Ruthenium-Catalyzed Cross-Metathesis of Trisubstituted Vinylsilanes with Light Alkenes

In the cross-metathesis reaction of tri(methyl, ethoxy)vinylsilanes with propene and/or 1-butene catalyzed by RuCl₂(PPh₃)₃ activated in benzene at 115–130 °C, a series of l-alkenylsilanes of general formula CH₃(CH₂)_mCH = CHSiMe_3−n(OEt)_n, where m=0, 1, and n=0–3 (1-silyl-1-alkenes), as well as of formula CH₂=C(Me)SiMe_3−n(OEt)_n, where n=1, 2 (2-silyl-1-alkenes), were obtained. Additional products determined were allysilanes of general formula CH₂=CHCH₂SiMe_3−n(OEt)_n and CH₃CH= CHCH₂SiMe_3−n(OEt)_n, where n=1–3. © 1997 John Wiley & Sons, Ltd.     

Synthesis and Crystal Structure of [Cr(thd)2(OEt)]2

The mixed‐ligand complex [Cr(thd)₂(OEt)]₂ [(thd)^– = anion of H(thd) = C₁₁H₂₀O₂ = 2,2,6,6‐tetramethylheptane‐3,5‐dione] appears as by‐product when EtOH/H₂O is used as solvent during preparation of Cr(thd)₃. [Cr(thd)₂(OEt)]₂ can be difficult to separate from Cr(thd)₃ by sublimation, but separation is easily accomplished by extracting Cr(thd)₃ with acetone. A detailed account for the sublimation behavior of [Cr(thd)₂(OEt)]₂/Cr(thd)₃ mixtures is advanced. Good yields of [Cr(thd)₂(OEt)]₂ are obtained when CrCl₃, H(thd), and Na(EtO) react in absolute EtOH. [Cr(thd)₂(OEt)]₂ is obtained in the form of green needle‐shaped crystals by recrystallization from toluene. The crystal structure is triclinic [a = 10.2919(15), b = 10.6686(16), c = 14.194(3) Å, α = 106.559(2), β = 107.869(2), and γ = 98.326(2)° at 295 K; space group P . The complex contains two crystallographic equivalent chromium atoms, which are bridged by two cis‐configured ethoxy groups, the four remaining sites in the octahedral coordination around each chromium atom being occupied by oxygen atoms from two thd ligands. The bond lengths and angles concur with the findings for related molecular complexes. The temperature dependence of the magnetic susceptibility of [Cr(thd)₂(OEt)]₂ follows Curie–Weiss law with Weiss constant θ ≈? –65 K and μ_p = 3.87 μ_B.     

A monooxorhenium(V) complex with an unusually long Re=O bond: the structure of [ReOI2(ame)(PPh3)] (Hame=2-(2-aminophenyl)ethanol)

The complex [ReOI₂(ame)(PPh₃)] (Hame=2-(2-aminophenyl)ethanol) was prepared from trans-[ReOI₂(OEt) (PPh₃)₂] and Hame in benzene. It contains an unusually long Re=O bond (1.717(5)?Å) and a large trans O=Re–O (ethanolate) bond angle of 171.4(2)°.     

Oxide promoted isomerisation of an isonitrile complex,H2Os3(CO)10[CN(CH2)3Si(OEt)3]

The isomerisation of H₂Os₃(CO)₁₀[CN(CH₂)₃Si(OEt)₃] to HOs₃(CO)₁₀-[CN(H)(CH₂)₃Si(OEt)₃] is accelerated by interaction with some oxides; both complexes afford HOs₃(CO)₁₀[CN(H)(CH₂)₃Si(OEt)_3it-x(O)x] as oxide supported clusters.     

