Bildung und struktur der Cyclophosphane P4(CMe3)2[P(CMe3)2]2 und P4(SiMe3)2[P(CMe3)2]2

Formation and Structure of the Cyclophosphanes P₄(CMe₃)₂[P(CMe₃)₂]₂ and P₄(SiMe₃)₂[P(CMe₃)₂]₂ n-Triphosphanes showing a SiMe₃ and a Cl substituent at the atoms P¹ and P², like (Me₃C)₂P? P(SiMe₃)? P(CMe₃)Cl 3 or (Me₃C)₂P? P(Cl)? P(SiMe₃)₂ 4 are stable only at temperatures below ?30°C. Above this temperature these compounds lose Me₃SiCl, thus forming cyclotetraphosphanes, P₄(CMe₃)₂[P(CMe₃)₂]₂ 1 out of 3 , P₄(SiMe₃)₂[P(SiMe₃)₂]₂ 2a (cis) and 2b (trans) out of 4 . The formation of 1 proceeds via (Me₃C)₂P? P?PCMe₃ 5 as intermediate compound, which after addition to cyclopentadiene to give the Diels-Alder-adduct 6 (exo and endo isomers) was isolated. 6 generates 5 , which then forms the dimer compound 1 . Likewise (Me₃C)₂P? P?P-SiMe₃ 8 (as proven by the adduct 7 ) is formed out of 4 , leading to 2a (cis) and 2b (trans). Compound 1 is also formed out of the iso-tetraphosphane P[P(CMe₃)₂]₂[P(CMe₃)Cl] 9 , which loses P(CMe₃)₂Cl when warmed to a temperature of 20°C. 1 crystallizes monoclinically in the space group P2₁/a (no. 14); a = 1762.0(15) pm; b = 1687.2(18) pm; c = 1170.5(9) pm; β = 109.18(5)° and Z = 4 formula units in the elementary cell. The molecule possesses E conformation. The central four-membered ring is puckered (approx. symmetry 4 2m; dihedral angle 47.4°), thus bringing the substituents into a quasi equatorial position and the nonbonding electron pairs into a quasi axial position. The bond lengths in the four-membered ring of 1 (d (P? P) = 222.9 pm) are only slightly longer than the exocyclic bonds (221.8 pm). The endocyclic bond angles \documentclass{article}\pagestyle{empty}\begin{document}$ \bar \beta $\end{document}(P/P/P) are 85.0°, the torsion angles are ±33° and d (P? C) = 189.7 pm.     

Die Reaktion des tert.Butyl-lithiums mit Aluminiumtribromid; Molekülstrukturen von [HAl(CMe3)2]3 und [LiHAl(CMe3)3]2

Reaction of tert.Butyl-lithium with Aluminiumtribromide; Molecular Structures of [HAl(CMe₃)₂]₃ and [LiHAl(CMe₃)₃]₂ The reaction of tert.butyl-lithium with aluminiumtrihalide at low temperatures was reinvestigated. Four compounds were isolated: trimeric di(tert.butyl)alane(III) 1 , monomeric (solution in benzene)/dimeric (solid state) lithium-tri(tert.butyl)alanate(III) 2 , tri(tert.butyl)alane 3 and lithium-tetra(tert.butyl)alanate 4 . X-ray structure analyses gave a planar sixmembered Al? H heterocycle for 1 and a Li? H-bridged dimer showing intramolecular interactions of lithium with C? H σ-bonds for 2 .     

Molekülstruktur und thermische Stabilität des metallacyclischen Platin(II)‐Komplexes [Li(TMEDA)]2Pt(CH2CMe2CMe2CH2)2

Molecular Structure and Thermal Stability of the Metallacyclic Platinum(II) Complex [Li(TMEDA)]₂Pt(CH₂CMe₂CMe₂CH₂)₂ The X‐ray investigation at the “ate‐complex” [Li(TMEDA)]₂Pt(CH₂CMe₂CMe₂CH₂)₂ ( 1 ) revealed a new structure type of homoleptic organometallic compounds of platinum(II). Differences of the molecular structure of the “ate‐complex” [Li(TMEDA)]₂Pt(CH₂CH₂CH₂CH₂)₂ ( 2 ) as well as similarities to the structure of the homologeous “ate‐complex” of nickel(II) [Li(TMEDA)]₂Ni(CH₂CMe₂CMe₂CH₂)₂ ( 3 ) are described. A possible mechanism of the thermal decomposition of the complex 1 is discussed.     

