SHOP-type nickel complexes with alkyl substituents on phosphorus, synthesis and catalytic ethylene oligomerization

The beta-keto phosphorus ylides (n-Bu)3P=CHC(O)Ph 6, (t-Bu)2PhP=CHC(O)Ph 7, (t-Bu)Ph2P=CHC(O)Ph 8, (n-Bu)2PhP=CHC(O)Ph 9, (n-Bu)Ph2P=CHC(O)Ph 10, Me2PhP=CHC(O)Ph 11 and Ph3P=CHC(O)(o-OMe-C6H4) 12 have been synthesized in 80-96% yields. The Ni(II) complexes [NiPh{Ph2PCH...C(...O)(o-OMeC6H4)}(PPh3)] 13, [NiPh{Ph(t-Bu)PCHC(O)Ph}(PPh3)] 15, [NiPh{(n-Bu)2PCH...C(...O)Ph}(PPh3)] 16 and [NiPh{Ph(n-Bu)PCH...C(...O)Ph}(PPh3)] 17 have been prepared by reaction of equimolar amounts of [Ni(COD)2] and PPh3 with the beta-keto phosphorus ylides 12 or 8-10, respectively, and characterized by 1H and 31P{1H} NMR spectroscopy. NMR studies and the crystal structure determination of 13 indicated an interaction between the hydrogen atom of the C-H group alpha to phosphorus and the ether function. The complexes [NiPh{Ph2PCHC(O)Ph}(Py)] 18, [NiPh{Ph(t-Bu)PCHC(O)Ph}(Py)] 19, [NiPh{(n-Bu)2PCH...C(...O)Ph}(Py)] 20, [NiPh{Ph(n-Bu)PCH...C(...O)Ph}(Py)] 21 and [NiPh{Me2PCH...C(...O)Ph}(Py)] 22 have been isolated from the reactions of [Ni(COD)2] and an excess of pyridine with the -keto phosphorus ylides Ph3PCH=C(O)Ph 3 or 8-11, respectively, and characterized by 1H and 31P{1H} NMR spectroscopy. Ligands 3, 8, 10 and 12 have been used to prepare in situ oligomerization catalysts by reaction with one equiv. of [Ni(COD)2] and PPh3 under an ethylene pressure of 30 or 60 bar. The catalyst prepared in situ from 12, [Ni(COD)2] and PPh3 was the most active of the series with a TON of 12700 mol C2H4 (mol Ni)-1 under 30 bar ethylene. When the beta-keto phosphorus ylide 8 was reacted in situ with three equiv. of [Ni(COD)2] and one equiv. of PPh3 under 30 bar of ethylene, ethylene polymerization was observed with a TON of 5500 mol C2H4 (mol Ni)-1.     

Synthesen und Strukturen von Übergangsmetall‐Komplexen mit Dithiophosphinato‐ und Trithiophosphonato‐Liganden

Syntheses and Structures of Transition Metal Complexes with Dithiophosphinato and Trithiophosphinato Ligands The reactions of MnCl₂ with Ph₂P(S)(SSiMe₃) produced [Mn(S₂PPh₂)₂(thf)₂] ( 1 ) and [Mn(S₂PPh₂)₂(dme)] ( 2 ) (DME = 1,2‐Dimethoxyethane). The compounds [Co₆(S₃PPh)₂(μ⁴‐S)₂(μ³‐S)₂(PPh₃)₄] ( 3 ), [Co₂(S₃PPh)₂(PPh₃)₂] ( 4 ), [Ni(S₂PPh)(PPhEt₂)₂] ( 5 ), [Ni(S₃PPh)(PPhEt₂)₂] ( 6 ) and [Cu₄(S₃PPh)₂(dppp)₂] ( 8 ) [dppp = 1,3‐Bis(diphenylphosphanyl)propane] were obtained from reactions of first‐row transition metal halides with PhP(S)(SSiMe₃)₂ in the presence of tertiary phosphines. In a reaction of PhP(S)(SSiMe₃)₂ with PhPEt₂ PhPEt₂PS₂Ph ( 7 ) was isolated. All compounds were characterized by X‐ray crystallography.     

