Zum Reaktionsverhalten des polycyclischen Oligoalumosiloxans [Ph2SiO]8[AlO(OH)]4 gegenüber Hexamethyldisilazan

The Reaction Behaviour of the Polycylic Oligoalumosiloxane [Ph₂SiO]₈[AlO(OH)]₄ towards Hexamethyldisilazane The reaction of the oligoalumosiloxane [Ph₂SiO]₈[AlO(OH)]₄ ( 1 ) with hexamethyldisilazane leads to the triple ionic [Ph₂SiO]₈[AlO₂]₂[AlO(O‐SiMe₃)]₂[NH₄·THF]₂·2 THF ( 2 ) and in the presence of pyridine to [Ph₂SiO]₈[AlO_1.5]₄·2py·1.5 C₇H₈ ( 3 ). Apart from the usual characterization techniques (NMR and IR spectroscopy) the molecular structures of 2 and 3 have been determined by single‐X‐ray diffraction analyses. Both alumosiloxanes 2 and 3 present new types of molecular structures with a central four membered Al₂O₂‐ring, on which the further aluminium atoms are attached via oxygen atoms. This leads to an Al₄‐lozenge, which is centered in subtriangles by oxygen atoms.     

Germanium(II)‐, Zinn(II)‐ und Blei(II)‐Derivate des polycyclischen Alumosiloxans [Ph2SiO]8[Al(O)OH]4

Germanium(II)‐, Tin(II)‐ and Lead(II)‐Derivatives of the polycyclic Alumosiloxane [Ph₂SiO]₈[Al(O)OH]₄ Five new derivatives of the polycyclic alumosiloxane [Ph₂SiO]₈[Al(O)OH]₄ have been synthesized by replacement of the protic hydrogen atoms on the hydroxy‐groups attached to the aluminium atoms by the divalent group 14 elements germanium, tin and lead. The compounds can be divided in those with one metal atom per alumosiloxane moiety, [Ph₂SiO]₈[Al(O)OH]₂[AlO₂]M (M=Ge, Sn), and those with complete substitution of the protic hydrogen atoms by metal atoms like [Ph₂SiO]₈[AlO₂]₄M₂ (M= Sn, Pb). Always one element of the series Ge, Sn, Pb is missing in the two types of compounds. Crystal structure analyses of [Ph₂SiO]₈[Al(O)OH]₂[AlO₂]₂M · 2 C₄H₈O₂ (M= Ge ( 1 ), Sn ( 2a )), [Ph₂SiO]₈[Al(O)OH]₂[AlO₂]₂Sn · 2 THF ( 2b ) and [Ph₂SiO]₈[AlO₂]₄M₂ (M= Sn ( 3 ), Pb ( 4 )) have been performed elucidating either polycyclic basket‐type ( 1 , 2a , 2b ) or closed polyhedral structures ( 3 , 4 ).     

Reactivity of [(Ph2Si)2O3]4[Al(OH)]4 and [(Ph2Si)2O3]4[Al(OLi)]4 towards NaOEt and LiOH. Synthesis of New Twelve‐membered Alumopolysiloxane Rings

The reaction between [(Ph₂Si)₂O₃]₄[Al(OH)]₄ ( 1 ) or [(Ph₂Si)₂O₃]₄[Al(OLi)]₄ ( 2 ) with sodium ethoxide, or lithium hydroxide in presence of CuI·H₂O leads to the formation of new alumopolysiloxane compounds. Indeed, transformations of 1 under the partial incorporation of the reactants are found giving rise to new heteroleptic inorganic macrocycles. The molecular structure of [(Ph₂Si)₂O₃]₄[Al(ONa)]₂[Al(OH)(NaOEt)]₂·2Et₂O ( 3 ) and [(Ph₂Si)₂O₃]₄[Al(OLi)]₂[Al(OH)(LiOH)]₂·2Et₂O·2THF ( 4 ) have been determined by single‐X‐ray diffraction analysis. Both alumosiloxanes 3 and 4 are constituted by a twelve‐membered ring.     

