Amidometallate von Seltenerdelementen. Synthese und Kristallstrukturen von [Na(12-Krone-4)2][M{N(SiMe3)2}3(OSiMe3)] (M = Sm,Yb), [Na(THF)3Sm{N(SiMe3)2}3(C≡C–Ph)], [Na(THF)6][Lu2(μ-NH2)(μ-NSiMe3){N(SiMe3)2}4] sowie von [NaN(SiMe3)2(THF)]2. Anwendungen der Seltenerdkomplexe als Polymerisationskatalysatoren

Amido Metalates of Rare Earth Elements. Syntheses and Crystal Structures of [Na(12-crown-4)₂][M{N(SiMe₃)₂}₃(OSiMe₃)] (M = Sm, Yb), [Na(THF)₃Sm{N(SiMe₃)₂}₃(C≡C–Ph)], [Na(THF)₆][Lu₂(μ-NH₂)(μ-NSiMe₃){N(SiMe₃)₂}₄], and of [NaN(SiMe₃)₂(THF)]₂. Applications of Rare Earth Metal Complexes as Polymerization Catalysts The amido silyloxy complexes [Na(12-crown-4)₂][M{N(SiMe₃)₂}₃(OSiMe₃)] with M = Sm ( 1 a ), Eu ( 1 b ), Yb ( 1 c ), and Lu ( 1 d ) were obtained from the trisamides M[N(SiMe₃)₃]₃ and NaOSiMe₃ in n-hexane in the presence of 12-crown-4; they form yellow to orange-red crystals, of which 1 a and 1 c were characterized crystallographically. The complexes crystallize isotypically with one another in the monoclinic space group I2/a with eight formula units per unit cell. The metal atoms of the complex anions are tetrahedrally coordinated by the three nitrogen atoms of the N(SiMe₃)₂^– ligands and by the oxygen atom of the OSiMe₃^– ligand. With 172.4° for 1 a and 179.3° for 1 c the bond angles M–O–Si are practically linear. With ethynylbenzene in the presence of NaN(SiMe₃)₂ in tetrahydrofuran the trisamides M[N(SiMe₃)₂]₃ react under formation of the complexes [Na(THF)₃M{N(SiMe₃)₂}₃ · (C≡C–Ph)] with M = Ce ( 2 a ), Sm ( 2 b ), and Eu ( 2 c ), of which 2 b was characterized crystallographically (monoclinic, space group P2₁/n, Z = 4). 2 b forms an ion pair in which the terminal carbon atom of the C≡C–Ph^– ligand is connected with the samarium atom of the Sm[N(SiMe₃)₂]₃ group and the sodium ion is side-on connected with the acetylido group. According to the crystal structure determination (space group P2₁2₁2₁, Z = 4) [Na(THF)₆][Lu₂(μ-NH₂)(μ-NSiMe₃) · {N(SiMe₃)₂}₄] ( 3 ), which is formed as a by-product, consists of [Na(THF)₆]⁺ ions and dimeric anions, in which the lutetium atoms are connected to form a planar Lu₂N₂ four-membered ring via a μ-NH₂ bridge with average Lu–N distances of 227.2 pm and via a μ-NSiMe₃ bridge of average Lu–N distances of 218.5 pm. According to the crystal structure determination (space group P 1, Z = 1) [NaN(SiMe₃)₂(THF)]₂ ( 4 ) forms centrosymmetric dimeric molecules with Na–N distances of the Na₂N₂ four-membered ring of 239.9 pm and distances Na–O of the terminally bonded THF molecules which are 226.7 pm. The vinylic polymerization of methylmethacrylate (MMA) catalyzed by 1 c resulted in high molecular weight polymethylmethacrylate (PMMA) with moderate yields. The reaction of 1 a or 2 b with MMA did not give PMMA. Insoluble polynorbornene was obtained in low yields by reaction of norbornene/methylaluminoxane (MAO) with 1 a , 1 c , or 2 b . The ring opening polymerization of ϵ-caprolacton or δ-valerolacton catalyzed by 2 b resulted in corresponding polylactones in quantitative yields.     