Iodoplumbate mit polymeren Anionen – Synthese und Kristallstrukturen von [Na3(OCMe2)12][Pb4I11(OCMe2)], (Ph4P)2[Pb5I12] und (Ph4P)4[Pb15I34(dmf)6]

Iodoplumbates with Polymeric Anions – Synthesis and Crystal Structures of [Na₃(OCMe₂)₁₂][Pb₄I₁₁(OCMe₂)], (Ph₄P)₂[Pb₅I₁₂], and (Ph₄P)₄[Pb₁₅I₃₄(dmf)₆] Reactions of PbI₂ with NaI in polar organic solvents followed by crystallization with large cations yield iodoplumbate complexes with various compositions and structures. [Na₃(OCMe₂)₁₂][Pb₄I₁₁(OCMe₂)] 3 , (Ph₄P)₂[Pb₅I₁₂] 4 and (Ph₄P)₄[Pb₁₅I₃₄(dmf)₆] 7 contain one-dimensional infinite anionic chains of face- or edge-sharing PbI₆ or PbI₅L (L = acetone, DMF) octahedra. [Na₃(OCMe₂)₁₂][Pb₄I₁₁(OCMe₂)] 3 : Space group P1 (No. 1), a = 1120.3(5), b = 1265.3(6), c = 1608.3(8) pm, α = 74.64(4), β = 70.40(4), γ = 85.24(4)°, V = 2071(2) · 10⁶ pm³; (Ph₄P)₂[Pb₅I₁₂] 4 : Space group C2/c (No. 15), a = 787.00(10), b = 2812.0(5), c = 3115.9(5) pm, β = 96.240(13)°, V = 6885(2) · 10⁶ pm³; (Ph₄P)₄[Pb₁₅I₃₄(dmf)₆] 7 : Space group P2₁/n (No. 14), a = 2278.8(4), b = 1782.6(3), c = 2616.8(4) pm, β = 114.432(13)°, V = 9678(3) · 10⁶ pm³.     

Monomeres Trilithium-tris[tert-butyldimethylsilylamido]phenylsilan,PhSi[NLi(THF)SiMe2CMe3]3 -- Darstellung und Kristallstruktur

Monomeric Trilithium-tris[tert-butyldimethylsilylamido]phenylsilane, PhSi[NLi(thf)SiMe₂CMe₃]₃ – Synthesis and Crystal Structure Lithiated tert-butyldimethylsilylamine reacts with trifluorophenylsilane in a molar ratio 2:1 or 3:1 to give the bis- and tris(silylamino)silanes 1 [(Me₃CSiMe₂NH)₂SiFPh] and 2 [(Me₃CSiMe₂NH)₃SiPh]. The trilithium derivative 3 [Me₃CSiMe₂NLi(thf)]₃SiPh is obtained in the reaction of 2 with n-BuLi in hexane/thf. 3 crystallizes as a monomer forming three planar four-membered (LiNSiN)-rings. The results of the crystal structure of 3 are discussed.     

(NPr 4 n )[SRev(S4)(S3CMe 2)]: Ein [SRev(S4)2]−-Derivat

Summary The preparation of (NPr ₄ ⁿ )[SRe(S₄)(S₃CMe ₂)] (1), (NPr ₄ ⁿ )[SRe(S₄)₂] (2), (NBu ₄ ⁿ )[SRe(S₄)₂] (3) and a new modification of (PPh ₄)[SRe(S₄)₂] (4) are reported, including the X-ray structures of1 and4.

Herrn Prof. Dr. A. Meller mit den besten Wünschen zum 60. Geburtstag gewidmet     

The first complexes and cyclodimerisations of methylphosphaalkyne (P[triple bond]CMe)

The first complexes and cyclodimerisations of methylphosphaalkyne, P[triple bond]CMe, are reported to arise from its reactions with a range of platinum(0) complexes and [W(CO)5(THF)]. A number of differences between the chemistry of this phosphaalkyne and that of its bulkier analogues have been highlighted and explained on steric grounds.     

Diruthenium tetraacetate monocation, [RuII/III2(O2CMe)4]+, building blocks for 3-D molecule-based magnets