Acid-Base Interactions of Pyrazine,Ethyl Acetate,Di-alcohols,and Lysine with the cyclic Alumosiloxane (Ph2SiO)8[Al(O)OH]4 in View of Mimicking Al2O3(H2O) Surface Reactions

The etherate of (Ph₂SiO)₈[Al(O)OH]₄ can be transformed into the pyrazine adduct (Ph₂SiO)₈[Al(O)OH]₄ · 3N(C₂H₂)₂N ( 1 ), the ethyl acetate adduct (Ph₂SiO)₈[Al(O)OH]₄ · 3H₃C-C(O)OC₂H₅ ( 2 ), the 1,6-hexane diol adduct (Ph₂SiO)₈[Al(O)OH]₄ · 2HO–CH₂(CH₂)₄CH₂–OH ( 3 ) and the 1,4-cyclohexane diol adduct (Ph₂SiO)₈[Al(O)OH]₄ · 4HO–CH(CH₂CH₂)₂CH–OH ( 4 ). In all compounds the OH groups of the starting material bind to the bases through O–H ··· N ( 1 ) or O–H ··· O hydrogen bonds ( 2 , 3 , 4 ) as found from single-crystal X-ray diffraction analyses. Whereas in 1 only three of the central OH groups bind to the pyrazines, in 2 two of them bind to the same carbonyl oxygen atom of the ethyl acetate resulting in an unprecedented O–H ··· O ··· H–O double hydrogen bridge. The hexane diol adduct 3 in the crystal forms a one-dimensional coordination polymer with an intramolecularly to two OH groups grafted hexane diol loop, while the second hexane diol is connecting intermolecularly. In the cyclohexane diol adduct 4 all OH groups of the central Al₄(OH)₄ ring bind to different diols, leaving one alcohol group per diol uncoordinated. These “free” OH groups form an (O-H ··· )₄ assembly creating a three-dimensional overall structure. When reacting with (Ph₂SiO)₈[Al(O)OH]₄ lysine loses water, turns into the cyclic 3-amino-2-azepanone, and transforms through chelation of one of the aluminum atoms the starting material into a new polycycle. The isolated compound has the composition (Ph₂SiO)₁₂[Al(O)OH]₄[Al₂O₃]₂ · 4 C₆H₁₂N₂O · 6(CH₂)₄O ( 5 ).     

Reaction of the Pincer‐type Ligand {2, 6‐[P(O)(OEt)2]2‐4‐tert‐Bu‐C6H2}— with [Ph3C]+[PF6]—. Unprecedented Rearrangement and Carbon‐Carbon Bond Formation

The reaction of the organolithium derivative {2, 6‐[P(O)(OEt)₂]₂‐4‐tert‐Bu‐C₆H₂}Li ( 1 ‐Li) with [Ph₃C]⁺[PF₆]^— gave the substituted biphenyl derivative 4‐[(C₆H₅)₂CH]‐4′‐[tert‐Bu]‐2′, 6′‐[P(O)(OEt)₂]₂‐1, 1′‐biphenyl ( 5 ) which was characterized by ¹H, ¹³C and ³¹P NMR spectroscopy and single crystal X‐ray analysis. Ab initio MO‐calculations reveal the intramolecular O···C distances in 5 of 2.952(4) and 2.988(5)Å being shorter than the sum of the van der Waals radii of oxygen and carbon to be the result of crystal packing effects. Also reported are the synthesis and structure of the bromine‐substituted derivative {2, 6‐[P(O)(OEt)₂]₂‐4‐tert‐Bu]C₆H₂}Br ( 9 ) and the structure of the protonated ligand 5‐tert‐Bu‐1, 3‐[P(O)(OEt)₂]₂C₆H₃ ( 1 ‐H). The structures of 1 ‐H, 5 , and 9 are compared with those of related metal‐substituted derivatives.     

POLYCYCLES AND CAGES IN MOLECULAR ALUMO-POLYSILOXANES—(Ph2SiO)8[Al(O)OH]4 Used as a Supramolecular Target and “Auto-Condensation” Within the Molecule

In this preliminary review the reaction of [Ph₂SiO]₈[AlO(OH)]₄ toward 1,3-diaminopropane and hexamethyldisilazane is discussed in view of supramolecular chemistry and access to structural transformations of the original polycycle. Two distinct adducts may be isolated in the first case: [Ph₂SiO]₈[AlO(OH)]₄· 3H₂N-CH₂CH₂CH₂-NH₂ and [Ph₂SiO]₈[AlO(OH)]₄· 2H₂N-CH₂CH₂CH₂-NH₂. Whereas in the 1:3 adduct the four protic hydrogen atoms of the inner Al₄(OH)₄ ring are involved in O…H…N hydrogen bridges to two terminal diaminopropanes and a bridging diaminopropane thus forming an O…H…N(H)₂-CH₂CH₂CH₂N(H)₂ …H…O loop, in the 1:2 adduct two such O…H…N(H)₂-CH₂CH₂CH₂N(H)₂…H…O loops are present. When [Ph₂SiO]₈[AlO(OH)]₄ is allowed to react with hexamethyldisilazane, again two different products may be obtained depending on the solvent: [Ph₂SiO]₈[AlO₂]₂[AlOO-SiMe₃]₂[NH₄· THF]₂ or [Ph₂SiO]₈[AlOO_0.5]₄· 2 py. This last reaction may be viewed as an inner condensation within [Ph₂SiO]₈[AlO(OH)]₄ loosing two equivalents of water. Both products of the reaction with hexamethyldisilazane have an inner Al₂O₂ four-membered cycle in common, to which Al₂O₄Si₂ eight-membered cycles are partly fused.     

