Not so alkyne like: A dialkyldisilyne (left, green) that can be isolated is synthesized and fully characterized. It coordinates to palladium and platinum in a η(2) -fashion giving complexes (red) with a trans-bent geometry, in contrast to η(2) -alkyne complexes. The complexes showed significant metallacycle character.

Nicht so Alkin‐artig: Ein isolierbares Dialkyldisilin (links, grün) wurde synthetisiert und vollständig charakterisiert. Bei seiner η2‐Koordination an Palladium und Platin entstehen Komplexe mit trans‐gebogener Geometrie (rot), die sich von η2‐Alkin‐Komplexen unterscheiden und beträchtlichen metallacyclischen Charakter zeigen.

Benzodisilacyclobutadienes 2 a-c were isolated as blue to green crystalline solids from the reaction of stable disilyne 1 and 1,2-dibromobenzenes in the presence of potassium graphite. In the solid state, substantial bond alternation was observed within the benzene rings of 2 a-c. In hexane, 2 a-c showed remarkable bathochromic shifts of the π→π* (HOMO→LUMO) absorption bands at 625-670 nm. NMR spectra and theoretical calculations indicated that the diamagnetic ring currents of the benzene rings of 2 a-c are considerably reduced by contributions from the antiaromatic 1,2-disilacyclobutadienes. In their entirety, the obtained results indicate that 2 a-c represent 8π-electron systems that contain an antiaromatic 1,2-disilacyclobutadiene.

Benzodisilacyclobutadienes 2a-c were isolated as blue to green crystalline solids from the reaction of stable disilyne 1 and 1,2-dibromobenzenes in the presence of potassium graphite.I nt he solid state,s ubstantial bond alternation was observed within the benzene rings of 2a-c.I n hexane, 2a-c showed remarkable bathochromic shifts of the p!p*( HOMO!LUMO) absorption bands at 625-670 nm. NMR spectra and theoretical calculations indicated that the diamagnetic ring currents of the benzene rings of 2a-c are considerably reduced by contributions from the antiaromatic 1,2-disilacyclobutadienes.Intheir entirety,the obtained results indicate that 2a-c represent 8p-electron systems that contain an antiaromatic 1,2-disilacyclobutadiene.