Microstructure Control of Ethene Homopolymers Through Tailored Ni,Pd(II) Catalysts - Late Transition Metal Polymerization Catalysis - page 49

Fig. 2.17 Crystal structure of compound 14b-d (ORTEP-plot, thermal ellipsoids
depicted with 50% probability). Solvent is omitted.

2.5.2
Solid State Structures

The palladium(II) complex 14b crystallizes in the monoclinic space group P 2 1 / c
(Fig. 2.17, Tab. 2.7).
Four molecules of tetrachloroethane were found in the unit cell per one metal
atom. Two of them are highly distorted and poorly defined which gets clear and
distinct in the high R -value obtained for 14b . The complex molecule itself, how-
ever, is reasonably well refined. Attempts to use partial occupation factors for sol-
vent molecules were not successful. Compound 14 c formed monoclinic crystals
which belong to the space group P 2 1 / n and complex 14d (Fig. 2.17, Tabs. 2.8, 2.9)
gave triclinic crystals of space group P 1 ([(DPPE)PdCl 2 ]: P 2 1 / c [54]).
Two molecules of acetonitrile were found to be enclosed within the unit cell of
14d , whereas 14 c contains one acetonitrile per unit cell. An increased P1-Pd-P2
angle of 88.54(4) in DPPE-

PdCl 2 14a (solvated with one molecule of dichloromethane) was observed, which
reflects the steric demand of the isopropyl moieties. [(DPPE)PdCl 2 ] shows approxi-
mately a square-planar arrangement of the two P and two Cl atoms around the
Pd center. In contrast, in 14b-d the square-planar coordination is highly distorted.

in 14d compared to 86.98(7) in 14 c or 85.82(7)