Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges...
-
Upload
james-nash -
Category
Documents
-
view
231 -
download
0
Transcript of Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges...
![Page 1: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/1.jpg)
Crystal Field Theory• Focus: energies of the d orbitals
• Assumptions
• 1. Ligands: negative point charges• 2. Metal-ligand bonding: entirely ionic
• strong-field (low-spin): large splitting of d orbitals
• weak-field (high-spin): small splitting of d orbitals
![Page 2: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/2.jpg)
![Page 3: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/3.jpg)
![Page 4: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/4.jpg)
_ _ _
_ _
dyzdxzdxy
dz2 dx2- y2
_ _ _ _ _
isolated metal ion
d-orbitals
E
d-orbital energy level diagram for tetrahedral
only high spin
![Page 5: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/5.jpg)
dyzdxz
dxy
dz2
dx2- y2
_ _ _ _ _
isolated metal ion
d-orbitals
E
d-orbital energy level diagram square planar
__
__
__
____
only low spin
![Page 6: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/6.jpg)
Crystal-Field Theory
square planar
Examples: Pd2+, Pt2+, Ir+, and Au3+.
![Page 7: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/7.jpg)
20_459
–
–
–
––
–– ––
–
dz2 dx2 – y2
dxy dyzdxz
(a) (b)
Tetrahedral Complexes
![Page 8: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/8.jpg)
![Page 9: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/9.jpg)
![Page 10: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/10.jpg)
High spin Low spin
![Page 11: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/11.jpg)
![Page 12: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/12.jpg)
• Spectrochemical Series: An order of ligand field strength based on experiment:
I- Br- S2- SCN- Cl- NO3- F-
C2O42- H2O NCS- CH3CN NH3 en
bipy phen NO2- PPh3 CN- CO
Weak Field
Strong Field
N N
2,2'-bipyridine (bipy)
NH2 NH2
Ethylenediamine (en)
N
N
1.10 - penanthroline (phen)
![Page 13: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/13.jpg)
Colors of Transition Metal Complexes
• Compounds/complexes that have color:
•absorb specific wavelengths of visible light (400 –700 nm)
•wavelengths not absorbed are transmitted and appear as color
![Page 14: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/14.jpg)
Color and Magnetism ColorColor of a complex depends on; (i) the metal, (ii) its oxidation state & (iii) ligands (i.e., everything)
For example, pale blue [Cu(H2O)6]2+ versus dark blue [Cu(NH3)6]2+.
Partially filled d orbitals usually give rise to colored complexes because they can absorb light from the visible region of the spectrum.
![Page 15: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/15.jpg)
Color and Magnetism Color
![Page 16: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/16.jpg)
Visible Spectrum
White = all the colors (wavelengths)
400 nm 700 nm
wavelength, nm
higher energy lower energy
(Each wavelength corresponds to a different color)
![Page 17: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/17.jpg)
![Page 18: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/18.jpg)
Complexes and ColorThe larger the gap, the shorter the wavelength of light absorbed by electrons jumping from a lower-energy orbital to a higher one.
![Page 19: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/19.jpg)
![Page 20: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/20.jpg)
[Ti(H2O)6]3+
Absorbs in green yellow.Looks purple.
![Page 21: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/21.jpg)
the spectrum for [Ti(H2O)6]3+ has a maximum absorption at 510 nm
Absorbs green & yellow,
transmits all other wavelengths, the
complex is purple.
![Page 22: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/22.jpg)
Crystal-Field Theory
[Ti(H2O)6]3+
![Page 23: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/23.jpg)
Electronic Configurations of Transition Metal Complexes
• d orbital occupancy depends on and pairing energy, P– e-’s assume the electron configuration with the
lowest possible energy cost– If > P ( large; strong field ligand)
• e-’s pair up in lower energy d subshell first
– If < P ( small; weak field ligand)• e-’s spread out among all d orbitals before any pair up
![Page 24: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/24.jpg)
d-orbital energy level diagramsoctahedral complex
d1
![Page 25: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/25.jpg)
d-orbital energy level diagramsoctahedral complex
d2
![Page 26: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/26.jpg)
d-orbital energy level diagramsoctahedral complex
d3
![Page 27: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/27.jpg)
d-orbital energy level diagramsoctahedral complex
d4
high spin < P
low spin
> P
![Page 28: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/28.jpg)
d-orbital energy level diagramsoctahedral complex
d5
high spin < P
low spin
> P
![Page 29: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/29.jpg)
d-orbital energy level diagramsoctahedral complex
d6
high spin < P
low spin
> P
![Page 30: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/30.jpg)
d-orbital energy level diagramsoctahedral complex
d7
high spin < P
low spin
> P
![Page 31: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/31.jpg)
d-orbital energy level diagramsoctahedral complex
d8
![Page 32: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/32.jpg)
d-orbital energy level diagramsoctahedral complex
d9
![Page 33: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/33.jpg)
d-orbital energy level diagramsoctahedral complex
d10
![Page 34: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/34.jpg)
20_441
Isomers(same formula but different properties)
Stereoisomers(same bonds, differentspatial arrangements)
Structuralisomers
(different bonds)
Opticalisomerism
Geometric(cis-trans)isomerism
Linkageisomerism
Coordinationisomerism
![Page 35: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/35.jpg)
Coordination complexes: isomers
Isomers: same atomic composition, different structures
We’ll check out the following types of isomers:HydrateLinkageCis-transOptical (Enantiomers)
Different composition!
![Page 36: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/36.jpg)
Water in outer sphere (water that is part of solvent)
Water in the inner sphere water (water is a ligand in the coordination sphere of the metal)
Hydrate isomers:
![Page 37: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/37.jpg)
Structural Isomerism 1
• Coordination isomerism: • Composition of the complex ion varies.