Übergangsmetallphosphidokomplexe. XII. Diphosphenkomplexe (DRPE)Ni[η2-(PR′)2] und die Struktur von (DCPE)NiP(SiMe3)2

Transition Metal Phosphido Complexes. XII. Diphosphene Complexes (DRPE)Ni[η²-(PR′)₂] and the Structure of (DCPE) NiP (SiMe₃)₂ LiP(SiMe₃)₂ reacts with the complexes (DRPE)NiCl₂ 1 (DRPE = R₂PCH₂CH₂PR₂; R = Et: DEPE a ; R = Cy: DCPE b ; R = Ph: DPPE c ) to form the diphosphene complexes (DRPE)Ni[η²-(PSiMe₃)₂] 5a–c . Using low temperature nmr measurements the monosubstitution products (DRPE)Ni[P(SiMe₃)₂]Cl 2a–c and the disubstitution products (DRPE)Ni[P(SiMe₃)₂]₂ 3a, 3c can be detected as intermediates. From the reaction of 1b the paramagnetic nickel(I) complex (DCPE)NiP(SiMe₃)₂ 4b can be isolated. Reacting 1a, 1b with LiP(SiMe₃)CMe₃ the complexes (DRPE)Ni[P(SiMe₃)CMe₃]Cl 8a, 8b , which are analogous to 2 , and the nickel(0) diphosphine complex (DEPE)Ni[η¹-P(SiMe₃)CMe₃P(SiMe₃)CMe₃] 9a can be detected n.m.r. spectroscopically, but no diphosphene complexes can finally be isolated. The diphosphene complexes (DRPE)Ni[η²(PPh)₂] 10a-c are available from reactions of PhP(SiMe₃)₂with l a - c. MeP(SiMe,), reacts only with 1b to give a diphosphene complex (DCPE)Ni[η²(PMe)₂] 11 b. Reacting [P(SiMe₃)CMe₃]₂ with 1a-c the diphosphene complexes (DRPE)Ni[η²(PCMe₃)₂] 12a-c can be obtained. 4b crystallizes monoclinic in the space group P2Jc with a = 1228.6 pm, b = 2387.1 pm, c = 2621.8 pm, β = 92.16°, and Z = 8 formula units. The nickel atom is nearly planar coordinated by three phosphorus- atoms, the phosphorus atom of the terminal P(SiMe₃)₂ group is pyramidally coordinated. The Ni? P bond distances of the two four-coordinated phosphorus atoms are with 219.2 pm and 220.2 pm only slightly shorter than the corresponding distance of the P-atom of the P(SiMe₃)₂ group with 223.5 pm. N.m.r. and mass spectral data are reported.     

Metallorganische Verbindungen der Lanthanoide. 88. Monomere Lanthanoid(III)-amide: Synthese und Röntgenstrukturanalyse von [Nd{N(C6H5)(SiMe3)}3(THF)], [Li(THF)2(μ-Cl)2Nd{N(C6H3Me2-2,6)(SiMe3)}2(THF)] und [ClNd{N(C6H3-iso-Pr2-2,6)(SiMe3)}2(THF)]

Organometallic Compounds of the Lanthanides. 88. Monomeric Lanthanide(III) Amides: Synthesis and X-Ray Crystal Structure of [Nd{N(C₆H₅)(SiMe₃)}₃(THF)], [Li(THF)₂(μ-Cl)₂Nd{N(C₆H₃Me₂-2,6)(SiMe₃)}₂(THF)], and [ClNd{N(C₆H₃-iso-Pr₂-2,6)(SiMe₃)} ₂(THF)] A series of lanthanide(III) amides [Ln{N(C₆H₅) · (SiMe₃)}₃(THF)_x] [Ln = Y ( 1 ), La ( 2 ), Nd ( 3 ), Sm ( 4 ), Eu ( 5 ), Tb ( 6 ), Er ( 8 ), Yb ( 9 ), Lu ( 10 )] could be prepared by the reaction of lanthanide trichlorides, LnCl₃, with LiN(C₆H₅)(SiMe₃). Treatment of NdCl₃(THF)₂ and LuCl₃(THF)₃ with the lithium salts of the bulky amides [N(C₆H₃R₂-2,6)(SiMe₃)]^? (R = Me, iso-Pr) results in the formation of the lanthanide diamides [Li(THF)₂(μ-Cl)₂Nd{N(C₆H₃Me₂-2, 6)(SiMe₃)}₂(THF)] ( 11 ) and [ClLn{N(C₆H₃-iso-Pr₂-2,6)(SiMe₃)} ₂(THF)] [Ln = Nd ( 12 ), Lu ( 13 )], respectively. The ¹H- and ¹³C-NMR and mass spectra of the new compounds as well as the X-ray crystal structures of the neodymium derivatives 3 , 11 and 12 are discussed.     

