Beiträge zur Chemie des Phosphors. 217 [1]. Hexaisopropyl-octadecaphosphan(6), P18i-Pr6—Darstellung und kernresonanzspektroskopische Strukturbestimmung

Contributions to the Chemistry of Phosphorus. 217. Hexaisopropyloctadecaphosphane(6), P₁₈i-Pr₆ – Preparation and Structure Determination by Nuclear Magnetic Resonance Hexaisopropyl-octadecaphosphane(6) ( 1 ) has been obtained by reaction of i-PrPCl₂ with P₄ and magnesium and subsequent thermolysis of the crude reaction product, and has been purely isolated as a yellow solid. According to NMR-spectroscopic investigations, 1 contains a new conjuncto-phosphate skeleton consisting of a P₁₁(5)- and a P₉(5)-structural element analogous to that of brexane, joined through a common P₂-bridge. Thus, 1 is 5,7,8,14,16,18-hexaisopropyl-heptacyclo[13.2.1.0^2,13.0^3,11.0^4,9.0^6,10.0^12,17]octadecaphosphane. Compound 1 is formed as a mixture of two configurational isomers 1a and 1b , which probably differ from each other by inversion of the configuration at the (PR)₂-bridge of the P₉(5) partial structure analogous to that of brexane.     

Beiträge zur Chemie des Phosphors. 223. Hexaisopropyl-icosaphosphan(6), P20i-Pr6 — Darstellung und kernresonanz-spektroskopische Strukturbestimmung von zwei Konstitutionsisomeren

Contributions to the Chemistry of Phosphorus. 223. Hexaisopropylicosaphosphane(6), P₂₀i? Pr₆ — Preparation and Structure Determination of Two Constitutional Isomers by Nuclear Magnetic Resonance Hexaisopropyl-icosaphosphane(6) has been obtained by reaction of i-PrPCl₂ with P₄ and magnesium and subsequent thermolysis of the crude reaction product. The compound is formed as a mixture of two constitutional isomers 1 and 2 of equal abundance, which have been almost purely isolated by HPLC as a mixture of the diastereomers 1 a , 1 b and in the form of the separate configurational isomers 2 a and 2 b , respectively. According to NMR-spectroscopic investigations, the new conjuncto-phosphane skeletons of 1 and 2 consist of a P₁₃(5)- and a P₉(5)-structural element analogous to that of brexane and of two P₁₁(5)-partial skeletons, respectively, joined in each case through a common P₂-bridge. Thus, 1 is 6,7,9,16,17,20-hexaisopropyloctacyclo[10.8.0.0^2,14.0^3,11.0^4,8.0^5,10.0^13,18.0^15,19]icosaphosphane and 2 is 7,9,15,17,19,20-hexaisopropyl-octacyclo[14.2.1.1^5,8.0^2,14.0^3,12.0^4,10.0^6,11.0^13,18]icosaphosphane. The phosphorus hydrogen compound P₂₀H₆ [22, 2c] should exhibit the same constitutional isomerism.     

Beiträge zur Chemie des Phosphors. 219 [1]. Tetraisopropyl-octadecaphosphan(4), P18i-Pr4 – Darstellung und kernresonanzspektroskopische Strukturbestimmung

Contributions to the Chemistry of Phosphorus. 219. Tetraisopropyloctadecaphosphane(4), P₁₈i-Pr₄ — Preparation and Structure Determination by Nuclear Magnetic Resonance Tetraisopropyloctadecaphosphane(4) ( 1 ) has been obtained by reaction of i-PrPCl₂ with P₄ and magnesium and subsequent thermolysis of the crude reaction product, and has been isolated in 95% purity. According to NMR-spectroscopic investigations, 1 contains a conjuncto-phosphane skeleton consisting of a P₁₁(5)- and a P₉(3)-structural element analogous to that of deltacyclane, joined through a common P₂-bridge. Thus, 1 is 8,14,16, 18-tetraisopropyloctacyclo[13.2.1.0^2,13.0^3,11.0^4,9.0^5,7.0^6,10.0^12,17]octadecaphosphane. Compound 1 is formed as a mixture of two configurational isomers 1 a and 1 b , which differ from each other in their spatial arrangements of the isopropyl group at P₈.     