Manganese(II) Complexes with Bridging Selenidoarsenate(III) Anions [AsSe2(Se2)]3− and [(AsSe2)2(μ‐Se2)]4−

Solvothermal reaction of [MnCl₂(terpy)] with elemental As and Se at a 1:1:2 molar ratio in H₂O/trien (10:1) at 150 °C affords the linear trimanganese(II) complex [{Mn(terpy)}₃(μ‐AsSe₄)₂] ( 1 ). The tridentate [AsSe₂(Se₂)]^3? anions of 1 chelate the terminal {Mn(terpy)}²⁺ fragments and bridge these through their remaining Se atom to the central {Mn(terpy)}²⁺ moiety. Weak interactions of Mn1···Se and Mn3···Se bonds with length 2.914(7) and 3.000(7) Å link the molecules of 1 into infinite chains. Treatment of [MnCl₂(cyclam)]Cl with As and Se at a 1:1:2 molar ratio in superheated H₂O/CH₃OH (1:1) at 150 °C yields the dinuclear complex [{Mn(cyclam)}₂ (μ‐As₂Se₆)] ( 2 ), whose novel [(AsSe₂)₂(μ‐Se₂)]^4? ligands bridge the Mn^II atoms in a μ‐1κ²Se¹, Se²: 2κ²Se⁵,Se⁶ manner.     

[{Cp2(tBuSe)Nb}2E] (E = O and Se) with bridging oxide or selenide ligands

The title compounds, μ‐oxido‐bis[(tert‐butylselenolato)bis(η⁵‐cyclopentadienyl)niobium(IV)] toluene solvate, [Nb₂(C₅H₅)₄(C₄H₉Se)₂O]·C₇H₈, and μ‐selenido‐bis[(tert‐butylselenolato)bis(η⁵‐cyclopentadienyl)niobium(IV)], [Nb₂(C₅H₅)₄(C₄H₉Se)₂Se], consist of niobium(IV) centres each bonded to two η⁵‐coordinated cyclopentadienyl groups and one tert‐butylselenolate ligand and are the first organometallic niobium selenolates to be structurally characterized. A bridging oxide or selenide completes the niobium coordination spheres of the discrete dinuclear molecules. In the oxide, the O atom lies on an inversion centre, resulting in a linear Nb—O—Nb linkage, whereas the selenide has a bent bridging group [Nb—Se—Nb = 139.76 (2)°]. The difference is attributable to strong π bonding in the oxide case, although the effects on the Nb—C and Nb—Se^tBu bond lengths are small.     

Photomagnetic Switching of Heterometallic Complexes [M(dmf)4(H2O)3(μ‐CN)Fe(CN)5]⋅H2O (M=Nd,La, Gd,Y) Analyzed by Single‐Crystal X‐ray Diffraction and Ab Initio Theory

Single‐crystal X‐ray diffraction measurements have been carried out on [Nd(dmf)₄(H₂O)₃(μ‐CN)Fe(CN)₅]?H₂O ( 1 ; dmf=dimethylformamide), [Nd(dmf)₄(H₂O)₃(μ‐CN)Co(CN)₅]?H₂O ( 2 ), [La(dmf)₄(H₂O)₃(μ‐CN)Fe(CN)₅]?H₂O ( 3 ), [Gd(dmf)₄(H₂O)₃(μ‐CN)Fe(CN)₅]?H₂O ( 4 ), and [Y(dmf)₄(H₂O)₃(μ‐CN)Fe(CN)₅]?H₂O ( 5 ), at 15(2) K with and without UV illumination of the crystals. Significant changes in unit‐cell parameters were observed for all the iron‐containing complexes, whereas 2 showed no response to UV illumination. Photoexcited crystal structures have been determined for 1 , 3 , and 4 based on refinements of two‐conformer models, and excited‐state occupancies of 78.6(1), 84(6), and 86.6(7) % were reached, respectively. Significant bond‐length changes were observed for the Fe–ligand bonds (up to 0.19 Å), the cyano bonds (up to 0.09 Å), and the lanthanide–ligand bonds (up to 0.10 Å). Ab initio theoretical calculations were carried out for the experimental ground‐state geometry of 1 to understand the electronic structure changes upon UV illumination. The calculations suggest that UV illumination gives a charge transfer from the cyano groups on the iron atom to the lanthanide ion moiety, {Nd(dmf)₄(H₂O)₃}, with a distance of approximately 6 Å from the iron atom. The charge transfer is accompanied by a reorganization of the spin state on the {Fe(CN)₆} complex, and a change in geometry that produces a metastable charge‐transfer state with an increased number of unpaired electrons, thus accounting for the observed photomagnetic effect.     

