$Pt(2,6-(Cy_2PCH_2)_2C_6H_3)(OTf);(OTf=CF_3SO_3^-)$ readily reacts with various amines to afford cationic amine complexes $[Pt(2,6-(Cy_2PCH_2)_2C_6H_3)(amine)](OTf);(amine=NH_3,;NHMe_2,;NHC_4H_8,;NH_2Ph,;NH_2(Tol-p))$ in high yields. These complexes have been fully characterized by IR, $^1H-,;^{19}F{^1H}-,;and;^{31}P{^1H}-NMR$ spectroscopy, and elemental analyses. Reaction of $Pt(2,6-(Cy_2PCH_2)_2C_6H_3)(OTf)$ with acrylonitrile quantitatively produced the ${pi}$-olefinic complex $Pt(2,6-(Cy_2PCH_2)_2C_6H_3)(CH_2=CHCN)](OTf)$ which is only stable in solution in the presence of acrylonitrile. Attempt at isolating this complex in the pure solid state was failed due to partial decomposition into $Pt(2,6-(Cy_2PCH_2)_2C_6H_3)(OTf)$ The equilibrium constants $(K_{eq}=[Pt(PCP)-(NH_2R)^+][CH_2=CHCN]/[Pt(PCP)(CH_2=CHCN)^+][NH_2R]:;[Pt(2,6-(Cy_2PCH_2)_2C_6H_3)(CH_2=CHCN)]^++NH_2R{ ightleftarrows}[Pt(2,6-(Cy_2PCH_2)_2C_6H_3)(NH_2R)]^++CH_2=CHCN=Ph,;p-tolyl)$ were calculated to be 0.28 (for R = Ph) and 3.1 (R = p-tolyl) at $21^{circ}C$. The relative stability of the ${sigma}$-donor amine versus the ${pi}$-olefinic acrylonitrile complex has been found largely dependent upon the amine-basicity $(pK_b)$, implicating that acrylonitrile practically competes with amine in the platinum coordination sphere. On the contrary to the formation of the acrylonitrile complex, no reaction of $Pt(2,6-(Cy_2PCH_2)_2C_6H_3)(OTf)$ with other olefins such as ethylene, styrene and methyl acrylate was observed.