Nitrido complexes bridged

W=W triple bond and formation of both nitrido and alkylidyne complexes of WV1. Crystal structure determination94 of [(OBu )3W=N] and [(OBu )3W IMe]2 has shown that the nitrido complex is polymeric with unsymmetrical W—N—W bridges. The alkylidyne complex is dimeric with a short W—C bond length of 1.76 A. As expected, this distance is significantly shorter than the one observed for the W—C double bond. 

Re centers are bridged by an en ligand [22]. Apparently this reaction, which involves displacement of water is not thermally rapid under the synthesis conditions. The study appears to be the first example of photosubstitution of a rhenium-nitrido complex. 

A new class of binuclear nitrido complexes of tetravalent osmium and ruthenium is described in which the metal atoms are symmetrically bridged by a nitride ligand to give a linear M-N—M unit They have the stoichiometries M2NX8(H20)2]3 and [M2N(NH3)8Y2]3+ (M = Os, Ru X = Cl, Br Y = Cl, Br, etc.). Studies are reported on their vibrational spectra, structures, and bonding. Preliminary studies are reported also on trinuclear complexes of osmium and iridium. Finally, the use of vibrational spectroscopy in the study of metal-nitrido and metal-oxo complexes is discussed briefly. 

Table V. Vibrational Spectra of Bridging Nitrido Complexes—Anionic Species...

Figure 4. Electronic spectra of some bridging nitrido complexes...

The orange complex is air sensitive in the solid state. It is reasonably soluble and stable in THF but decomposes in nonpolar solvents, such as benzene, to give polymeric halogen-bridged products.9 It is paramagnetic with a magnetic moment of 3.63 BM, and its IR spectrum shows a very intense band at about 820 cm-1 due to coordinated THF. Its reactions with tertiary phosphines in THF give a series of molybdenum (III) tertiary phosphine complexes,9 and with trimethyl-silyl azide Mo(V) nitrido complexes are formed.8... 

Relatively few nitrido complexes of Ru are known examples are [Ru(N)Xi] 119 and some organometallic ones mentioned in the next section. Examples of osmium hydrides are OsH3(BFLi)(PR3)2 that has an Os/u.-H2BH2 bridge, OsH6(PR3)2, [OsH5(PR3)3]+, and OsH4(PR3)3. 

Complexes of the (ra s-lTcO(OH)] and [TCO2] Cores Oxo-Bridged (Tc203l and Other Binuclear Complexes [TcSl Complexes Nitrido Complexes Imido and Hydrazido Complexes Complexes Not Containing Multiply Bonded Ligands... 

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