SYNTHESIS, CHARACTERIZATION AND REACTIVITY OF NOVEL COORDINATION-COMPOUNDS OF PD(II) AND PT(II) WITH PHENYL-2-PYRIDINYL ACETYLENE X-RAY STRUCTURE OF TRANS-(PT[(O-NC5H4)C-C(PH)]CL-2(SET(2)))

The reaction of phenyl-2-pyridinyl acetylene (1) with [MCL(2)(SEt(2))] (M=Pd, Pt) affords {M[(o-NC5H4)C=C(Ph)](SEt(2))Cl-2} (M=Pd, Pt(2a-b) in almost quantitative yield. The reaction of 2b with nucleophiles suc h as water adn diethylamine lead to nucleophilic addition of these mol ecules to the activated C=C bond to produce {Pt(cis-(o-NC5H4)CH2C(O)(P h)]Cl-2(SEt(2))} (3) and {Pt[(cis-(o-NC5H4)CH=C(Ph)(NEt(2))]Cl-2(HNEt( 2))} (4), respectively. The reaction of 1 with equimolar amounts of Na 2PdCl4 yields the cyclopalladated complex {Pd[(o-NC5H4)(Cl)C=C(Ph)](mu -Cl)}(2) (5). On the other hand, only products resulting from the hydr olysis of the C=C bond are found in the reaction of 1 with K2PtCl4. Th e X-ray structure determination of 2b shows a monoclinic system, space group P2(1)/n, with a = 9.083 (2), b = 11.238 (2), c = 17.913 (3) Ang strom, b = 93.00 (2)degrees, V = 1826 Angstrom(3), Z = 4, D-x = 1.947 g.cm(3), R = 0.062 and Rw = 0.075 for the unique reflections and param eters.