Use valence bond theory to show bonding in the following.
A. [MN(H2O)6]^2+
B. [Pt(OH)4]^2-
C.Fe(CO)5
A. [MN(H2O)6]^2+
In [MN(H2O)6]^2+, the central metal ion is M and the ligands are six H2O molecules. The valence bond theory suggests that each H2O molecule can donate a lone pair of electrons from its oxygen atom to form a coordinate covalent bond with the metal ion. In this case, each H2O molecule donates one lone pair of electrons to M. Thus, there are six coordinate bonds between M and the H2O ligands.
B. [Pt(OH)4]^2-
In [Pt(OH)4]^2-, the central metal ion is Pt and the ligands are four OH- ions. The valence bond theory suggests that each OH- ion can donate a lone pair of electrons from its oxygen atom to form a coordinate covalent bond with the metal ion. In this case, each OH- ion donates one lone pair of electrons to Pt. Thus, there are four coordinate bonds between Pt and the OH- ligands.
C. Fe(CO)5
In Fe(CO)5, the central metal ion is Fe and the ligands are five CO molecules. The valence bond theory suggests that each CO molecule can donate a lone pair of electrons from its oxygen atom to form a coordinate covalent bond with the metal ion. In this case, each CO molecule donates one lone pair of electrons to Fe. Thus, there are five coordinate bonds between Fe and the CO ligands.
A. [MN(H2O)6]^2+:
Step 1: Determine the valence electrons of the central atom.
In this case, we have manganese (Mn), which is in group 7 and has 5 valence electrons (4s^2 3d^5).
Step 2: Identify the ligands.
The ligands in this complex are water molecules (H2O).
Step 3: Determine the oxidation state of the central atom.
Since the complex is positively charged (+2), we deduce that the oxidation state of Mn is +2.
Step 4: Construct the electron configuration and find the hybridization state of the central atom.
The electron configuration of Mn in the +2 oxidation state is [Ar] 3d^5. The five valence electrons in the 3d orbitals can form five bonds through hybridization. Mn undergoes sp^3d^2 hybridization to accommodate the six water ligands.
Step 5: Draw the molecular orbital diagram to show the bonding.
Each oxygen atom in the water ligands contributes one lone pair of electrons toward the coordination bond. These electrons combine with the empty d orbitals of Mn to form coordination bonds.
The final structure will have Mn at the center surrounded by six water molecules, with the coordination bonds formed by the overlap of the Mn d orbitals and the lone pairs on water oxygen atoms.
B. [Pt(OH)4]^2-:
Step 1: Determine the valence electrons of the central atom.
In this case, we have platinum (Pt), which is in group 10 and has 10 valence electrons (5s^2 4d^10).
Step 2: Identify the ligands.
The ligands in this complex are hydroxide ions (OH^-).
Step 3: Determine the oxidation state of the central atom.
Since the complex is negatively charged (-2), we deduce that the oxidation state of Pt is +2.
Step 4: Construct the electron configuration and find the hybridization state of the central atom.
The electron configuration of Pt in the +2 oxidation state is [Xe] 4f^14 5d^8 6s^2. Since Pt is in the +2 oxidation state, only the 5d and 6s orbitals are involved in bonding. Pt undergoes sp^3 hybridization to accommodate the four hydroxide ligands.
Step 5: Draw the molecular orbital diagram to show the bonding.
Each hydroxide ligand donates one lone pair of electrons toward the coordination bond. These electrons combine with the empty d orbitals of Pt to form coordination bonds.
The final structure will have Pt at the center surrounded by four hydroxide ions, with the coordination bonds formed by the overlap of the Pt d orbitals and the lone pairs on hydroxide oxygen atoms.
C. Fe(CO)5:
Step 1: Determine the valence electrons of the central atom.
In this case, we have iron (Fe), which is in group 8 and has 8 valence electrons (4s^2 3d^8).
Step 2: Identify the ligands.
The ligands in this complex are carbon monoxide molecules (CO).
Step 3: Determine the oxidation state of the central atom.
Since there is no charge specified for the complex, we assume the oxidation state of Fe to be 0.
Step 4: Construct the electron configuration and find the hybridization state of the central atom.
