Complete the exercises below. The complex [Mn(NH₃)₆]²⁺ contains five unpaired electrons. Sketch the energy-level diagram for the d orbitals, and indicate the placement of electrons for this complex ion. Is the ion a high-spin or a low-spin complex?

Name: Chemistry: The Central Science
Author: Brown
ISBN: 9780134414232

Guida verificata passo dopo passo

Step 1: Identify the oxidation state of manganese in the complex [Mn(NH₃)_6]^{2+}. Since NH₃ is a neutral ligand, the oxidation state of Mn is +2.

Step 2: Determine the electron configuration of Mn^{2+}. Manganese (Mn) has an atomic number of 25, so its electron configuration is [Ar] 3d^5 4s^2. For Mn^{2+}, remove two electrons from the 4s orbital, resulting in [Ar] 3d^5.

Step 3: Sketch the energy-level diagram for the d orbitals. In an octahedral field, the d orbitals split into two sets: t_{2g} (lower energy) and e_g (higher energy).

Step 4: Place the five d electrons in the energy-level diagram. Since the complex has five unpaired electrons, each electron will occupy a separate orbital, filling the t_{2g} and e_g orbitals singly before any pairing occurs.

Step 5: Determine if the complex is high-spin or low-spin. The presence of five unpaired electrons indicates that the complex is a high-spin complex, as all d orbitals are singly occupied before any pairing occurs.

Concetti chiave

Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.

Crystal Field Theory

Crystal Field Theory (CFT) explains how the arrangement of ligands around a central metal ion affects the energy levels of its d orbitals. In an octahedral complex like [Mn(NH₃)₆]²⁺, the d orbitals split into two energy levels: the lower-energy t₂g and the higher-energy e_g orbitals. The extent of this splitting is influenced by the nature of the ligands and the metal ion's oxidation state.

Video consigliato:

Percorso guidato

01:18

The study of ligand-metal interactions helped to form Ligand Field Theory which combines CFT with MO Theory.

High-Spin vs. Low-Spin Complexes

High-spin and low-spin complexes refer to the arrangement of electrons in the d orbitals based on the strength of the ligand field. High-spin complexes have more unpaired electrons due to weaker field ligands that do not cause significant splitting, while low-spin complexes have fewer unpaired electrons as stronger field ligands lead to greater splitting, allowing electrons to pair up in lower energy orbitals.

Video consigliato:

Percorso guidato

01:28

For octahedral complexes, Weak-Field Ligands create High-spin complexes and Strong-Field Ligands create Low-spin complexes.

Electron Configuration of Transition Metals

The electron configuration of transition metals is crucial for determining their magnetic properties and oxidation states. For manganese in [Mn(NH₃)₆]²⁺, the electron configuration is [Ar] 3d⁵ 4s², and upon losing two electrons to form the ion, it becomes [Ar] 3d⁵. The presence of five unpaired electrons indicates that this complex is high-spin, as the electrons occupy higher energy orbitals before pairing.

Video consigliato:

Percorso guidato