks

Physical Chemistry

Read Explanation

Ionic and Molecular Compounds

Read Explanation

Chemical Reactions

Read Explanation

Making Measurements

Read Explanation

Chemistry Branches

Read Explanation

The Earths Atmosphere

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free