1, 4-disilabenzene preparation

Of the (276)-(277) structures, the 1,3-isomer (276a) is the most stable. The calculation of ISE also shows that the 1,3-isomer possesses a greater value for the energy of aromatic stabilization (see the values of R). The preparation of hexamethyl-l,4-disilabenzene has been reported (82-JA6884). According to ab initio calculations on 1,4-disilabenzene (277) and its isomers (278)-(280) (85JOM51), structure (277) is more stable than its valence isomers (278) (by 5.9 kcal/mol, 3-21G //STO-3G) and (280) (by... 

After the successful preparation of silabenzene 24 by hydrogen elimination from 27, it was tempting to try to generate 1,4-disilabenzene 31 by pyrolysis of the easily accessible disilacyclohexadiene 3041 (equation 9). 

An attempt to prepare a ruthenium complex containing a disilabenzene ligand (Scheme 11) led instead to the complex 34, which is best described as a metallodisilanorbornadiene <20010M1195>. 

---