15612-93-8

Upstream product

• 54099-82-0 2Na⁽¹⁺⁾*W(CO)5^(2-) = Na₂[W(CO)5] 
• 103-71-9 phenyl isocyanate 
• 103-72-0 phenyl isothiocyanate 

Relevant academic research and scientific papers

Siliciumhaltige Carben-Komplexe. XIV. Untersuchungen zur Frage der Aciditaet der Si-H-Gruppe in Silylcarben-Komplexen (CO)5MC(XR)SiHR'2 (M = Cr, W; XR = OEt, NR2)

The very unstable carbene complexes (CO)5MC(OEt)Si(H)Mes2 (1a: M=W; 1b: M=Cr; Mes=mesityl) were prepared by reaction of M(CO)6 with Li, followed by alkylation with BF4.Corresponding complexes with smaller substituents at the silicon atom were considerably less stable.While 1a yielded the aminocarbene complexes (CO)5WC(NHR)Si(H)Mes2 upon reaction with H2NR (R=Me, Et, CH2CH=CH2, i-Pr), reaction with HNR2 was strongly influenced by steric effects.Dialkylaminocarbene complexes (CO)5WC(NR2)Si(H)Mes2 were only obtained with the sterically less demanding amines HNMe2 or HNC4H8.Complex 1b only reacted with H2NMe.The X-ray structure analysis of (CO)5WC(NC4H8)Si(H)Mes2 (2f) showed that the hydrogen atom at silicon is strongly screened and hardly accessible.Although spectroscopic data of the new complexes indicate a slight enhancement of the acidity of the Si-H group compared with R2SiH2, no deprotonation was possible using several bases.

Reactions of dianionic carbonylmetalates with heteroallenes: Reduction of carbonyl sulfide, isothiocyanates, isocyanates, and carbodiimides by group 6 and 8 carbonylmetalates

Dianionic carbonylmetalates of the group 6 and group 8 metals can reduce a number of heteroallenes X=C=Y to coordinated O≡X ligands, provided X is a first-row element (N or O) which can form a strong triple bond with C. Thus Na2[M(CO)4] (M = Fe, Ru) and Na2[M(CO)5] (M = Cr, W) react readily with COS to give [M(CO)5] (M = Fe, Ru) and [M(CO)6] (M = Cr, W) in good yield, as established by absorbance mode IR for Fe and W and by isolation of the known derivatives [M(CO)4I2] (M = Fe, Ru) and [N(n-Bu)4][M(CO)5Br] (M = Cr, W), while CS2 does not give thiocarbonyl complexes with Na2[W(CO)5] or Na2[Fe(CO)4]. It is suggested on the basis of IR and stoichiometry that the COS reductions are reductive disproportionations leading to thiocarbonate formation. Isothiocyanates RNCS (R = Ph, Me) give moderate yields of the corresponding isonitrile complexes [M(CO)4(CNR)] with Na2[Fe(CO)4], but not with Na2[Ru(CO)4]. A similar reaction of PhNCS with Na2[Cr(CO)5] gives low yields of [Cr(CO)5(CNPh)], but [W(CO)5(CNPh)] can only be isolated after addition of oxalyl chloride to the intermediate isothiocyanate complex. Reduction of PhNCO with Na2[W(CO)5] leads to 84% and 5% solution yields of [W(CO)6] and [W(CO)5(CNPh)], respectively, consistent with control of the reduction of unsymmetrical heteroallenes by the relative triple bond strengths in the product C≡X ligands (C≡O > C≡N > C≡S).

Siliciumhaltige Carben-Komplexe VIII. HSiR3-Eliminierung aus Carben-Komplexen des Types (CO)5MC(NHR')SiR3 (M= Cr, Mo, W)

Upon heating solid monoalkylamino(silyl)carbene complexes (CO)5MC(NHR')SiR3 (M= W: SiR3= SiPh3, R'= Me, Et, n-Bu, C6H11, Ph; SiR3= SiMePh2, R'= Me, Et.M=Mo, Cr: R=Ph, R'= Me, Et) beyond their melting points, HSiR3 elimination with formation of the isonitr