3931
tion environment of each iron atom is octahedral with the cyclopentadienyl group occupying three coordination sites; the tin and two carbonyls are located at the three remaining sites. The bonding in the [n-CsHsMo(CO)~]moiety is similar to that in [n-C5HjMo(CO)3]26and [ ( T - C ~ H ~ ) ~ M P(CH3)2}(C0)4]7 O~H{ in which the metal atom is a seven-coordinated atom with the cyclopentadienyl group occupying three coordination sites. Bond lengths and interatomic angles are given in Table I. The tin-molybdenum bond length of 2.891 A is the first such bond distance reported. It is considerably shorter than the expected distance of 3.00 A based on the sum of the covalent radii of tin (1.39 A)S Table I. Bond Distances and Interatomic Angles and Their Estimated Standard Deviationse ~~
Bond
Distance, A 2.891 (5) 2.583 (7) 2.598 (7) 2.50 (1) 2.35 (5)b 1.96 (4)b 1.19 ( 5 ) b 1 . 4 6 (7)b 2 . 1 4 (6)b 1.68 (6)b 1 . 2 0 (6)b 1 .45 ( 8 ) b 2.12 (6)b 1.79 (6)b 1.17 (6)b 1.47 ( 8 ) b
Angle Mo-Sn-Fel Mo-Sn-Fe, Mo-Sn-C1 Fel-Sn-Fe2 Fel-Sn-CI Fez-Sn-C1 Mo-C-0
c-c-c
Sn-Fe,-C
