Tag: bonding in metal carbonyls

Questions Related to bonding in metal carbonyls

$Cr - C$ bond in the compound $[Cr(CO) _6]$ shows $\pi$ - character due to :

chemistry coordination chemistry bonding in metal carbonyls metal carbonyls coordination compounds

  1. covalent bonding

  2. coordinate bonding

  3. synergic bonding

  4. ionic bonding

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Correct Option: C
Explanation:
  1. Synergic bonding is the description of the bonding of $\pi$ - configuration ligands to the transition metal which involves donation of electrons through back bonding.
    2. Mainly carbonyl ligands in complex compounds involves in this type of bonding.

$\left[ {C{O _2}{{(CO)} _8}} \right]$ displays:

chemistry coordination chemistry bonding in metal carbonyls metal carbonyls coordination compounds

  1. One-Co Co bond, six terminal CO and two bridging CO

  2. One-Co Co bond, four terminal CO and four bridging CO

  3. No-Co Co bond, six terminal CO and two bridging CO

  4. No-Co Co bond, four terminal CO and four bridging CO

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Correct Option: C

Which of the following factors tends to increase the stability of metal ion complexes?

chemistry coordination chemistry bonding in metal carbonyls metal carbonyls coordination compounds

  1. Higher ionic radius of the metal ion

  2. Higher charge/size ratio of the metal ion

  3. Lower ionisation potential of the metal ion

  4. Lower basicity of the ligand

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Correct Option: B
Explanation:
For a given ligand, the stability of complexes of metallic ions having the same charge on them decreases with the increase of the size of the central metal ions. Again if the charge of central metal ion is more and the site is small, then the stability of the complex is more. Higher charge/size ratio of metal ion i.e highly charged cation and the smaller cation can form more stable complexes.
Answer will be B.

Consider the following complexes $[V(CO) _6]^-,[Cr(CO) _6]$ and $[Mn(CO) _6]^+$. Then incorrect statement(s) about metal carbonyls is /are

chemistry coordination chemistry bonding in metal carbonyls metal carbonyls coordination compounds

  1. 'C-O' bond is strongest in the cation and weakest in the anion

  2. 'C-O' bond order is less in the cation than in anion

  3. 'C-O' bond longer in the cation than in anion or neutral carbonyl

  4. 'M-C' bond order is higher in the carbon than in anionic or neutral carbonyl.

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Correct Option: A

If CO ligands are substituted by NO in respective neutral carbonyl compounds then which of the following will not be correct formula?

chemistry coordination chemistry bonding in metal carbonyls metal carbonyls coordination compounds

  1. $Cr(CO) _3(NO) _2$

  2. $Fe(CO) _2(NO) _2$

  3. $Cr(NO) _4$

  4. $Ni(CO) _2(NO) _2$

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Correct Option: A

The V-C distance in ${\text{V}}{\left( {{\text{CO}}} \right) _{\text{6}}}\;{\text{and}}\;\left[ {{\text{V}}{{\left( {{\text{CO}}} \right)} _{\text{6}}}} \right]$ are respectively (in pm) -

chemistry coordination chemistry bonding in metal carbonyls metal carbonyls coordination compounds

  1. 200, 200

  2. 193, 200

  3. 200, 193

  4. 193, 193

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Correct Option: C

Which of the following statement is correct regarding the compound ${\text{''}}\left[ {{{\left( {{\text{CO}}} \right)} _{\text{3}}}{\text{Fe}}{{\left( {{\text{CO}}} \right)} _{\text{3}}}{\text{Fe}}{{\left( {{\text{CO}}} \right)} _{\text{3}}}} \right]{\text{'}}$

chemistry coordination chemistry bonding in metal carbonyls metal carbonyls coordination compounds

  1. The ${{\text{d}} _{{\text{C - O}}}}$ (bridging) is greater than ${{\text{d}} _{{\text{C - O}}}}$ (terminal)

  2. The bond order of bridging C-O bond is greater than that of terminal C-O bond

  3. The E.A.N. value of each Fe-atom is 35

  4. the oxidation state of Fe in this complex is (-1)

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Correct Option: A

For the complex $\left[ {{\text{Fe}}{{\left( {{\text{Co}}} \right)} _{\text{3}}}} \right]$ what is wrong:-

chemistry coordination chemistry bonding in metal carbonyls metal carbonyls coordination compounds

  1. It is $\sigma {\text{ - \pi }}$ bonded organometallic compound

  2. In the complex value of x = 6

  3. Int he complex CO is ${\text{\pi }} - {\text{acid}}$ ligand

  4. It is trigonal bipyramidal shape

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Correct Option: A

The strongest -CO bond is present in 

chemistry coordination chemistry bonding in metal carbonyls metal carbonyls coordination compounds

  1. ${\left[ {{\text{Cr}}{{\left( {{\text{CO}}} \right)} _{\text{6}}}} \right]^ + }$

  2. $\left[ {{\text{Fe}}{{\left( {{\text{CO}}} \right)} _5}} \right]\;$

  3. ${\left[ {{\text{V}}{{\left( {{\text{CO}}} \right)} _{\text{6}}}} \right]^{\text{ - }}}$

  4. all have equation

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Correct Option: B

Which of the following statement is correct regarding metal carbonyl?

chemistry coordination chemistry bonding in metal carbonyls metal carbonyls coordination compounds

  1. In ${Mn} _{2}{(CO)} _{10}$ bond order of $Mn-Mn$ is $0$

  2. In ${Fe} _{2}{(CO)} _{9}$ bond order of $Fe-Fe$ is $1$

  3. In $Ni{(CO)} _{4}$, all bond length are same

  4. $Fe{(CO)} _{5}$ is diamagnetic

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Correct Option: D