Zweikernkomplexe des Typs Mn2(CO)8E(CF3)2E′R (E = P,As; E′ = S,Se, Te): Darstellung und Struktur

Perfluoromethyl Element Ligands. XLII Binuclear Complexes of the Type Mn₂(CO)₈E(CF₃)₂E′R (E = P, As; E′ = S, Se, Te): Synthesis and Structure Complexes of the type Mn₂(CO)₈E(CF₃)₂E′R, in which the groups E(CF₃)₂ and E′R act as bridging ligands, are prepared either by direct reactions of Mn₂(CO)₁₀ with (F₃C)₂EE′R (E = P, As; E′ = S, Se, Te) or by substitution of the iodine bridge in the representatives Mn₂(CO)₈ E(CF₃)₂I (E = P, As) with mercury compounds Hg(E′R)₂. As a rule the binuclear systems contain four‐membered heterocycles (Mn₂EE′). However, the reactions of Mn₂(CO)₁₀ with (F₃C)₂PE′P(CF₃)₂ (E′ = S, Se) yield five‐membered rings [Mn₂P(E′P)]. The compounds have been characterized by spectroscopic (NMR, IR, MS), analytic (C, H) and X‐ray diffraction investigations. The pyramidal Mn₂E′R fragment shows dynamic behaviour in solution via inversion between two identical structures.     

Synthese gemischt chalkogenido‐verbrückter Dirheniumkomplexe vom Typ Re2(μ‐ER)(μ‐E′R′)(CO)8 (E,E′ = S,Se, Te; R,R′ = org. Rest)

Synthesis of Mixed Chalcogenido‐Bridged Dirhenium Complexes of the Type Re₂(μ‐ER)(μ‐E′R′)(CO)₈ (E, E′ = S, Se, Te; R, R′ = org. Residue) Hydrido sulfido bridged complexes Re₂(μ‐H)(μ‐SR)(CO)₈ (R = Ph, naph, Cy) react with the base DBU to give the salts [DBUH][Re₂(μ‐SR)(CO)₈]. Upon addition of electrophiles R′E′Br (E′R = SPh, SePh, TePh) to the in situ prepared salts mixed chalcogenido bridged complexes Re₂(μ‐SR)(μ‐E′R′)(CO)₈ were formed. The structures of the new compounds Re₂(μ‐SCy)(μ‐SePh)(CO)₈ and Re₂(μ‐Snaph)(μ‐TePh)(CO)₈ were determined by single crystal X‐ray analyses. For the preparation of analogous selenido tellurido bridged complexes Re₂(μ‐SePh)(μ‐TeR)(CO)₈ the novel hydrido selenido bridged complex Re₂(μ‐H)(μ‐SePh)(CO)₈ was prepared from Re₂(CO)₈(NCMe)₂ and PhSeH. Its structure was determined by single crystal X‐ray analysis. Subsequent deprotonation with DBU gave in situ [DBUH][Re₂(μ‐SePh)(CO)₈] which upon addition of RTeBr (R = Ph, Buⁿ, Bu^t) formed the desired complexes Re₂(μ‐SePh)(μ‐TeR)(CO)₈. The reaction with Bu^tTeBr also yielded the novel spirocyclic complex (μ₄‐Te){Re₂(μ‐SePh)(CO)₈}₂ in low amounts. It was identified by single crystal X‐ray analysis. Re₂(μ‐SePh)(μ‐TeBu^t)(CO)₈ is oxidised in chloroform in the presence of air to give the novel complex (μ‐Te–Te‐μ){Re₂(μ‐SePh)(CO)₈}₂. All mixed chalcogenido bridged dirhenium complexes were proved to be dynamic in solution by ¹³C NMR spectroscopy. The dynamic behaviour is based on the fast and permanent inversion of the sulfido and selenido bridges. The tellurido bridges are rigid on the time scale of ¹³C NMR spectroscopy.     

