Five-, six- and eight-membered ring organosilicon chalcogenides of the types Z2(SiMe2)2E (Z = Me2Si, H2C; E = S, Se, Te), Z(SiMe2E)2MR2 (Z = Me2Si, H2C, O; E = S, Se, Te; M = Si, Ge, Sn, R = Me, Ph) and (SiMe2ZSiMe2E)2 (Z = Me2Si, H2C; E = S, Se)

Reactions of ClMe₂Si–Z–SiMe₂Cl (Z = SiMe₂ (1a), CH₂ (1c), O (1e)) with Li₂E (E = S, Se) yielded eight-membered ring compounds (SiMe₂ZSiMe₂E)₂ (3a–d) as well as acyclic oligomers (SiMe₂ZSiMe₂E)_x of different chain lengths. If 1:1 molar mixtures of 1a, 1c or 1e and a diorganodichlorosilane, -germane or -stannane (R₂MCl₂) are reacted with Li₂E (E = S, Se, Te), six-membered ring compounds Z(SiMe₂E)₂MR₂ (4a–7g) are formed exclusively. Five-membered rings Z₂(SiMe₂)₂E (Z = SiMe₂ (8a–c), CH₂ (9a–c); E = S, Se, Te) are obtained starting from the tetrasilane ClMe₂Si–(SiMe₂)₂–SiMe₂Cl (1b) or the disilylethane ClMe₂Si–(CH₂)₂–SiMe₂Cl (1d) by treatment with Li₂E. All products were characterized by multinuclear NMR spectroscopy (¹H, ¹³C, ²⁹Si, ¹¹⁹Sn, ⁷⁷Se, ¹²⁵Te, including coupling constants) and the effects of the different ring sizes towards NMR chemical shifts are discussed.     

Darstellung und charakterisierung von verbindungen des typs (CH3)3ME(CF3)2 (M = Si,Ge, Sn; E = P,As)

Various preparative routes for the synthesis of (CH₃)₃SiP(CF₃)₂ are discussed. The most favourable method, reaction of (CH₃)₃MPH₂ with HE(CF₃)₂, provides a good yield of (CH₃)₃ME(CF₃)₂ compounds (M = Si, Ge, Sn; E = P, As). The reaction rate is dependent on M (Si < Ge <Sn) und E (P < As). The stability and reactivity of the (CH₃)₃ME(CF₃)₂ compounds are discussed. The new compounds were characterized by NMR and IR spectra and by cleavage reactions of the M-E bond. ¹H, ¹⁹F NMR and IR spectral data are reported.     

Spektroskopische Untersuchungen an R3MF-Verbindungen (M = Si,Ge, Sn)

Spectroscopical Investigations on R₃MF Compounds (M = Si, Ge, Sn) The IR and RAMAN spectra of a number of R₃MF compounds (M? Si, Ge, Sn) have been recorded. The frequencies of the vibrational spectra were almost completely assigned. The measurements of the IR-spectra were investigated (as for as possible) in all states of aggregations. The force of the intermolecular interactions were discussed by means of the spectroscopic data.     

Protolyses of (CH3)3SnM(CH3)3 (M = Sn,Ge, Si,C)

Product and kinetic studies on the reactions of hydrogen chloride in methanol solution with the substrates (CH₃)₃SnM(CH₃)₃ (M = Sn; Ge and Si) show that both SnM and SnCH₃ cleavage reactions occur, at similar rates, and are followed by other reactions giving complex but explicable mixtures of products. Similar behaviour is observed for trifluoroacetolysis in carbon tetrachloride solution, and some intermediates are observable. Trifluoroacetolysis of (CH₃)₃SnC(CH₃)₃ results in exclusive SnCH₃ cleavage. The very slow apparent solvolysis in acetic acid solution is thought to involve reaction with dissolved oxygen.     

Interaction between cobaltocenium and decamethylcobaltocenium salts and Ph3ELi (E = Si,Ge, Sn)

Reactions of cobaltocenium salts [(C₅R₅)₂Co]PF₆ (R = H, Me) with Ph3ELi (E = Si, Ge, Sn) and with Ph₂SbLi mainly follow two pathways (nucleophilic addition and one-electron reduction), yielding cobalt cyclopentadiene-cyclope ntadienyl complexes (⁴-Ph₃EC₅R₅)(⁵-C₅R₅)Co (R = H, E = Si, Ge, Sn; R = Me, E = Si) and cobaltocenes (C₅R₅)₂Co (R = H, Me), respectively. The contribution of nucleophilic addition of Ph₃ELi decreases in the order of elements Si > Ge > Sn and when hydrogen atoms are replaced by methyl groups in the initial cobaltocenium salt. Thermal decomposition of cobalt cyclopentadiene-cyclopentadienyl complexes results in substituted cobaltocenes.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya. No. 10, pp. 2557–2560, October, 1996.     

