The chemistry of cyclometalated compounds has attracted much research interest in past years. They are known for their ample applications in numerous fields: organic synthesis, photochemistry, catalysis, and as potential biologically active materials. Numerous Palladacycles bearing Ph2PCH2PPh2-P,P, (dppm) were described before showing different ways of coordination.
We now report Palladacycles of the type [Pd2(Ph2PCH2PPh2−P,P)2(C,N:C,N)] can undergo a spontaneous slow chelate−to−bridging diphosphine coordination shift in solution when (C,N:C,N) is derived from −4,4´−sulfonyldianiline or −4,4´−oxydianiline and 2,3,4-trimethoxybenzylidene. Following this strategy a synthetic procedure was devised that culminates in isolation of the first crystallographically characterized tetranuclear palladium structures.