Synthesis and characterization of alkynes β-diketonate copper(I) complexes

The reactions of 1,3,5-tris-(trimethylsilylethynyl)benzene (1) with Cu2O and 1,1,1,5,5,5,-hexafluoroacetylacetone in alkyne to Cu ratios 1:0.5, 1:1 and 1:3 in CH2Cl2 at room temperature give copper complexes (eta(2)-1,3,5-tris(trimethylsilylethynyl)benzene)(Cu(hfac)) (2), (eta(2):eta(2)-1,3,5-tris(trimethylsilylethynyl)benzene)(Cu(hfaC))(2) (3) and (eta(2):eta(2):eta(2)-(1,3,5-tris(trimethylsilylethynyl)benzene))(2)(Cu(hfac)(3)(4), respectively. In the same conditions, 2,5-bis-(trimethylsilylethynyl)thiophene (5) reacts with 0.5 or I equiv. of Cu2O to give (eta(2):eta(2)-2,5-bis(trimethylsilylethynyl)thiophene)(Cu(hfac)) (6) and (eta(2):eta(2)-2,5-bis(trimethylsilylethynyl)thiophene)(Cu(hfac))(2) (7), respectively, and 1,4-bis(trimethylsilyl)-1,3-butadiyne (8) with 0.5 equiv. of Cu2O give (eta(2):eta(2)-1,4-bis(trimethylsilyl)-1,3-butadiyne)(Cu(hfac))(2) (9). All the new compounds have been characterized by analytical and spectroscopic methods and their thermal properties were examined by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). (C) 2004 Elsevier B.V. All rights reserved.