Synthesis and Thermal Behaviour of Compounds in the System [Ph4P]Cl/BiCl3 and the Crystal Structures of [Ph4P]3[Bi2Cl9] · 2 CH2Cl2 and [Ph4P]2[Bi2Cl8] · 2 CH3COCH3

Six polynuclear chlorobismuthates are formed in the reaction between BiCl₃ and Ph₄PCl by variation of the molar ratio of the educts, the solvents and the crystallisation methods: [Ph₄P]₃[Bi₂Cl₉] · 2 CH₂Cl₂, [Ph₄P]₃[Bi₂Cl₉] · CH₃COCH₃, [Ph₄P]₂[Bi₂Cl₈] · 2 CH₃COCH₃, [Ph₄P]₄[Bi₄Cl₁₆] · 3 CH₃CN, [Ph₄P]₄[Bi₆Cl₂₂], and [Ph₄P]₄[Bi₈Cl₂₈]. We report the crystal structure of [Ph₄P]₃[Bi₂Cl₉] · 2 CH₂Cl₂ which crystallises with triclinic symmetry in the S. G. P1 No. 2, with the lattice parameters a = 13.080(3) Å, b = 14.369(3) Å, c = 21.397(4) Å, α = 96.83(1)°, β = 95.96(1)°, γ = 95.94(2)°, V = 3943.9(1) ų, Z = 2. The anion is formed from two face‐sharing BiCl₆‐octahedra. [Ph₄P]₂[Bi₂Cl₈] · 2 CH₃COCH₃ crystallises with monoclinic symmetry in the S. G. P2₁/n, No. 14, with the lattice parameters a = 14.045(5) Å, b = 12.921(4) Å, c = 17.098(3) Å, β = 111.10(2)°, V = 2894.8(2) ų, Z = 2. The anion is a bi‐octahedron of two square‐pyramids, joined by a common edge. The octahedral coordination is achieved with two acetone ligands. [Ph₄P]₄[Bi₄Cl₁₆] · 3 CH₃CN crystallises in the triclinic S. G., P1, No. 2, with the lattice parameters a = 14.245(9) Å, b = 17.318(6) Å, c = 24.475(8) Å, α = 104.66(3)°, β = 95.93(3)°, γ = 106.90(4)°, V = 5486(4) ų, Z = 2. Two Bi₂Cl₈ dimers in syn‐position form the cubic anion. Lattice parameters of [Ph₄P]₃[Bi₂Cl₉] · CH₃COCH₃ are also given. The solvated compounds are desolvated at approximately 100 °C. [Ph₄P]₃[Bi₂Cl₉] · 2 CH₂Cl₂ and [Ph₄P]₃[Bi₂Cl₉] · CH₃COCH₃ show the same sequence of phase transitions after desolvation. All compounds melt into a liquid in which some order is observed and transform on cooling into the glassy state.     

Two new metal derivates of the alumosiloxane [Ph2SiO]8[AlO(OH)]4: [Ph2SiO]8[AlO2(Na)]4 · 5(THF) and [Ph2SiO]8[AlO(OH)]2[AlO2]2[Zn(OH)]2 · 2(OEt2)

When the polycyclic alumosiloxane [Ph₂SiO]₈[AlO(OH)]₄ is allowed to react with either cyclopentadienyl sodium in tetrahydrofuran or with dimethyl zinc in diethyl ether the organic ligands on the metal elements are eliminated as cyclopentadiene or methane and the metals are bonded to oxygen atoms in the alumosiloxane forming [Ph₂SiO]₈[AlO₂(Na)]₄ · 5(THF) or [Ph₂SiO]₈[AlO(OH)]₂[AlO₂]₂[Zn(OH)]₂ · 2(OEt₂), respectively. X-ray structure determinations reveal that in the sodium derivative the original polycycle rests almost unchanged while in the zinc derivative the inner skeleton is rearranged.     