Diruthenium tetracarboxylates monocations are utilized as building blocks for cubic 3-D network structured molecule-based magnets. [Ru(II/III)(2)(O(2)CMe)(4)](3)[M(III)(CN)(6)] [M = Cr (1a), Fe (2), Co (3)] were prepared in aqueous solution. Powder X-ray diffraction indicates that they have body-centered cubic structures (space group = Imm, a = 13.34, 13.30, and 13.10 A for 1a, 2, and 3, respectively), which was confirmed for 1a by Reitveld analysis of the synchrotron powder data [a = 13.3756(5) A]. [Ru(2)(O(2)CMe)(4)](3)[M(III)(CN)(6)].xMeCN [M = Cr, x = 1.8 (1b); M = Mn, x = 3.3 (4)] were prepared from acetonitrile. The magnetic ordering of 1a (33 K), 1b (34.5 K), 2 (2.1 K), and 4 (9.6 K) was determined from the temperature dependencies of the in-phase (chi') alternating current (AC) susceptibility. The field dependence of the magnetization, M(H), at 2 K for 1a showed an unusual constricted hysteresis loop with a coercive field, H(cr), of 470 Oe while the M(H) data for 1b, 2, and 4 showed a normal hysteresis loop with a coercive field of 1670, 10, and 990 Oe, respectively. The (57)Fe M?ssbauer spectrum of 2 is consistent with the presence of low spin Fe(III) (delta = -0.05 mm/s; DeltaE = 0.33 mm/s) at room temperature, and the onset of 3-D magnetic ordering at lower temperature (<2 K). The effects of M(III) in [M(III)(CN)(6)](3-), and the large zero-field splitting (D) of diruthenium tetracarboxylates are discussed. The increasing critical temperatures T(c), with increasing S could not be accounted for by mean field models without significantly different J values for 1a, 4, and 2. By fitting the T(c) data with mean field models [H = -2JS(Ru).(S(M) - micro(B)(g(Ru)S(Ru) + g(M)S(M))H], J/k(B) are 4.46, 1.90, and 0.70 K for 1a, 4, and 2, respectively.     

Synthesis and Structure Characterization of a Manganese(Ⅱ) Complex With Eight Coordination Geometry: [Mn(O_2CMe)_2(phen)_2]

The title compound [Mn(O2CMe)2(phen)2] (phen = 1,10-phenanthroline) 1 has been synthesized and structurally determined by single-crystal X-ray diffraction. The crystal is of orthor- hombic, space group Pbcn, with a = 12.554(4), b = 10.168(3), c = 17.704(5) , V = 2259.7(12) 3, Z = 4, C28H22MnN4O4, Mr = 533.44, Dc = 1.568 g/cm3, F(000) = 1100, Rint = 0.0242, T = 293(2) K and μ = 0.631 mm–1. The final R = 0.0687 and wR = 0.1960 for 2046 observed reflections with I > 2σ(I). The structure of the complex consists of one Mn(II) core coordinated by two bidentate-bound CH3COO- groups and two η2-phen groups forming an eight-coordinate geometrical configuration.     

Symmetric and asymmetric dinuclear manganese(IV) complexes possessing a [MnIV2(mu-O)2(muO2CMe)]3+ core and terminal Cl- ligands

The synthesis of new dinuclear manganese(IV) complexes possessing the [Mn(IV)(2)(mu-O)(2)(mu-O(2)CMe)](3+) core and containing halide ions as terminal ligands is reported. [Mn(2)O(2)(O(2)CMe)Cl(2)(bpy)(2)](2)[MnCl(4)] (1; bpy = 2,2'-bipyridine) was prepared by sequential addition of [MnCl(3)(bpy)(H(2)O)] and (NBzEt(3))(2)[MnCl(4)] to a CH(2)Cl(2) solution of [Mn(3)O(4)(O(2)CMe)(4)(bpy)(2)]. The complex [Mn(IV)(2)O(2)(O(2)CMe)Cl(bpy)(2)(H(2)O)](NO(3))(2) (2) was obtained from a water/acetic acid solution of MnCl(2).4H(2)O, bpy, and (NH(4))(2)[Ce(NO(3))(6)], whereas the [Mn(IV)(2)O(2)(O(2)CR)X(bpy)(2)(H(2)O)](ClO(4))(2) [X = Cl(-) and R = Me (3), Et (5), or C(2)H(4)Cl (6); and X = F(-), R = Me (4)] were prepared by a slightly modified procedure that includes the addition of HClO(4). For the preparation of 4, MnF(2) was employed instead of MnCl(2).4H(2)O. [Mn(2)O(2)(O(2)CMe)Cl(2)(bpy)(2)](2)[MnCl(4)].2CH(2)Cl(2) (1.2CH(2)Cl(2)) crystallizes in the monoclinic space group C2/c with a = 21.756(2) A, b = 12.0587(7) A, c = 26.192(2) A, alpha = 90 degrees, beta = 111.443(2) degrees, gamma = 90 degrees, V = 6395.8(6) A(3), and Z = 4. [Mn(2)O(2)(O(2)CMe)Cl(H(2)O)(bpy)(2)](NO(3))(2).H(2)O (2.H(2)O) crystallizes in the triclinic space group Ponemacr; with a = 11.907(2) A, b = 12.376(2) A, c = 10.986(2) A, alpha = 108.24(1) degrees, beta = 105.85(2) degrees, gamma = 106.57(1) degrees, V = 1351.98(2) A(3), and Z = 2. [Mn(2)O(2)(O(2)CMe)Cl(H(2)O)(bpy)(2)](ClO(4))(2).MeCN (3.MeCN) crystallizes in the triclinic space group Ponemacr; with a = 11.7817(7) A, b = 12.2400(7) A, c = 13.1672(7) A, alpha = 65.537(2) degrees, beta = 67.407(2) degrees, gamma = 88.638(2) degrees, V = 1574.9(2) A(3), and Z = 2. The cyclic voltammogram (CV) of 1 exhibits two processes, an irreversible oxidation of the [MnCl(4)](2)(-) at E(1/2) approximately 0.69 V vs ferrocene and a reversible reduction at E(1/2) = 0.30 V assigned to the [Mn(2)O(2)(O(2)CMe)Cl(2)(bpy)(2)](+/0) couple (2Mn(IV) to Mn(IV)Mn(III)). In contrast, the CVs of 2 and 3 show only irreversible reduction features. Solid-state magnetic susceptibility (chi(M)) data were collected for complexes 1.1.5H(2)O, 2.H(2)O, and 3.H(2)O in the temperature range 2.00-300 K. The resulting data were fit to the theoretical chi(M)T vs T expression for a Mn(IV)(2) complex derived by use of the isotropic Heisenberg spin Hamiltonian (H = -2JS(1)S(2)) and the Van Vleck equation. The obtained fit parameters were (in the format J/g) -45.0(4) cm(-)(1)/2.00(2), -36.6(4) cm(-)(1)/1.97(1), and -39.3(4) cm(-)(1)/1.92(1), respectively, where J is the exchange interaction parameter between the two Mn(IV) ions. Thus, all three complexes are antiferromagnetically coupled.     

