J. Am. Chem. SOC.1993,115, 345-347
345
Supplementary Material Available: Experimental details of the with other adduct^,^-^ cycloaddition of 2 to c60 occurs across a crys,tal structure determination for 1, fully labeled view of the 6,6 ring junction of the framework. The average bond lengths structure, and tables of atomic coordinates, equivalent isotropic for the $6- and 6,6-junctions in the c60 framework, other than those related to atoms connected to C(30) and C(31), are 1.43 thermal parameters, bond angles, and bond lengths (15 pages); (4) and 1.39 (4) A, respectively, in good agreement with the listing of observed and calculated structure factors for 1 (8 pages). observed values for the osmylated and platinum c o m p l e ~ e s . ~ ~ . ~Ordering ~ information is given on any current masthead page. The four sp2-sp3bond lengths C(22)-C(30), C(29)-C(30), C(31)-C(32), and C(31)-C(39) average 1.52 (4) A, and the C(30)-C(31) bond length is 1.62 (4) A. These values reproduce almost exactly those of the osmate adduct.3b It seems likely that the length of the C(30)-C(31) bond is greatly increased because Generation and Characterization of Isomeric the overall bending deformation of the sp3 angles at C(30) and Iron-Silylene and Iron-Silene Cationic Complexes in C(31) is accommodated at the cost of increased bond stretching. the Gas Phase Figure 1 shows that the cyclohexene unit defined by C(30)-C(31)-C(61)