Condensation reaction through base assistance within (Ph2SiO)8[AlO(OH)]4

When the polycyclic alumosiloxane (Ph₂SiO)₈[AlO(OH)]₄, which may be isolated as the diethyl ether adduct (Ph₂SiO)₈[AlO(OH)]₄·4OEt₂, is allowed to react with the double N-methylpiperidine (nmp) adduct of monochloroalane, AlH₂Cl·2nmp (1) (crystal structure analysis), the polycycle (Ph₂SiO)₈[AlO(O)_0.5]₄·2nmp (2) is obtained. Compared to the starting material and apart from the coordinating bases, the compound formally has lost two water molecules. The structure of (Ph₂SiO)₈[AlO(O)_0.5]₄·2nmp (2) can be derived from (Ph₂SiO)₈[AlO(OH)]₄ by substituting the central Al₄(OH)₄ motif through an Al₄O₂ entity which consists of a central Al₂O₂ ring coordinated to two further aluminum atoms through almost trigonal planar oxygen atoms. Using tris(ethylene)diamine (ted) as base and reacting it with (Ph₂SiO)₈[Al(OH)]₄, we have been able to isolate and completely characterize an intermediate on the way to these formally condensed alumosiloxane polycycles like in (Ph₂SiO)₈[AlO(O)_0.5]₄·2nmp (2). It has the composition (Ph₂SiO)₈[AlO(O)_0.25]₄·(OH·ted)₂·(OH₂·ted) (3) and has, compared to the starting material, the same number of hydrogen, oxygen, aluminum and silicon atoms within the inner molecular framework. Nevertheless, its structure is very different: whereas half of the molecule is structurally similar to (Ph₂SiO)₈[AlO(OH)]₄, with OH-groups forming hydrogen bridges to the nitrogen atoms of ted and connecting two aluminum atoms, the other half contains a unique oxygen atom which is in an almost planar trigonal bonding mode to three aluminum atoms. Furthermore, this part of the molecule has an aluminum atom to which a water molecule is coordinated, one of the hydrogen atoms being involved in hydrogen bonding to a further tris(ethylene)diamine (ted). This structure gives some important insights in the possible mechanism of the “condensation reaction” within (Ph₂SiO)₈[AlO(OH)]₄.     

A Sterically Hindered Phosphonic Acid with a Hydrogen‐Bonded Cage Structure: [4‐tert‐Bu‐2,6‐Mes2‐C6H2P(O)(OH)2·H2O]4

The synthesis and molecular structure of the novel phosphonic acid 4‐tert‐Bu‐2,6‐Mes₂‐C₆H₂P(O)(OH)₂ ( 1 ) is reported. Compound 1 crystallizes in form of its monohydrate as a hydrogen‐bonded cluster ( 1·H₂O )₄ comprizing four phosphonic acid molecules (O···O 2.383(3)‐3.006(4) Å). Additionally, sterically hindered terphenyl‐substituted phosphorus compounds of the type 4‐tert‐Bu‐2,6‐Mes₂‐C₆H₂PR(O)(OH) ( 5 , R = H; 7 , R = O₂CC₆H₄‐3‐Cl; 9 , R = OEt) were prepared, which all show dimeric hydrogen‐bonded structures with O···O distances in the range 2.489(2)–2.519(3) Å. Attempts at oxidizing 5 using H₂O₂, KMnO₄, O₃, or Me₃NO in order to give 1 failed. Crystallization of 5 in the presence of Me₃NO gave the novel hydrogen bonded aggregate 4‐tert‐Bu‐2,6‐Mes₂‐C₆H₂PH(O)(OH)·ONMe₃ ( 6 ) showing an O–H···O distance of 2.560(4) Å.     