Low coordinate germanium and tin compounds (ArO)2ME and (ArO)2MM′Ln M=Ge, Sn; E=S, Se, –NSiMe3 M′=Cr, W, Fe, Pt [Ar=2,4,6-tris((dimethylamino)methyl)phenyl-]

The reactions of the divalent species (ArO)₂M (Ar=2,4,6-[(CH₃)₂NCH₂]₃C₆H₂; M=Ge, Sn) with either Me₃SiN₃, elemental S₈, Se or transition metal complexes M′(CO)_n+1 (M′=Fe, n=4; M′=Cr, W; n=5) (Ph₃P)₂Pt·C₂H₄ have resulted in the isolation of either the new stable formal metallanimines (ArO)₂M=N–SiMe₃, germanethione, -selone (ArO)₂Ge=E (E=S, Se) (the expected formations of the stannanethione and -selone were not observed), or the (ArO)₂M=M′(CO)_n, (ArO)₂M=Pt(PPh₃)₂ complexes, respectively. The direct oxidation of the (ArO)₂M species with various oxidizing agents led to the formation of the corresponding metalloxanes [(ArO)₂M–O–]₂. All of the chalcogenido- and transition metal–metal 14 complexes have been physicochemically and chemically characterized. The reactions of the (ArO)₂Ge=E (E=S, Se) compounds with 3,5-di-tert-butyl-1,2-benzoquinone produced, by extrusion of sulfur or selenium, the dioxametalloles corresponding to the formal addition of the divalent species (ArO)₂M to the benzoquinone. A substitution reaction of chalcogen (S/Se) has been observed permitting to go from germaneselone to germanethione.     

Vibrational assignment of some X3MCo(CO)4 molecules (M = Si,Ge, Sn and X = Cl,Br, I)

The infrared and Raman vibrational spectra of X₃MCo(CO)₄ compounds (M = Si, Ge, Sn and X = Cl, Br, I) including depolarization measurements are presented. These spectra result in complete vibrational assignments which are different from those reported previously.     

Darstellung,Charakterisierung und Struktur funktionalisierter Fluorphosphaalkene des Typs R3E–P=C(F)NEt2 (R/E = Me/Si,Me/Ge,CF3/Ge,Me/Sn)

Preparation, Characterization, and Structure of Functionalized Fluorophosphaalkenes of the Type R₃E–P=C(F)NEt₂ (R/E = Me/Si, Me/Ge, CF₃/Ge, Me/Sn) P‐functionalized 1‐diethylamino‐1‐fluoro‐2‐phosphaalkenes of the type R₃E–P=C(F)NEt₂ [R/E = Me/Si ( 2 ), Me/Ge ( 3 ), CF₃/Ge ( 4 ), Me/Sn ( 5 )] are prepared by reaction of HP=C(F)NEt₂ ( 1 , E/Z = 18/82) with R₃EX (X = I, Cl) in the presence of triethylamine as base, exclusively as Z‐Isomers. 2–5 are thermolabile, so that only the more stable representatives 2 and 4 can be isolated in pure form and fully characterized. 3 and 5 decompose already at temperatures above –10 °C, but are clearly identified by ¹⁹F and ³¹P NMR‐measurements. The Z configuration is established on the basis of typical NMR data, an X‐ray diffraction analysis of 4 and ab initio calculations for E and Z configurations of the model compound Me₃Si–P=C(F)NMe₂. The relatively stable derivative 2 is used as an educt for reactions with pivaloyl‐, adamantoyl‐, and benzoylchloride, respectively, which by cleavage of the Si–P bond yield the push/pull phosphaalkenes RC(O)–P=C(F)NEt₂ [R = tBu ( 6 ), Ad ( 7 ), Ph ( 8 )], in which π‐delocalization with the P=C double bond occurs both with the lone pair on nitrogen and with the carbonyl group.     