Kristallstrukturen der Samarium-Amido-Komplexe [Sm(l-X){N(SiMe3)2}2(THF)]2 mit X = Cl,Br

Crystal Structures of the Samarium Amido Complexes [Sm(l-X){N(SiMe₃)₂}₂(THF)]₂ with X = Cl, Br The crystal structures of the title compounds have been determined by X-ray methods. [Sm(μ-Cl) · {N(SiMe₃)₂}₂(THF)]₂ ( 1 ): Space group P2₁/n, Z = 2, lattice dimensions at 223 K: a = 1429.5(2), b = 1302.3(3), c = 1658.6(3) pm, β = 114.212(10)°, R = 0.0561. [Sm(μ-Br) · {N(SiMe₃)₂}₂(THF)]₂ ( 2 ): Space group Pbca, Z = 4, lattice dimensions at 223 K: a = 1850.0(7), b = 1611.0(9), c = 1888.1(6) pm, R = 0.0497. 1 and 2 form centrosymmetric dimeric complexes via μ-X-halogeno bridges. The samarium atoms are coordinated in a distorted trigonal-bipyramidal surrounding, the THF molecule and one of the bridging halogen atoms being in axial positions.     

Synthesis and Structural Characterization of Several Ytterbium Bis(trimethylsilyl)amides Including Base‐free [Yb{N(SiMe3)2}2(μ‐Cl)]2 — A Coordinatively Unsaturated Complex with Additional Agostic Yb···(H3C—Si) Interactions

The reaction of YbCl₃ with two equivalents of NaN‐(SiMe₃)₂ has afforded a mixture of several ytterbium bis(trimethylsilyl) amides with the known complexes [Yb{N(SiMe₃)₂}2(μ‐Cl)(thf)]₂ ( 1 ) and [Yb{N(SiMe₃)₂}₃]( 4 ) as the main products and the cluster compound [Yb₃Cl₄O{N(SiMe₃)₂}₃(thf)₃]( 2 ) as a minor product. Treatment of 1 and 2 with hot n‐heptane gave the basefree complex [Yb{N(SiMe₃)₂}₂(μ‐Cl)]₂ ( 3 ) in small yield. The structures of compounds 1—4 and the related peroxo complex [Yb₂{N(SiMe₃)₂}₄(μ‐O₂)(thf)₂]( 5 ) have been investigated by single crystal X‐ray diffraction. In the solid‐state, 3 shows chlorobridged dimers with terminal amido ligands (av. Yb—Cl = 262.3 pm, av. Yb—N = 214.4 pm). Additional agostic interactions are observed from the ytterbium atoms to four methyl carbon atoms of the bis(trimethylsilyl)amido groups (Yb···C = 284—320 pm). DFT calculations have been performed on suitable model systems ([Yb₂(NH₂)₄(μ‐Cl)₂(OMe₂)₂]( 1m ), [Yb₂(NH₂)₄(μ‐Cl)₂]( 3m ), [Yb‐(NH₂)₃]( 4m ), [Yb₂(NH2₄(μ‐O₂)(OMe₂)₂]( 5m ), [Yb{N‐(SiMe₃)₂}₂Cl] ( 3m/2 ) and Ln(NH₂)₂NHSiMe₃ (Ln = Yb ( 6m ), Y ( 7m )) in order to rationalize the different experimentally observed Yb—N distances, to support the assignment of the O—O stretching vibration (775 cm ^‐1) in the Raman spectrum of complex 5 and to examine the nature of the agostic‐type interactions in σ‐donorfree 3 .     

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.     

[Cs(Toluol)3(FIn{N(SiMe3)2}3)], ein Fluoroindat mit gestreckter Cs–F–In-Achse

[Cs(toluene)₃(FIn{N(SiMe₃)₂}₃)], a Fluoroindate with Rectified Cs–F–In Axis The metalate [Cs(FIn{N(SiMe₃)₂}₃)] has been prepared by the reaction of In[N(SiMe₃)₂]₃ with CsF in THF: The title compound 1 can be obtained by recrystallization from toluene as colorless airsensitive needles. 1 has been characterized by NMR-, IR-, and MS-techniques as well as by an X-ray structure determination. The result of the structure analysis shows an prolated molecule with an almost linear Cs–F–In axis [174.7(1)°]. The Cs⁺ center is surrounded by the indate ion and three toluene molecules in a distorted tetrahedral fashion.     