Vanadium(V) Oxo and Imido Calix[8]arene Complexes: Synthesis,Structural Studies,and Ethylene Homo/Copolymerisation Capability

Interaction of p‐tert‐butylcalix[8]areneH₈ (L⁸H₈) with [NaVO(OtBu)₄] (formed in situ from VOCl₃) afforded the complex [Na(NCMe)₅][(VO)₂L⁸H]?4 MeCN ( 1 ?4 MeCN). Increasing [NaVO(OtBu)₄] to 4 equiv led to [Na(NCMe)₆]₂[(Na(VO)₄L⁸)(Na(NCMe))₃]₂?10 MeCN ( 2 ?10 MeCN). With adventitious oxygen, reaction of 4 equiv of [VO(OtBu)₃] with L⁸H₈ afforded the alkali‐metal‐free complex [(VO)₄L⁸(μ³‐O)₂] ( 3 ); solvates 3 ?3 MeCN and 3 ?3 CH₂Cl₂ were isolated. For the lithium analogue, the order of addition had to be reversed such that lithium tert‐butoxide was added to L⁸H₈ and then treated with 2 equiv of VOCl₃; crystallisation afforded [(VO₂)₂Li₆[L⁸](thf)₂(OtBu)₂(Et₂O)₂]?Et₂O ( 4 ?Et₂O). Upon extraction into acetonitrile, [Li(NCMe)₄][(VO)₂L⁸H]?8 MeCN ( 5 ?8 MeCN) was formed. Use of the imido precursors [V(NtBu)(OtBu)₃] and [V(Np‐tolyl)(OtBu)₃] and L⁸H₈, afforded [tBuNH₃][{V(p‐tolylN)}₂L⁸H]?3 1/2 MeCN ( 6 ?3 1/2 MeCN). The molecular structures of 1 to 6 are reported. Complexes 1 , 3 , and 4 were screened as precatalysts for the polymerisation of ethylene in the presence of cocatalysts at various temperatures and for the copolymerisation of ethylene with propylene. Activities as high as 136 000 g (mmol(V) h)^?1 were sometimes achieved; higher molecular weight polymers could be obtained versus the benchmark [VO(OEt)Cl₂]. For copolymerisation, incorporation of propylene was 7.1–10.9 mol % (compare 10 mol % for [VO(OEt)Cl₂]), although catalytic activities were lower than [VO(OEt)Cl₂].     

(Ph4P)2[Be3(μ‐OH)3(H2O)6]Cl5: Kristallstruktur und DFT‐Rechnungen

Bis(tetraphenylphosphonium)‐tris(μ‐hydroxo)hexaaquatriberylliumpentachloride, (Ph₄P)₂[Be₃(μ‐OH)₃(H₂O)₆]Cl₅ ( 1 ), was surprisingly obtained by reaction of (Ph₄P)N₃ · n H₂O with BeCl₂ in dichloromethane suspension and subsequent crystallization from acetonitrile to give single crystals of composition 1· 5.25CH₃CN. According to the crystal structure determination space group P , Z = 2, lattice dimensions at 100 K: a = 1354.8(2), b = 1708.7(2), c = 1753.2(2) pm, α = 114.28(1)°, β = 94.80(1)°, γ = 104.51(1)°, R₁ = 0.0586] the [Be₃(μ‐OH)₃(H₂O)₆]³⁺ cations form six‐mem‐bered Be₃O₃ rings with boat conformation and distorted tetrahedrally coordinated beryllium atoms with the terminally coordinated H₂O molecules. The structure ist characterized by a complicated three dimensional hydrogen‐bridging network including O–H ··· O, O–H ··· Cl, and O–H ··· NCCH₃ contacts. DFT calculations result in nearly planar [Be₃(OH)₃] six‐membered ring conformations.     

The First [4+2]‐Coordinated Tetraorganolead Compound: Synthesis,Structure and Conversion into a Triorganolead Cation,a Benzoxaphosphaplumbole,and Diorganolead Dihalides

The syntheses and molecular structures, as determined by single‐crystal X‐ray diffraction analysis, of the first intramolecularly [4+2]‐coordinated tetraorganolead compound {4‐t‐Bu‐2, 6‐[P(O)(OEt)₂]₂C₆H₂}PbPh₃ ( 2 ) and the triphenyllead chloride adduct of the first intramolecularly coordinated benzoxaphosphaplumbole {[1(Pb), 3(P)‐Pb(Ph)₂OP(O)(OEt)‐5‐t‐Bu‐7‐P(O)(OEt)₂]C₆H₂·Ph₃PbCl} ( 3a ) are reported. The reaction of 2 with [Ph₃C]⁺ [PF₆]^— and p‐MeC₆H₄SO₃H, respectively, provides the triorganolead salts {4‐t‐Bu‐2, 6‐[P(O)(OEt)₂]₂C₆H₂}PbPh₂⁺X^— ( 4 , X = PF₆; 4a , X = p‐MeC₆H₄SO₃). Reaction of 2 with bromine and hydrogen chloride, respectively, gives the diorganolead dihalides {4‐t‐Bu‐2, 6‐[P(O)(OEt)₂]₂C₆H₂}PbPhX₂ ( 5 , X = Br; 6 , X = Cl).     