Beiträge zur Chemie des Phosphors. 212. Tetraisopropyl-dodecaphosphan(4), P12i-Pr4 – Darstellung,Eigenschaften und Moleküldynamik

Contributions to the Chemistry of Phosphorus. 212. Tetraisopropyldodecaphosphane(4), P₁₂i-Pr₄ – Preparation, Properties, and Molecular Dynamics According to an earlier crystal structure analysis, tetraisopropyldodecaphosphane(4) ( 1 ) exhibits the symmetry C₂, and the substituents are arranged in all-trans position [3]. We have now found by NMR spectroscopic studies that in solution a second configurational isomer of the symmetry C_S ( 1b ) exists in addition to the molecule present in the crystal ( 1a ). The transformation of 1a into 1b , which can only occur through a quasi synchronous inversion at the atoms P³ and P⁴ or P⁹ and P¹⁰, takes place at a noticeable rate already below room temperature.     

Beiträge zur Chemie des Phosphors. 169. 31P-NMR-spektroskopischer Nachweis und Struktur von Hexaphosphan(6), P6H6

Contributions to the Chemistry of Phosphorus. 169. ³¹P-NMR Spectroscopic Detection and Structure of Hexaphosphane(6), P₆H₆ Phosphane mixtures containing 5–10 P-% of hexaphosphane(6), P₆H₆, are obtained by thermolysis of a mixture of chain-type phosphorus hydrides P_nH_n+2 (n = 2–7) at 25–35°C. According to the complete analysis of the ³¹P{¹H}-NMR spectrum on the basis of selective population transfer experiments, P₆H₆ has the constitution of 1-phosphino-cyclopentaphosphane. An indication of the constitutional isomer with a six-membered phosphorus-ring and all trans orientation of the hydrogen atoms and the free electron pairs, respectively, has not been found. From the δ(³¹P) data of the phosphanes with five-membered rings P_nH_n (n = 5, 6) a relationship for the chemical shifts of this class of compounds as a function of their structural parameters is derived.     

Beiträge zur Chemie des Phosphors. 222. Pentaisopropyl-tridecaphosphan(5), P13i-Pr5– Struktur in Lösung und im Kristall

Contributions to the Chemistry of Phosphorus. 222. Pentaisopropyltridecaphosphane(5), P₁₃iPr₅ – Structure in Solution and in the Crystal In an earlier investigation [3] pentaisopropyltridecaphosphane(5) ( 1 ) had been obtained by reacting i-PrPCl₂, P₄ and magnesium and subsequently thermolysing the crude reaction product, but had been structurally characterized only incompletely. We have now corroborated the earlier postulated constitution by NMR spectroscopic studies and an X-ray structural analysis. Thus 1 is 3,4,7,10,11-pentaisopropyl-pentacyclo[7.4.0.0^2,6.0^5,13.0^8,12]tridecaphosphane. In solution two configurational isomers 1 a and 1 b exist in the relative abundance of about 2 : 1, which have the symmetry C₁ and C_s, respectively. When crystallizing pure 1 b precipitates, which at room temperature in solution is retransformed into the isomeric mixture 1 a , 1 b by inversion of the configuration. Any indications of an additional symmetric diastereomer have not been found. Obviously, in isomer 1 b the inversion barrier of the atom P⁷ is markedly higher than for the atoms of the two-atom bridges P³? P⁴ and P¹⁰? P¹¹, respectively.     

