Valence Bond Theory -Trick to find Hybridisation/Geometry/Magnetic Moment OF Complex Examples OF C.N.-2,3,4,5 (Some Imp Shortcut)

[Cu(NH_3)_4]^(2+) has hybridisation and magnetic moment

With the help of valence bond theory (VBT) , explain hybridisation geometry and magnetic behaviour of (NiCl_4)^(2-) complex .

Valence Bond Theory(VBT) || Assumptions OF VBT and Important Aspects || Complexes with CN=4

Assign the hybridisation, shape and magnetic moment of K_(2)[Cu(CN)_(4)]

Give an account of the valence bond theory . Explain the geometry and magnetic behaviour of the complex ion [Fe(CN)_(6)]^(4-) on the basis of the theory .

Velence bond theroy describes the bonding in complexs in terms of coordinate -covalent bond resulting from overlap filled ligand orbitals with vacant metal hybrid orbitals This theory explains magnetic behaviour and geometrical shape of coordination compounds Magnetic moment of a complex compound can be determined experimentally and theoretically by using spin only formula Magnetic moment sqrtn (n+2)BM (where n = No. unpaired electrons) . Ni^(2+) cation combines with a uninegative monodentate ligand X^(Θ) to form paramagnetic complex [NiCI_(4)]^(2-) The number of unpaired electrons(s) in central metal cation and geometry of this complex respectively are (a) One,tetrahedral (b) Two,tetrahedral (c ) One,square planar (d) Two, square planar .

Velence bond theroy describes the bonding in complexs in terms of coordinate -covalent bond resulting from overlap filled ligand orbitals with vacant metal hybrid orbitals This theory explains magnetic behaviour and geometrical shape of coordination compounds Magnetic moment of a complex compound can be determined experimentally and theoretically by using spin only formula Magnetic moment sqrtn (n+2)BM (where n = No. unpaired electrons) . The value of of spin only magnetic moment for octahedral complex of the following configuration is 2.84BM The correct statement is (a) d^(4) (in weak field ligand) (b) d^(2) (in weak field and in strong field ligand) (c) d^(3) (in weak field and in strong field ligand) (d) d^(5) (in strong field ligand) .

Valence bond theory for bonding in transition metal complexes was developed by Pauling. From the valence bond point of view, formation of a complex involves reaction between Lewis bases (ligands) and a Lewis acid (metal atom or metal ion) with the formation of coordination covalent (or dative) bonds between them. The model utilizes hybridization of metal s, p and d valence orbitals to account for the observed structures and magnetic properies of complexes. Valence bond theory is able to deal satisfactorily with many stereo chemical and magnetic properies but is has nothing to say about electronic spectra or the reason for the kinetic inertness of chromium (III) and low spin cobalt (III) octahedral complexes. To understand this and more other features of transition metal we must turn to other theories like crystal field theory etc. Pure crystal field theory assumes that the only interaction between the metal ion and the ligands is an electrostatic or ionic one with the ligands being regarded as negative point charges. This theory is quite successful in interpreting many important properties of complexes. The hybridization of [NiCl_(2)(PPh_(3))_(2)]" and "[NiCl_(2).(Pme_(3))_(2)] are respectively (consider PPh_(3) a bulkier ligand than Pme_(3) ) :