There are two compounds of the formula Pt(NH3)2Cl2:

NH3 Cl
| |
Cl---Pt---Cl Cl ----Pt-----NH3
| |
NH3 NH3

The compound on the right, cisplatin, is used in cancer therapy. The compound on the left, transplatin, is ineffective for cancer therapy. Both compounds have a square-planar geometry.

(a) Which compound has a nonzero dipole moment?
(b) The reason cisplatin is a good anticancer drug is that it binds tightly to DNA. Cancer cells are rapidly dividing, producing a lot of DNA. Consequently, cisplatin kills cancer cells at a faster rate than normal cells. However, since normal cells also are making DNA, cisplatin also attacks healthy cells, which leads to unpleasant side effects. The way both molecules bind to DNA involves the Cl- ions leaving the Pt ion, to be replaced by two nitrogens in DNA. Draw a picture in which a long vertical line represents a piece of DNA. Draw the Pt(NH3)2 fragments of cisplatin and transplatin with the proper shape. Also draw them attaching to your DNA line. Can you explain from your drawing why the shape of the cisplatin causes it to bind to DNA more effectively than transplatin?

Question

contestada

Respuesta :

FlaxenReflection FlaxenReflection · Answer 1 · 2019-12-20T11:44:45+01:00

Answer:

a) Cis -isomer value is not equal to zero.

b) Individual bond moment does not cancel to each other.

Explanation:

a)

Two compounds of [tex]Pt(NH_{3})_{2}Cl[/tex] is as follows.

In attachment.

b)

The bond moment of [tex]2Pt-NH_{3}[/tex] and [tex]2Pt-Cl[/tex] bond are equal in magnitude and opposite in direction thus they cancel each other.

Therefore, net dipole moment is zero.

Whereas in case of cisplatin, individual bond moment does not cancel each hence net dipole moment is non zero.