Beiträge zur Chemie des Phosphors. 170. Konstitutions- und Konfigurationsisomere von Hexaphosphan(8), P6H8

Contributions to the Chemistry of Phosphorus. 170. Constitutional and Configurational Isomers of Hexaphosphane(8), P₆H₈ Phosphane mixtures containing 5–10 P-% of hexaphosphane(8), P₆H₈, are obtained by thermolysis of diphosphane, P₂H₄, or as residue from distillation of crude diphosphane [3]. By complete analysis of the ³¹P{¹H}-NMR spectrum on the basis of selective population transfer experiments, the following P₆H₈-isomers with a branched phosphorus skeleton have been identified and structurally characterized: the two diastereomers of 2-phosphinopentaphosphane ( 1a : erythro; 1b : threo), two of the three diastereomers of 3-phosphinopentaphosphane ( 2a : erythro, erythro; 2b : erythro, threo), and the highly symmetric 2,3-diphosphinotetraphosphane ( 3 ). The correlation between the diastereomers and the observed spin systems results from the preferred gauche orientation of neighboring free electron pairs, the dependence of ¹J(PP) on dihedral angles as well as the ³J(PP) and ⁴J(PP) long range couplings. Any indications of the diastereomers of n-P₆H₈ with an unbranched chain of phosphorus atoms have not been found.     

Beiträge zur Chemie des Phosphors. 227. HP4º als Komplexligand: Bildung und Eigenschaften von [(η5-C5H5)2ZrCl(P4H)], [(η5-C5Me5)2ZrCl(P4H)] und [(η5-C5H5)3Zr(P4H)]

Contributions to the Chemistry of Phosphorus. 227. HP₄º as a Complex Ligand: Formation and Properties of [(η⁵-C₅H₅)₂ZrCl(P₄H)], [(η⁵-C₅Me₅)₂ZrCl(P₄H)], and [(η⁵-C₅H₅)₃Zr(P₄H)] The novel complexes [(η⁵-C₅H₅)₂ZrCl(P₄H)] ( 1 ), [(η⁵-C₅Me₅)₂ZrCl(P₄H)] ( 2 ), and [(η⁵-C₅H₅)₃Zr(P₄H)] ( 3 ) have been obtained by reaction of a solution of (Na/K)HP₄ with the zirconocen derivatives [(η⁵-C₅H₅)₂ZrCl₂], [(η⁵-C₅Me₅)₂ZrCl₂], and [(η⁵-C₅H₅)₃(η¹-C₅ H₅)Zr] under suitable conditions. The structure of the compounds 1 – 3 , which are only stable in solution, has been elucidated by means of ³¹P-NMR spectroscopy. It is highly probable that the exo,endo isomer exists in each case. In addition, further isomers of lower relative abundancies have been observed, in which the ligands presumably exhibit a different spatial orientation relatively to each other.     

Beiträge zur Chemie des Phosphors. 168 [1]. Zur Kenntnis der Isomere von Tetraphosphan(6), P4H6

Contributions to the Chemistry of Phosphorus. 168. About the Isomers of Tetraphosphane(6), P₄H₆ Additional informations about the ³¹P-NMR parameters of d,l- and meso-n-P₄H₆ as well as of iso-P₄H₆ have been obtained by ³¹P-NMR spectroscopic investigations of mixtures of phosphanes containing 26—48 P-% of tetraphosphane(6). On the basis of the differences in the ³J(PP)-coupling constants the observed AA′BB′-spin systems have been reassigned to the various diastereomers of n-P₄H₆.     

Beiträge zur Chemie des Phosphors. 167 [1, 2]. Konstitutions- und Konfigurationsisomere von Pentaphosphan(7), P5H7

Contributions to the Chemistry of Phosphorus. 167. Constitutional and Configurational Isomers of Pentaphosphane(7), P₅H₇ Phosphane mixtures containing 10—15 P-% of pentaphosphane(7), P₅H₇, are obtained by thermolysis of diphosphane, P₂H₄, or as residue from distillation of crude diphosphane [3]. According to the complete analysis of the ³¹P{¹H}-NMR spectrum on the basis of selective population transfer experiments, P₅H₇ exists as a mixture of three diastereomers of n-P₅H₇ — 1a (erythro, erythro), 1b (erythro, threo), 1c (threo, threo) — and of the constitutional isomer 2-phosphinotetraphosphane 2 (iso-P₅H₇, largest relative isomeric abundance). The correlation between the diastereomers and the observed spin systems results from the preferred gauche orientation of neighboring free electron pairs, the dependence of ¹J(PP) on dihedral angles, and the ³J(PP) long range couplings. From the ³¹P-NMR data of the phosphane molecules P_nH_n+2 with n = 1—5 general relationships for the δ(³¹P) values and the ¹J(PP) coupling constants of chain-type phosphorus hydrides as a function of their structural parameters are derived.     

