1. 18 electron rule: EAN rule (Effective Atomic Number)
In 1927, developed by Sidgwick
d electrons of metal + electrons of ligand = 18 electrons
d3      d4     d5     d6      d7      d8     d9     d10
Sc     Ti     V     Cr     Mn     Fe     Co     Ni  Cu Zn
Y      Zr    Nb     Mo    Tc     Ru     Rh    Pd Ag Cd
Ta      W     Re     Os     Ir      Pt  Au Hg

3. Ni: 1s22s22p63d84s2 : it is better to promote 4s electron to 3d,
therefore Ni(0) is d10.
Cu(I), Ag(I), and Au(I) is d10, Zn2+, Cd2+, and Hg2+ is d10
Ti(IV) serves as a good index for memorizing the d electrons
Because it is a d0 metal ion.
TiCl4 is colorless, diamagnetic liquid
TiCl3 is violet color

4. tetrahedral
octahedral
Square planar
Trigonal bipyramid

5. Electrons
Ligand 1
수소라디칼(H radical), 알킬 라디칼(alkyl radical), 아릴 라디칼(aryl radical) , 할로겐 라디칼(halogen radical), NO (굽은 형태) 2
CO, CS, RCN, R3N, R3P, R3As, RCN, R2S, 수소음이온(H-), 알킬음이온(R-), 알켄 (alkene), η3-알릴 양이온(η3-allyl+), 알킨(alkyne), 니트로실 양이온(NO+), 할로겐 음이온(X-) 3
η3-알릴 라디칼(η3-allyl), NO (직선형) 4
η3-알릴 음이온(η3-allyl-), η4-C4R4(η4-cyclobutadiene), η4-비공액디엔(nonconjugate diene), η4-공액디엔(conjugate diene) 5
η5-C5R5 라디칼(η5-cyclopentadienyl radical) 6
η5-C5R5 음이온(η5-cyclopentadienyl anion), η6-C6R6, η7-C7R7 양이온(cycloheptatrienyl cation) 7
η7-C7R7 라디칼(cycloheptatrienyl radical) 8
η8-C8R8 (cyclooctatetraene)

7. Ni(CO)4, Fe(CO)5, Cr(CO)6, Ni(CO)4,
For Mn, Mn(CO)5: 17 electrons
Mn(CO)6: 19 electrons
Mn(CO)5  (CO)5Mn-Mn(CO)5
HMn(CO)5, CH3Mn(CO)5, ClMn(CO)5
CH3Mn(CO)5
CH3- + Mn(CO)5+ 

9. 18 Electron Rule: strong field ligand such as CO, Hydride, Cycanide anion.
Not good for Aqua complex: Weak Field Ligand such as H2O is not matched with 18 electron rule.
Late transition metal is better than early transition metals.  

10. Exceptions
Early trantion metals
(η5-C5H5)2ZrCl2: 5ex2+4e+2e=16e, 
(CH3)3TaCl2는 1ex3+5e+2e=10e
(CH3)6W는 1ex6+6e=12e
For early transition metals, there is not enough room to attach many ligands to satisfy 18 electron rule.
Coordination number: number of ligand to bind to metal. Coordination number cannot be larger than the maximun oxidation number or the group number of element.
For Late transition Metals
(PPh3)3Pt: 2ex3+10e=16e
(η5-C5H5)2Ni:5ex2+10e=20e

11. d8complex: 16 electrons
Pt(II), Pd(II), Cu(III), Ir(I), Rh(I): square planar
For example,
Cl(PPh3)3Rh(I) (Wilkinson’s complex), Cl(PPh3)2(CO)Ir(I) (Vaska’ complex), (PPh3)2(CCPh)2Pt(II)
even though they contains strong field ligand

15. 1.3 Mechanism in Organometallic Chemistry
oxidative addition (산화성부가반응) and
reductive elimination (환원성 제거반응 )
2. insertion (삽입반응) and deinsertion
(이탈반응)
3. Oxidative coupling (산화성결합반응)and
Reductive Cleavage (환원성결합분열)

16. 1. oxidative addition (산화성부가반응) and reductive elimination (환원성 제거반응 )
two electron oxidative addtion (이전자 산화성부가반응) and
one electron oxidative addition (일전자 산화성부가반응)
A; 16 electron complexes
B: 18 electron complexes

17. H2Fe(CO)2-4
20 electron complex
Na2Fe(CO)4
18 electron complex
[RFe(CO)4]+X-
18 electron complex

19. Rh(II), Co(II) d7 complex

20. 1965, Chatt and Davidson
Kinetic Factor
Thermodynamic Factor

21. In 1982, Bergman, Graham, Jones

22. Endo methyl migration: aromatic stablization energy

23. Reductive Elimination: spontaneous
To do reductive elimination, two ligands should be placed
at cis-position
Concerted Mechanism

24. Transphos Ligand: Pd(II) is dsp2 (square planar):
no reductive elimination
Addition of CH3I allows to make cis-dimethyl to undergo
reductive elimination.

25. 2. Elimination of one of ligand to make T-shape to Y shape.
3. Reduce the electron density of central metal
Ligand off from metal by heat or light, oxidize the metal,
addition of strong pi-acceptor ligand such as CO, maleic
anhydride, quinone, tetracyanoethylene

26. 1. Insertion (삽입반응) and Deinsertion (이탈반응)

27. Migratory Insertion: cis position and concerted mechanism
Order: h3-allyl ≥ Et 〉Me 〉PhCH2 〉vinyl ≥aryl, ROCH2 〉HOCH2
Hard to migrate to CO:   Hydride(H-), acyl (CH3CO), CF3 ,Heteroatome: RO-, R2N

28. Decarbonylation

29. Hydride Insertion: cis-addition,
4-centered transition state
For example: hydroboration, hydrosilylation,
hydroformylation
Reverse Reaction: b-Hydride Elimination
The reason why it is hard to make a long chain
alkylmetal complex

30. Alkyl Migration into olefin: olefin polymerization

31. Order of Migration of sigma liand-metal complex to Olefin:
H >> R, vinyl, aryl> RCO>>RO, R2N
Heteroatom is hard to migrate because of strong bond of
heteroatom bearing lone pair to metal

32. Alkyne undergoes migratory insertion,
but further successive reaction make
polymer compounds, which make complication.
Other Insertion, deinsertion substrate;
isocyanide (:C≡NR), carbene(:CR2), SO2 , etc

33. Nucleophilic Addition Reaction (친핵부가반응)
reverse sterechemistry to migratory insertion
High valent metal species: electron deficient metal

34. Trans-Addition Product

35. 1.4.3 Oxidative coupling (산화성결합반응) Reductive Cleavage (환원성결합분열)
Order of Reactivity
1.4.3  Oxidative coupling (산화성결합반응)
Reductive Cleavage (환원성결합분열)
M: +2 Increase

36. Electron withdrawing or strained molecules
For alkyne, electron-withdrawing is no necessary