Formation of cation-anion complexes in photochemical reaction of molybdenocene dinydride with iron pentacarbonyl. Crystal structures of [Cp2Mo(CO)H]+[Fe3(CO)11H]- and [Cp2Mo(CO)H]+[CpMo(CO)3]-(triclinic modification)

In the course of the Cp2MoH2 reaction with Fe(Co)5 in boiling benzene under UV irradiation the [Cp2Mo(CO)H]+ [Fe3(CO)11H]- (1) and [Cp2Mo(CO)H]+[CpMo(CO)3]- (2), the structure of which is established by the X-ray diffraction analysis (autodiffractometer ''Syntex P21'', lambda MoKsub(α), graphite monochromator, theta/2 theta-scanning, full-matrix least square method, isotropic for 1 from 2112 reflexes up to R=0.11 and anisotropic for 2 from 3770 hkl up to R=0.052). In 1 and 2 the [CpMo(CO)H]+ fragment represents a wedge-shaped sandwich with a shielded conformation of rjngs. In 1 the angle between the rings is 33,9 deg, mean distance Mo-C(C5H5) 2.28 (3), Mo-C (CO) 2.03 (3), Mo-H 1.78 (10) A, in 2 corresponding parameters are 32.4 deg; 2.296 (7); 2.020 (6) and 1.87 (7) A. In a monomeric anion of the complex 2 the mean distance Mo-C(C5H5) 2.385(5) A, bonds Mo-C(CO) in error limits are equivalent and have the length 1.929(6)-1.932(5) A. The crystals 1 aAe monoclinic with unit cell parameters: a=-12.258(2), b=12.005(2), c=17.333(4) A, β=94.10(3) deg, Z=4, sp.gr. P21/c. The crystals 2 are triclinic: a= 7.962(1), b=10.691(2), c=10.896(2) A , α=96.64(2), β=95.27(2), γ=81.10(1) deg, Z=2, sp.gr. P anti 1. The probable scheme of 1 and 2 formation process is discussed