**4. Conclusion**

Various cyclometalated Pt(II) complexes were structurally investigated by X-ray crystallography. The use of strong field C donor ligands provides an important route to Pt(II) complexes with interesting photophysical properties, with different applications, mainly in OLED devices. There are several classes of cyclometalated Pt(II) complexes which were not investigated so far for their emission properties, such as the cycloplatinated imino complexes, but this field continuously expands and a growing number of reports dealing with this topic are being published.