Beiträge zur Chemie des Phosphors. 200. Tetraisopropyl-tetradecaphosphan(4), P14(i-Pr)4 – Darstellung und strukturelle Charakterisierung

Contributions to the Chemistry of Phosphorus. 200. Tetraisopropyl-tetradecaphosphane(4), P₁₄(i-Pr)₄ – Preparation and Structural Characterization Tetraisopropyl-tetradecaphosphane(4) ( 1 ) has been obtained by reacting i-PrPCl₂, P₄, and magnesium and subsequently thermolysing the crude reaction product, and has been isolated in pure form. Whereas the ³¹P{¹H}-NMR spectrum provides only limited structural information, the ¹³C{¹H, ³¹P}-DEPT-NMR and the ¹H{³¹P}-NMR spectrum of 1 reveals the presence of two symmetrical configurational isomers 1a and 1c and one asymmetrical diastereomer 1b . This would only be possible, if 1 is 3,4,10,11-tetraisopropyl-hexacyclo[6.6.0.0^2,6.0^5,14.0^7,12.0^9,13]tetradecaphosphane. When crystallizing 1 pure 1a precipitates, which at +10°C in solution is retransformed into the isomeric mixture 1a , 1b , 1c by inversion of the configuration.     

Beiträge zur Strukturchemie phosphorhaltiger Ketten und Ringe. 16. Die Molekül- und Kristallstruktur des Triisopropyl-undecaphosphans P11(i-Pr)3

Structural Chemistry of Phosphorus Containing Chains and Rings. 16. Molecular and Crystal Structure of the Triisopropylundecaphosphane P₁₁(i-Pr)₃ The compound 4,7,11-triisopropyl-pentacyclo[6.3.0.0^2.6.0^3.10.0^5.9]undecaphosphane, C₉H₂₁P₁₁, crystallizes triclinically in the space group P1 with a = 1 045.3 pm, b = 1 057.2 pm, c = 1 075,0 pm, α = 101.00°, β = 98.89°, γ = 112.27° and Z = 2. The main structural feature is a phosphorus skeleton with approximate symmetry D₃ composed of six five-membered rings which are asymmetrically substituted by the isopropyl groups. The (average) bond lengths are d(P? P) = 221.6 pm, d(P? C) = 187.5 pm, d(C? C) = 151.4 pm, d(C? H) = 108 pm with 217.6 ≤ d(P? P) ≤ 226.4 pm. The geometry of the substituents is quite normal.     

Beiträge zur Chemie des Phosphors. 171. 31P-NMR-spektroskopischer Nachweis von Heptaphosphan(9), P7H9: erythro- und threo-2,3-Diphosphino-pentaphosphan

Contributions to the Chemistry of Phosphorus. 171. ³¹P-N.M.R. Spectroscopic Detection of Heptaphosphane(9), P₇H₉: erythro- and threo-2,3-Diphosphinopentaphosphane Small amounts of heptaphosphane(9), P₇H₉, could be detected ³¹P-NMR spectroscopically in mixtures of higher phosphanes P_nH_n+2 which are obtained as residue from distillation of crude diphosphane [2] or by thermolysis of P₂H₄. According to the results of a spectrum analysis on the basis of selective population transfer experiments, the heptaphosphane(9) in question is one of the possible constitutional isomers with maximum branching, namely 2,3-diphosphinopentaphosphane ( 4 ), which is present in the erythro and threo from 4a and 4b , respectively. The correlation between the diastereomers and the observed spin systems results from the determination of the corresponding molecular conformation by means of significant ¹J(PP) and ³J(PP) coupling constants. 4 is the first structurally characterized compound with seven chain-like connected phosphorus atoms.     