Zur Darstellung phosphido‐chalkogenido‐verbrückter Dirheniumkomplexe vom Typ Re2(μ‐PCy2)(μ‐ER)(CO)8 (E = S,Se, Te; R = org. Rest)

Synthesis of Phosphido Chalcogenido Bridged Dirhenium Complexes of the Type Re₂(μ‐PCy₂)(μ‐ER)(CO)₈ (E = S, Se, Te; R = org. Residue) The reaction of Re₂(μ‐Br)(μ‐PCy₂)(CO)₈ with nucleophiles MER (M = Na, Li; E = S, Se, Te; R = org. residue) gives via substitution of the bromido bridge phosphido chalcogenido bridged dirhenium complexes of the general formula Re₂(μ‐PCy₂)(μ‐ER)(CO)₈. The new compounds were characterized by IR, ¹H and ¹³C NMR spectroscopic data and by elemental analyses. In addition the molecular structures for E = S, Se, Te and R = Ph as well as for E = S and R = H, n‐Bu, 2‐pyridyl have been established by single crystal X‐ray analysis. ¹³C NMR spectra of Re₂(μ‐PCy₂)(μ‐EPh)(CO)₈ (E = S, Se, Te) prove that the sulfur and selenium compounds are at room temperature dynamic molecules due to inversion of the pyramidal chalcogenido bridge. The tellurium compound, however, is rigid on the time scale of ¹³C NMR spectroscopy. Eventually the reactivity of the SH function of the novel complex Re₂(μ‐PCy₂)(μ‐SH)(CO)₈ was investigated by reaction with Re₂(CO)₈(MeCN)₂. In toluene at 90 °C the novel spirocyclic complex Re₂(μ‐PCy₂)(CO)₈(μ₄‐S)Re₂(μ‐H)(CO)₈ was formed by SH oxidative addition.     

Reaktive E=C(p‐p)π‐Systeme. 54 [1] Reaktionen des Perfluor‐2‐arsapropens,F3CAs=CF2 (1), mit H‐aciden Verbindungen Me2EH (E = N,P, As) und MeE′H (E′ = O,S, Se)

Reactive E=C(p‐p)π‐Systems. 54 [1] Reactions of perfluoro‐2‐arsapropene, F₃CAs=CF₂ (1), with H‐acidic compounds Me₂EH (E = N, P, As) and MeE′H (E′ = O, S, Se) The reactions of the perfluoro‐2‐arsapropene ( 1 ) with H‐acidic compounds Me₂EH (E = N, P, As) and MeE′H (E′ = O, S, Se), respectively, proceed via addition to the As=C double bond yielding either secondary arsanes F₃C(H)AsCF₂X (X = NMe₂, PMe₂, OMe, SMe) or AsX derivatives (X = AsMe₂, SeMe). Me₂‐AsH is obviously a border case nucleophile because, besides the AsX derivative as main product, small amounts of the arsane are formed indicative for the reverse addition pathway. With the strong base Me₂NH, the addition is followed immediately by HF elimination producing the fairly stable arsaalkene F₃CAs=C(F)NMe₂ ( 4 ) which had already been obtained by reaction of HAs(CF₃)₂ with three equivalents of Me₂NH. The novel rather labile compounds were identified by spectroscopic (NMR, GC/MS) investigations. – Quantum chemical DFT calculations [B3LYP/6‐311+G(d,p)] were carried out to determine the relative energy of the isomeric products and the thermodynamics of the addition reactions.     

Perfluormethyl-Element-Liganden. Reaktionen der Metallhydride π-C5H5(CO)3 MH (M = Cr,Mo, W) mit Organoelement-Elementverbindungen des Typs R2EER2 und RE′ E′ R (E = As; E′ = S,Se; R = CH3 CF3)

Perfluoromethyl Element Ligands. XXX. Reactions of the Metal Hydridesπ-C₅H₅(CO)₃MH (M = Cr, Mo, W) with Organoelement-Element Compounds of the Type R₂ EER₂ and RE′ ′E ′R (E = P, As; E′ = S, Se; R = CH₃, CF₃) Cleavage reactions of R₂EER₂ and RE′E′R, respectively, (E = P, As; E′ = S, Se; R = CH₃, CF₃) with complexes π-C₅H₅(CO)₃MH (M = Cr, Mo, W) are used (a) to prepare known and novel complex subsituted phosphanes, arsanes, sulfanes, or selanes π-C₅H₅(CO)₃MER₂ (I) and π-C₅H₅(CO)₃ME′R (II), respectively, (b) to study the reactivity trends as a function of E, E′, R, and M (see Inhaltsübersicht). The tendency observed for the formation of the binuclear complexes [π-C₅H₅(CO)₂MER₂]₂ and [π-C₅H₅(CO)₂ME′R]₂, respectively, in following reactions of I and II increases in the series W ? Mo ≤ Cr and SeCF₃ < As(CF₃)₂ < SCF₃ ≈ P(CF₃)₂ < SeMe < AsMe₂ ?; PMe₂ ≈ SMe.     