Conformational structure of N-(silylmethyl)anilines PhNHCH2SiMe n (OEt)3-n (n = 0–3)

As show the data of IR spectroscopy and quantum-chemical calculations (B3LYP/6-311+G**), N-(silylmethyl)anilines PhNHCH₂SiMe _n (OEt)_3?n in inert media have an intramolecular hydrogen bond NH?OSi. N-[(Trimethylsilyl)methyl]aniline PhNHCH₂SiMe₃ in inert solvents exists as a mixture of two conformers close in energy.     

Crystal Structure of the Complex of 1,2-Bis[2-(o-hydroxyphenoxy)ethoxy]ethane with Ammonium Thiocyanate

The complex of the podand 1'2-bis[2-(o-hydroxyphenoxy)ethoxy]ethane (L) with ammoniumthiocyanate, [NH₄(SCN)L], was prepared, studied by single crystal X-ray diffraction. This is a host-guestcomplex; in its molecule the podand L is wrapped around the NH ₄ ⁺ cation, which forms hydrogen bondswith all the six oxygen atoms of the podand and one hydrogen bond with the sulfur atom of the SCN^- anion. The geometric parameters (bond lengths, bond angles, torsion angles, etc.) of the molecule of [NH₄(SCN)L] and packing of the molecules in the crystal were determined. The molecules are linked into infinite polymeric chains by intermolecular hydrogen bonds O-H···NCS.     

Darstellung und Eigenschaften spirocyclischer Titan(IV)-amide Ti[-NMe-SiMe2-Y-SiMe2-NMe-]2 mit Y = NMe,O und CH2

Preparation and Properties of Spirocyclic Ti(IV) Amides Ti( –NMe–SiMe₂–Y–Sime₂–NMe–)₂ with Y ? NMe, 0, and CH₂ The title compounds have been obtained from the reaction of TiBr₄ with the di-lithiated α, ω-bifunctional amines Y(SiMe₂NHMe)₂ in yields of about 50%. The compounds are monomeric, crystalline and of considerable stability. Their constitution has been proved by elemental analyses, ¹H n.m.r., i.r., and Raman spectra. A synthesis is described for the hitherto unknown diamine CH₂(SiMe₂NHMe)₂.     

Vanadium(II) alkyls. Synthesis and X-ray crystal structures of trans-VMe2(dmpe)2 and cis-V(CH2SiMe3) 2(dmpe)2

Treatment of the vanadium(II) tetrahydroborate complex trans-V(η¹-BH₄)₂(dmpe)₂ with (trimethylsilyl) methyllithium gives the new vanadium(II) alkyl cis-V(CH₂SiMe₃)₂(dmpe)₂, where dmpe is the chelating diphosphine 1,2-bis(dimethylphosphino)ethane. Interestingly, this complex could not be prepared from the chloride starting material VCl₂(dmpe)₂. The CH₂SiMe₃ complex has a magnetic moment of 3.8 μ_B, and has been characterized by ¹H NMR and EPR spectroscopy. The cis geometry of the CH₂SiMe₃ complex is somewhat unexpected, but in fact the structure can be rationalized on steric grounds. The X-ray crystal structure of cis-V(CH₂SiMe₃)₂(dmpe)₂ is described along with that of the related vanadium(II) alkyl complex trans-VMe₂(dmpe)₂. Comparisons of the bond distances and angles for VMe₂(dmpe) ₂, V---C = 2.310(5) Å, V---P = 2.455(5) Å, and P---V---P = 83.5(2)° with those of V(CH₂SiMe₃)₂(dmpe)₂, V---C = 2.253(3) Å, V---P = 2.551(1) Å, and P ---V---P = 79.37(3)° show differences due to the differing trans influences of alkyl and phosphine ligands, and due to steric crowding in latter molecule. The V---P bond distances also suggest that metal-phosphorus π-back bonding is important in these early transition metal systems. Crystal data for VMe₂(dmpe)₂ at 25°C: space group P2₁/n, with a = 9.041(1) Å, b = 12.815(2) Å, c = 9.905(2) Å, β = 93.20(1)°, V = 1145.8(5) ų, Z = 2, R_F = 0.106, and R_wF =0.127 for 74 variables and 728 data for which I 2.58 σ(I); crystal data for V(CH₂SiMe₃)₂(dmpe)₂ at −75°C: space group C2/c, with a = 9.652(4) Å, b = 17.958(5) Å, c = 18.524(4) Å, β = 102.07(3)°, V= 3140(3) ų, Z = 4, R_F = 0.033, and R_wF = 0.032 for 231 variables and 1946 data for which I 2.58 σ(I).     

