Oxidation Number of [Cr(PPh?CO?)]

Understanding the oxidation state of chromium in organic complexes, such as [Cr(PPh?CO?)], is essential in various fields of chemistry, including inorganic and organometallic chemistry.

Introduction to the Concept

The term oxidation state or oxidation number refers to the hypothetical charge an atom would have if the compound was composed of ions. This concept is crucial for predicting and understanding the reactivity of different chemical species.

Distinguishing the Complex

The complex in question should be correctly identified as [Cr(PPh?CO?)]. Here, PPh? stands for triphenylphosphine and CO? represents the perchlorate ligand. This complex features a central chromium atom with coordination to a tridentate phosphine ligand and five perchlorate ligands.

Step-by-Step Calculation of Oxidation State

The goal is to determine the oxidation state of chromium (Cr) in the complex [Cr(PPh?CO?)]. The first step is to set up the equation that balances the oxidation states of all elements in the complex.

Cr: The oxidation state of chromium is denoted as x. PPh?: Phosphine (PPh?) has an overall charge of 0. Each phosphorus (P) has an oxidation state of 3, and each phenyl (Ph) group is neutral. CO?: Perchlorate (CO??) has an overall charge of -1. Each carbon (C) has an oxidation state of 5, and oxygen (O) has an oxidation state of -2.

The overall charge of the complex is 0, which provides the equation:

x 0 5(-1) 0

Executing the calculation:

x - 5 0

x 5

However, when we re-evaluate the complex, it is evident that the oxidation state of Cr is actually zero. The equation should be:

x 0 0 0

Hence, the oxidation state of Cr can be calculated as:

x 0

Conclusion

The oxidation number of chromium in the complex [Cr(PPh?CO?)] is 0. This means that the chromium atom is in its native or zero-valent state within this complex structure, contributing to the overall neutral charge of the molecule.

Understanding the oxidation states of elements in organic complexes is crucial for a comprehensive grasp of their bonding and reactivity. Whether you're a student, an academic, or a researcher, this knowledge is pivotal in advancing your understanding in the field of chemistry.