Preparation of Tellurium‐Nitrogen containing Moieties in Ionic Chainmolecules,Heterocycles, as well as (CF3Se)2Te, (CF3S)2Se,and (CH3)2Te(X)Y (X = Y = NCO,NSO; X = Cl,Y = NSO)

The reaction between Cl₂Te(NSO)₂, Cl₆Te₂N₂S and Cl₂Te(N=S=N)₂TeCl₂ with MCl₃ provided the compounds [(Cl₂Te)₂N⁺][MCl₄^–] (M = Ga, Al, Fe). Treating Cl₆Te₂N₂S with M′Cl₃ yielded besides [(Cl₂Te)₂N⁺][M′Cl₄^–] (M′ = Al, Fe) the sulfur containing compound [ClTeNSNS⁺][M′Cl₄^–]. The structure for [ClTeNSNS⁺][FeCl₄^–] was established by an X‐ray structure analysis. With Te(NSO)₂ and CF₃SCl, via Cl₂Te(NSO)₂, the known compound Te₂NCl₅ was formed. Tetrafluoroditelluradiazetidine was obtained from TeF₄ and [(CH₃)₃Si]₂NH which on treating with (CH₃)₃SiCl provided the corresponding chloroderivative. In addition metathetical reaction between Cl₂TeNSNS and CF₃C(O)OAg yielded [CF₃C(O)O]₂TeSNSN. Similarly (CH₃)₂Te(NSO)_2–xCl_x (x = 0,1) and (CH₃)₂Te(NCO)₂ were made from (CH₃)₂TeCl₂ and AgNSO or AgNCO, respectively. Halogination of Cl₂Te(N=S=N)₂TeCl₂ with Cl₂ or Br₂ yielded Cl₆Te₂N₂S and Cl₄Br₂Te₂N₂S. The bromoderivate was also prepared from Cl₂Te(NSO)₂ and Br₂. AgNSO was synthesized by treating CF₃C(O)OAg with (CH₃)₃SiNSO. Two other synthons (CF₃Se)₂Te and (CF₃S)₂Se were obtained from CF₃SeCl and Na₂Te and from Hg(SCF₃)₂ plus SeCl₄, respectively.     

Synthese und Kristallstrukturen der homoleptischen Phosphaniminato‐Kationen [E(NPPh3)3]+ (E = S,Se, Te) mit Iodid und Triiodid als Gegenionen

Synthesis and Crystal Structures of the homoleptic Phosphoraneiminato Cations [E(NPPh₃)₃]⁺ (E = S, Se, Te) with Iodide and Triiodide Counter Ions N‐Iod‐triphenylphosphaneimine, INPPh₃, reacts with the chalcogenes sulfur, selenium and tellurium in boiling tetrahydrofuran to give the phosphoraneiminato complexes [E(NPPh₃)₃]⁺[¹/₂ I₃^–, ¹/₂ I^–] · THF (E = S ( 1 ), E = Se ( 2 )) and [Te(NPPh₃)₃]⁺I₃^– ( 3 ), respectively. The componds form red crystals which are characterized by IR spectroscopy and by crystal structure determinations. The homoleptic cations [E(NPPh₃)₃]⁺ have pyramidal structures with short EN and PN bond lengths, corresponding to double bonds. 1 : Space group Pa 3, Z = 8, lattice dimensions at –80 °C: a = b = c = 2192.9(1) pm, R₁ = 0.0299. 2 : Space group Pa 3, Z = 8, lattice dimensions at –80 °C: a = b = c = 2202.5(1) pm, R₁ = 0.0357. 3 : Space group Pca2₁, Z = 4, lattice dimensions at –90 °C; a = 1075.8(2); b = 1988.8(4); c = 2437.2(3) pm, R₁ = 0.0443.     

