Investigation of C–C Bond Activation of sp–sp2 C–C Bonds of Acetylene Derivatives via Photolysis of Pt Complexes

Carbon–carbon bond activation reactions of acetylene derivatives featuring sp–sp3 C–C bonds or both sp–sp2 and sp–sp single C–C bonds were studied via photolysis of platinum compounds. Novel Pt0–acetylene complexes with η2 coordination of the alkynes were synthesized and characterized. Irradiation of (dtbpe)­Pt­(η2-H3CCCCH3) (1), (dtbpe)­Pt­[η2-(H3C)3CCCC­(CH3)3] (3), and [(dtbpe)­Pt]2(μ2-η2:η2-H3CCCCCCH3) (6) with UV light (λ >300 nm) produced the activation product (dtbpe)­Pt­(D)­(C6D5) (2) as a result of C–D bond activation of the solvent (C6D6), whereas (dtbpe)­Pt­(η2-F3CCCCF3) (4) and (dippe)­Pt­(η2-F3CCCCF3) (5) remained unchanged upon irradiation for 22 h. Photolysis of [(dtbpe)­Pt]2(μ2-η2:η2-PhCCCCPh) (7) and (dippe)­Pt­(η2-PhCCCCPh) (9) resulted in [(dtbpe)­(Ph)­Pt]2(μ-CCCC−) (8) and (dippe)­Pt­(Ph)­(CCCCPh) (10), respectively, showing exclusive C–C bond activation through sp–sp2 type C–C bonds. Both of the products stayed unchanged upon heating to 150 °C overnight.