Hydride Reactivity of NiII?X?NiII Entities: Mixed‐Valent Hydrido Complexes and Reversible Metal Reduction

After the lithiation of PYR‐H₂ (PYR^2?=[{NC(Me)C(H)C(Me)NC₆H₃(iPr)₂}₂(C₅H₃N)]^2?), which is the precursor of an expanded β‐diketiminato ligand system with two binding pockets, its reaction with [NiBr₂(dme)] led to a dinuclear nickel(II)–bromide complex, [(PYR)Ni(μ‐Br)NiBr] ( 1 ). The bridging bromide ligand could be selectively exchanged for a thiolate ligand to yield [(PYR)Ni(μ‐SEt)NiBr] ( 3 ). In an attempt to introduce hydride ligands, both compounds were treated with KHBEt₃. This treatment afforded [(PYR)Ni(μ‐H)Ni] ( 2 ), which is a mixed valent Ni^I? μ‐H? Ni^II complex, and [(PYR‐H)Ni(μ‐SEt)Ni] ( 4 ), in which two tricoordinated Ni^I moieties are strongly antiferromagnetically coupled. Compound 4 is the product of an initial salt metathesis, followed by an intramolecular redox process that separates the original hydride ligand into two electrons, which reduce the metal centres, and a proton, which is trapped by one of the binding pockets, thereby converting it into an olefin ligand on one of the Ni^I centres. The addition of a mild acid to complex 4 leads to the elimination of H₂ and the formation of a Ni^IINi^II compound, [(PYR)Ni(μ‐SEt)NiOTf] ( 5 ), so that the original Ni^II(μ‐SEt)Ni^IIX core of compound 3 is restored. All of these compounds were fully characterized, including by X‐ray diffraction, and their molecular structures, as well as their formation processes, are discussed.     

Highly Fluorinated Tris(indazolyl)borate Silylamido Complexes of the Heavier Alkaline Earth Metals: Synthesis,Characterization, and Efficient Catalytic Intramolecular Hydroamination

Heteroleptic silylamido complexes of the heavier alkaline earth elements calcium and strontium containing the highly fluorinated 3‐phenyl hydrotris(indazolyl)borate {F₁₂‐Tp^{4Bo, 3Ph}}^? ligand have been synthesized by using salt metathesis reactions. The homoleptic precursors [Ae{N(SiMe₃)₂}₂] (Ae=Ca, Sr) were treated with [Tl(F₁₂‐Tp^{4Bo, 3Ph})] in pentane to form the corresponding heteroleptic complexes [(F₁₂‐Tp^{4Bo, 3Ph})Ae{N(SiMe₃)₂}] (Ae=Ca ( 1 ); Sr ( 3 )). Compounds 1 and 3 are inert towards intermolecular redistribution. The molecular structures of 1 and 3 have been determined by using X‐ray diffraction. Compound 3 exhibits a Sr ??? MeSi agostic distortion. The synthesis of the homoleptic THF‐free compound [Ca{N(SiMe₂H)₂}₂] ( 4 ) by transamination reaction between [Ca{N(SiMe₃)₂}₂] and HN(SiMe₂H)₂ is also reported. This precursor constitutes a convenient starting material for the subsequent preparation of the THF‐free complex [(F₁₂‐Tp^{4Bo, 3Ph})Ca{N(SiMe₂H)₂}] ( 5 ). Compound 5 is stabilized in the solid state by a Ca???β‐Si?H agostic interaction. Complexes 1 and 3 have been used as precatalysts for the intramolecular hydroamination of 2,2‐dimethylpent‐4‐en‐1‐amine. Compound 1 is highly active, converting completely 200 equivalents of aminoalkene in 16 min with 0.50 mol % catalyst loading at 25 °C.     