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.     

Die Tris(triisopropylsilyl)pnikogene: Synthese und Charakterisierung von [E(SiiPr3)3] (E = P,As, Sb)

The Tris(triisopropylsilyl)pnikogenes: Synthesis and Characterisation of [E(Si ⁱ Pr₃)₃] (E = P, As, Sb) The compounds [E(SiⁱPr₃)₃] (E = P, As, Sb) ( 1 – 3 ) were prepared in high yields by the reaction of (Na/K)₃E with ⁱPr₃SiCl in DME. They were characterised by ¹H‐, ¹³C‐, ²⁹Si‐ and ³¹P‐NMR spectroscopy, mass spectrometry and single crystal X‐ray diffraction. Compound 1 , recently obtained in a different way, shows an unusual trigonal planar coordination of the central phosphorus atom. However, 2 and 3 , featuring increasing covalence radii of the central atoms, show an increasingly pyramidal structure. 1 – 3 crystallise isotyp in the cubic spacegroup Pa 3, the lattice constants are: 1 : a = 1860.1(2) pm, 2 : a = 1873.6(2) pm, 3 : a = 1897.1(2) pm.     

Neue 1,1′-Ferrocendichalkogenato-Komplexe des Rutheniums und Osmiums

New 1,1′-Ferrocene Dichalcogenato Complexes of Ruthenium and Osmium Both trinuclear 1,1′-ferrocene dichalcogenato complexes(¹) such as fc(E[ML_n])₂ ( 1a—c ) (with [ML_n] = Ru(CO)₂Cp*; E = S, Se, Te) and dinuclear [3]ferrocenophane derivatives of the type fcE₂[ML_n] (with [ML_n] = Ru(CO)(η⁶-C₆Me₆) ( 2a, b ), Ru(NO)Cp* ( 3a, b ) (E = S, Se) or Os(NO)Cp* ( 4a—c ) (E = S, Se, Te)) were synthesized and characterized by their IR-, ¹H- and ¹³C NMR spectra as well as their mass spectra. The molecular structure of fcS₂[Os(NO)Cp*] ( 4a ) was determined by an X-Ray structure analysis; the long Fe…?Os distance of 431.1(1)pm excludes any direct bonding interactions.     

Heterokuban‐Cluster‐Verbindungen (NEt4){Y=M[(μ3‐S)Re(CO)3]3(μ3‐E)} (M = W oder Mo,Y = O oder S,E = S oder Se): Strukturen,Spektroskopie und Elektrochemie

Heterocubane Cluster Compounds (NEt₄){Y=M[(μ₃‐S)Re(CO)₃]₃(μ₃‐E)} (M = W or Mo, Y = O or S, E = S or Se): Structures, Spectroscopy, and Electrochemistry Thiometallates [MS₄]^2– (M = Mo, W) or [WOS₃]^2– react with Re(CO)₅(O₃SCF₃) and Li₂E (E = S or Se) to yield the following compounds which were structurally characterized: (NEt₄){S=W[(μ₃‐S)Re(CO)₃]₃(μ₃‐S)}(NEt₄) ( 1 ), (NEt₄){O/S=W[(μ₃‐S)Re(CO)₃](μ₃‐S)}(NEt₄) ( 1 / 2 ), (mixed crystals), (NEt₄){S=W[(μ₃‐S)Re(CO)₃]₃(μ₃‐Se)}(NEt₄) ( 3 ) and (NEt₄){S=Mo[(μ₃‐S)Re(CO)₃]₃(μ₃‐S)}(NEt₄) ( 4 ). The heterocubane anions 1 – 4 contain electron‐rich centers such as rhenium(I) or sulfide whereas molybdenum(VI) or tungsten(VI) act as acceptor sites. Accordingly, the absorption spectra show long‐wavelength metal‐to‐ligand charge transfer transitions, and cyclic voltammetry reveals a quasi‐reversible reduction of the clusters. Although both six‐coordinate rhenium(I) and four‐coordinate metal(VI) centers are present in the clusters there is no evidence for significant metal‐to‐metal charge transfer interaction.     

