Synthesis characterisation and stability of mixed aryldichalcogenide bis(diphenylphosphino)ethanenickel(II) complexes. X-ray structure of Ni(dppe)(SeC₆H₄S)

Mixed chalcogenide complexes of the type Ni(dppe)(SeC₆H₄S) (dppe=bis(diphenylphosphino)ethane), Ni(dppe)(SC₅H₃NCO₂) and Ni(dppe)(EC₅H₃NE′) (E=NH, E′=O; E=E′=NH) have been prepared from the reactions of Ni(dppe)Cl₂ with the appropriate aryldichalcogen or pyridine-based compound, using Et₃N as a base. The relative solution and thermal stabilities of the above compounds, other mixed chalcogen ones, Ni(dppe)(SC₆H₄O), Ni(dppe)(SC₆H₄CO₂) and Ni(dppe)(SC₆H₄NH), and the homoleptic compounds Ni(dppe)(EC₆H₄E′) (E=E′=O, E=E′=S; R=H, Me), were established by a combination of electron impact mass spectrometry (EIMS) and fast atom bombardment (FABMS). The most stable ones were the compounds with homoleptic sulfur ligands.