[Yb3OBr4{N(SiMe3)2}3 (THF)3], ein Amido-Komplex des Ytterbiums mit clusterähnlichem Aufbau

[Yb₃OBr₄{N(SiMe₃)₂}₃(THF)₃], an Amido Complex of Ytterbium with a Clusterlike Structure The title compound has been prepared from YbBr₃ and NaN(SiMe₃)₂ in THF suspension, forming yellow single crystals from hexane solutions which were characterized by a crystal structure determination. Space group P1 , Z = 2, lattice dimensions at ?100°C: a = 1085.4(1), b = 1410.2(1), c = 1912.0(1) pm; α = 78.62(1)°, β = 80.61(1)°, γ = 73.45(1)°, R = 0.025. In the molecular structure of [Yb₃OBr₄{N(SiMe₃)₂}₃(THF)₃] the three ytterbium atoms together with the μ₃-oxygen atom and a μ₃-bromine atom form a distorted trigonal bipyramid. In addition, three μ₂-Br atoms coordinate the Yb atoms in the equatorial plane, whereas the THF molecules and the N(SiMe₃)₂^? ligands are terminally coordinated, thus forming a distorted octahedrally surrounding of the Yb atoms.     

Yttrium bis(alkyl) and bis(amido) complexes bearing N,O multidentate ligands. Synthesis and catalytic activity towards ring‐opening polymerization of L‐lactide

Methoxy‐modified β‐diimines HL ¹ and HL ² reacted with Y(CH₂SiMe₃)₃(THF)₂ to afford the corresponding bis(alkyl)s [L¹Y(CH₂SiMe₃)₂] ( 1 ) and [L²Y(CH₂SiMe₃)₂] ( 2 ), respectively. Amination of 1 with 2,6‐diisopropyl aniline gave the bis(amido) counterpart [L¹Y{N(H)(2,6‐iPr₂? C₆H₃)}₂] ( 3 ), selectively. Treatment of Y(CH₂SiMe₃)₃(THF)₂ with methoxy‐modified anilido imine HL ³ yielded bis(alkyl) complex [L³Y(CH₂SiMe₃)₂(THF)] ( 4 ) that sequentially reacted with 2,6‐diisopropyl aniline to give the bis(amido) analogue [L³Y{N(H)(2,6‐iPr₂? C₆H₃)}₂] ( 5 ). Complex 2 was “base‐free” monomer, in which the tetradentate β‐diiminato ligand was meridional with the two alkyl species locating above and below it, generating tetragonal bipyramidal core about the metal center. Complex 3 was asymmetric monomer containing trigonal bipyramidal core with trans‐arrangement of the amido ligands. In contrast, the two cis‐located alkyl species in complex 4 were endo and exo towards the O,N,N tridentate anilido‐imido moiety. The bis(amido) complex 5 was confirmed to be structural analogue to 4 albeit without THF coordination. All these yttrium complexes are highly active initiators for the ring‐opening polymerization of L ‐LA at room temperature. The catalytic activity of the complexes and their “single‐site” or “double‐site” behavior depend on the ligand framework and the geometry of the alkyl (amido) species in the corresponding complexes. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5662–5672, 2007     

Dinuclear Dysprosium and Ytterbium Complexes Incorporating N,N‐Bis(pyrrolyl‐α‐methyl)‐N‐methylamine Ligand: Syntheses and Structures

Reaction of DyCl₃ with two equivalents of NaN(SiMe₃)₂ in THF yielded {Dy(μ‐Cl)[N(SiMe₃)₂]₂(THF)}₂ ( 1 ). X‐ray crystal structure analysis revealed that 1 is a centrosymmetric dimer with asymmetrically bridging chloride ligands. The metal coordination arrangement can be best described as distorted trigonal bipyramid. The bond lengths of Ln–Cl and Ln–N showed a decreasing trend with the contraction of the size of Ln³⁺. Treatment of N,N‐bis(pyrrolyl‐α‐methyl)‐N‐methylamine (H₂dpma) with 1 and known compound {Yb(μ‐Cl)[N(SiMe₃)₂]₂(THF)}₂, respectively, led to the formations of [Dy(μ‐Cl)(dpma)(THF)₂]₂ ( 2 ) and {Yb(μ‐Cl)[N(SiMe₃)₂]₂(THF)}₂ ( 3 ). Compounds 2 and 3 were fully characterized by single‐crystal X‐ray crystallography, elemental analysis, and ¹H NMR spectroscopy. Structure determination indicated that 2 and 3 exhibit as centrosymmetric dimers with asymmetrically bridging chloride ligands. One pot reactions involving LnCl₃ (Ln = Dy and Yb), LiN(SiMe₃)₂, and H₂dpma were explored and desired products 2 and 3 were not yielded, which indicated that 1 and {Yb(μ‐Cl)[N(SiMe₃)₂]₂(THF)}₂ are the demanding precursors to synthesize Dysprosium and Ytterbium complexes supported by dpma^2– ligand. Compounds 2 and 3 are the first reported lanthanide complexes chelated by dpma^2– ligand.     

