合成领域取得的一项突破性进展，进入了一个意想不到的稳定状态：一系列可分离的配合物，其中C6、C8、C10、C12、C16、C20、C24和C28多炔二亚基链跨越两个铂原子。
A synthetic breakthrough into an unanticipated stability regime: a series of isolable complexes in which C6, C8, C10, C12, C16, C20, C24, and C28 polyynediyl chains span two platinum atoms.
作者信息
Zheng Qinglin, Bohling James C, Peters Thomas B, Frisch Anja C, Hampel Frank, Gladysz J A
机构信息
Institut für Organische Chemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Henkestrasse 42, 91054 Erlangen, Germany.
出版信息
Chemistry. 2006 Aug 25;12(25):6486-505. doi: 10.1002/chem.200600615.
The reaction of trans-[PtCl(p-tol){P(p-tol)3}2] (PtCl) and H(C[triple chemical bond]C)2H (cat. CuI, HNEt2) gives PtC4H (82 %), which can be cross-coupled with excess HC[triple chemical bond]CSiEt3 (acetone, O2, CuCl/TMEDA; Hay conditions) to yield PtC6Si (77 %). The addition of nBu4N+F- in wet acetone gives PtC6H (84 %), and further addition of ClSiMe3 (F- scavenger) and excess HC[triple chemical bond]CSiEt3 (Hay conditions) yields PtC(8)Si (23 %). Similar cross-coupling reactions of PtCxH (generated in situ for x>6) and excess H(C[triple chemical bond]C)2SiEt3 give a) x=4, PtC8Si (29 %), PtC12Si (30 %), and PtC16Si (1 %); b) x=6, PtC10Si (59 %) and PtC14Si (7 %); c) x=8, PtC12Si (42 %); and d) x=10, PtC14Si (20 %). Hay homocoupling reactions of PtC4H, PtC6H, PtC8H, and PtC10H give PtC8Pt, PtC12Pt, PtC16Pt, and PtC20Pt (88-70 %), but PtC12H decomposes too rapidly. However, when PtC12Si and PtC14Si are subjected to Hay conditions, protodesilylation occurs in the presence of the oxidizing agent and PtC24Pt (36 %) and PtC28Pt (51 %) are isolated. Reactions of PtC6H and PtC10H with PtCl (CuI, HNEt2) give PtC6Pt (56 %) and PtC10Pt (84 %). The effect of the chain lengths in PtCxPt upon thermal stabilities (>200 degrees C for x< or =20), IR nu(C[triple chemical bond]C) patterns (progressively more bands), colors (yellow to orange to deep red), UV/Vis spectra (progressively red-shifted and more intense bands with epsilon>400,000 M(-1) cm(-1)), redox properties (progressively more difficult oxidations), and NMR spectra (many monotonic trends) are analyzed, including implications for the sp carbon allotrope carbyne. Whereas all other dodecaynes and tetradecaynes rapidly decompose at room temperature, PtC24Pt and PtC28Pt remain stable at >140 degrees C. Crystal structures of PtCxSi (x=6, 8, 10) and PtCxPt (x=6, 8, 10, 12) have been determined.
反式-[PtCl(p - 甲苯基){P(p - 甲苯基)3}2]（PtCl）与H(C≡C)2H（催化剂CuI，HNEt2）反应生成PtC4H（产率82%），其可与过量的HC≡CSiEt3（丙酮，O2，CuCl/TMEDA；海氏条件）交叉偶联生成PtC6Si（产率77%）。在湿丙酮中加入nBu4N+F−得到PtC6H（产率84%），进一步加入ClSiMe3（F−清除剂）和过量的HC≡CSiEt3（海氏条件）得到PtC8Si（产率23%）。PtCxH（x>6时原位生成）与过量的H(C≡C)2SiEt3的类似交叉偶联反应得到：a）x = 4时，PtC8Si（产率29%）、PtC12Si（产率30%）和PtC16Si（产率1%）；b）x = 6时，PtC10Si（产率59%）和PtC14Si（产率7%）；c）x = 8时，PtC12Si（产率42%）；d）x = 10时，PtC14Si（产率20%）。PtC4H、PtC6H、PtC8H和PtC10H的海氏均偶联反应得到PtC8Pt、PtC12Pt、PtC16Pt和PtC20Pt（产率88 - 70%），但PtC12H分解太快。然而，当PtC12Si和PtC14Si在海氏条件下反应时，在氧化剂存在下发生原硅基脱除反应，分离得到PtC24Pt（产率36%）和PtC28Pt（产率51%）。PtC6H和PtC10H与PtCl（CuI，HNEt2）反应得到PtC6Pt（产率56%）和PtC10Pt（产率84%）。分析了PtCxPt中链长对热稳定性（x≤20时>200℃）、红外ν(C≡C)模式（谱带逐渐增多）、颜色（从黄色到橙色再到深红色）、紫外/可见光谱（谱带逐渐红移且强度增加，ε>400,000 M−1 cm−1）、氧化还原性质（氧化逐渐变得更困难）和核磁共振光谱（许多单调趋势）的影响，包括对sp碳同素异形体卡宾的影响。所有其他十二炔和十四炔在室温下迅速分解，而PtC24Pt和PtC28Pt在>140℃时仍保持稳定。已测定了PtCxSi（x = 6、8、10）和PtCxPt（x = 6、8、10、12）的晶体结构。
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