50 Synthesis and Subsequent Reactions of Wire-Like Sp Carbon Chains Capped by Bis(tri-p-tolylphosphine)Arylplatinum and Trialkylsilyl Endgroups

Wednesday, November 4, 2009
Ballroom A+B (Camino Real Hotel)
Nancy Weisbach , Department of Chemistry, Texas A&M University, College Station, TX
Sébastien Gauthier , Department of Chemistry, Texas A&M University, College Station, TX
John A. Gladysz , Department of Chemistry, Texas A&M University, College Station, TX

Molecules in which sp carbon chains span two transition metals have attracted great attention from both fundamental and applied perspectives. The longer the chains, the closer the complexes model the polymeric sp carbon allotrope, carbyne, which remains the poorest characterized and understood of the classical carbon allotropes. Our research group has an ongoing interest in synthesizing platinum complexes containing long sp carbon chains of the type trans,trans-Ar(p-Tol3P)2Pt(C≡C)2nPt(Pp-Tol3)2Ar (PtC4nPt, Ar = p-Tol, C6F5; n = 1-7). The PtC4nPt complexes are synthesized by homocoupling of trans-Ar(p-Tol3P)2Pt(C≡C)nH (PtC2nH) under Hay conditions (CuCl/TMEDA complex, O2). Terminal polyynes with more than four sp hybridized carbon atoms are too labile to isolate and are obtained by in situ protodesilylation of trans-Ar(p-Tol3P)2Pt(C≡C)nSiR3 (PtC2nSi; R = Et, i-Pr) with wet n-Bu4N+F-. Hay cross coupling of trans-Ar(p-Tol3P)2Pt(C≡C)n-2H and H(C≡C)2SiR3 produces the PtC2nSi precursors. The terminal polyynes and benzyl azide undergo also 3+2 "click" cycloadditions in the presence of CuSO4/ascorbic acid to give 1,2,3-triazole derivatives trans-Ar(p-Tol3P)2Pt(C≡C)n-1C=CHN(CH2C6H5)N=N (PtC2n-2HN3bz, n = 2-6), which are all structurally characterized.

See more of: Wednesday Poster Session
See more of: Abstract Submission