A novel aggregate of [Mn2(mu-O)2] units: [Mn8O10(O2CMe)6(H2O)2(bpy)6]4+ with a serpentine core

The synthesis, characterization and initial reactivity studies are reported of the mixed-valence (Mn(IV)6Mn(III)2) title compound, which possesses an unusual serpentine-like core and is the highest average oxidation state (+3.75) Mn(x) (x > 4) cluster to date.     

A Novel 3D Supramolecular Network Constructed from [Cu(4,4'-bipyridine)(O_2CMe)_2]_2 Molecular Ladders by Hydrogen Bonding

1 INTRODUCTION In recent years, the assembly of extended supra- molecular architectures from molecular building units has yielded a new generation of materials with diverse network topologies[1～3]. A number of such frameworks have been found to exhibit fascinating physical and chemical properties. The investigation of hydrogen bonding is important for many practical applications, such as the design of antibiotics and development of new materials with programmed properties[4]. A great va…     

Metallorganische verbindungen des iridiums und rhodiums: XXVI. CH-metallierung und hydridbildung im system Ir2Cl2(C8H14)4/PR3(PR3 = P(CH2CMe3)3, t-BuP(CH2CMe3)2, t-Bu2PCH2CMe3; i-Pr3P

Treatment of Ir₂Cl₂(C₈H₁₄)₄ with the phosphines t-Bu_3?nP(CH₂CMe₃)_n (n = 3,2,1) in hot toluene followed by crystallization of the products from C₇H₈/ EtOH mixtures gave the cyclometallated hydrides (C₈H₁₄)₂Ir-μ-Cl₂$\text{IrH[CH}{}_2\text{CMe}{}_2\text{CH}{}_2\text{P}$(CH₂CMe₃)₂][P(CH₂ (I) [t-BuP(CH₂CMe₃)₂]₂H₂Ir-μ-Cl₂$\text{IrH[CH}{}_2\text{CMe}{}_2\text{CH}{}_2\text{P}$Bu^t(CH₂CMe₃)][t-BuP(CH₂CMe₃)₂] (II), and [(t-Bu₂$\text{PCH}{}_2\text{CMe}{}_2\text{CH}{}_2\text{)HI}$rCl]₂ (III). The dihydrides IrH₂Cl[t-BuP(CH₂CMe₃)₂]₂ (IIa) and IrH₂Cl(t-Bu₂PCH₂CMe₃)₂ (IIIa) were also isolated; these species were, however, more conveniently obtained by bubbling hydrogen through the solution of Ir₂Cl₂ (C₈H₁₄)₄ and the respective phosphine in toluene. i-Pr₃ reacted with the olefiniridium(I) precursor in C₇H₈/EtOH to yield the carbonyl complexes (i-Pr₃P)₂H₂Ir-μ-Cl₂Ir(CO)(PPrⁱ₃)₂ (IV) and IrCl(CO)(PPⁱ₃)₂ (IVa), no cyclometallated product being detected. The stereochemistries of the complexes were deduced from IR, ¹H, ³¹P, and ¹³C NMR data. The crystal structures of IIIa and IVa were also determined.