[Ga(en)3][Ga3Se7(en)] · H2O: Ein Galliumchalkogenid mit Ketten aus [Ga3Se6Se2/2(en)]3–-Bicyclen

[Ga(en)₃][Ga₃Se₇(en)] · H₂O: A Gallium Chalcogenide with Chains of [Ga₃Se₆Se_2/2(en)]^3– Bicycles The new selenidogallate [Ga(en)₃][Ga₃Se₇(en)] · H₂O ( I ) was produced from a ethylendiamine suspension of Ga and Se at 130 °C. I crystallizes in the orthorhombic space group Pna2₁ with unit constants a = 1347.9(3) pm, b = 961.6(1) pm, c = 1967.6(4) pm and Z = 4. The crystal structure contains an anion so far not observed in gallium chalcogenides. It is built from [Ga₃Se₆Se_2/2(en)]^3– bicycles of three Ga^IIIL₄ tetrahedra (L = en, Se) connected via selenium corners to linear chains. The cations, Ga^III ions coordinated by three ethylendiamine in a distorted octahedral geometry are positioned in the holes of the hexagonal rod packing of these chains.     

Intra‐ and intermolecular Se...X (X = Se,O) interactions in selenium‐containing heterocycles: 3‐benzoylimino‐5‐(morpholin‐4‐yl)‐1,2,4‐diselenazole

In the selenium‐containing heterocyclic title compound {systematic name: N‐[5‐(morpholin‐4‐yl)‐3H‐1,2,4‐diselenazol‐3‐ylidene]benzamide}, C₁₃H₁₃N₃O₂Se₂, the five‐membered 1,2,4‐diselenazole ring and the amide group form a planar unit, but the phenyl ring plane is twisted by 22.12 (19)° relative to this plane. The five consecutive N—C bond lengths are all of similar lengths [1.316 (6)–1.358 (6) Å], indicating substantial delocalization along these bonds. The Se...O distance of 2.302 (3) Å, combined with a longer than usual amide C=O bond of 2.252 (5) Å, suggest a significant interaction between the amide O atom and its adjacent Se atom. An analysis of related structures containing an Se—Se...X unit (X = Se, S, O) shows a strong correlation between the Se—Se bond length and the strength of the Se...X interaction. When X = O, the strength of the Se...O interaction also correlates with the carbonyl C=O bond length. Weak intermolecular Se...Se, Se...O, C—H...O, C—H...π and π–π interactions each serve to link the molecules into ribbons or chains, with the C—H...O motif being a double helix, while the combination of all interactions generates the overall three‐dimensional supramolecular framework.     

Oxidative addition of different electrophiles with rhodium(I) carbonyl complexes of unsymmetrical phosphine–phosphine monoselenide ligands

Dimeric chlorobridge complex [Rh(CO)₂Cl]₂ reacts with two equivalents of a series of unsymmetrical phosphine–phosphine monoselenide ligands, Ph₂P(CH₂)_nP(Se)Ph₂ {n = 1( a ), 2( b ), 3( c ), 4( d )}to form chelate complex [Rh(CO)Cl(P∩Se)] ( 1a ) {P∩Se = η²‐(P,Se) coordinated} and non‐chelate complexes [Rh(CO)₂Cl(P～Se)] ( 1b–d ) {P～Se = η¹‐(P) coordinated}. The complexes 1 undergo oxidative addition reactions with different electrophiles such as CH₃I, C₂H₅I, C₆H₅CH₂Cl and I₂ to produce Rh(III) complexes of the type [Rh(COR)ClX(P∩Se)] {where R = ? C₂H₅ ( 2a ), X = I; R = ? CH₂C₆H₅ ( 3a ), X = Cl}, [Rh(CO)ClI₂(P∩Se)] ( 4a ), [Rh(CO)(COCH₃)ClI(P～Se)] ( 5b–d ), [Rh(CO)(COH₅)ClI‐(P～Se)] ( 6b–d ), [Rh(CO)(COCH₂C₆H₅)Cl₂(P～Se)] ( 7b–d ) and [Rh(CO)ClI₂(P～Se)] ( 8b–d ). The kinetic study of the oxidative addition (OA) reactions of the complexes 1 with CH₃I and C₂H₅I reveals a single stage kinetics. The rate of OA of the complexes varies with the length of the ligand backbone and follows the order 1a > 1b > 1c > 1d . The CH₃I reacts with the different complexes at a rate 10–100 times faster than the C₂H₅I. The catalytic activity of complexes 1b–d for carbonylation of methanol is evaluated and a higher turnover number (TON) is obtained compared with that of the well‐known commercial species [Rh(CO)₂I₂]^?. Copyright © 2006 John Wiley & Sons, Ltd.     