Synthese und Struktur der Komplexe [(n‐Bu)4N]2[{(THF)Cl4Re≡N}2PdCl2], [Ph4P]2[(THF)Cl4Re≡N‐PdCl(μ‐Cl)]2 und [(n‐Bu)4N]2[Pd3Cl8]

Synthesis and Crystal Structure of the Complexes [(n‐Bu)₄N]₂[{(THF)Cl₄Re≡N}₂PdCl₂], [Ph₄P]₂[(THF)Cl₄Re≡N‐PdCl(μ‐Cl)]₂ and [(n‐Bu)₄N]₂[Pd₃Cl₈] The threenuclear complex [(n‐Bu)₄N]₂[{(THF)Cl₄Re≡N}₂ PdCl₂] ( 1 ) is obtained in THF by the reaction of PdCl₂(NCC₆H₅)₂ with [(n‐Bu)₄N][ReNCl₄] in the molar ration 1:2. It forms orange crystals with the composition 1· THF crystallizing in the monoclinic space group C2/c with a = 2973.3(2); b = 1486.63(7); c = 1662.67(8)pm; β = 120.036(5)° and Z = 4. If the reaction is carried out with PdCl₂ instead of PdCl₂(NCC₆H₅)₂, orange crystals of hitherto unknown [(n‐Bu)₄N]₂[Pd₃Cl₈] ( 3 ) are obtained besides some crystals of 1· THF. 3 crystallizes with the space group P1¯ and a = 1141.50(8), b = 1401.2(1), c = 1665.9(1)pm, α = 67.529(8)°, β = 81.960(9)°, γ = 66.813(8)° and Z = 2. In the centrosymmetric complex anion [{(THF)Cl₄Re≡N}₂PdCl₂]^2— a linear PdCl₂ moiety is connected in trans arrangement with two complex fragments [(THF)Cl₄Re≡N]^— via asymmetric nitrido bridges Re≡N‐Pd. For Pd(II) thereby results a square‐planar coordination PdCl₂N₂. The linear nitrido bridges are characterized by distances Re‐N = 163.8(7)pm and Pd‐N = 194.1(7)pm. The crystal structure of 3 contains two symmetry independent, planar complexes [Pd₃Cl₈]^2— with the symmetry 1¯, in which the Pd atoms are connected by slightly asymmetric chloro bridges. By the reaction of equimolar amounts of [Ph₄P][ReNCl₄] and PdCl₂(NCC₆H₅)₂ in THF brown crystals of the heterometallic complex, [Ph₄P]₂[(THF)Cl₄Re≡N‐PdCl(μ‐Cl)]₂ ( 2 ) result. 2 crystallizes in the monoclinic space group P2₁/n with a = 979.55(9); b = 2221.5(1); c = 1523.1(2)pm; β = 100.33(1)° and Z = 2. In the central unit ClPd(μ‐Cl)₂PdCl of the centrosymmetric anionic complex [(THF)Cl₄Re≡N‐PdCl(μ‐Cl)]₂^2— the coordination of the Pd atoms is completed by two nitrido bridges Re≡N‐Pd to nitrido complex fragments [(THF)Cl₄Re≡N]^— forming a square‐planar arrangement for Pd(II). The distances in the linear nitrido bridges are Re‐N = 163.8(9)pm and Pd‐N = 191.5(9)pm.     

Synthesis,Crystal Structures,and Nonlinear Optical Properties of Two Cubane‐Like Cluster Compounds [(n‐Bu)4N]3[MoS4Ag3Cl4] and [Et4N]3[WOS3Cu3I4]

The compounds [(n‐Bu)₄N]₃[MoS₄Ag₃Cl₄] ( 1 ) and [Et₄N]₃[WOS₃Cu₃I₄] ( 2 ) were synthesized and characterized. Compound 1 crystallizes in the rhombohedral system, space group R3c with a = 17.194(1), b = 17.194(1), c = 39.194(3)Å, Z = 6, V = 10034.7(11)ų. Compound 2 crystallizes in the rhombohedral system, space group R3c with a = 14.461(2), b = 14.461(2), c = 34.952(2)Å, Z = 6, V = 6329.9(13)ų. The X‐ray crystallographic structure determinations show that these two cluster compounds consist of a slightly distorted cubic core. Nonlinear optical (NLO) properties of these two clusters were investigated by using Z‐scan techniques with an 8 ns pulsed laser at 532 nm; both clusters exhibit strong nonlinear optical absorption effect (effective α₂ = 1.18 × 10^—10 m · W^—1 for 1 and 1.0 × 10^—10 m · W^—1 for 2 ).     

