Wolfgang Ehrenreich

Fragmentierung des schwefeldiimidsystems in tBu2PN=S=NPtBu2 an dreikernigen osmiumclustern. Synthese, feströrperstruktur und dynamische eigenschaften von Os3(CO)11[PtBu2(NH2)] und HOs3(CO)9PtBu2N(H)S]

Abstract The phosphino-substituted sulphur diimide, S(NP t Bu 2 ) 2 , reacts with the trinuclear osmium clusters Os 3 (CO) 11 (NCMe) and H 2 Os 3 (CO) 10 with cleavage of one of the NS bonds to give the cluster compounds Os 3 (CO) 11 [P t Bu 2 (NH 2 )] (I) and HOs 3 (CO) 9 [P t Bu 2 N(H)S] (II), respectively. In the solid state, I contains a closed Os 3 triangle with the phosphine ligand bonded equatorially to an osmium atom through the phosphorus. In solution intramolecular dynamic processes are observed which are explained by carbonyl migration and pseudoration mechanisms. The osmium cluster II, in the solid state, forms an irregular Os 3 triangle which is bridged by a [P t Bu 2 N(H)S] system, and the longest edge of which is bridged by a μ 2 -hydride. In contrast to I, molecule II is relatively rigid in solution; only pseudorotations are observed as dynamic phenomena.

Addition von phosphino- und arsino-substituierten schwefeldiimiden an H2Os3(CO)10: Kristallstruktur und dynamische struktureffekte von H2Os3(CO)10(tBu2PNSNAstBu2). Fragmentierung des NSN-gerüstes in H2Os3(CO)10(tBu2PNSNPtBu2)

Abstract The trinuclear cluster H 2 Os 3 (CO) 10 reacts with phosphino- and arsino-substituted sulphur diimides t Bu 2 E′NSNE t Bu 2 (E, E′=P, As) to give the addition products H 2 Os 3 (CO) 10 ( t Bu 2 E′NSNE′Bu 2 ) ( 1 – 3 ) containing an intact NSN system. In these clusters one of the hydrides is terminal, the other one occupies a bridging position on the metal framework. The X-ray crystal structure analysis of the mixed derivative H 2 Os 3 (CO) 10 ( t Bu 2 PNSNAs′Bu 2 ) ( 2 ) reveals the cis , trans -configurated sulphur diimide ligand to be coordinated equatorially through the phosphorus atom. The variable-temperature 13 C and 1 H NMR spectra exhibit a dynamic phenomenon in solution which is interpreted by a cyclic ligand-site exchange involving the two hydrides as well as one axial and one equatorial carbonyl at the hydrogen-bearing osmium atom. The bis(di-t-butylphosphino) derivative 1 is stable only at low temperatures; above 0°C the compound undergoes fragmentation of the NSN system leading to the cluster HOs 3 (CO) 9 [P t Bu 2 N(H)S].

The coordination chemistry of iminooxosulphuranes: IV: The reactions of [WH(CO)3(η-C5H5)] with iminooxosulphuranes and diiminosulphuranes

Abstract The tungsten hydride [WH(CO) 3 (η-C 5 H 5 )] reacts with iminooxosulphuranes, RNSO (R = C 6 H 4 Me-2, C 6 H 4 Me-4), to give the tungsten sulphinamides [W{S(O)NHR}(CO) 3 (η-C 5 H 5 ]. Diiminosulphuranes bearing electron-withdrawing substituents, R′NSNSO 2 C 6 H 4 Me-4 (R′ = C 6 H 5 , SO 2 C 6 H 4 Me-4), insert into the metalhydrogen bond of [WH(CO) 3 (η-C 5 H 5 )] to give [W{S(NR)NHSO 2 C 6 H 4 -Me-4}(CO) 3 (η-C 5 H 5 )], whilst bis( p -tolylimino)sulphurane, S(NC 6 H 4 Me-4) 2 , gives the tungstacycle [W{S(NHC 6 H 4 Me-4)N(C 6 H 4 ME-4)C(0)}(CO) 2 (η-C 5 H 5 )]. A comprehensive mechanism is discussed.

Schwefeldiimid, S(NH)2, und monosubstituierte Schwefeldiimide, S(NR)(NH), mit R = tert-Butyl und Trimethylsilyl / Sulfur Diimide, S(NH)2, and Monosubstituted Sulfur Diimides, S(NR)(NH), with R = tert-Butyl and Trimethylsilyl

The unstable parent compound of the sulfur diimides, S(NH)2 (1), has been obtained in solution by stoichiometric protonation of the anion SN22- in K2SN2 with acetic acid. An analogous protonation of the salts S(NR)(NK) leads to the m onosubstituted sulfur diimides S(NR)(NH) containing bulky substituents such as R = tert-butyl (2) and R = trimethylsilyl (3); 2 and 3 can be isolated as white solids below -40 °C. The temperature-dependent 1H NMR spectra of 1-3 indicate the presence of two isomers in solution (ratio 4:1) which are reversible interconverted.

Die Addukte von Bis(di-tert-butylphosphino)- und Bis(di-tertJ-butylarsino)schwefeldiimid mit Cyclopentadienyl-hydridometall- Komplexen CpM(CO)3H (M = Cr, Mo, W) / The Adducts of Bis(di-tert-butylphosphino)- and Bis(di-tert-butylarsino) Sulfur Diimides with Cyclopentadienyl Hydridometal Complexes CpM(CO)3H (M = Cr, Mo, W)

The new sulfur diimides S(NPBut2)2 (a) and S(NAsBut2)2 (b) react with the hydrido- metal complexes CpM(CO)3H (M = Cr (1), Mo (2), and W (3)) to give 1:1 adducts which contain a three-electron acyl-chelate ligand. Only one of the two PBut2 and AsBut2 substituents, respectively, becomes coordinated to the metal; the hydrido ligand of the starting complex (CpM(CO)3H (1-3) is transfered to a N atom of the sulfur diimide system. The structures of the adducts (1a-3a and 1b-3b) are discussed on the basis of their infrared and 1H, 13C, and 31P NMR spectra. The X-ray analysis of 3a confirms the presence of a four-membered metallocycle containing W, C(acyl), N, and P.**