Reactions of 5,6,11,12-tetradehydrodibenzo[a,e]cyclooctene with 1,2-C6H4(SiMe2)2Pt(PPh 3)2 and Pt(CH2=CH2) (PPh3)2. X-ray structure determination of resulting double silylated compounds and platinum-alkyne complexes

Article abstract of DOI:10.1016/s0020-1693(97)05682-x

The platinum complex of 5,6,11,12-tetradehydrodibenzo[a,e]cyclooctene (1), [(Ph₃P)₂Pt]₂[1], was synthesized quantitatively by the reaction of 1 with Pt(CH₂=CH₂)(PPh₃)₂. The reaction of 1 with 1,2-C₆H₄(SiMe₂)₂Pt(PPh ₃)₂ gave 5,5,10,10,15,15,20,20-octamethyl-5,10,15,20-tetrahydro-5,10,15,20- tetrasiladibenzo[b,n]tetraphenylene ([C₆H₄(SiMe₂)₂]₂(C ₁₆H₈)) and [(Ph₃P)₂Pt] [C₆H₄(SiMe₂)₂-C₁₆H ₈] (C₆H₄(SiMe₂)₂C₁₆H ₈=5,5,16,16-tetramethyl-5,16-dihydro-10,11-didehydro-5,16- disiladibenzo[a,e]naphtho[c]cyclooctene) as well as [(Ph₃P)₂Pt]₂[1]. The central eight-membered ring of [C₆H₄(SiMe₂)₂]₂(C ₁₆H₈) has a typical tub-shaped structure, while that of [(Ph₃P)₂Pt]₂[1] is much less folded. The structure of [(Ph₃P)₂Pt][C₆H₄(SiMe ₂)₂C₁₆H₈] lies between those of [C₆H₄(SiMe₂)₂]₂(C ₁₆H₈) and [(Ph₃P)₂Pt]₂[1]. Crystal data: [(Ph₃P)₂Pt]₂[1]·2toluene, C₈₈H₆₈P₄Pt₂·2C ₇H₈, monoclinic, P2₁/n, a=16.369(2), b=30.104(6), c=17.120(3) A?, β=102.69(1)°, V=8230(2) A?³, Ζ=4. [C₆H₄(SiMe₂)₂]₂(C ₁₆H₈), C₃₆H₄₀Si₄, monoclinic, P2₁/c, a=18.421(2), b=11.131(1), c=16.444(1) A?, β=94.540(4)°, V=3361(4) A?³, Ζ=4. [(Ph₃P)₂Pt][C₆H₄(SiMe ₂)₂C₁₆H₈], C₆₂H₃₄P₂PtSi₂, triclinic, P1?, a=13.538(2), b=17.244(4), c=12.510(3) A?, α=111.10(2), β=104.93(1), γ=80.06(2)°, V=2622(1) A?³, Ζ=2.