Reaction of Pt(PnBu3)2Cl2 (1) or Pt(AsnBu3)2Cl2 (2) with stoichiometric amounts of 1,3,5-triethynylbenzene, [1,3,5-(H-C=C-)3C6H3 (3) yields monomeric, [1,3,5-Cl(PnBu3)2Pt-C=C-)3C6H3] (4), [1,3,5-(Cl(ASnBu3)2Pt-C=C-)3C6H3] (5) or polymeric, {1,3,5-[(PnBu3)2Pt-C=C-]3C6H3-}n (6), {1,3,5-[(AsnBu3)2Pt-C=C-]3C6H3-}n (7) complexes. Treatment of (1) with (3) and 2,5-diethynyl-p-xylene, H-C=C-C6H2(CH3)2-C=C-H (8) in varying molar ratios yields a series of high molecular weight cross linked platinum metal containing polyyne copolymers.