S3.1 Periodic Table - Transition Metals Flashcards
Transition Metal properties
- incomplete d-sublevel
- complex ions with ligands
- good catalytic properties
- varying magnetic properties
- high melting point
Transition Metal
element with an incomplete d-subshell that is able to form cations with an incomplete d-subshell
Ferromagnetism
Permanent magnetism caused by unpaired electrons aligning parallel to eachother in domains irrespective of wheter a external magnetic/electrical field is applied
Paramagnetism
spinning unpaired electrons create a small magnetic field and make the complex weakly magnetic when a external magnetic/electrical field is applied
Diamagnetism
shown when all the electrons in the complex are spin-paired creating very weak & opposes magnetic or electrical field
ligands
A molecule/ion/species with a lone pair of electrons that forms a dative covalent bond with a central metal ion
bidentate ligand
- donate 2 pairs of electrons from 2 different atoms on the same molecule to central metal ion
ex: C2O4 (2-) (ethanedioate)
ex.: H2NCH2CH2NH2 (diaminoethane)
monodentate ligand
- donate 1 pair of electrons to central metal ion
ex: h2O, NH3, Cl-
Paramagnetic vs Diamagnetic
para
* unpaired => spinning e- cause dipole
* attracted to electromagnetic fields
dia
* only paired
* repelled by magnetic field
TM complexes
central metal ion surrounded by ligands covalently bonded to them
hexadentate ligand
donate 6 electrons to the central metal ion
ex: ethylenediaminetetraacetic acid (EDTA)
Derermining classification of ligand
- What is coordination no. of metal complex (no. of bonds)
- how many atoms is ligand using to bond to the metal complex?
crystal field theory
d orbitals placed in isotropic elctrostatic field => orbital increases in energy and electrons repel energy from charges
why do TM form colored complexes?
orbitals in t2g energy level absorb light and transmitt visible light which our eyes detect
factors affecting crytsal field energy
- nuclear charge of metal = CFE increases down group
- oxidation state = CFE increases as oxidation state increases
- geometry of complex = CFE only for octahedral
- charge density = greater; greater CFE (spectrochemical series)
Splitting orbitals in CFE
dx^2-y^2 and dx^2
Why scandium is NOT a TM
Scandium(III) ion has no electrons in d subshell
(Definition of TM is that it MUST have incomplete d-subshell)
Why zinc is NOT TM
Has a completely filled d-subshell
(By definition Tm have incomplete d subshell)
Why zinc is a colorless TM
- zinc ion has complete s subshell
- color arises due to splitting energy within 3d subshell
- there are no d orbital electrons that CAN transition
why TM form colored compounds
- TM have incomplete d-subshell
- ligand causes d orbital split
- Light is absorbed and electrons transition to a higher energy level
- energy gap coprresponds to light in visible region of spectrum
- color observed is the complementary color
Trend in TM color if stronger ligand
stronger ligand= larger seperation = higher energy absorbed = shorter wavelength = bluer/purpler
heterogenous catalyst
cataölyst is in different state to the reactents
crytsal field splitting in octahedral complex
- splits into two sets with energy differences
- dxy,dxz,dzy lower in energy
- dz^2 and dx^2-y^2 higher in energy
