Reaktion von Oxomolybdän-Komplexen mit Alkyldithiocarbazaten. Darstellung und Charakterisierung von Hydrazido- und Diazenido-Komplexen des Molybdäns / Reaction of Oxomolybdenum Complexes with Alkyldithiocarbazates. Synthesis and Characterization of Hydrazido- and Diazenido Complexes of Molybdenum

Abstract

<jats:title>(2).</jats:title><jats:p>The reaction of alkyldithiocarbazates NH<jats:sub>2</jats:sub>NHC(S)SR′ with MoO<jats:sub>2</jats:sub>(S<jats:sub>2</jats:sub>CNR<jats:sub>2</jats:sub>)<jats:sub>2</jats:sub> R, R′ = Me, Et) yields the diazenido hydrazido complexes Mo(NNC(S)SR′)(NH<jats:sub>2</jats:sub>NC(S)SR′)(S<jats:sub>2</jats:sub>CNR<jats:sub>2</jats:sub>)<jats:sub>2</jats:sub> (1), reaction with the molybdenum hydroxylamidate complex MoO<jats:sub>2</jats:sub>(ONMe<jats:sub>2</jats:sub>)<jats:sub>2</jats:sub> gives the diazenidobis( hydrazido) complex Mo(NNC(S)SMe)(NH<jats:sub>2</jats:sub>NC(S)SMe)<jats:sub>2</jats:sub>(Me<jats:sub>2</jats:sub>NO)-CH<jats:sub>3</jats:sub>OH The crystal structures of <jats:bold>1 a </jats:bold>(R = Me, R′ = Et) and <jats:bold>2 </jats:bold>have been determined. The metal atoms in <jats:bold>1 a </jats:bold>and <jats:bold>2 </jats:bold>are seven coordinated and have MoN<jats:sub>2</jats:sub>S<jats:sub>5</jats:sub> and MoN<jats:sub>3</jats:sub>O<jats:sub>2</jats:sub>S<jats:sub>2</jats:sub> ligand arrays, respectively. Both compounds contain the approximately linear diazenido ligand NNC(S)SR in addition to one <jats:bold>(1a) </jats:bold>or two <jats:bold>(2) </jats:bold>N,S-chelating hydrazido(1-) ligands NH<jats:sub>2</jats:sub>NC(S)SR. When <jats:bold>1a </jats:bold>is treated with HCl, the dimeric complex (Me<jats:sub>2</jats:sub>NCS<jats:sub>2</jats:sub>)(O)Mo(μ-NNC(S)SEt)<jats:sub>2</jats:sub> Mo(S<jats:sub>2</jats:sub>CNMe<jats:sub>2</jats:sub>) <jats:bold>(4) </jats:bold>is obtained. X-ray crystallography showed <jats:bold>4</jats:bold> to be an asymmetric dinuclear complex, with a Mo-Mo distance of 267.2(1) pm. One Mo site has a square pyramidal MoOS<jats:sub>2</jats:sub>N<jats:sub>2</jats:sub> geometry, while the other one has an approximately trigonal prismatic MoN<jats:sub>2</jats:sub>S<jats:sub>4</jats:sub> geometry. The mean N-N distance in <jats:bold>4 </jats:bold>is 135(1) pm. The reaction of NH<jats:sub>2</jats:sub>NHC(S)SMe with MoO<jats:sub>2</jats:sub>(acac)<jats:sub>2</jats:sub> yields Mo(Me<jats:sub>2</jats:sub>CNNC(S)SMe)(NNC(S)SMe)(MeSC(S)NNC(S)SMe) (3). Its structure has been determined by X-ray crystallography. 3 contains a unique combination of three different N- and S-chelating ligands: the Schiff base Me<jats:sub>2</jats:sub>C=NNC(S)SMe, the highly bent bidentate diazenido ligand NNC(S)SMe (∡ Mo-N-N = 142.1(5)°), and the novel planar tridentate ligand MeSC(S)NNC(S)SMe. The latter can be taken as neutral diacyldiazene or, more likely, as the dianion of the as yet unknown MeSC(S)NH -NHC(S)SMe. The N - N distance in this ligand is 136.1(9) pm.</jats:p>

Diverse Post-Metathesis Reactivities of Mixed Amido-Isothiocyanato Molybdenum Complexes

“…To the best of our knowledge, complexes of L 2 are unknown, although the unsymmetrical free thiourea SC­(HNSiMe 3 )­(NMe 2 ) has been reported . Nevertheless, coordination compounds of related ligands are known. , Notably, only low-oxidation state Group 6 metal centers (Mo II ) have been reported to accommodate κ 2 - N , S thioureato ligands, while three-membered N , S -chelated Mo V and Mo VI complexes can be found in a few examples with dithiocarbazate- and thiosemicarbazone-based multidentate donors …”