Which of the following does not contain any coordinate bond ?

Options

A. `H _(3) O^(+)`
B. `BF_(4) ^(-)`
C. `HF _(2) ^(-)`
D. `NH_(4) ^(+)`

Explanation

To determine which of the given options does not contain any coordinate bond, we will analyze each option step by step.

### Step 1: Understand Coordinate Bonds
A coordinate bond (or dative bond) occurs when one atom donates a pair of electrons to another atom that does not have a pair to share. This is typically represented by an arrow pointing from the donor atom to the acceptor atom.

### Step 2: Analyze Each Option
1. **H3O+ (Hydronium ion)**:
- In H3O+, the oxygen atom has a lone pair of electrons which it donates to a hydrogen ion (H+). This results in the formation of a coordinate bond.
- **Conclusion**: H3O+ contains a coordinate bond.

2. **BF4- (Tetrafluoroborate ion)**:
- In BF4-, boron is electron-deficient and can accept a pair of electrons from one of the fluorine atoms. This results in the formation of a coordinate bond.
- **Conclusion**: BF4- contains a coordinate bond.

3. **NH4+ (Ammonium ion)**:
- In NH4+, nitrogen donates its lone pair of electrons to a hydrogen ion (H+) to form the ammonium ion. This also results in a coordinate bond.
- **Conclusion**: NH4+ contains a coordinate bond.

4. **HF2- (Dihydrogen fluoride ion)**:
- In HF2-, the bonding occurs primarily through hydrogen bonds between the fluorine atoms and hydrogen. There is no donation of a lone pair from one atom to another to form a coordinate bond.
- **Conclusion**: HF2- does not contain a coordinate bond.

### Final Answer
Based on the analysis, the species that does not contain any coordinate bond is **HF2-**.