Ate complexes of Ge(II) and Sn(II) with bidentate ligands [LiE(OCH2CH2NMe2)3]2 (E=Ge, Sn): synthesis and structure

The reaction of equimolar quantities of LiOCH₂CH₂NMe₂ and E¹⁴(OCH₂CH₂NMe₂)₂ (E¹⁴=Ge, Sn) in ether yielded new ate complexes [LiE¹⁴(OCH₂CH₂NMe₂)₃]₂ (E¹⁴=Ge (1), Sn (2)) with bidentate ligands. The compounds 1 and 2 are white crystalline substances which are highly soluble in THF and pyridine and very sensitive to the traces of oxygen and moisture. The structures of these compounds are studied by X-ray diffraction analysis. The ate complexes 1 and 2 are powerful nucleophiles and may be employed as ligands (neutral) in the coordination chemistry of the transition metals. The electronegative O-substituents at the divalent E¹⁴ atoms render them less oxidizable than alkyl- or aryl-substituted derivatives, and the bidentate ligands, owing to intramolecular donor-acceptor interactions, make them more thermodynamically stable compared to monodentate ligands.     

Reactions of silicon-, germanium- and tin-containing carbene complexes of tungsten Ph3E-CW(OBu)3 (E=Si, Ge, Sn) with hydrogen chloride: crystal structures of carbene complexes Ph3E-CHWCl2(OBu)2 (E=Si, Ge)

The novel organosilicon, -germanium and -tin-containing carbene complexes of tungsten of the type Ph₃E-CHWCl₂(OBu^t)₂ (E=Si, Ge, Sn) have been prepared by the reaction of heteroelement-containing carbene complexes of tungsten Ph₃E-CW(OBu^t)₃ (E=Si, Ge, Sn) with hydrogen chloride. The tin-containing carbene complex was identified in solution by ¹H NMR spectroscopy. Silicon- and germanium-containing carbene complexes were isolated in high yields as crystalline solids and characterized by elemental analysis, IR, ¹H NMR, ¹³C NMR and ²⁹Si NMR spectroscopy and X-ray diffraction studies. The geometry of the W atoms in the compounds can be described as a distorted square pyramid.     

Electric birefringences and solution-state conformations of molecules C6H5SM(CH3)3 ; M = C,Si, Ge or Sn

Dipole moment and electric birefringence studies are reported for the series of molecules C₆H₅SM(CH₃)₃ in cyclohexane solution; M = C, Si, Ge or Sn. The experimental data are analysed to determine the preferred solution-state conformations. The dihedral angles between the C₆H₅ and C_arSM planes are, in turn, 82 ± 11°, 80 ± 11°, 66 ± 12° and 46 ± 10°.     

Tuning the excited-state properties of [M(SnR3)2(CO)2(alpha-diimine)] (M = Ru, Os; R = Me, Ph)

The influences of R, the alpha-diimine, and the transition metal M on the excited-state properties of the complexes [M(SnR3)2(CO)2(alpha-diimine)] (M = Ru, Os; R = Ph, Me) have been investigated. Various synthetic routes were used to prepare the complexes, which all possess an intense sigma-bond-to-ligand charge-transfer transition in the visible region between a sigma(Sn-M-Sn) and a pi*(alpha-diimine) orbital. The resonance Raman spectra show that many bonds are only weakly affected by this transition. The room-temperature time-resolved absorption spectra of [M(SnR3)2(CO)2(dmb)] (M = Ru, Os; R = Me, Ph; dmb = 4,4'-dimethyl-2,2'-bipyridine) show the absorptions of the radical anion of dmb, in line with the SBLCT character of the lowest excited state. The excited-state lifetimes at room temperature vary between 0.5 and 3.6 microseconds and are mainly determined by the photolability of the complexes. All complexes are photostable in a glass at 80 K, under which conditions they emit with very long lifetimes. The extremely long emission lifetimes (e.g., tau = 1.1 ms for [Ru(SnPh3)2(CO)2(dmb)]) are about a thousand times longer than those of the 3MLCT states of the [Ru(Cl)(Me)(CO)2(alpha-diimine)] complexes. This is due to the weak distortion of the former complexes in their 3SBLCT states as seen from the very small Stokes shifts. Remarkably, replacement of Ru by Os hardly influences the absorption and emission energies of these complexes; yet the emission lifetime is shortened because of an increase of spin-orbit coupling. The quantum yield of emission at 80 K is 1-5% for these complexes, which is lower than might be expected on the basis of their slow nonradiative decay.     