Koordinationspolymere 1, 2‐Dithiooxalato‐ und 1, 2‐Dithioquadratato‐Komplexe. Synthese und Strukturen von [BaCr2(bipy)2(1, 2‐dtox)4(H2O)2], [Ni(cyclam)(1, 2‐dtsq)]·2DMF, [Ni(cyclam)Mn(1, 2‐dtsq)2(H2O)2]·2H2O und [H3O][H5O2][Cu(cyclam)]3[Cu2(1, 2‐dtsq)3]2

Coordination Polymeric 1, 2‐Dithiooxalato and 1, 2‐Dithiosquarato Complexes. Syntheses and Structures of [BaCr₂(bipy)₂(1, 2‐dtox)₄(H₂O)₂], [Ni(cyclam)(1, 2‐dtsq)]·2DMF, [Ni(cyclam)Mn(1, 2‐dtsq)₂(H₂O)₂]·2H2₂, and [H₃O][H₅O₂][Cu(cyclam)]₃[Cu₂(1, 2‐dtsq)₃]₂ 1, 2‐Dithioxalate and 1, 2‐dithiosquarate ions have a pair of soft and hard donor centers and thus are suited for the formation of coordination polymeric complexes containing soft and hard metal ions. The structures of four compounds with building blocks containing these ligands are reported: In [BaCr₂(bipy)₂(1, 2‐dtox)₄(H₂O)₂] Barium ions and pairs of Cr(bipy)(1, 2‐dtox)₂ complexes form linear chains by the bisbidentate coordination of the dithiooxalate ligands towards Ba²⁺ and Cr³⁺. In [Ni(cyclam)(1, 2‐dtsq)]·2DMF short NÖH···O hydrogen bonds link the NiS₂N₄‐octahedra with C_2v‐symmetry to an infinite chain. In [Ni(cyclam)Mn(1, 2‐dtsq)₂(H₂O)₂]·2H₂O the 1, 2‐dithiosquarato ligand shows a rare example of S‐coordination towards manganese(II). The sulfur atoms of cis‐MnO₂S₄‐polyedra are weakly coordinated towards the axial sites of square‐planar NiN₄‐centers, thus forming a zig‐zag‐chain of Mn···Ni···Mn···Ni polyhedra. [H₃O][H₅O₂][Cu (cyclam)]₃[Cu₂(1, 2‐dtsq)₃]₂ contains square planar [Cu^II(cyclam)]²⁺ ions and dinuclear [Cu^I₂(1, 2‐dtsq)₃]^4— ions. Here each copper atom is trigonally planar coordinated by S‐donor atoms of the ligands. The Cu…Cu distance is 2.861(4)Å.     

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 .     

Oxidation of a dinuclear manganese(II) complex to an oxide‐bridged dimanganese(IV) complex

Bis{μ‐2‐[bis(pyridin‐2‐ylmethyl)amino]acetato}bis[diaquamanganese(II)] bis(trifluoromethanesulfonate) monohydrate, [Mn₂(C₁₄H₁₄N₃O₂)₂(H₂O)₄](CF₃O₃S)₂·H₂O, (I), and bis{μ‐3‐[bis(pyridin‐2‐ylmethyl)amino]propionato}bis[aquamanganese(II)] bis(trifluoromethanesulfonate) dihydrate, [Mn₂(C₁₅H₁₆N₃O₂)₂(H₂O)₂](CF₃O₃S)₂·2H₂O, (II), form binuclear seven‐coordinate complexes. Oxidation of (II) with ammonium hexanitratocerate(IV), (NH₄)₂[Ce(NO₃)₆], gave the oxide‐bridged dimanganese(IV) complex di‐μ‐oxido‐bis(bis{3‐[bis(pyridin‐2‐ylmethyl)amino]propionato}manganese(IV)) bis[triaquatetranitratocerate(IV)], [Mn₂O₂(C₁₅H₁₆N₃O₂)₂][Ce(NO₃)₄(H₂O)₃]₂, (III). The manganese complexes in (II) and (III) sit on a site of symmetry.     

