Steric control in the formation of Co2(CO)6-alkyne complexes from Group 14 tetraalkynes and their reactions with acid

A series of tetrakis(trimethylsilylethyne) derivatives of Group 14 metals (2–4) was prepared. Co2(CO)6 complexes 5–10 were synthesised by the reaction of 2–4 with Co2(CO)8. From the silyl and germyl based compounds 2 and 3, either one or two alkynes could be complexed with Co2(CO)6. In contrast, the tin derived compound 4 could accommodate up to four Co2(CO)6 complexes. The longest wavelength UV-Vis absorbances of the silicon and …