Darstellung,Kristallstrukturen, Schwingungsspektren und Normalkoordinatenanalyse von trans‐(n‐Bu4N)2[Pt(ECN)2(ox)2], E = S,Se

Synthesis, Crystal Structure, Vibrational Spectra, and Normal Coordinate Analysis of trans ‐( n ‐Bu₄N)₄[Pt(ECN)₂(ox)₂], E = S, Se By reaction of (n‐Bu₄N)₂[Pt(ox)₂] with (SCN)₂ and (SeCN)₂ in dichloromethane trans‐(n‐Bu₄N)₂[Pt(SCN)₂(ox)₂] ( 1 ) und trans‐(n‐Bu₄N)₂[Pt(SeCN)₂(ox)₂] ( 2 ) are formed. The crystal structures of 1 (triclinic, space group P1, a = 10.219(2), b = 11.329(2), c = 12.010(3) Å, α = 114.108(15), β = 104.797(20), γ = 102.232(20)°, Z = 1) and 2 (triclinic, space group P1, a = 10.288(1), b = 11.332(1), c = 12.048(1) Å, α = 114.391(9), β = 103.071(10), γ = 102.466(12)°, Z = 1) reveal, that the compounds crystallize isotypically with centrosymmetric complex anions. The bond lengths are Pt–S = 2.357, Pt–Se = 2.480 and Pt–O = 2.011 ( 1 ) und 2.006 Å ( 2 ). The oxalato ligands are nearly plane with O–C–C–O torsion angles of 1.7–3.6°. The via S or Se coordinated linear groups are inclined between both oxalato ligands with Pt–E–C angles of 100.4 (E = S) and 97.4° (Se). In the vibrational spectra the PtE stretching vibrations are observed at 299–314 ( 1 ) and 189–200 cm^–1 ( 2 ). The PtO stretching vibrations are coupled with internal vibrations of the oxalato ligands and appear in the range of 400–800 cm^–1. Based on the molecular parameters of the X‐ray determinations the IR and Raman spectra are assigned by normal coordinate analysis. The valence force constants are f_d(PtS) = 1.75, f_d(PtSe) = 1.35 and f_d(PtO) = 2.77 mdyn/Å. The NMR shifts are δ(¹⁹⁵Pt) = 5435.2 ( 1 ), 5373.7 ( 2 ) and δ(⁷⁷Se) = 353.2 ppm with the coupling constant ¹J(SePt) = 37.4 Hz.     

Darstellung,Kristallstrukturen und Schwingungsspektren von trans‐[Pt(N3)4(ECN)2]2–, E = S,Se

Synthesis, Crystal Structures, and Vibrational Spectra of trans ‐[Pt(N₃)₄(ECN)₂]^2–, E = S, Se By oxidative addition to (n‐Bu₄N)₂[Pt(N₃)₄] with dirhodane in dichloromethane trans‐(n‐Bu₄N)₂[Pt(N₃)₄(SCN)₂] and by ligand exchange of trans(n‐Bu₄N)₂[Pt(N₃)₄I₂] with Pb(SeCN)₂ trans‐(n‐Bu₄N)₂[Pt(N₃)₄(SeCN)₂] are formed. X‐ray structure determinations on single crystals of trans‐(Ph₄P)₂[Pt(N₃)₄(SCN)₂] (triclinic, space group P 1, a = 10.309(3), b = 11.228(2), c = 11.967(2) Å, α = 87.267(13), β = 75.809(16), γ = 65.312(17)°, Z = 1) and trans‐(Ph₄P)₂[Pt(N₃)₄(SeCN)₂] (triclinic, space group P 1, a = 9.1620(10), b = 10.8520(10), c = 12.455(2) Å, α = 90.817(10), β = 102.172(10), γ = 92.994(9)°, Z = 1) reveal, that the compounds crystallize isotypically with octahedral centrosymmetric complex anions. The bond lengths are Pt–S = 2.337, Pt–Se = 2.490 and Pt–N = 2.083 (S), 2.053 Å (Se). The approximate linear Azidoligands with N^α–N^β–N^γ‐angles = 172,1–175,0° are bonded with Pt–N^α–N^β‐angles = 116,7–120,5°. In the vibrational spectra the platinum chalcogen stretching vibrations of trans‐(n‐Bu₄N)₂[Pt(N₃)₄(ECN)₂] are observed at 296 (E = S) and in the range of 186–203 cm^–1 (Se). The platinum azide stretching modes of the complex salts are in the range of 402–425 cm^–1. Based on the molecular parameters of the X‐ray determinations the IR and Raman spectra are assigned by normal coordinate analysis. The valence force constants are f_d(PtS) = 1.64, f_d(PtSe) = 1.36, f_d(PtN^α) = 2.33 (S), 2.40 (Se) and f_d(N^αN^β, N^βN^γ) = 12.43 (S), 12.40 mdyn/Å (Se).     