• [Cr(NH3)5SO4]Br
• and [Cr(NH3)5Br]SO4
![Page 38: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/38.jpg)
Coordination-Sphere Isomers
• Example[Co(NH3)5Cl]Br vs. [Co(NH3)5Br]Cl
• Consider ionization in water [Co(NH3)5Cl]Br [Co(NH3)5Cl]+ + Br-
[Co(NH3)5Br]Cl [Co(NH3)5Br]+ + Cl-
![Page 39: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/39.jpg)
Structural Isomerism 2
• Ligand isomerism: • Same complex ion structure but point of
attachment of at least one of the ligands differs.
• [Co(NH3)4(NO2)Cl]Cl
• and [Co(NH3)4(ONO)Cl]Cl
![Page 40: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/40.jpg)
Linkage Isomers
![Page 41: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/41.jpg)
Linkage isomers
Bonding to metal may occur at the S or the N atom
Example: C NS
Bonding occurs from N atom to metal
Bonding occurs from S atom to metal
![Page 42: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/42.jpg)
Linkage Isomers
[Co(NH3)5(NO2)]Cl2
Pentaamminenitrocobalt(III)chloride
[Co(NH3)5(ONO)]Cl2
Pentaamminenitritocobalt(III)chloride
![Page 43: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/43.jpg)
Stereoisomers
• Stereoisomers– Isomers that have the same bonds, but different
spatial arrangements• Geometric isomers
– Differ in the spatial arrangements of the ligands
![Page 44: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/44.jpg)
Stereoisomerism 1
• Geometric isomerism (cis-trans):
• Atoms or groups arranged differently spatially relative to metal ion
• Pt(NH3)2Cl2
![Page 45: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/45.jpg)
![Page 46: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/46.jpg)
20_444
H3N
Co
H3N
NH3
NH3
Cl
Cl
H3N
Co
H3N
NH3
Cl
Cl
NH3
Cl
Cl
Co
Cl
Cl
Co
(a) (b)
![Page 47: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/47.jpg)
cis isomer trans isomerPt(NH3)2Cl2
Geometric Isomers
![Page 48: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/48.jpg)
cis isomer trans isomer[Co(H2O)4Cl2]+
Geometric Isomers
![Page 49: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/49.jpg)
Stereoisomers: geometric isomers (cis and trans)
Cl-
Cl
Co Cl
NH3H3N
H3N
NH3
Cl
Co NH3NH3H3N
H3N
Cl
Cl-
![Page 50: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/50.jpg)
Stereoisomers
• Optical isomers– isomers that are nonsuperimposable mirror
images• said to be “chiral” (handed)• referred to as enantiomers
– A substance is “chiral” if it does not have a “plane of symmetry”
![Page 51: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/51.jpg)
Stereoisomerism 2
• Optical isomerism:
• Have opposite effects on plane-polarized light
• (no superimposable mirror images)
![Page 52: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/52.jpg)
20_448
Left hand Right hand
Mirror imageof right hand
![Page 53: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/53.jpg)
Two coordination complexes which are enantiomers
NH3
Co Cl
ClH2O
H3N
H2O
NH3
Co NH3H2OCl
Cl
H2O
![Page 54: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/54.jpg)
Plane of symmetry Achiral (one structure)
Chirality: the absence of a plane of symmetryEnantiomers are possible
A molecule possessing a plane of symmetry is achiral and a superimposible on its mirror image
Enantiomers are NOT possible
No plane of symmetryChiral (two enantiomer)
NH3
Co H2O
H2OCl
Cl
NH3
NH3
Co Cl
ClH2O
H3N
H2O
NH3
Co NH3H2OCl
Cl
H2O
Are the following chiral or achiral structures?
![Page 55: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/55.jpg)
Enantiomers: non superimposable mirror images
A structure is termed chiral if it is not superimposable on its mirror image
Two chiral structures: non superimposable mirror images:
Enantiomers!
Structure Mirror imageOf structure
![Page 56: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/56.jpg)
Which are enantiomers (non-superimposable mirror images) and which are identical (superimposable mirror
images)?
![Page 57: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/57.jpg)
![Page 58: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/58.jpg)
![Page 59: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/59.jpg)
Mirror images [Co(en)3]
1
2
1
23
3
4
4
5
5
6
6
![Page 60: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/60.jpg)
Enantiomers: non superimposable mirror images
A structure is termed chiral if it is not superimposable on its mirror image
Two chiral structures: non superimposable mirror images:
Enantiomers!
Structure Mirror imageOf structure
![Page 61: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/61.jpg)
20_449
N
N
N
N
N
NCo
N
N
N
N
N
NCo
Mirror imageof Isomer I
Isomer I Isomer II
N
N
N
N
N
NCo
![Page 62: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/62.jpg)
Enantiomers
A molecule or ion that exists as a pair of enantiomers is said to be chiral.
![Page 63: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/63.jpg)
20_450
Cl
Cl
N
N
N
NCo
Cl
Cl
N
N
N
NCo
Cl
Cl
N
N
N
NCo
Cl
Cl
N
N
N
NCo
Cl
Cl
N
N
N
NCo
Isomer IIIsomer I
cistrans
Isomer II cannot besuperimposed exactlyon isomer I. They arenot identical structures.
The trans isomer andits mirror image areidentical. They are notisomers of each other.
Isomer II has the samestructure as the mirrorimage of isomer I.(b)(a)
![Page 64: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/64.jpg)
![Page 65: Crystal Field Theory Focus: energies of the d orbitals Assumptions 1.Ligands:negative point charges 2.Metal-ligand bonding: entirely ionic strong-field.](https://reader034.fdocuments.in/reader034/viewer/2022052215/56649daa5503460f94a99040/html5/thumbnails/65.jpg)