Download Assignment-Week_I

Organometallic Chemistry
Questions Set-I
Section-I (1 mark)
Q1.
The electron count for the below complex is:
(a) 16 e
Q2.
(d) 19 e
(b) 1
(c) 2
(d) 3
The oxidation state of molybdenum in [(-tropylium) Mo (CO)3]+ is
(a) +2
Q4.
(c) 18 e
During oxidative addition, the oxidation state of metal increased by
(a) 0
Q3.
(b) 17 e
(b) +1
(c) 0
(d) -1
Identify the 18 e species in the list below:
(a) [Ni(H2O)6]2+, (b) Fe(CO)5,
(c) (-C6H6)2Ru, (d) V(CO)6
Q5.
Consider 18 e rule as a guide and find out the metal in this complex, [M(C5H5)(CO)4(CH3)]
(a) Ti (b) V (c) Cr (d) Mn
Q6.
The following reaction is Mn2(CO)10 + Br2 > 2MnBr(CO)5
(a) reductive elimination (b) oxidative addition (c) insertion (d) addition
Q7.
The -acceptor ligand attached to the metal, the rate of reductive elimination:
(a) enhance (b) lessen (c) no role (d) completely cease
Q8.
If a migratory ligand is chiral than the reactor, usually the migratory insertion
proceeds with:
(a) retention of configuration (b) inversion of configuration (c) loss of chirality (d) not
predictable
Q9.
Write the product of the following reaction:
(a)
(b)
(c)
(d)
Q10.
(a)
(b)
(c)
(d)
In the below hydrocyanation reaction generally which metal catalyst has been used?
Pd
Ni
Pt
Rh
Section-II (2 marks)
Q11. Among the complexes (i) (C6H6)2Cr, (ii) [HMn(CO)5], (iii) [(CH3CO)Rh(CO)I3]-,
and (iv) CpFe(CO)2(CH3), the 18-electron rule is not followed in :
(a) (ii) and (iii)
Q12.
(a)
(b)
(c)
(d)
Q13.
(b) (iii) only
(c) (i) and (iv)
(d) (ii) only
The oxidative addition and reductive elimination steps are favoured by:
electron rich metal centres
electron deficient metal centres
electron deficient and electron rich metal centres respectively
electron rich and electron deficient metal centres respectively
Identify the 18 e species in the list below:
(a) Fe(CO)4 , (b) Ni(CO)3(PPh3), (c) Cr(CO)5, (d) Cr(C5H5)2
Q14.
In Fe2(CO)9, the total number of metal-metal (Fe-Fe) bonds are :
(a) 1 (b) 2 (c) 3 (d) 4
Q15.
The rate of oxidative addition increases with the alkyl radicals:
(a) Me > 1˚ > 2˚ > 3˚ (b) 1˚ > 2˚ > 3˚ > Me (c) 3˚ > 2˚ > 1˚ > Me (d) 3˚ > 2˚ > Me > 1˚
Q16.
In SN2 oxidative addition, the reactivity of alkyl halides follows the order:
(a) MeI > EtI > i-PrI (b) i-PrI > EtI > MeI (c) EtI > MeI > i-PrI (d) i-PrI > MeI > EtI
Q17.
Complete the following reaction
HCo(CO)4 + MeC(O)Co(CO)4 >
(a) MeCOOH + 2Co(CO)4 (b) MeCOOH + Co2(CO)8
(d) MeCHO + Co2(CO)8
(c) MeCHO + 2Co(CO)4
Q18. The rate of migratory insertion changes with bulky ligands coordinated to the metal
and the Lewis acid such as AlCl3 as:
(a)
(b)
(c)
(d)
Q19.
both enhance the rate
both lessen the rate
bulky ligands enhance and Lewis acid lessen the rate
bulky ligands lessen and Lewis acid enhance the rate
Factors which facilitate the reductive elimination are:
(a) A high formal positive charge, the presence of less bulky groups on the metal
(b) A high formal positive charge, the presence of more bulky groups on the metal
(c) A low formal positive charge, the presence of bulky groups on the metal
(d) A low formal positive charge, the presence of less bulky groups on the metal
Q20.
(a)
(b)
(c)
Which one is the Schrock-Osborn’s catalyst?
(d)
Section-III (2 marks)
Q21.
(a)
(b)
(c)
(d)
Q22.
(a)
(b)
(c)
The order of CO bond strengths in the following metal hexacarbonyls
[V(CO)6]- < [Cr(CO)6] < [Mn(CO)6]+
[V(CO)6]- < [Mn(CO)6]+ < [Cr(CO)6]
[Mn(CO)6]+ < [Cr(CO)6] < [V(CO)6][Cr(CO)6] < [Mn(CO)6]+ < [V(CO)6]What is the intermediate A in the following equilibrium?
(d)
Q23.
Draw the correct structure of the product in the following reaction
(a)
(b)
(c)
(d)
Q24. The relative reactivity of alkenes for hydroformylation reaction with HCo(CO)4 is as
follows:
(a)
(b)
(c)
(d)
Q25. The hydroformylation of ethylene oxide is catalysed by Rh-catalyst. Write down the
product formation in the following reaction.
(a)
(b)
(c)
(d)
Q26.
Write the correct conformer of the product in the below reaction:
(a)
(b)
(c)
(d)
Q27.
Draw the correct structure of the product in the following reaction
(a)
(b)
(c)
(d)
Q28. Write the correct product in the following hydrogenation reaction using Wilkinson’s
catalyst.
(a)
(b)
(c)
(d)
Q29.
(a)
Write the product using Schrock’s molybdenum catalyst:
(b)
(c)
(d)
Q30. When nickel carbonyl catalyst and acetylene are used instead of HCo(CO) 4 catalyst
and alkene, respectively; what will happen?
(a)
(b)
(c)
(d)