2-pyridylbis(diphenylphosphino)methane chemistry. Synthesis and structures of [Cu(μ−η2:η1(Ph2P)2−CHC5H4N)(THF)]2(BF4)2 and [Ni(Ph2PCH2C5H4N)2]-[NiCl4]·0.85CH2Cl2and [Ni(Ph2PCH2C5H4N)2]-[NiCl4]·0.85CH2Cl2

Reaction of 2-pyridylbis(diphenylphosphino)methane (NPP) with [Cu(NCMe)4]BF4 and with [Ni(H2O)6]Cl2 forms [Cu(NPP)(THF)]2(BF4)2 (after recrystallization in the presence of THF) (1) and NiCl2(NPP) (2) respectively Attempts to recrystallize2 led ultimately to the ligand cleavage product [Ni(Ph2PCH2C5H4N)2][NiCl4]·0.85CH2Cl2 (3). Complex1 crystallizes in the monoclinic space groupP21/n witha=13.148(2),b=19.221(2),c=13.458(2) Å3, β=108.61(1)o,V=3222.6(8) ÅZ=2. The structure was refined onF2 toR1=0.11,wR2=0.14 (R1=0.044 forI≥2σ(I)) for 5661 observed reflections. Complex3 crystallizes in the triclinic space groupP1 witha=12.795(2),b=17.535(1),c=10.203(1) Å, α=107.564(6), β=114.260(8), γ=78.435(8)o,V=1982.1(8) Å3;Z=2. The structure was refined onF toR1=0.044,Rw=0.059 for 3534 observed reflections. Dinuclear complex1 has crystallographically imposed centrosymmetry with the NPP ligands arranged in a head-to-tail fashion. The Cu...Cu separation of 3.372(1) Å is too long to support significant metal-metal interaction. Complex3 results from the cleavage of a {PPh2} unit from the NPP ligand and contains an approximately square nickel atom surrounded by two Ph2PCH2C5H4N ligands coordinated in a head-to-head fashion.