Silylchalcogenolates MESiR(t)Bu(2) (M = Na, Cu, Zn, Fe; E = S, Se, Te; R = tBu, Ph) and disilyldichalcogenides tBu2RSiE-ESiRtBu2 (E = S, Se, Te; R = tBu, Ph): synthesis, properties, and structures

The sodium silyl chalcogenolates NaESiR(t)Bu(2) (R = Ph, (t)Bu; E = S, Se, Te), accessible by the nucleophilic degradation of S, Se, or Te by the sodium silanides NaSiR(t)Bu(2) (R = Ph, (t)Bu), have been characterized by X-ray structure analysis. Protonolysis of the sodium silyl chalcogenolates yields the corresponding chalcogenols. The Cu and Zn chalcogenolates, [Cu(SSiPh(t)Bu(2))](4) and [ZnCl(SSi(t)Bu(3))(THF)](2), have been synthesized by metathesis reactions of CuCl with NaSSiPh(t)Bu(2) and of ZnCl(2) with NaSSi(t)Bu(3), respectively. The solid-state structures of the transition metal thiolates have been determined. The compounds (t)Bu(2)RSiE-ESiR(t)Bu(2) (R = Ph, (t)Bu; E = S, Se, Te) are accessible via air oxidation. With the exception of (t)Bu(3)SiS-SSi(t)Bu(3), these compounds were analyzed using X-ray crystallography and represent the first structurally characterized silylated heavy dichalcogenides. Oxidative addition of (t)Bu(3)SiTe-TeSi(t)Bu(3) to Fe(CO)(5) yields [Fe(TeSi(t)Bu(3))(CO)(3)](2), which has also been structurally characterized.     

Synthesis and characterisation of six Fe(II or III), Co(II) or Zr(IV) complexes containing the ligand [CH(SiMe2R)P(Ph)2NSiMe3] (R = Me, NEt2) and of [Co{N(SiMe3)C(Ph)C(H)P(Ph)2NSiMe3}2]

The C,N-(trimethylsilyliminodiphenylphosphoranyl)silylmethylmetal complexes [Fe(L)₂] (3), [Co(L)₂] (4), [ZrCl₃(L)]·0.83CH₂Cl₂ (5), [Fe(L)₃] (6), [Fe(L′)₂] (7) and [Co(L′)₂] (8) have been prepared from the lithium compound Li[CH(SiMe₂R)P(Ph)₂NSiMe₃] [1a, (R = Me) {≡ Li(L)}; 1b, (R = NEt₂) {≡ Li(L′)}] and the appropriate metal chloride (or for 7, FeCl₃). From Li[N(SiMe₃)C(Ph)C(H)P(Ph)₂NSiMe₃] [≡ Li(L″)] (2), prepared in situ from Li(L) (1a) and PhCN, and CoCl₂ there was obtained bis(3-trimethylsilylimino- diphenylphosphoranyl-2-phenyl-N-trimethylsilyl-1-azaallyl-N,N′)cobalt(II) (9). These crystalline complexes 3-9 were characterised by their mass spectra, microanalyses, high spin magnetic moments (not 5) and for 5 multinuclear NMR solution spectra. The X-ray structure of 3 showed it to be a pseudotetrahedral bis(chelate), the iron atom at the spiro junction.     

Übergangsmetall-substituierte acylphosphane und phosphaalkene : XX. Dipolare [3 + 2]-Cycloadditionen eines acetylendicarbonsäureesters an die metallophosphaalkene (η-C5Me5)(CO)2Fe---P=C(R)SiMe3 (R = Ph, SiMe3)

The metallo-phosphaalkenes (η⁵-C₅Me₅)(CO)₂FeP=C(R)(SiMe₃) (Ia: R = SiMe₃, Ib: R = Ph) and MeO₂C---CC---CO₂Me undergo a dipolar [3+2]-cycloaddition to afford the metallo-heterocycles [(η⁵-C₅Me₅)(CO)

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=C(R)SiMe₃] (IIIa,b) with exocyclic P=C double bonds.     