Untersuchungen zu Reaktionen des Diphosphanylsilans iPr2Si(PH2)2 mit Erdalkalimetallsilazaniden

The reaction of iPr₂Si(PH₂)₂ ( 1 ) with [Ca{N(SiMe₃)₂}₂(THF)₂] at 25 °C in molar ratio 1:1 yields the compound [Ca₃{iPr₂Si(PH)₂}₃(THF)₆] ( 2 ). Compound 2 consists of two Ca₂P₃ trigonal bipyramids with one conjoint calcium corner and SiiPr₂ bridged phosphorus atoms. In contrast, the same reaction at 60 °C yield the complex [Ca({P(SiiPr₂)₂PH}₂(THF)₄] ( 3 ). The isotype strontium compound [Sr({P(SiiPr₂)₂PH}₂(THF)₄] ( 4 ) was obtained from the reaction of iPr₂Si(PH₂)₂ with [Sr{N(SiMe₃)₂}₂(DME)₂]. The Compounds 2 – 4 were characterised by single crystal X‐ray diffraction, elemental analysis as well as IR and NMR spectroscopic techniques.     

Dispersion‐Force‐Assisted Disproportionation: A Stable Two‐Coordinate Copper(II) Complex

The synthesis of the first linear coordinated Cu^II complex Cu{N(SiMe₃)Dipp}₂ ( 1 Dipp=C₆H₅‐2,6Prⁱ₂) and its Cu^I counterpart [Cu{N(SiMe₃)Dipp}₂]^? ( 2 ) is described. The formation of 1 proceeds through a dispersion force‐driven disproportionation, and is the reaction product of a Cu^I halide and LiN(SiMe₃)Dipp in a non‐donor solvent. The synthesis of 2 is accomplished by preventing the disproportionation into 1 by using the complexing agent 15‐crown‐5. EPR spectroscopy of 1 provides the first detailed study of a two‐coordinate transition‐metal complex indicating strong covalency in the Cu?N bonds.     

Synthese und Insertionsreaktionen von Cp2′HfCl{As(SiMe3)2} (Cp′ = C5H4Me)

Synthesis and Insertion Reactions of Cp₂′HfCl{As(SiMe₃)₂} (Cp′ = C₅H₄Me) The reaction of Cp₂′HfCl₂ (Cp′ = C₅H₄Me) with Li(THF)_2,5As(SiMe₃)₂ (1 : 1) at room temperature gives the terminal hafnocene arsenido complex Cp₂′HfCl{As(SiMe₃)₂} ( 1 ) in high yield. 1 inserts CS₂ and PhNC into the Hf? As bond yielding Cp₂′HfCl{η²-S₂CAs(SiMe₃)₂} ( 2 ) and Cp₂′HfCl{η²-N(Ph)CAs(SiMe₃)₂} ( 3 ). The thermally sensitive complexes 1–3 were characterised spectroscopically and crystal structure determinations were carried out on 1 and 3 which shows the η² bonding mode of the N(Ph)CAs(SiMe₃)₂ ligand in the latter.     

Ring‐to‐Cage Structural Conversion via Template Effect in a Gold(I) Metallosupramolecular System