Beiträge zur Chemie des Phosphors. 179. Triisopropyl-undecaphosphan(3), P11(i-Pr)3 – Darstellung,Eigenschaften und Moleküldynamik

Contributions to the Chemistry of Phosphorus. 179. Triisopropyl-undecaphosphane(3), P₁₁(i-Pr)₃ – Preparation, Properties, and Molecular Dynamics Triisopropyl-undecaphosphane(3) ( 1 ) has been obtained by reacting i-PrPCl₂, P₄, and magnesium and subsequently thermolysing the crude reaction product, and has been isolated in pure form. According to a two dimensional ³¹{¹H} n.m.r. spectrum 1 is a 4, 7, 11-triisopropylpentacyclo[6.3.0.0^2,6.0^3,10. 0^5,9]undecaphosphane. Compound 1 is formed as a mixture of two configurational isomers 1a and 1b , which differ from each other in the orientation of the isopropyl groups. When crystallizing pure 1b precipitates, which in solution is retransformed into the isomeric mixture 1a , 1b by inversion of the configuration.     

Beiträge zur Chemie des Phosphors. 117. Synthese und Eigenschaften der Hexaorganyl-octaphosphane(6) P8R6, R = Me,Et, Pri

Contributions to the Chemistry of Phosphorus. 117. Synthesis and Properties of the Hexaorganyl-octaphosphanes(6) P₈R₆, R = Me, Et, Prⁱ The Hexaorganyl-octaphosphanes(6) P₈Me₆ ( 1 ), P₈Et₆ ( 2 ), and P₈Pr ( 3 ) have been obtained by reacting mixtures of the corresponding organyldichlorophosphanes and phosphorus(III) chloride with magnesium. In the case of 1 and 2 the organyl-cyclophosphanes (PR)_n can also be used in the reaction with phosphorus(III) chloride and magnesium. Besides, mainly P₇R₅ as well as other polycyclic organylphosphanes are formed. 2 and 3 have been isolated as pure substances, whereas 1 was concentrated to ?50 mol-% in the product mixture. According to their ³¹P-NMR spectra the three compounds possess a pentalane-analogous P₈-skeleton with the substituents within each five-membered ring in trans position and the substituents of different five-membered rings next to the zero bridge in cis position; the organyl groups in the 3, 7 position are trans oriented with respect to the free electron pairs of the bridgehead atoms. Therefore, the structures of 1 – 3 differ from the known tert-butyl compound P₈Bu, whereas the corresponding phosphorus hydride P₈H₆ has the same pentalane-analogous P₈-skeleton, thus being a bicyclo[3.3.0]octaphosphane.     

Beiträge zur Chemie des Phosphors. 221 [1]. Stannylsubstituierte Bicyclo [1.1.0]tetraphosphane: Bildung und Eigenschaften von R3Sn(H)P4 (R  CH3, C6H5, c-C6H11, o-C7H7)

Contributions to the Chemistry of Phosphorus. 221. Stannyl-Substituted Bicyclo[1.1.0]tetraphosphanes: Formation and properties of R₃Sn(H)P₄ (R ? CH₃, C₆H₅, c-C₆H₁₁, o-C₇H₇) The unsymmetrically substituted bicyclo[1.1.0]tetraphosphanes Me₃Sn(H)P₄ ( 1 ), Ph₃Sn(H)P₄ ( 2 ), (c-Hex)₃Sn(H)P₄ ( 3 ) and (o-Tol)₃Sn(H)P₄ ( 4 ) have been obtained by reaction of a solution of (Na/K) HP₄ with R₃ SnCl (R ? Me, Ph, c-Hex, o-Tol) under proper conditions. The structure of the compounds 1 – 4 , which are only stable in solution, has been elucidated by means of ³¹P-NMR-spectroscopy. Whereas 3 exists at ?60°C as the exo,endo isomer, 1, 2 and 4 are fluctuating molecules at room temperature and probably invert between the three possible configurational isomers (exo,exo-, exo,endo- and endo,endo-form).     