Perfluormethyl-element-liganden XXVlI [1] Darstellung und spektroskopische untersuchung von W(CO)5L-komplexen (L = R2EER′2, R2EE′R; R,R′ = CH3; CF3; E = P,As; E′ = S,Se, Te)

W(CO)₅L complexes (L = R₂EER′₂, R₂EE′R; R, R′ = CH₃, CF₃; E = P, As; E′ = S, Se, Te) have been prepared by reaction of W(CO)₅·THF with L at room temperature or by redistribution reaction of W(CO)₅E₂Me₄ with E₂(CF₃)₄ or E′₂Me₂ as well as by cleavage of E₂(CF₃)₄ with W(CO)₅EMe₂H. The new compounds were characterized by analytical and spectroscopic (IR, NMR, MS) methods; by comparison with of the data of free and coordinated ligands the effects of complexation are studied.     

Preparation and properties of the formamidino complexes [M(π-C5H5){HC(NR)2}(CO)2] (M = molybdenum or tungsten; R = aryl or alkyl)

The preparation and properties of the complexes [M(π-C₅H₅){HC(NR)₂}CO)₂] (M = Mo, W; R = aryl or alkyl) are reported. The complex [Mo(π-C₅H₅){HC(N-p-tolyl)₂}(CO)₂] could be prepared by (a) reaction of MoCp(CO)₃Cl with M′{HC(N-p-tolyl)₂} (M′ = K, Ag or Cu); (b) irradiation of MoCp(CO)₃Cl with HC(HN-p-tolyl)N-p-tolyl); and (c) reaction of [MoCp(CO)₃]₂ with M′{HC(N-p-tolyl)₂} (M′ = Ag or Cu). The several routes to this complex give indications of the mechanisms of formation. The structure of these complexes and the bonding nature of the metal with the formamidino group is discussed on basis of the ¹H and ¹³C NMR and IR spectra.Reaction of N,N′-dimethyl formamidine with MCp(CO)₃Cl gave the complex [M(π-C₅H₅){HC(NMe)N(CO)Me}(CO)₂], containing a carbonyl inserted between the metal and the formamidino group. Irradiation of this carbamoyl complex caused decarbonylation, yielding the complex [M(π-C₅H₅){HC(NMe)₂}CO)₂].     

Rationally functionalized deltahedral zintl ions: synthesis and characterization of [Ge9-ER3]3-, [R3E-Ge9-ER3]2-, and [R3E-Ge9-Ge9-ER3]4- (E=Ge, Sn; R=Me, Ph)

Six new derivatized deltahedral Zintl ions have been synthesized by reactions between the known Zintl ions Ge(9) (n-) with the halides R(3)EX and/or the corresponding anions R(3)E(-) for E=Ge or Sn. This rational approach is based on our previous discovery that these derivatization reactions are based on nucleophilic addition to the clusters. All species were structurally characterized as their salts with potassium countercations sequestered in 2,2,2-crypt or [18]crown-6 ether. The tin-containing anions were characterized also in solutions by (119)Sn NMR spectroscopy. The reaction types for such substitutions and the structures of the new anions are discussed.     

Heterobimetallic Mo---Sn complexes. Reactions of [Mo(CO)3(CH3CN)2(Cl)(SnRCl2)] (R = Me, Ph) with 4(4-XC6H4)3 (X = Cl, F, H, Me, MeO)

Three families of heterobimetallic compounds were obtained by reaction of [Mo(CO)₃(CH₃CN)₂(Cl)(SnRCl₂)] (R = Ph, Me) with P(4-XC₆H₄)₃ (X = Cl, F, H, Me, MeO). The type of compound obtained dependent on the solvent and concentration of the starting compound. So, [Mo(CO)₂(CH₃COCH₃)₂(PPh₃)(Cl)(SnRCl₂)]·nCH₃COCH₃ (R = Ph, n = 0.5; R = Me, n = 1) (type I) and [Mo(CO)₃{P(4-XC₆H₄)₃}(μ-Cl)(SnRCl₂)]₂ (R = Ph, X = Cl, F, H, Me, MeO; R = Me, X = Cl, F) (type II) were isolated from acetone solution in ca 0.05 M and 0.1 M concentrations, respectively. However, [Mo(CO)₃(CH₃CN) {P(4-XC₆H₄)₃}(Cl)(SnRCl₂)] (R = Ph, X = H; R = Me, X = Cl, F, H) (type III) were obtained from dichloromethane solution independently of the concentration used. All new complexes showed a seven-coordinate environment at molybdenum, containing Mo---Cl and Mo---Sn bonds. Mössbauer spectra indicated a four-coordination at tin for type III complexes.