The electron configuration of Fe in the 0 oxidation state is [Ar] 3d^8 4s^2. Since Fe is in the 0 oxidation state, all the 3d, 4s, and 4p orbitals are available for bonding. Fe undergoes sp^3d^2 hybridization to accommodate the five carbon monoxide ligands.
Step 5: Draw the molecular orbital diagram to show the bonding.
Each carbon monoxide ligand donates one lone pair of electrons toward the coordination bond. These electrons combine with empty d orbitals of Fe to form coordination bonds.
The final structure will have Fe at the center surrounded by five carbon monoxide molecules, with the coordination bonds formed by the overlap of the Fe d orbitals and the lone pairs on carbon monoxide carbon atoms.
To understand the bonding in the given compounds using valence bond theory, we need to consider the concept of hybridization and the formation of sigma and pi bonds.
A. [MN(H2O)6]^2+
In this compound, the central metal ion is M (Manganese), and it is bonded to six water (H2O) ligands. Manganese has an atomic number of 25, meaning it has 25 electrons. The electronic configuration of Mn is [Ar] 3d5 4s2.
To form bonds, Mn promotes two of its 3d electrons to the 4s orbital, giving it an excited state electronic configuration of [Ar] 3d5 4s0. Then, the hybridization takes place, where one 4s, three 4p, and two 4d orbitals hybridize to form six sp3d2 hybrid orbitals around Mn.
Each water molecule donates a lone pair of electrons from an oxygen atom to form a sigma bond with one of the hybrid orbitals of Mn. This results in six sigma bonds between Mn and the oxygen atoms.
Therefore, the bonding in [Mn(H2O)6]^2+ involves the formation of six sigma bonds between Mn and the water ligands.
B. [Pt(OH)4]^2-
In this compound, the central metal ion is Pt (Platinum), and it is bonded to four hydroxide (OH) ligands. Platinum has an atomic number of 78, meaning it has 78 electrons. The electronic configuration of Pt is [Xe] 4f14 5d9 6s1.
To form bonds, Pt promotes one of its 5d electrons to the 6s orbital, giving it an excited state electronic configuration of [Xe] 4f14 5d10 6s0. Then, the hybridization takes place, where one 6s, three 5d, and one 6p orbitals hybridize to form five sp3d hybrid orbitals around Pt.
Each hydroxide molecule donates a lone pair of electrons from an oxygen atom to form a sigma bond with one of the hybrid orbitals of Pt. Additionally, Pt forms dative bonds using two of its hybrid orbitals by overlapping with the electron pairs from oxygen atoms. These dative bonds are formed using Pt's empty 5d orbitals and the electron pairs from the oxygen atoms.
Therefore, the bonding in [Pt(OH)4]^2- involves the formation of four sigma bonds between Pt and the OH ligands, as well as the formation of two dative bonds.
C. Fe(CO)5
In this compound, the central metal ion is Fe (Iron), and it is bonded to five carbon monoxide (CO) ligands. Iron has an atomic number of 26, meaning it has 26 electrons. The electronic configuration of Fe is [Ar] 3d6 4s2.
To form bonds, Fe promotes two of its 3d electrons to the 4s orbital, giving it an excited state electronic configuration of [Ar] 3d6 4s0. Then, the hybridization takes place, where one 4s, three 4p, and two 4d orbitals hybridize to form six sp3d2 hybrid orbitals around Fe.
Each carbon monoxide molecule forms a sigma bond with one of the hybrid orbitals of Fe by utilizing the lone pair of electrons on the C atom to overlap with the hybrid orbital of Fe. Additionally, Fe forms dative bonds using two of its hybrid orbitals by overlapping with the electron pairs from carbon monoxide. These dative bonds are formed using Fe's empty 3d orbitals and the electron pairs from the carbon monoxide.
Therefore, the bonding in Fe(CO)5 involves the formation of five sigma bonds between Fe and the CO ligands, as well as the formation of two dative bonds.
In summary, valence bond theory explains the bonding in these compounds by considering hybridization, the formation of sigma bonds through orbital overlapping, and the formation of dative bonds using empty orbitals and electron pairs.