REACTIONS OF TETRAAKLYLDIINDANE(4), R2IN-INR2 (R = CH(SIME3)(2)), WITH TERT-BUTYL AND PHENYL ISONITRILES - FORMATION OF ADDUCTS WITH RETENTION OF THE IN-IN BOND

Tetrakis[bis(trimethylsilyl)methyl]diindane-(4) (I) reacts with tert-b utyl or phenyl isonitrile not by the insertion of the isonitrile carbo n atom into its In-In single bond but by the formation of weak adducts with one isonitrile molecule coordinated to each of the coordinativel y unsaturated In atoms. While the tert-butyl isonitrile adduct 5 is al most centrosymmetric in the solid state with the largest possible sepa ration between the bulky tert-butyl groups, the phenyl groups are neig hbored and parallel in the corresponding phenyl derivative 6. The In-i n distances of both compounds (2.8483 Angstrom on average for 5 and 2. 8482(6) Angstrom for 6) are identical and only slightly lengthened com pared! with the starting compound 1 (2.828(1) Angstrom).