Reduction of Digallane [(dpp‐bian)Ga?Ga(dpp‐bian)] with Group 1 and 2 Metals

The reduction of digallane [(dpp‐bian)Ga? Ga(dpp‐bian)] ( 1 ) (dpp‐bian=1,2‐bis[(2,6‐diisopropylphenyl)imino]acenaphthene) with lithium and sodium in diethyl ether, or with potassium in THF affords compounds featuring the direct alkali metal–gallium bonds, [(dpp‐bian)Ga? Li(Et₂O)₃] ( 2 ), [(dpp‐bian)Ga? Na(Et₂O)₃] ( 3 ), and [(dpp‐bian)Ga? K(thf)₅] ( 7 ), respectively. Crystallization of 3 from DME produces compound [(dpp‐bian)Ga? Na(dme)₂] ( 4 ). Dissolution of 3 in THF and subsequent crystallization from diethyl ether gives [(dpp‐bian)Ga? Na(thf)₃(Et₂O)] ( 5 ). Ionic [(dpp‐bian)Ga]^?[Na([18]crown‐6)(thf)₂]⁺ ( 6 a ) and [(dpp‐bian)Ga]^?[Na(Ph₃PO)₃(thf)]⁺ ( 6 b ) were obtained from THF after treatment of 3 with [18]crown‐6 and Ph₃PO, respectively. The reduction of 1 with Group 2 metals in THF affords [(dpp‐bian)Ga]₂M(thf)_n (M=Mg ( 8 ), n=3; M=Ca ( 9 ), Sr ( 10 ), n=4; M=Ba ( 11 ), n=5). The molecular structures of 4 – 7 and 11 have been determined by X‐ray crystallography. The Ga? Na bond lengths in 3 – 5 vary notably depending on the coordination environment of the sodium atom.     

The Phase Diagram of the System [Ph4P]Br/BiBr3. Synthesis,Crystal Structure,Thermal Behaviour,and Vibrational Spectra of [Ph4P]3[Bi2Br9] · CH3COCH3 and two Modifications of [Ph4P]4[Bi6Br22]

The phase diagram of the system [Ph₄P]Br/BiBr₃ was investigated with the aid of DSC, TG and temperature dependent X‐ray powder diffraction measurements. By varying the reaction conditions, stoichiometry and crystallisation conditions of the reaction between BiBr₃ and [Ph₄P]Br four polynuclear bromobismuthates are formed. We report here the crystal structure of the solvation product [Ph₄P]₃[Bi₂Br₉] · CH₃COCH₃, which crystallises with monoclinic symmetry in the S. G. P2₁/n No. 14, a = 12.341(1), b = 32.005(3), c = 19.929(3) Å, β = 99.75(2)°, V = 7758(7) ų, Z = 4 and the crystal structures of two modifications of the compound [Ph₄P]₄[Bi₆Br₂₂]. The α‐form, crystallises with triclinic symmetry in the S. G. P1 No. 2, a = 13.507(4) Å, b = 14.434(4) Å, c = 17.709(5) Å, α = 81.34(2)°, β = 72.42(2)°, γ = 72.53(2)°, V = 3132.7(1) ų, Z = 2. The high‐temperature β‐form, crystallises with triclinic symmetry in the S. G. P1 No. 2, a = 13.893(4) Å, b = 14.267(3) Å, c = 16.580(3), α = 100.13(2)°, β = 96.56(2)°, γ = 110.01(2)°, V = 2985.5(1) ų, Z = 2. Lattice parameters of [Ph₄P]₄[Bi₈Br₂₈] are also given. The thermal behaviour of the compounds and in addition the vibrational spectra of [Ph₄P]₃[Bi₂Br₉] · CH₃COCH₃ are presented and discussed.     

