The chemistry of cyclopentadienyl nitrosyl compounds of molybdenum. Part 13. Hydrazine, hydrazido(1–)-, and hydrazido(2–)-complexes

Abstract

Me), affords ( i ) simple hydrazine adducts, [Mo(y-C,-H,) (N H RNR'R") (NO)X,] (1 ), (ii) hydrazido( 1 -)-complexes, [ Mo(q-C5H5) (NRN R'R") I (NO)] (2), and (iii) hydrazido(2-) complexes, [{Mo(q-C,H,)(NO)X},NNR'R"] (4). Protonation of (2) or (4) with HBF, gives the hydrazine adducts [MO(T~-C,H,)I(NHRNR'R'')(NO)] [BF,] (3). Thespecies (l), on the basis of spectral data, may contain either a unidentate or a chelating hydrazine, the latter forming a three-membered ring with the metal. Species (2) may also contain a three-membered MoNN chelate ring which on protonation affords (3), whose structure is known to involve a bidentate hydrazine bound to only one metal atom. The binuclear species (4) contain the hydrazido(2-)-ligand asymmetrically bridging the two Mo atoms, one N atom being bound to one Mo atom by a 6-and a (p,+d,)-donor bond, and the other Mo atom being attached to both N atoms via CT bonds in a three-membered ring. The chemical and structural relationships between (1 ), (2), (3), and (4) are discussed.

Recent organometallic nitrosyl chemistry

“…Similar reaction of Cp2Mo(NO) (j72-S2CNMe2) with trifluoroacetic Nucleophilic attack of hydride on the cationic complex [CpRe(NO)(CO)2]+ produces the neutral formyl complex CpRe(NO)(CO)(CHO) (53). Its subsequent reduction and decomposition reactions123 have been extensively studied and are the principal subject of an enlightening review article.151 Hydride reduction of the second carbonyl group in 53 has been achieved to produce a diformyl complex 54 plex cannot be isolated, but it has been fully characterized by IR and XH NMR spectroscopies. A manganese analogue of the diformyl complex 54, i.e.…”

Electrochemical Cleavage of NdN Bonds at a Mo2(μ-SMe)3 Site Relevant to the Biological Reduction of Dinitrogen at a Bimetallic Sulfur Centre

“…Interconversion of protons [43] or of alkyl groups [44] on the nitrogen atoms of mononuclear side-on bonded hydrazido(1 À ) complexes has been reported. In [W(Cp*)Me 4 (h 2 -NHNH 2 )], two different fluxional processes take place.…”

“…[43] A similar site-exchange mechanism was reported for [MoCp(NMeNMe 2 )I(NO)] (R Me, M {MoCpI(NO)}, DG = 59 kJ mol À1 , Scheme 6). [44] If similar fluxional processes take place for [Mo 2 Cp 2 -(m-SMe) 3 (m-N 2 H 2 Ph)], species A and B would be related by a proton 1,2-shift, while C would arise from a MoÀNÀNÀMo ring opening analogous to the one depicted in Scheme 6.…”

Preparation and characterization of two unsubstituted hydrazido(1-) complexes, W(.eta.5-C5Me5)Me4(.eta.2-NHNH2) and [W(.eta.5-C5Me5)Me3(.eta.2NHNH2)]+[SO3CF3]-

“…It is generally believed (although there is no direct evidence) that dinitrogen is activated by and reduced at a molybdenum center in nitrogenase, with the possible assistance of a second metal (most likely Fe).1 For this reason the coordination of molecular nitrogen to one or more transition metals and its reduction to ammonia have been the subject of a great deal of research in the past 2 decades. 16 The long-term goals are to understand the inorganic chemistry at metal centers in nitrogenaseslf and to design in the formation of N2H5+ and WCp*Me4(NHNH2) (1, eq 2) in good yield. Ivory-colored crystals of WCp*Me4(NHNH2) can…”