Synthesis of cis-[Ru(CO)2(S2X)2] [X = CNMe2, COEt, PPh2, P(OEt)2] and Molecular Structure of [Ru(CO){η2-S2P(OEt)2}{μ,η1,η2-S2P(OEt)2}]2

Two routes to 1,1-dithiolate complexes cis-[Ru(CO)₂(S₂X)₂] [X = NMe₂, OEt, PPh₂, P(OEt)₂] are presented. From the reaction of NH₄S₂P(OEt)₂ with the ruthenium(II) complex generated upon reduction of RuCl₃.3H₂O by CO in 2-methoxyethanol, along with the expected mononuclear product, cis-[Ru(CO)₂{η²-S₂P(OEt)₂}₂], binuclear [Ru(CO){η²-S₂P(OEt)₂} {μ,η¹,η²-S₂P(OEt)₂}]₂ was also produced. The latter has been crystallographically characterized and shows a trans-arrangement of carbonyls and cis-arrangement of terminal and bridging dithiolate ligands.     

[Ni(iPr2Im)2Br2]: A Convenient Entry into NHC Nickel ­Chemistry

The reaction of the NHC iPr₂Im [NHC=N‐heterocyclic carbene, iPr₂Im = 1, 3‐bis(isopropyl)imidazolin‐2‐ylidene] with freshly prepared NiBr₂ in thf or dme results in the formation of the air stable nickel(II) complex trans‐[Ni(iPr₂Im)₂Br₂] ( 2 ). Complex 2 was structurally characterized. Thermal analysis (DTA/TG) reveals a very high decomposition temperature of 298 °C. Reduction of 2 with sodium or C₈K in the presence of the olefins COD (cyclooctadiene) or COE (cyclooctene) affords the highly reactive compounds [Ni₂(iPr₂Im)₄(COD)] ( 1 ) and [Ni(iPr₂Im)₂(COE)] ( 4 ). Alkylation of 2 with organolithiums leads to the formation of trans‐[Ni(iPr₂Im)₂(R)₂] [R = Me ( 5 ), CH₂SiMe₃ ( 6 )], whereas the reaction of 2 with LiCp* [Cp* = (η⁵‐C₅(CH₃)₅)] at 80 °C causes the loss of one NHC ligand and affords [(η⁵‐C₅(CH₃)₅)Ni(iPr₂Im)Br] ( 7 ).     

Studies,on the synthesis,structure, IR spectra and reactivity of a new dinuclear Mo(0) complex, [Et4N]2[Mo2(CO)8(SCH2CO2Et)2]

Reaction of Et₄NI, NaSCH₂CO₂Et and Mo(CO)₆ in CH₃CN affords a new dinuclear molybdenum (0) complex, [Et₄N]₂[Mo₂(CO)₈(SCH₂CO₂Et)₂] (1). Electrochemistry and reactivity investigation indicate that 1 undergoes an interesting two-electron oxidation in a single step (-0.43 V) and a substitution of its carbonyls by coordinating solvents resulting in two kinds of Mo(I)-complexes, Mo₂(CO)₈(SCH₂CO₂Et)₂ and (Mo₂(CO)₆SCH₂CO₂Et)₂(CH₃CN)₂. vC=O and vMo-CO have been assigned. The crystal and molecular structure has been determined from three-dimensional X-ray data. 1 crystallized in the triclinic, space group with a=10.362(1), b=10.391(1), c= 10.815(2)Å; α=91.64(2)°, β=100.07(2)°, γ=114.46(1)°; Z=1; R=4.8% for 2975 reflections with I>3σ(I). Nonbonding of Mo … Mo [3.939(1)Å] and the configuration of MoS₂Mo unit in 1 are very different from those in related Mo(I)-product. These results confirm our previous speculation that the two-electron character derives from creation or cleavage of a metal-metal single bond coupled with structural rearrangement in a bridged bimetallic center.     