Vierkernige Clusterkomplexe vom Typ [MM′(AuPR3)2(μ‐H)(μ‐PCy2)(μ4‐PCy)(CO)6] (M,M′ = Mn,Re; R = Ph,Cy, Et): Synthese,Struktur und Topomerisierung

Tetranuclear Cluster Complexes of the Type [MM′(AuR₃)₂(μ‐H)(μ‐PCy₂)(μ₄‐PCy)(CO)₆] (M,M′ = Mn, Re; R = Ph, Cy, Et): Synthesis, Structure, and Topomerisation The dirhenium complex [Re₂(μ‐H)(μ‐PCy₂)(CO)₇(ax‐H₂PCy)] ( 1 ) reacts at room temperature in thf solution with each two equivalents of the base DBU and of ClAuPR₃ (R = Ph, Cy, Et) in a photochemical reaction process to afford the tetranuclear clusters [Re₂(AuPR₃)₂(μ‐H)(μ‐PCy₂)(μ₄‐PCy)(CO)₆] (R = Ph ( 2 ), Cy ( 3 ), Et ( 4 )) in yields of 35–48%. The homologue [Mn₂(μ‐H)(μ‐PCy₂)(CO)₇(ax‐H₂PCy)] ( 5 ) leads under the same reaction conditions to the corresponding products [Mn₂(AuPR₃)₂(μ‐H)(μ‐PCy₂)(μ₄‐PCy)(CO)₆] (R = Ph ( 6 ), Et ( 8 )). Also [MnRe(μ‐H)(μ‐PCy₂)(CO)₇(ax/eq‐H₂PCy)] ( 9 ) reacts under formation of [MnRe(AuPR₃)₂(μ‐H)(μ‐PCy₂)(μ₄‐PCy)(CO)₆] (R = Ph ( 10 ), Et ( 11 )). All new cluster complexes were identified by means of ¹H‐NMR, ³¹P‐NMR and ν(CO)‐IR spectroscopic measurements. 2 , 4 and 10 have also been characterized by single crystal X‐ray structure analyses with crystal parameters: 2 triclinic, space group P 1, a = 12.256(4) Å, b = 12.326(4) Å, c = 24.200(6) Å, α = 83.77(2)°, β = 78.43(2)°, γ = 68.76(2)°, Z = 2; 4 monoclinic, space group C2/c, a = 12.851(3) Å, b = 18.369(3) Å, c = 40.966(8) Å, β = 94.22(1)°, Z = 8; 10 triclinic, space group P 1, a = 12.083(1) Å, b = 12.185(2) Å, c = 24.017(6) Å, α = 83.49(29)°, β = 78.54(2)°, γ = 69.15(2)°, Z = 2. The trapezoid arrangement of the metal atoms in 2 and 4 show in the solid structure trans‐positioned an open and a closed Re…Au edge. In solution these edges are equivalent and, on the ³¹P NMR time scale, represent two fluxional Re–Au bonds in the course of a topomerization process. Corresponding dynamic properties were observed for the dimanganese compounds 6 and 8 but not for the related MnRe clusters 10 and 11 . 2 and 4 are the first examples of cluster compounds with a permanent Re–Au bond valence isomerization.     