Solvatomorphism in (E)‐2‐(2,6‐dichloro‐4‐hydroxybenzylidene)hydrazinecarboximidamide

The structures of orthorhombic (E)‐4‐(2‐{[amino(iminio)methyl]amino}vinyl)‐3,5‐dichlorophenolate dihydrate, C₈H₈Cl₂N₄O·2H₂O, (I), triclinic (E)‐4‐(2‐{[amino(iminio)methyl]amino}vinyl)‐3,5‐dichlorophenolate methanol disolvate, C₈H₈Cl₂N₄O·2CH₄O, (II), and orthorhombic (E)‐amino[(2,6‐dichloro‐4‐hydroxystyryl)amino]methaniminium acetate, C₈H₉Cl₂N₄O⁺·C₂H₃O₂⁻, (III), all crystallize with one formula unit in the asymmetric unit, with the molecule in an E configuration and the phenol H atom transferred to the guanidine N atom. Although the molecules of the title compounds form extended chains via hydrogen bonding in all three forms, owing to the presence of different solvent molecules, those chains are connected differently in the individual forms. In (II), the molecules are all coplanar, while in (I) and (III), adjacent molecules are tilted relative to one another to varying degrees. Also, because of the variation in hydrogen‐bond‐formation ability of the solvents, the hydrogen‐bonding arrangements vary in the three forms.     

Bis(Phenoxy‐Imine) Zr Complexes/Et3Al/Heteropoly Compound Catalyst Systems for Ethylene Polymerization

Bis(phenoxy‐imine) Zr complexes upon activation with Et₃Al/(Ph₃C)_mH_n[PMo₁₂O₄₀] · 8 H₂O (average: m/n = 2:1) were demonstrated to be highly active catalysts for the polymerization of ethylene. One of the complexes formed narrow‐molecular‐weight distributed polyethylene ( 1.45) with a very high activity (5640 kg‐PE · mol‐cat⁻¹ · h⁻¹), representing the first example of a MAO‐ and borate‐free, highly active, single‐site catalyst system based on a Group 4 transition metal complex and a heteropoly compound.

Catalysis of ethylene with bis(phenoxy‐imine) Zr complexes activated with Et₃Al/(Ph₃C)_mH_n[PMo₁₂O₄₀] · 8 H₂O.     

Chloro- und Polyselenoselenate(II) Darstellung,Struktur und Eigenschaften von [Ph3(C2H4OH)P]2[SeCl4] · MeCN, [Ph4P]2[Se2Cl6] und [Ph4P]2[Se(Se5)2]

Chloro- and Polyselenoselenates(II): Synthesis, Structure, and Properties of [Ph₃(C₂H₄OH)P]₂[SeCl₄] · MeCN, [Ph₄P]₂[Se₂Cl₆], and [Ph₄P]₂[Se(Se₅)₂] By symproportionation of elemental selenium and SeCl₄ in polar protic solvents the novel chloroselenates(+II), [SeCl₄]^2? and [Se₂Cl₆]^2?, could be stabilized; they were crystallized with voluminous organic cations. They were characterized from complete X-ray structure analysis. Yellow-orange [Ph₃(C₂H₄OH)P]₂[SeCl₄] · MeCN (space group P1 , a = 10.535(4), b = 12.204(5), c = 16.845(6) Å, α = 77.09(3)°, β = 76.40(3)°, γ = 82.75(3)° at 140 K) contains in its crystal structure monomeric [SeCl₄]^2? anions with square-planar coordination of Se(+II). The mean Se? Cl bond length is 2.441 Å. In yellow [Ph₄P]₂[Se₂Cl₆] (space group P1 , a = 10.269(3), b = 10.836(4), c = 10.872(3) Å, α = 80.26(3)°, β = 79.84(2)°, γ = 72.21(3)° at 140 K) a dinuclear centrosymmetric [Se₂Cl₆]^2? anion, also with square-planar coordinated Se(+II), is observed. The average terminal and bridging Se? Cl bond distances are 2.273 and 2.680 Å, respectively. From redox reactions of elemental Se with boranate/thiolate in ethanol/DMF the bis(pentaselenido)selenate(+II) anion [Se(Se₅)₂]^2? was prepared as a novel type of a mixed-valent chalcogenide. In dark-red-brown [Ph₄P]₂[Se(Se₅)₂] (space group P2₁/n, a = 12.748(4), b = 14.659(5), c = 14.036(5) Å, β = 108.53(3)° at 140 K) centrosymmetric molecular [Se(Se₅)₂]^2? anions with square-planar coordination of the central Se(+II) by two bidentate pentaselenide ligands is observed (mean Se? Se bond lengths: 2.658 Å at Se(+II), 2.322 Å in [Se₅]_2?). The resulting six-membered chelate rings with chair conformation are spirocyclically linked through the central Se(+II). The vibrational spectra of the new anions are reported.