New polyfunctional silicon-containing amines C6[CH2CH2SiMe(OCH2CH2NR2)2]6 (R = H,Me) and their reactions with cobalt(ii) chloride and dicobalt octacarbonyl

Hexakis[bis(2-aminoethoxy)methylsilylethyl]benzene and hexakis[bis(N,N-dimethyl-2-aminoethoxy)methylsilylethyl]benzene C₆[(NR₂CH₂CH₂O)₂SiMeCH₂CH₂]₆ (4, R = H; 5, R = Me) were prepared from hexakis(methyldichlorosilylethyl)benzene C₆(Cl₂MeSiCH₂CH₂)₆ and 2-aminoethanol or N,N-dimethyl-2-aminoethanol, respectively. Compounds 4 and 5 react with anhydrous cobalt (ii) chloride to give poorly soluble dodecachloro{hexakis[bis(2-aminoethoxy)methylsilylethyl]benzene}hexacobalt and dodecachloro{hexakis[bis(N,N-dimethyl-2-aminoethoxy)methylsilylethyl]benzene}hexacobalt {Co₆[(NR₂CH₂CH₂O)₂SiMeCH₂CH₂]₆C₆}Cl₁₂ (R = H or Me), respectively. Polyfunctional amine 4 reacts with dicobalt octacarbonyl to produce hexakis[bis(2-aminoethoxy)methylsilylethyl]benzenedicobalt(ii) tetrakis(tetracarbonylcobaltate) {Co₂[(NH₂CH₂CH₂O)₂SiMeCH₂CH₂]₆C₆}[Co(CO)₄]₄. N,N-Dimethyl-substituted polyfunctional amine 5 is lowly reactive in the reaction with Co₂(CO)₈, whereas the simplest model of this compound, viz., bis(N,N-dimethyl-2-aminoethoxy)dimethylsilane (NMe₂CH₂CH₂O)₂SiMe₂, slowly reacts with Co₂(CO)₈ to give tris[bis(N,N-dimethyl-2-aminoethoxy)dimethylsilane]cobalt(ii) bis(tetracarbonylcobaltate) {Co[(NMe₂CH₂CH₂O)₂SiMe₂]₃}[Co(CO)₄]₂. Thermal decomposition and transformations of the resulting complexes under the action of oxygen and water were studied.     

Unexpected Zwitterionic Allenyls from Silylenes and a Fischer Alkynylcarbene: A Remarkable Silylene-Promoted Rearrangement

The silylenes Si(tBu₂bzam)R (tBu₂bzam=N,N′-bis(tertbutyl)benzamidinate; R=mesityl, CH₂SiMe₃) attack the C_carbene atom of the Fischer alkynyl(ethoxy)carbene complex [W(CO)₅{C(OEt)C₂Ph}] to give, after a striking rearrangement, zwitterionic σ-allenyl complexes in which the original carbene C atom forms part of the allene C₃ fragment and also of a Si-C-N-C-N five-membered ring after insertion into a Si−N bond of the original amidinatosilylene. These remarkable allenyl products, which contain two stereogenic groups, are selectively formed as single diastereomers.     

