STRUCTURAL CHARACTERIZATION OF THE HYDROGEN-BRIDGED HETEROBIMETALLIC COMPLEX (ETA5-C5H5)2(CO)NB(MU-H)FE(CO)4

The structure of the product of the reaction of (η5-C5H5)2NbH3 with Fe(CO)5, (775-C5H5)2(CO)Nb(°µ-H)Fe(CO)4, has been determined by X-ray diffraction techniques. Crystals are monoclinic, space group P2/1c, with cell parameters a=7.835 (3) υ, b=13.508 (2) υ, c=15.165 (2) υ, β=97.05 (2)°, and Z=4. The structure was refined to R=0.033 and Rw=0.042 for 3063 unique observed data. The molecule contains a triangular Nb-H-Fe group with parameters Nb-Fe=3.324 (1) υ, Nb-H=1.91 (3) υ, H-Fe=1.61 (3) υ, and Nb-H-Fe=141 (2)°. The geometry about Nb is typical for (η5-C5H5)2MX., compounds, with a ring bending angle of 136.3°. The geometry about Fe is a nearly regular trigonal bipyramid (neglecting the bridging hydrogen) with the Nb atom in an axial position. NMR studies suggest a possibly different structure in solution. © 1979, American Chemical Society. All rights reserved.