Transition Metals Flashcards
What is the electron configuration exception for transition metals?
Chromium and Copper
Chromium = [Ar] 4s^1 3d^5
Copper= [Ar]4s^1 3d^10
Chromium prefers half-filled orbitals since it is more stable
How do you figure out the electron configuration for a cation transition metal
you remove electrons from the s orbital first
What are the main molecular geometries for coordination complexes
linear geometry, square planar, octahedral, tetrahedral
What is a linear geometry
two ligands are attached
what is a octahedral
6 ligands attached
what is a square planar
4 ligands attached in a plane
what is tetrahedra;l
4 ligands in a pyramid shape
what is the charge on the outside of the transition metal complex
the overall charge that the counterion neutralizes
what do ligands do?
They act as Lewis bases that donate electrons
what is a chelating ligand/ polydentate
it is a ligand that forms multiple bonds
what type of ligand is ethylenediamine (en)
it forms two bonds (bidentate) and donates 2 lone pairs
What type of ligand is an oxalate ion (ox) (C2O4^2-)
It is a bidentate, it forms two bonds
What type of ligand is a ethylenediaminetetraacetate (EDTA)
it is polydentate and donates 6 lone pairs
What is the coordination #?
It is the # of atoms attached to the metal NOT the # of ligands
What is the name of H20
Aqua
What is the name of NH3
Ammine
What is the name of CO (carbon monoxide)
Carbonyl
What is the name of ethylenediamine (en)
Ethylenediamine
What is the naming rule for anion ligands?
You add and “-o”
What is the name for Bromide, Br-
Bromo
What is the name for Chloride, Cl-
Chloro
What is the name for Hydroxide, (OH)-
Hydroxo
What is the name for Cyanide (CN-)
Cyano
What is the name for Nitrite, NO2-
Nitro
What is the name for Oxalate? C2O4^2-
Oxalato
What is the name for EDTA
Ethylenediaminetetraaceto
What is the name for Chromium when it is an anion in a transition metal complex?
Chromate
What is the name for Cobalt when
it is an anion in a transition metal complex?
Cobaltate
What is the name for Copper when it is an anion in a transition metal complex?
Cuprate
What is the name for Gold when it is an anion in a transition metal complex?
Aurate
What is the name for Iron when it is an anion in a transition metal complex?
Ferrate
What is the name for Lead when it is an anion in a transition metal complex?
Plumbate
What is the name for Manganese when it is an anion in a transition metal complex?
Manganate
What is the name for Molybdenum when it is an anion in a transition metal complex?
Molybdate
What is the name for Nickel when it is an anion in a transition metal complex?
Nickelate
What is the name for Platinum when it is an anion in a transition metal complex?
Platinate
What is the name for Silver when it is an anion in a transition metal complex?
Argentate
What is the name for Tin when it is an anion in a transition metal complex?
Stannate
What is the name for Zinc when it is an anion in a transition metal complex?
Zincate
whats the highest oxidation state of manganese?
+7
what are the prefixes for when there is already a prefix within a ligand?
bis, tris, tetrakis
what are isomers?
they are compounds with the same chemical formula but different structures
What is a structural isomer?
the atoms (and # of them) are the same but they have different connectivities
what are the two types of structural isomers?
Coordination isomers and linkage isomers
What is a coordination isomer?
it occurs when it is possible to exchange ligands and counterions or a solvent molecule such as H2O
What type of isomer is [Co(NH3)5 Br]Cl and [Co(NH3)5 Cl]Br
This is a coordination isomer, the Br- and Cl- are exchanged
What type of isomer is [Cr(H2O)4 Cl2]Cl * 2H2O and
[Cr(H2O)6 ]Cl 3
A coordination isomer, the Chloride and Water molecules exchange places
What are linkage isomers
They form when a ligand that is attached to a metal can attach with different atoms
What type of isomer is NO2
a linkage isomer, the oxygen or nitrogen can donate an electron pair
What are the names of the two isomer forms of NO2
Nitro when the nitrogen attaches (NO2)
Nitrito when the Oxygen attaches (ONO)
What type of isomer is Cyanide? (CN-)
it is a linkage isomer, either carbon or nitrogen can donate the electron pair
What are the names of the two isomer forms of Cyanide
Cyano when Carbon attaches
Isocyano when the nitrogen attaches
What type of isomer is thiocyanide? (SCN-)
Thiocyanato when the nitrogen bonds
isothiocyanato when the sulfur bonds
What are stereoisomers?
they are isomers with the same connectivities but different spatial arrangements
What are the types of stereoisomers
Geometric and optical
what are geometric stereoisomers?
cis/trans and fac/mer
When do ligands have cis/trans isomers?
when two identical ligands are present
what defines a cis isomer?
If the two identical ligands are next to one another (adjacent)
what defines a trans isomer?
when they are opposites/ across from one another
When do ligands have fac/mer isomers?
when there are 3 identical ligands
when are ligands considered fac?
when they form a 90° angle (adjacent) triangle
When are ligands considered Mer?
When they form a 180° arc
what types of complexes cannot form geometric isomers and why?
tetrahedral complexes cannot form geometric isomers because all the angles are fixes at 109°
what are optical isomers and where are they seen most commonly?
opitcal isoers are stereoisomers that are mirror images of eachother and are nonsuperimposable
what does it mean to be non-superimposable
they cannot be stacked identically
What is the rule for optical isomers and tetrahedral molecules?
optical isomers will exist if the molecule has 4 different atoms or groups of atoms attached
What is the rule for octahedral geometries and optical isomers?
Transition metal complexes that are octahedral and have 3 bidentate ligands (can form 2 bonds) are optical isomers
What is Crystal Field Theory?
it considers the electrostatic bonding of a complex
What affects the electron configuration in Crystal Field Theory?
the charge attraction between the transition metal and the ligand
The repulsion of the electrons
How does the electrostatic repulsion affect the energies of d-orbitals?
the d orbitals are no longer energy equivalent
What are the different d orbitals?
dxy, dyz, dxz, dz^2, dx^2-y^2
they are not energy equivalent
which d orbitals are higher energy and why?
The dx^2-y^2 and dz^2 have higher energies because the orbitals lie directly on the axis
The dxy, dyz,dxz have lower energer because they are lying between the axis
What is a high spin configuration?
∆O is small, it is more energetically favorable to put an electron in the higher energy orbitals (dx^2-dy^2) and dz^2
ligands are weak
What is low spin configuration
∆O is large, it is more energetically favorable to overcome the e- repulsion than the ∆O
the lower dxy, dxz, and dyz orbitals are filled
ligands are strong field electrons
What does CNOX stand for
Carbon donors>Nitrogen donor ligands are strong ligands
Oxygen donors > Halide ligands are weak ligands
What are the strong ligands?
CO, CN- > NO2^- > NH3, en
What are the weak ligands
H2O > OH-, ONO-> C2O4^2- > Halides
what happens when a transition metal complex is exposed to white light
the electron gets excited and moves up a d orbital and falls back down
What are the colors on the color wheel?
ROYGBV
red (750-650), orange (650-580), yellow(580-490), green(490-460), blue(460-430), violet (430-400)
what does it mean when a complex has a longer wavelength?
it has a weak ligand and has a lower energy gap
what does it mean when a complex has a shorter wavelength
it has a strong ligand and a higher energy gap
What color do we see and what is absorbed?
The wavelength is the measure of absorbed light and we see the complementary color (opposite on the wheel) reflected back at us
If you have more strong ligands compared to weak ligands in a complex, what spin does it have?
it will have a low spin
