Coordination Chemistry

This option is correct because complex pentamminenitrito chromium (III) chloride exhibits the linkage isomerism.

The capped square antiprismatic molecular geometry describes the shape of compounds where nine atoms, groups of atoms, or ligands are arranged around a central atom, defining the vertices of a gyroelongated square pyramid. Example is ReH₉^2-.

The heme group is a prosthetic group containing a porphyrin ring with a central iron atom (Fe2+). This iron is crucial for oxygen binding in hemoglobin and myoglobin, and for electron transfer in cytochromes.

In square planar complexes, the geometry is prevalent for transition metal complexes with d⁸ configuration. Thus, the central atom (Pt) in carboplatin has dsp² hybridisation with square planar geometry.

In a weak field ligand system, the electron filling of splitting of d-orbital corresponds to Hund’s rule, followed by pairing. In strong field ligand system, the electron filling of splitting of d-orbital corresponds to pairing at initial stage. For Fe³⁺ electronic configuration is d⁵. For d⁵ in weak field ligand system, CFSE = 3 (- 4) + 2 (6) = - 12 + 12 = 0 Dq (All electrons is unpaired, 3 in t_2g and 2 in e_g) For d⁵ in strong field ligand system, CFSE = 5 (- 4) + 0 = - 20 Dq + 2P
(two paired electrons and one electron is unpaired in t_2g and 0 electron in e_g orbital) Hence, the CFSE for octahedral complexes of Fe³⁺ in a weak field and strong field ligand systems are 0 and -20 Dq+2P respectively.

V²⁺ has d³ electronic configuration and it is empowered in a weak field ligand. The term symbol is calculated by the formula- 2s+1 LJ For d³, n = 3 s = n/2 = 3/2 2s + 1 = 4 L = 3 = F J = (L + s) to (L - s) = 2, 1, 0 term symbols = 2s + 1 LJ = ⁴F_9/2, ⁴F_7/2, ⁴F_5/2, ⁴F_3/2 The ground state term for V²⁺ is ⁴F_3/2.

Ground state term for Mn⁴⁺ is ⁶S_5/2. Ground state term for Fe²⁺ is ⁵D₄. Ground state term for Co³⁺ is ⁵D₄.

Fe³⁺ and Fe²⁺ have d⁵ and d⁶ electronic configurations and both are in high spin ligand system. The term symbol is calculated by the formula- 2s+1 LJ For d⁵, n = 5 s = n/2 = 5/2 2s + 1 = 6 L = 0 = S J = (L + s) to (L - s) = 5/2 Possible term symbol for Fe³⁺ = 2s + 1 LJ = ⁶S_5/2 Similarly, possible term symbols for Fe²⁺ = ⁵D₄, ⁵D₃, ⁵D₂, ⁵D₁, ⁵D₀ The ground state term for Fe³⁺ is ⁶S_5/2. The ground state term for Fe²⁺ is ⁵D₄.

(η-C₅H₅)₂Ti has zero number of unpaired electrons and possesses a diamagnetic nature.

On the basis of ligand field theory, the spectrochemical series is an empirically-derived list of ligands ordered by the size of the splitting CFSE that they produce. It can be seen that the low-field ligands are all pi-donors, the high field ligands are pi-acceptors, and ligands such as H₂O and NH₃, which are neither of the two, are in the middle. The spectrochemical series is give as: I− < Br− < S²⁻ < SCN− < Cl− < NO₃⁻ < N₃⁻ < F⁻ < OH⁻ < C₂O₄²⁻ < H₂O < NCS⁻ < CH₃CN < py (pyridine) < NH₃ < en (ethylenediamine) < bipy (2,2'-bipyridine) < phen (1,10-phenanthroline) < NO₂⁻ < PPh₃ < CN⁻ < CO Hence, S^2-, SCN^- and NO₃^- are all weak field ligands.

[FeF₆]^3- and [Mn(H₂O)₆]³⁺ both have sp³d² hybridisation and hence, are outer orbital or high spin complexes.

A and B both have a paramagnetic nature with 2 unpaired electrons respectively. Hence, these are identical in the number of unpaired electrons.

The coordination complexes [Mn(NH₃)₆]²⁺, [(Ph₄As)₂Mn(NO₂)₄], [Mn(EDTA)(NH₃)]^2- and [Mn(S₂C₆H₃Me)₂]^- have the coordination numbers of 6, 8, 7 and 4 respectively. Hence, the representation of the codes P - 5, Q - 2, R - 1, S - 4 is the correct answer.

Cobalt (II) carbonate is the inorganic compound with the formula CoCO₃. This reddish paramagnetic solid is an intermediate in the hydrometallurgical purification of cobalt from its ores, as an inorganic pigment and as a precursor to catalysts.

The term hapticity is used to describe how a group of contiguous atoms of a ligand are coordinated to a central atom.