Ein neues Oxophosphat (IV/III)-Anion – Darstellung und Kristallstruktur von Na6P4O10 · 2 H2O

A New Oxophosphate (IV/III) Anion – Preparation and Crystal Structure of Na₆P₄O₁₀ · 2 H₂O A new oxophosphate anion, P₄O₁₀^6?, was obtained by cleavage and simultaneous oxidation of the cyclo-hexaphosphate(III) anion in a solution of aqueous ammonia and ethanol. With sodium it forms a salt with the composition Na₆P₄O₁₀ · 2 H₂O. The crystal structure has been determined by single crystal X-ray diffraction (3 745 diffractometer data), the cell constants were obtained from X-ray powder data, space group P1 ; a = 6.004(1), b = 6.173(2), c = 11.496(2) Å, α = 99.26(2)°, β = 95.92(2)°, γ = 117.63(2)°, Z = 1, R = 0.044. The backbone of the anion is formed by phosphorus atoms directly bonded to each other. The coordination of each phosphorus atom is completed to four by oxygene. The resulting oxidation numbers are +III for the inner phosphorus atoms and +IV for the terminal phosphorus atoms. The site symmetry of the anion is approximately C_2h. Based on a ³¹P-NMR spectra of a solution the coupling constants of the AA ‘BB’ system were determined.     

Beiträge zur Chemie des Phosphors. 226. 2,3,4,6-Tetra-tert-butyl-2,4-dioxobicyclo[3.1.0]hexaphosphan,P6BuO2

Contributions to the Chemistry of Phosphorus. 226. 2,3,4,6-Tetra-tert-butyl-2,4-dioxobicyclo[3.1.0]hexaphosphane, P₆Bu O₂ Under suitable conditions, the reaction of tetra-tert-butylhexaphosphane, P₆Bu ( 1 ), with cumene hydroperoxide gives rise to the corresponding dioxide P₆BuO₂ ( 3 ) which could be isolated as the adduct P₆BuO₂ · 0.7 C₉H₁₂O₂. According to a complete analysis of the ³¹P{¹H}-NMR spectrum compound 3 is 2,3,4,6-tetra-tert-butyl-2,4-dioxobicyclo[3.1.0]hexaphosphane, in which the oxygen atoms are bonded exocyclically to the five-membered phosphorus ring of 1 . When the oxidation reaction proceeds a fission of the bicyclic P₆ skeleton takes place.     

Synthese und dynamisches Verhalten von [Rh2(μ-H)3H2(PiPr3)4]+. Beiträge zur Reaktivität des Tetrahydridodirhodium-Komplexes [Rh2H4(PiPr3)4]

Synthesis and Dynamic Behaviour of [Rh₂(μ-H)₃H₂(PiPr₃)₄]⁺. Contributions to the Reactivity of the Tetrahydridodirhodium Complex [Rh₂H₄(PiPr₃)₄] An improved synthesis of [Rh₂H₄(PiPr₃)₄] ( 2 ) from [Rh(η³-C₃H₅)(PiPr₃)₂] ( 1 ) or [Rh(η³-CH₂C₆H₅)(PiPr₃)₂] ( 3 ) and H₂ is described. Compound 2 reacts with CO or CH₃OH to give trans-[RhH(CO)(PiPr₃)₂] ( 4 ) and with ethene/acetone to yield a mixture of 4 and trans-[RhCH₃(CO)(PiPr₃)₂] ( 5 ). The carbonyl(methyl) complex 5 has also been prepared from trans-[RhCl(CO)(PiPr₃)₂] ( 6 ) and CH₃MgI. Whereas the reaction of 2 with two parts of CF₃CO₂H leads to [RhH₂(η²-O₂CCF₃) · (PiPr₃)₂] ( 8 ), treatment of 2 with one equivalent of CF₃CO₂H in presence of NH₄PF₆ gives the dinuclear compound [Rh₂H₅(PiPr₃)₄]PF₆ ( 9a ). The reactions of 2 with HBF₄ and [NO]BF₄ afford the complexes [Rh₂H₅(PiPr₃)₄]BF₄ ( 9b ) and trans-[RhF(NO)(PiPr₃)₂]BF₄ ( 11 ), respectively. In solution, the cation [Rh₂(μ-H)₃H₂(PiPr₃)₄]⁺ of the compounds 9a and 9b undergoes an intramolecular rearrangement in which the bridging hydrido and the phosphane ligands are involved.     

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.