Bonding and Coordination Chemistry

Question 1

Orbital

Answer 1

Volume where electrons are likely to be found

Question 2

In phase

Answer 2

constructive interface - waves are the same

Question 3

Out of phase

Answer 3

destructive interface - waves cancel each other out and result in a node

Question 4

Valence bond theory

Answer 4

When orbitals overlap, a bond is made

Question 5

Hybridization

Answer 5

Combining atomic orbitals to get hybrid orbitals

Question 6

σ (sigma) bonds

Answer 6

When orbital overlap puts density between the two atoms on the internuclear axis (horizontal overlap)

Question 7

π (pi) bonds

Answer 7

When orbital overlap occurs above and below the internuclear axis (vertical overlap)

Question 8

Pauli Exclusion Principle

Answer 8

2 electrons max per orbital

Question 9

Aufbau Principle

Answer 9

Fill in so electrons have the lowest energy possible

Question 10

Hund Principle

Answer 10

Singly occupy orbitals with the same energy before doubly occupying them

Question 11

Molecular Orbital (MO) Theory

Answer 11

When bonds form and atomic orbitals combine, we get molecular orbitals (MO) that cover the entire molecule

Question 12

Paramagnetism

Answer 12

Aligns with magnetic field (has unpaired electrons)

Question 13

Diamagnetism

Answer 13

Weakly repelled by magnetic field (has no unpaired electrons)

Question 14

Electronegativity

Answer 14

Ability of an atom to draw electron density towards itself in a bond

Question 15

Coordinate bond

Answer 15

Results when a lone pair is donated to a metal center

Question 16

Ligands

Answer 16

anionic or neutral compounds that have electron pairs available to donate to metal centers

Question 17

Dentate

Answer 17

How many times the ligand donates electron pairs to the metal center (how many times it “bites” the metal)

Question 17

Donor atom

Answer 17

atom with lone pairs on it that form the coordinate bond in the metal center

Question 18

Chelating Ligands

Answer 18

Poly and bidentate ligand

Question 19

Coordination number

Answer 19

Number of times a donor ligand coordinate to a metal center

Question 20

How is hybridization determined?

Answer 20

The number of domains around the central atom
Domains Hybridization
2 sp
3 sp2
4 sp3
5 sp4
6 sp5

Question 21

How do you do an MO diagram?

Answer 21

of e = # of spin up/down arrows, one e = 1 arrow
1) Fill up up 1s (does not count for valuence)
2( Fill up rest with total valence electrons

Question 22

How do you get the bond order?

Answer 22

The number of antibonding cancel out the number of binding electrons. Whatever you are left with is bonding order. If the bonding order is greater than 0, it exists.

Question 23

How can you determine the number of dentate/coordination number?

Answer 23

1) Assume all ligands are monodentate, unless they are en (2), EDTA (6), or oxalate (2)
2) Total up amount of denatate to get coordination number

Question 24

How do you name complex cations?

Answer 24

prefix - ligands - metal - charge - "ion" 1) Alphabetize the ligands 2) Give them prefixes 3) Find the metal's oxidation state *must add up with ligands charge to equal overall charge

Question 25

How do you name complex anions?

Answer 25

prefix - ligands - metal - charge - "ion" 1) Alphabetize the ligands 2) Give them prefixes 3) Drop the metal's ending to "ate" (few exceptions) 3) Find the metal's oxidation state (possible to be -) *must add up with ligands charge to equal overall charge

Question 26

What do all the axes look like and their names?

Answer 26

dxy, + sign with clover off axes dxz, + sign with clover off axes dyz, + sign with clover off axes dx2 - y2 , + sign with clover over top off axes dz2, one line with hourglass and belt, dotted axes

Question 27

Where are the ligands for octahedral, tetrahedral, and square planar

Answer 27

Octahedral and tetrahedral same Square planar - ligands on y and x axes

Question 28

Octahedral energy set up

Answer 28

dz2 dx2-y2 dxy dxz dyz

Question 29

Tetrahedral energy set up

Answer 29

dxy dxz dyz dz2 dx2-y2

Question 30

Square planar energy set up

Answer 30

dx2-y2 dxy dz2 dxz dyz

Question 31

How do you solve spin problems?

Answer 31

1. Determine if strong or weak based on spectrochemical series *strong - low spin [2, small gap, 3] *weak - high spin [2, big gap, 3] 2) Fill out the charge on the metal and then how many d electrons it has, then fill in dashes

Question 32

How do you fill the dashes in low vs high spin complexes?

Answer 32

high spin - fill each space if possible low spin - pair all electrons if possible

Question 33

How does color work for complexes?

Answer 33

Whatever they absorb, they reflect back which is the color that appears due to electrons moving between lower and higher split d orbitals

Question 34

How do you solve for gap energy in kj/mol?

Answer 34

1) Planck's constant x speed of light 2) Divide by nm x 10 to the -9 3) Convert to kJ by dividing by 1/1000 4) Multiply by Avogadro's number to get kj/mol *6.022 x 10 to the 23

Question 35

The longer the wavelength...

Answer 35

...the lower the energy

Question 36

How do you solve color appearance problems given two complex compounds?

Answer 36

1) Figure out what color it absorbs and reflects it given nm 2) If the octahedral energy is greater than the tetrahedral energy, then it absorbs the opposite light

Question 37

If the nm is above 700, that means ...

Answer 37

The light is infrared

Question 38

What is the wavelength and color of high-spin and low-spin complexes?

Answer 38

High - longer wavelength, appears blue Low - shorter wavelength, appears red

Question 39

How do complexes work (Lewis acid-base definition)?

Answer 39

Ligands donate electron pairs and the metal centers accept/gain electrons

Question 40

How does spin work in high/low spin complexes?

Answer 40

High - spin is maximized Low - spin in minimized

Question 41

Spectrochemical series

Answer 41

Ranking of ligands based on their d splitting strength

Question 42

How do different ligands affect color?

Answer 42

When a ligand is added, the complex changes, changing the gap energy, changing the wavelength absorbed, thus changing the color