A unique example of a ring‐to‐cage structural conversion in a multinuclear gold(I) coordination system with d ‐penicillamine (d ‐H₂pen) is reported. The reaction of [Au₂Cl₂(dppe)] (dppe=1,2‐bis(diphenylphosphino)ethane) with d ‐H₂pen in a 1:1 ratio gave [Au₄(dppe)₂(d ‐pen)₂] ([ 1 ]), in which two [Au₂(dppe)]²⁺ units are linked by two d ‐pen S atoms in a cyclic form so as to have two bidentate‐N,O coordination arms. The subsequent reaction of [ 1 ] with Cu(OTf)₂ afforded [Au₄Cu(dppe)₂(d ‐pen)₂]²⁺ ([ 2 ]²⁺), in which a Cu^II ion is chelated by the two coordination arms in [ 1 ] to form an Au^I₄Cu^II bicyclic metallocage. A similar reaction using Cu(NO₃)₂ was accompanied by the ring expansion of [ 1 ] to [Au₈(dppe)₄(d ‐pen)₄], leading to the production of [Au₈Cu₂(dppe)₄(d ‐pen)₄]⁴⁺ ([ 3 ]⁴⁺). In [ 3 ]⁴⁺, two Cu^II ions are each chelated by the two coordination arms to form an Au^I₈Cu^II₂ tricyclic metallocage, accommodating a nitrate ion. The use of Ni(NO₃)₂ or Ni(OAc)₂ instead of Cu(NO₃)₂ commonly gave a tricyclic metallocage of [Au₈Ni₂(dppe)₄(d ‐pen)₄]⁴⁺ ([ 4 ]⁴⁺), but a water molecule was accommodated inside the Au^I₈Ni^II₂ metallocage.     

Amido-Komplexe von Mangan(II). Synthese und Kristallstrukturen von [Mn(NPh2)2(THF)]2 und Na2[Mn(NPh2)4] · 2 C7H8

Amido Complexes of Manganese(II). Syntheses and Crystal Structures of [Mn(NPh₂)₂(THF)]₂ and Na₂[Mn(NPh₂)₄] · 2 C₇H₈ The silylated amido complex [Mn{N(SiMe₃)₂}₂ · (THF)] reacts in toluene solution with diphenylamine under ligand exchange to form the diphenylamido complex [Mn(NPh₂)₂(THF)]₂ ( 1 ), which forms orange-red columnar crystals. 1 reacts in THF solution with NaN(SiMe₃)₂ and after crystallization from toluene yellow-orange Na₂[Mn(NPh₂)₄] · 2 C₇H₈ ( 2 ) is obtained. According to the crystal structure analyses the manganese atoms in 1 (space group P2₁/c, Z = 2) are linked via the N atoms of two of the NPh₂^– groups to form centrosymmetric Mn₂N₂ four-membered rings with Mn–N bonds of almost the same length. 2 (space group I4₁/a, Z = 4) forms a three-dimensional space-lattice structure, which arises from ”︁inner solvation”︁”︁ of the sodium atoms with the phenyl rings of the NPh₂^– group.     

[(THF)2Na(Ph2N)2Sm{N(SiMe3)2}2], ein Amido-Komplex des Samariums mit sandwichartig koordiniertem Natriumion

[(THF)₂Na(Ph₂N)₂Sm{N(SiMe₃)₂}₂], an Amido Complex of Samarium with a Sandwich-like Coordinated Sodium Ion The title compound has been prepared from Sm[N(SiMe₃)₂]₃, NaN(SiMe₃)₃, and HNPh₂ in THF solution forming yellow-green single crystals, which were characterized by a crystal structure determination. The complex forms an ion pair in which the sodium ion is coordinated by two THF molecules and by two phenyl groups of the diphenylamido groups in a sandwich-like fashion. The samarium atom is tetrahedrally coordinated by the four nitrogen atoms of the NPh₂^– and the N(SiMe₃)₂^– ligands.     

Two‐Coordinate Iron(I) Complex [Fe{N(SiMe3)2}2]−: Synthesis,Properties, and Redox Activity

First‐row two‐coordinate complexes are attracting much interest. Herein, we report the high‐yield isolation of the linear two‐coordinate iron(I) complex salt [K(L)][Fe{N(SiMe₃)₂}₂] (L=18‐crown‐6 or crypt‐222) through the reduction of either [Fe{N(SiMe₃)₂}₂] or its three‐coordinate phosphine adduct [Fe{N(SiMe₃)₂}₂(PCy₃)]. Detailed characterization is gained through X‐ray diffraction, variable‐temperature NMR spectroscopy, and magnetic susceptibility studies. One‐ and two‐electron oxidation through reaction with I₂ is further found to afford the corresponding iodo iron(II) and diiodo iron(III) complexes.     

