Sign in
12thPass logo
New chatPYQ LibraryDoubtsRank report
Sign in to see Recents

Your guest activity stays on this device

Sign in to save progress →
Sign in

Coordination Compounds question

2016 · Shift 1 · Q12
Guest · filters and generic practice availableBrowsing as a guest · PYQ filters and generic practice are available. Sign in only for personalised features and saved progress.
  1. PYQ Library
  2. /JEE Advanced
  3. /Chemistry
  4. /Coordination Compounds
  5. /2016 · Shift 1 · Q12

Coordination Compounds question

2016 · Shift 1 · Q12

JEE AdvancedChemistryCoordination CompoundsNumerical+3 / −1
The possible number of geometrical isomers for the complex [CoL2Cl2]−[CoL_2Cl_2]^-[CoL2​Cl2​]− (L= H2NCH2CH2O−H_2NCH_2CH_2O^-H2​NCH2​CH2​O−) is (are)...
Numerical answer
View written solutionFree

Correct answer: 5

Step-by-step Derivation:

  1. Analyze the Complex and its Components:

    • The complex is [CoL2Cl2]−[CoL_2Cl_2]^-[CoL2​Cl2​]−.
    • The central metal atom is Cobalt (Co).
    • The ligand L is H2NCH2CH2O−H_2NCH_2CH_2O^-H2​NCH2​CH2​O− (2-aminoethoxide or ethanolaminate). This is an unsymmetrical bidentate ligand because its donor atoms are different: Nitrogen (N) from the amino group and Oxygen (O) from the ethoxide group. We can represent it as (N-O).
    • The other ligand is Cl−Cl^-Cl− (chloro), which is a monodentate ligand.

  2. Determine the Oxidation State and Coordination Number of Cobalt:

    • Let the oxidation state of Co be x.
    • The charge of ligand L is -1.
    • The charge of the Cl ligand is -1.
    • The overall charge of the complex is -1.
    • Therefore, the equation for the oxidation state is: x + 2*(-1) + 2*(-1) = -1
    • x - 4 = -1 => x = +3. The oxidation state of cobalt is +3.
    • The coordination number is determined by the number of donor atoms bonded to the central metal. Ligand L is bidentate (2 donor atoms), and there are two L ligands. The Cl ligand is monodentate, and there are two Cl ligands.
    • Coordination Number = 2 * (2) + 2 * (1) = 6.

  3. Determine the Geometry of the Complex:

    • A coordination number of 6 for a d6d^6d6 ion like Co(III) typically results in an octahedral geometry.
    • The complex can be represented as [M(AB)2X2][M(AB)_2X_2][M(AB)2​X2​], where M=Co, AB=L, and X=Cl.

  4. Identify Possible Geometrical Isomers: We can classify the isomers based on the relative positions of the two chloro ligands.

    Case 1: trans-dichloro isomers The two Cl ligands are opposite to each other (180° apart). The two bidentate (N-O) ligands must occupy the four remaining equatorial positions. There are two ways to arrange the unsymmetrical (N-O) ligands in the equatorial plane:

    • Isomer 1: The two nitrogen atoms are trans to each other, and the two oxygen atoms are also trans to each other. This can be described as trans(Cl,Cl), trans(N,N), trans(O,O). This isomer is achiral.

    • Isomer 2: The two nitrogen atoms are cis to each other, and the two oxygen atoms are also cis to each other. This can be described as trans(Cl,Cl), cis(N,N), cis(O,O). This isomer is chiral.

    Thus, there are 2 geometrical isomers where the chloro ligands are trans.

    Case 2: cis-dichloro isomers The two Cl ligands are adjacent to each other (90° apart). We can now arrange the two (N-O) ligands in the remaining four positions. This leads to three different arrangements based on the relative positions of the N and O donor atoms.

    • Isomer 3: The two nitrogen atoms are cis to each other, and the two oxygen atoms are trans to each other. This can be described as cis(Cl,Cl), cis(N,N), trans(O,O). This isomer is chiral.

    • Isomer 4: The two nitrogen atoms are trans to each other, and the two oxygen atoms are cis to each other. This can be described as cis(Cl,Cl), trans(N,N), cis(O,O). This isomer is chiral.

    • Isomer 5: The two nitrogen atoms are cis to each other, and the two oxygen atoms are also cis to each other. This can be described as cis(Cl,Cl), cis(N,N), cis(O,O). This isomer is also chiral.

    Thus, there are 3 geometrical isomers where the chloro ligands are cis.

  5. Calculate the Total Number of Geometrical Isomers: The total number of possible geometrical isomers is the sum of the isomers from both cases. Total isomers = (Number of trans-isomers) + (Number of cis-isomers) Total isomers = 2 + 3 = 5.

Conclusion:

The complex [CoL2Cl2]−[CoL_2Cl_2]^-[CoL2​Cl2​]− (where L is the unsymmetrical bidentate ligand H2NCH2CH2O−H_2NCH_2CH_2O^-H2​NCH2​CH2​O−) has a total of 5 possible geometrical isomers.

PreviousNext

More from Coordination Compounds

  • Among [Ni(CO)4​], [NiCl4​]2−, [Co(NH3)4)Cl2]Cl, Na3​[CoF6​], Na2​O2​ and CsO2​, the total number of paramagnetic compound is2016 · MCQ
  • The geometries of the ammonia complexes of Ni2+, Pt2+ and Zn2+, respectively, are2016 · MCQ
  • For the octahedral complexes of Fe3+ in SCN − (thiocyana-to-S) and in CN − ligand environments, the difference between the spin-only magnetic moments in Bohr magnetons (when approximated to the nearest integer) is ​…2015 · Numerical
  • Among the complex ions, [Co(NH2​−CH2​−CH2​−NH2​)2​Cl2​]+, [CrCl2​(C2​O4​)2​]3−, [Fe(H2​O)4​)OH)2​]+, [Fe(NH3​)2​(CN)4​]−, [Co(NH2​−CH2​−CH2​−NH2​)2​(NH3​)Cl]2+ and [Co(NH3​)4​(H2​O)Cl]2+, the number of complex ions…2015 · Numerical
  • In the complex acetylbromidodicarbonylbis(triethylphosphine) iron(II), the number of Fe−C bond(s) is ​.2015 · Numerical
  • Match each coordination compound in List I with an appropriate pair of characteristics from List II and select the correct answer using the code given below the lists. {en = H2NCH2CH2NH2; atomic numbers : Ti = 22, Cr = 24; Co = 27; Pt = 78} Includes table2014 · MCQ
  • Consider the following complex ions : P, Q and R. P=[FeF6​]3−, Q=[V(H2​O)6​]2+ and R=[Fe(H2​O)6​]2+ The correct order of the complex ions, according to their spin-only magnetic moment values (in…2013 · MCQ
  • The pair(s) of coordination complexes/ions exhibiting the same kind of isomerism is(are)2013 · Multiple correct