Synthese von Nitrenkomplexen mit N-Trimethylsilylanilin. II. Charakterisierung und Kristallstruktur der Rhenium(V)-phenylnitren-Komplexe mer-[Re(NPh)Cl3(NH2Ph)(Ph3P)] und trans-[Re(NPh)(OMe)Cl2(Ph3P)2]

Synthesis of Phenylnitrene Complexes with N-Trimethylsilylaniline. II. Characterization and Crystal Structure of the Rhenium(V) Complexes mer-[Re(NPh)Cl₃(NH₂Ph)(Ph₃P)] and trans-[Re(NPh)(OMe)Cl₂(Ph₃P)₂] Reaction of [ReOCl₃(Ph₃P)₂] with N-trimethylsilylaniline yields mer-[Re(NPh)Cl₃(Ph₃P)₂], which reacts under air with excess of N-trimethylsilylaniline to form [Re(NPh)Cl₃ · (NH₂Ph)(Ph₃P)]. Crystallization from CH₂Cl₂/MeOH affords [Re(NPh)(OMe)Cl₂(Ph₃P)₂] as an additional product. [Re(NPh)Cl₃(NH₂Ph)(Ph₃P)] crystallizes in the monoclinic space group P2₁/n with a = 1 192.3(3); b = 1 918.9(3); c = 1 266.3(3) pm; β = 101.71(1)°; Z = 4. The rhenium atom has a distorted octahedral environment with the Cl atoms in meridional positions. The phenyl nitrene ligand is coordinated with an almost linear arrangement Re? N1? C40 = 166.8(6)° and with a bond distance Re?N = 170.5(6) pm. [Re(NPh)(OMe)Cl₂(Ph₃P)₂] · 1/2CH₂Cl₂ crystallizes in the triclinic space group P1 : a = 1 103.1(4); b = 1 227.9(4); c = 1 711.3(5) pm; α = 70.48(3)°; β = 72.71(3)°; γ = 80.03(3)°; Z = 2. The rhenium atom exhibits a distorted octahedral coordination with the Cl atoms and the phosphine ligands in trans positions. As a consequence of the competition of the nitrene ligand and the trans-coordinated methoxy group the Re?;N bond length is slightly lengthened to 173.2(7) pm, while the Re? O bond length of 193.4(6) pm is short. The bond angles Re? N? C70 and Re? O? C80 are 173.3(7)° and 139.1(7)°, respectively.     

Copper(I) Complexes of Anionic Tridentate CNC Pincer Ligands

New monoanionic CNC pincer ligands, [N{SiMe₂CH₂(RIm)}₂]^– (R = tBu, iPr, Ph) featuring three different N-heterocyclic carbenes and a disilylamido moiety is reported. Treatment of the lithium salt of [N{SiMe₂CH₂(RIm)}₂]^– with Cu^IOTf afforded the corresponding copper complexes [N{SiMe₂CH₂(RIm)}₂]Cu in 41–56 % yield. X-ray crystal structures of [N{SiMe₂CH₂(RIm)}₂]Cu show that they are monomeric and feature three-coordinate, pseudo T-shaped copper(I) sites. The X-ray crystal structure of one of the precursor lithium complexes, [N{SiMe₂CH₂(tBuIm)}₂]Li is also presented.     

Stabilisation of [Fe2(CO)9] and [Ru2(CO)9] bu substitution with bridging diphosphorus ligands

Reaction of [Fe₂(CO)₉] with a half molar amount of R₂PYPR₂ (Y = CH₂, R = Ph, Me, OMe or OPrⁱ; Y = N(Et), R = OPh, OMe or OCH₂; Y = N(Me), R = OPrⁱ or OEt) leads to the ready formation of a product which on irradiation with ultraviolet light rapidly decarbonylates to the heptacarbonyl derivative [Fe₂(μ-CO)(CO)₆{μ-R₂PYPR₂}]. Treatment of the latter with a slight excess of the appropriate ligand results, under photochemical conditions, in the formation of the dinuclear pentacarbonyl complex [Fe₂(μ-CO)(C))₄{μ-R₂PYPR₂}₂] but under thermal conditions in the formation of the mononuclear species [Fe(CO)₃{R₂PYPR₂}]. Reaction of [Ru₃(CO)₁₂] with an equimolar amount of (RO)₂PN(R′)P(OR)₂ (R′ = Me, R = Prⁱ or Et; R′ = Et, R = Ph or Me) under either thermal or photochemical conditions produces [Ru₃(CO)₁₀{μ-(RO)₂PN(OR)₂}] which reacts further with excess (RO)₂PN(R′)P(OR)₂ on irradiation with ultraviolet light to afford the dinuclear compound [Ru₂(μ-CO)(CO₄{μ-(RO)₂PN(R′)P(OR)₂}₂]. The molecular structure of [Ru₂(μ-CO)(CO)₄{μ-(MeO)₂PN(Et)P(OMe)₂}₂], which has been determined by X-ray crystallography, is described.     

