Chapter 13.2 Flashcards
Colored Complexes
What is the color of transition metals related to?
The presence of partially filled d orbitals
**Colored Complexes **
Why are scandium and zinc colorless?
Scandium has an empty d orbital while zinc has a filled d orbital
The Visible Spectrum
What wavelengths does the visible spectrum range in between?
400 nm and 700 nm
The Visible Spectrum
What does the color of a substance depend on?
What colors are transmitted and what colors are absorbed
Transition Metals Appear Coloured because they Absorb Visible Light
Why do transition metals appear colored?
Their ions absorb white light which has colors of visible region
D Orbital Splits into 2 Sublevels
What is special about the d orbitals in an isolated transition metal atom?
All of the orbitals are degenerate meaning they have the same energy
D Orbital Splits into 2 Sublevels
When do the d orbitals split into 2 sub levels?
In the electric field produced by ligand’s lone pair of electrons
D Orbital Splits into 2 Sublevels
What occurs when ligh passes through a complex?
A 3d electron is moved from the low energy sub level to high energy sub level. A photon of a certain color is absorbed and its complementary color is displayed
D Orbital Splits into 2 Sublevels
What does the color of the complex depend on?
-The nuclear charge as well as identity of central ion
-Charge Density of ligand
-Geometry of complex ion
-Number of d electrons present and hence oxidation number of central ion
The Nuclear Charge and Identity of the Central Metal Ion
What does the strength of the coordinate bond depend on?
Electrostatic attraction between the lone pair of electrons on ligand and the nuclear charge of the central ion. Ligands interact more effectivle with the d orbitals of ions with higher charge
Charge Density of the Ligand
What do ligands of higher density allow the complex to do?
Absorb shorter wavelength and results in larger split of d orbitals
Charge Density of the Ligand
What is the spectrochemical series?
Arranges ligands according to energy difference produced between 2 sets of d orbitals
Charge Density of the Ligand
What is the relationship between the charge density and the size of ion.
The charge density increases with decreasing ion size. Therefore smaller ions wil have larger splitting of d orbitals and will produce shorter wavelengths
Geometry of Complex
What does the splitting in energy of d orbitals depend on in correspondnace to geometry?
Relative orientation and change in coordination number
Number of d electrons and oxidation state of the central metal ion
What is the strength dependent on?
The strength of the interaction between the ligand and the central metal ion depends on
the number of d electrons and hence the oxidation state of the metal