Binuclear CpV,Cp*V,and Cp*Ta Complexes containing Organochalcogenolato Bridges, μ‐ER (E = Sulfur,Selenium, Tellurium; R = Methyl,Phenyl, and Ferrocenyl)

Photolysis of the halfsandwich tetracarbonylmetal complexes CpV(CO)₄, Cp*V(CO)₄ and Cp*Ta(CO)₄ in solution in the presence of di(organyl)dichalcogenides E₂R₂ (E = S, Se, Te; R = Me, Ph, Fc) leads to diamagnetic doubly organochalcogenolato‐bridged compounds, [Cp⁽⁾M(CO)₂(μ‐ER)]₂. According to the X‐ray structure determinations carried out for [CpV(CO)₂(μ‐TeMe)]₂, [Cp*V(CO)₂(μ‐TePh)]₂ and [Cp*Ta(CO)₂(μ‐SPh)]₂, the molecular framework consists of a folded M₂(μ‐ER)₂ ring with the cyclopentadienyl ligands in cis‐configuration and the organyl substituents R in a syn‐equatorial arrangement, thus forming a bowl‐shaped molecule with the four terminal CO ligands protruding into the inner sphere. The M…M distances (in the range between 305 and 330 pm) are not considered to indicate direct bonding interactions. The vanadium complexes [Cp⁽⁾V(CO)₂(μ‐ER)]₂ are completely decarbonylated in the presence of an excess of E₂R₂ in boiling toluene, and in many cases the paramagnetic quadruply‐bridged products, [CpV(μ‐ER)₂]₂, can be isolated.     

Hypervalent Organoselenium(II) Compounds with Organophosphorus Ligands. Crystal and Molecular Structure of [2‐(iPr2NCH2)C6H4]Se[S2PR′2] (R′ = Ph,OiPr)

Redistribution reactions between diorganodiselenides of type [2‐(R₂NCH₂)C₆H₄]₂Se₂ [R = Et, iPr] and bis(diorganophosphinothioyl disulfanes of type [R′₂P(S)S]₂ (R = Ph, OiPr) resulted in the hypervalent [2‐(R₂NCH₂)C₆H₄]SeSP(S)R′₂ [R = Et, R′ = Ph ( 1 ), OiPr ( 2 ); R = iPr, R′ = Ph ( 3 ), OiPr ( 4 )] species. All new compounds were characterized by solution multinuclear NMR spectroscopy (¹H, ¹³C, ³¹P, ⁷⁷Se) and the solid compounds 1 , 3 , and 4 also by FT‐IR spectroscopy. The crystal and molecular structures of 3 and 4 were determined by single‐crystal X‐ray diffraction. In both compounds the N(1) atom is intramolecularly coordinated to the selenium atom, resulting in T‐shaped coordination arrangements of type (C,N)SeS. The dithio organophosphorus ligands act monodentate in both complexes, which can be described as essentially monomeric species. Weak intermolecular S ··· H contacts could be considered in the crystal of 3 , thus resulting in polymeric zig‐zag chains of R and S isomers, respectively.     

Darstellung und spektroskopische Charakterisierung der Difluoramino-fluoriminium-Hexafluorometallate F2NC(F)NX2+MF6– (X = H,D; M = As,Sb)

Preparation and Spectroscopic Characterization of the Difluoroaminofluoro-iminium-hexafluorometallates F₂NC(F)NX₂⁺MF₆^– (X = H, D; M = As, Sb) Difluorocyanamin, F₂NCN, does not react with the superacids XF/MF₅ (X = H, D; M = As, Sb) under formation of protonated nitrilium salts. At –78 °C iminium salts of the general form F₂NC(F)NX₂⁺MF₆^– are observed, which are characterized by vibrational and nmr spectroscopy. The structure and vibrational frequencies were computed ab initio at the Hartree-Fock (HF/6-31 + G*) and correlated Møller-Plesset (MP2/6-31 + G*) levels of theory.     

