Which of the following complex is used in cancer treatment?

Options

A. `Na_(2)CoCl_(4)`
B. `cis - [PtCl_(2)(NH_(3))_(2)]`
C. mer `-[Co(NH_(3))_(3)Cl_(3)]`
D. `cis - K_(2)[Pt Cl_(2)Br_(2)]`

Answer

To determine which complex is used in cancer treatment, we need to analyze the provided options and identify the one that is known for its application in oncology. The well-known complex used in cancer treatment is **cisplatin**.

### Step-by-Step Solution:

1. **Identify the Complexes**: We start by looking at the given options for complexes. Typically, these would be coordination compounds that might contain metals.

2. **Know the Common Cancer Treatment Complex**: Among the various complexes, **cisplatin** is a recognized drug used in chemotherapy for treating various types of cancer, including testicular, ovarian, bladder, and lung cancers.

3. **Structure of Cisplatin**: The structure of cisplatin can be described as follows:
- It contains a platinum (Pt) atom at its center.
- It is coordinated with two chloride ions (Cl) and two ammonia (NH3) molecules.
- The arrangement of these ligands around the platinum atom is such that they form a square planar geometry.

4. **IUPAC Name of Cisplatin**: The IUPAC name for cisplatin is **cis-diamminedichloroplatinum(II)**. This name reflects the ligands attached to the platinum and its oxidation state.

5. **Mechanism of Action**: Cisplatin works by binding to DNA within cancer cells. It forms cross-links in the DNA, which prevents the cancer cells from dividing and growing, ultimately leading to cell death.

6. **Conclusion**: Based on the information, the complex used in cancer treatment is **cisplatin**. Therefore, the correct answer from the options provided would be the one that corresponds to cisplatin.

### Final Answer:
**Cisplatin** is the complex used in cancer treatment.

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