Synthese und Molekülstruktur von [Al(SiMe3)3(DBU)] (DBU = 1,8-Diazabicyclo[5.4.0]undec-7-en)

Synthesis and Molecular Structure of [Al(SiMe₃)₃(DBU)] (DBU = 1,8-Diazabicyclo[5.4.0]undec-7-ene) [Al(SiMe₃)₃(OEt₂)] reacts with DBU (DBU = 1,8-diazabicyclo[5.4.0]undec-7-ene) at 0 °C yielding [Al(SiMe₃)₃ · (DBU)] ( 1 ). 1 was characterised spectroscopically (¹H, ¹³C, ²⁹Si, ²⁷Al NMR, IR, MS) and by X-ray structure determination [monoclinic, C2/c, a = 33.053(2), b = 9.307(1), c = 20.810(1) Å, β = 124.07(2)°, V = 5302.4(5) ų, Z = 8, 218(2) K]. 1 does not react with [Cp₂ZrCl₂] even in boiling toluene.     

Gemischtligandkomplexe des Rheniums. V. Die Bildung von Nitrenkomplexen durch Kondensation von Aceton an koordinierten Nitridoliganden. Darstellung und Strukturen von fac-[Re{NC(CH3)2CH2C(O)CH3}X3(Me2PhP)2]-Komplexen (X = Cl,Br)

Mixed-ligand Complexes of Rhenium. V. The Formation of Nitrene Complexes by Condensation of Acetone at Coordinated Nitrido Ligands. Syntheses and Structures of fac-[Re{NC(CH₃)₂CH₂C(O)CH₃}X₃(Me₂PhP)₂] Complexes (X = Cl, Br) The reaction of rhenium(V)-mixed-ligand complexes of the general formula [ReN(Cl)(Me₂PhP)₂(R₂tcb)] (HR₂tcb = N? (N,N-dialkylthiocarbamoyl)benzamidine) with HCl or HBr in acetone initializes a condensation of the solvent and results in nitrene-like compounds as a consequence of a nucleophilic attack of the coordinated nitrido ligand on the condensed acetone. The chelate ligands are removed during this reaction and complexes of the type fac-[Re{NC(CH₃)₂CH₂C(O)CH₃}X₃(Me₂PhP)₂] (X = Cl, Br) are formed. fac-[Re{NC(CH₃)₂CH₂C(O)CH₃}Cl₃(Me₂PhP)₂] crystallizes triclinic in the space group P1, a = 8.575(4); b = 9.088(3); c = 18.389(9) Å; α = 75.67(3)°, β = 85.30(3)°, γ = 70.58(4)°; Z = 2. A final R value of 0.031 was obtained on the basis of 6011 independent reflections with I ≥ 2σ(I). Rhenium is coordinated in a distorted octahedral environment with the three chloro ligands in facial positions. The rhenium-nitrogen bond (1,68(1) Å) is only slightly longer than typical Re? N bonding distances in nitrido complexes. fac-[Re{NC(CH₃)₂CH₂C(O)CH₃}Br₃(Me₂PhP)₂] is isomorphous with the chloro complex. Triclinic cell with a = 8.625(4); b = 9.198(3); c = 18.581(5) Å; α = 75.62(3)°, β = 85.40(3)°, γ = 70.91(3)°; Z = 2. The R value converged at 0.049 on the basis of 3644 independent reflections with I ≥ 2σ(I). fac-[Re{NC(CH₃)₂CH₂C(O)CH₃}Cl₃(Me₂PhP)₂] as well as fac-[Re{NC(CH₃)₂CH₂C(O)CH₃}Br₃(Me₂PhP)₂] crystallizes in the noncentrosymmetric space group P1.