Regioselektive Ringöffnungen von einfach ungesättigten triangularen Clusterkomplexen [M2Rh(μ‐PR2)(μ‐CO)2(CO)8] (M2 = Re2, Mn2; R = Cy,Ph; M2 = MnRe,R = Ph) mit Diphosphanen

Regioselective Ring Opening Reactions of Unifold Unsaturated Triangular Cluster Complexes [M₂Rh(μ‐PR₂)(μ‐CO)₂(CO)₈] (M₂ = Re₂, Mn₂; R = Cy, Ph; M₂ = MnRe, R = Ph) with Diphosphanes Equimolar amounts of the triangular title compounds and chelates of the type (Ph₂P)₂Z (Z = CH₂, DPPM ; C=CH₂, EPP ) react in thf solution at –40 to –20 °C under release of the labile terminal carbonyl ligand attached to the rhodium atom in good yields (70–90%) to ring‐opened unifold unsaturated complexes [MRh(μ‐PR₂)(CO)₄M(DPPM bzw. EPP)(μ‐CO)₂(CO)₃] (DPPM: M₂ = Re₂, R = Cy 1 , Ph 2 ; Mn₂, Cy 5 , Ph 6 ; MnRe, Cy 7 . EPP: M₂ = Re₂, R = Cy 8 ; Mn₂, Cy 10 ). Complexes 1 , 2 and 8 react subsequently under minor uptake of carbon monoxide and formation of the valence saturated complexes [ReRh(μ‐PR₂)(CO)₄M(DPPM bzw. EPP) (CO)₆] (DPPM: R = Cy 3 , Ph 4 . EPP: R = Cy 9 ). Separate experiments ascertained that the regioselective ring opening at the M–M‐edge of the title compounds is limited to reactions with diphosphanes chelates with only one chain member and that the preparation of the unsaturated complexes demands relatively good donor ability of both P atoms. As examples for both types of compounds the molecular structures of 8 and 3 have been determined from single crystal X‐ray structure analysis. Additionally all new compounds are identified by means of ν(CO)IR, ¹H‐ and ³¹P‐NMR data. This includes complexes with a modified chain member in 1 and 5 which, after deprotonation reaction to carbanionic intermediates, could be trapped with [PPh₃Au]⁺ cations as rac‐[MRh(μ‐PR₂)(CO)₄M((Ph₂P)₂CHAuPPh₃)(μ‐CO)₂(CO)₃] (M₂ = Re 17 , Mn 18 ) and products rac‐[MRh(μ‐PR₂)(CO)₄M((Ph₂P)₂CHCH₂R)(μ‐CO)₂(CO)₃] (M₂ = Re, R = Ph 19 , n‐Bu 21 , Me 23 ; Mn, Ph 20 , n‐Bu 22 , Me 24 ) which result from Michael‐type addition reactions of 8 or 10 with strong nucleophiles LiR.     

Über Chalkogenidhalogenide des Rheniums: Synthese und Kristallstrukturen der Dreieckscluster Re3E7X7 (E = S,Se; X = Cl,Br)

On Chalcogenide Halogenides of Rhenium: Synthesis and Crystal Structures of the Triangular Clusters Re₃E₇X₇ (E = S, Se; X = Cl, Br) The compounds Re₃E₇X₇ are obtained from rhenium tetrahalides ReX₄, elemental chalcogens and the respective chalcogen halides E₂X₂ or SeX₄ (E = S, Se; X = Cl, Br). Re₃S₇Cl₇, Re₃S₇Br₇ and Re₃Se₇Br₇ are formed in solutions of sulfur or selenium halides or SiBr₄ in form of black crystals and crystallize isotypically in the trigonal space group P31c. Re₃Se₇Cl₇ is formed by solid state reaction of ReCl₄, Se and SeCl₄ or by thermal decomposition of Se₄[ReCl₆], crystallizing as red, in thin layers transparent crystals in the orthorhombic space group Pbcm. The crystal structures consist of discrete positively charged cluster units and halide ions according to the formula [Re₃(μ₃-E)(μ₂-E₂)₃X₆]⁺X^–. In the rhenium triangular clusters the Re–Re distances range from 269,0 to 270,4 pm for the sulfur and from 273,3 to 275,3 pm for the selenium containing compounds. The Re₃ units are capped by chalcogen atoms, three E₂ groups form bridges over the edges of the Re₃ triangles. The trigonal and the orthorhombic structure type show differences in the site symmetry of the clusters (C₃ vs. C_s) and in the stacking sequence of the molecules, which are packed in the motif of a closest packing of spheres.