MOLECULAR-WEIGHT DETERMINATION AND ESTABLISHMENT OF A RODLIKE STRUCTURE FOR ORGANONICKEL POLYMERS -[NI(PR(3))(2)AR-F](N)-

Molecular weights (M) of organonickel polymers PMePh(2))(2)-1,4-C6F4-N i(PBu(3))(2)]-1,4-C6F4](n)- and -[Ni(PMePh(2))(2)-4,4'-C12F8](n)- have been obtained from GPC. traces using both a direct calibration (relat ive to polystyrene standards) and a ''universal'' calibration (indepen dent of the standards' nature). The universal method, requiring intrin sic viscosity data, produced M values consistent with light scattering measurements, while the direct method produced ($) over bar M values substantially too low. Using [eta] = K ($) over bar(alpha) and an iter ative data-fitting procedure gave alpha = 1.5 for both polymers, and d ilute-solution viscosity measurements revealed [eta] to be independent of the solvent nature; both observations indicate that these polymers possess a rodlike structure. The GPC behavior of 13 related organonic kel oligomeric species (X-[Ni(PR(3))(2)Ar-F](n)-H, where n = 1-4, X = (ArH)-H-F or Br, Ar-F = 1,4-C6F4 or 4,4'-C12F8, and R = Me, n-Bu, or P h) was consistent with the polymer performance, in that all oligomers eluted at a given retention time possessed higher MW than did polystyr ene eluted at the same time. This is due to the high repeating unit ma ss which counteracts the expected effect of their rigid-rod shapes. Wh ile differences in the fluoroaryl bridging units were found to have no effect on the retention times of the oligomers, separate curves were defined when ancillary PR(3) ligands were uniformly different (i.e., P MePh(2) vs PBu(3)); Oligomers having mixed PR(3) ligands belonged to o ne of those two GPC curves which is always the one corresponding to th e PR(3) at the terminal nickel atoms.