Platinum (Pt) is a 5d-series transition metal. Its complexes commonly exhibit low-spin configurations because the crystal-field splitting energy (Δ) is generally large compared with the electron-pairing energy (P).

Spin State, Hybridisation and Magnetic Nature of Platinum Complexes

Complex	Oxidation State	d-Electron Configuration	Geometry	Hybridisation	Magnetic Nature
[Pt(NH3)2Cl2]	+2	5d8	Square planar	dsp2	Diamagnetic
[PtCl4]2-	+2	5d8	Square planar	dsp2	Diamagnetic
[PtCl6]2-	+4	5d6	Octahedral	d2sp3	Diamagnetic

Important Points

1. Platinum(II) complexes with a d8 configuration commonly adopt square-planar geometry and are diamagnetic.
2. Platinum(IV) complexes with a d6 configuration commonly form low-spin octahedral complexes.
3. The large crystal-field splitting of 5d metals generally favours electron pairing.
4. Platinum does not necessarily form low-spin complexes in every possible coordination environment. The electronic configuration and geometry must also be considered.

Conclusion

Platinum commonly forms low-spin complexes because its 5d orbitals generally experience large crystal-field splitting. However, the spin state must be determined by considering the electronic configuration, geometry and ligand environment.

Make the table truly copy-paste friendlyCorrect the spin-state wording