A charge-separation-type ionic solid composed of hexanuclear complexes with a macrocyclic tetragold(I) metalloligand

The reaction of Na[Co^III(d -ebp)] (d -H₄ebp = N,N′-ethylenebis[d -penicillamine]) with [(Au^ICl)₂(dppe)] (dppe = 1,2-bis[diphenylphosphino]ethane) gave a cationic Au^I₄Co^III₂ hexanuclear complex, [Co^III₂(L^Au4)]²⁺ ([ 1 ]²⁺), where [L^Au4]⁴⁻ is a cyclic tetragold(I) metalloligand with a 32-membered ring, [Au^I₄(dppe)₂(d -ebp)₂]⁴⁻. Complex [ 1 ]²⁺ crystallized with NO₃⁻ to produce a charge-separation (CS)-type ionic solid of [ 1 ](NO₃)₂. In [ 1 ](NO₃)₂, the complex cations are assembled to form cationic supramolecular hexamers of {[ 1 ]²⁺}₆, which are closely packed in a face-centered cubic (fcc) lattice structure. The nitrate anions of [ 1 ](NO₃)₂ were accommodated in hydrophilic and hydrophobic tetrahedral interstices of the fcc structure to form tetrameric and hexameric nitrate clusters of {NO₃⁻}₄ and {NO₃⁻}₆, respectively. An analogous CS-type ionic solid formulated as [Ni^IICo^III(L^Au4)](NO₃) ([ 2 ](NO₃)) was obtained when a 1:1 mixture of Na[Co^III(d -ebp)] and [Ni^II(d -H₂ebp)] was reacted with [(Au^ICl)₂(dppe)], accompanied by the conversion of the diamagnetic, square-planar [Ni^II(d -H₂ebp)] to the paramagnetic, octahedral [Ni^II(d -ebp)]²⁻. While the overall fcc structure in [ 2 ](NO₃) was similar to that of [ 1 ](NO₃)₂, none of the nitrate anions were accommodated in any hydrophobic tetrahedral interstice, reflecting the difference in the complex charges between [ 1 ]²⁺ and [ 2 ]⁺.     

Lanthanide(II) Complexes of the Dihydrotriazinido Ligand [N{C(Ph)=N}2C(tBu)Ph]−

The potassium dihydrotriazinide K(L^Ph,tBu) ( 1 ) was obtained by a metal exchange route from [Li(L^Ph,tBu)(THF)₃] and KOtBu (L^Ph,tBu = [N{C(Ph)=N}₂C(tBu)Ph]). Reaction of 1 with 1 or 0.5 equivalents of SmI₂(thf)₂ yielded the monosubstituted Sm^II complex [Sm(L^Ph,tBu)I(THF)₄] ( 2 ) or the disubstituted [Sm(L^Ph,tBu)₂(THF)₂] ( 3 ), respectively. Attempted synthesis of a heteroleptic Sm^II amido‐alkyl complex by the reaction of 2 with KCH₂Ph produced compound 3 due to ligand redistribution. The Yb^II bis(dihydrotriazinide) [Yb(L^Ph,tBu)₂(THF)₂] ( 4 ) was isolated from the 1:1 reaction of YbI₂(THF)₂ and 1 . Molecular structures of the crystalline compounds 2 , 3· 2C₆H₆ and 4· PhMe were determined by X‐ray crystallography.     

Two‐Coordinate Iron(I) Complex [Fe{N(SiMe3)2}2]−: Synthesis,Properties, and Redox Activity

First‐row two‐coordinate complexes are attracting much interest. Herein, we report the high‐yield isolation of the linear two‐coordinate iron(I) complex salt [K(L)][Fe{N(SiMe₃)₂}₂] (L=18‐crown‐6 or crypt‐222) through the reduction of either [Fe{N(SiMe₃)₂}₂] or its three‐coordinate phosphine adduct [Fe{N(SiMe₃)₂}₂(PCy₃)]. Detailed characterization is gained through X‐ray diffraction, variable‐temperature NMR spectroscopy, and magnetic susceptibility studies. One‐ and two‐electron oxidation through reaction with I₂ is further found to afford the corresponding iodo iron(II) and diiodo iron(III) complexes.