Synthese und Struktur der Komplexe [(Me2PhP)3Cl2Re≡N‐RuCl2(C6H6)] und [(Me2PhP)3Cl2Re≡N‐RhCl(COD)]

Synthesis and Crystal Structure of the Complexes [(Me₂PhP)₃Cl₂Re≡N‐RuCl₂(C₆H₆)] and [(Me₂PhP)₃Cl₂Re≡N‐RhCl(COD)] The heteronuclear complex [(Me₂PhP)₃Cl₂Re≡N‐RuCl₂(C₆H₆)] ( 1 ) is obtained by the reaction of [ReNCl₂(PMe₂Ph)₃] with [RuCl₂(C₆H₆)]₂ in C₆H₅CN in form of red crystals with the composition 1 ·C₆H₅CN crystallizing in the monoclinic space group P2₁/c with a =1149.77(8), b = 3085.9(3), c = 1172.1(1) pm, β = 104.766(9)° and Z = 4. In the dinuclear complex the complex fragment [RuCl₂(C₆H₆)] is connected by an asymmetric nitrido bridge with the nitrido complex [ReNCl₂(PMe₂Ph)₃]. The nitrido bridge is characterised by a bond angle Re‐N‐Ru of 170.6(3)° and distances Re‐N = 170.2(5) and Ru‐N = 199.0(5) pm. The reaction of [ReNCl₂(PMe₂Ph)₃] with [RhCl(COD)]₂ in benzonitrile yields orange crystals of [(Me₂PhP)₃Cl₂Re≡N‐RhCl(COD)] ( 2 ) with the space group P2₁/c and a = 1522.3(2), b = 1274.85(4), c = 1921.2(2) pm, β = 106.759(7)° and Z = 4. The monovalent Rh atom exhibits a square planar coordination with the two π‐bonds of the cycloocta‐1, 5‐diene occupying cis positions. The distances in the almost linear nitrido bridge (Re‐N‐Rh = 174.8(4)°>) are Re‐N = 172.2(6) pm and Rh‐N = 195.6(6) pm.     

Synthesis,Structures and Reactivity of Lanthanoid(II) Formamidinates of Varying Steric Bulk

New reactive, divalent lanthanoid formamidinates [Yb(Form)₂(thf)₂] (Form=[RNCHNR]; R=o‐MeC₆H₄ (o‐TolForm; 1 ), 2,6‐Me₂C₆H₃ (XylForm; 2 ), 2,4,6‐Me₃C₆H₂ (MesForm; 3 ), 2,6‐Et₂C₆H₃ (EtForm; 4 ), o‐PhC₆H₄ (o‐PhPhForm; 5 ), 2,6‐iPr₂C₆H₃ (DippForm; 6 ), o‐HC₆F₄ (TFForm; 7 )) and [Eu(DippForm)₂(thf)₂] ( 8 ) have been prepared by redox transmetallation/protolysis reactions between an excess of a lanthanoid metal, Hg(C₆F₅)₂ and the corresponding formamidine (HForm). X‐ray crystal structures of 2 – 6 and 8 show them to be monomeric with six‐coordinate lanthanoid atoms, chelating N,N′‐Form ligands and cis‐thf donors. However, [Yb(TFForm)₂(thf)₂] ( 7 ) crystallizes from THF as [Yb(TFForm)₂(thf)₃] ( 7 a ), in which ytterbium is seven coordinate and the thf ligands are “pseudo‐meridional”. Representative complexes undergo C? X (X=F, Cl, Br) activation reactions with perfluorodecalin, hexachloroethane or 1,2‐dichloroethane, and 1‐bromo‐2,3,4,5‐tetrafluorobenzene, giving [Yb(EtForm)₂F]₂ ( 9) , [Yb(o‐PhPhForm)₂F]₂ ( 10) , [Yb(o‐PhPhForm)₂Cl(thf)₂] ( 11) , [Yb(DippForm)₂Cl(thf)] ( 12) and [Yb(DippForm)₂Br(thf)] ( 16) . X‐ray crystallography has shown 9 to be a six‐coordinate, fluoride‐bridged dimer, 12 and 16 to be six‐coordinate monomers with the halide and thf ligands cis to each other, and 11 to have a seven‐coordinate Yb atom with “pseudo‐meridional” unidentate ligands and thf donors cis to each other. The analogous terbium compound [Tb(DippForm)₂Cl(thf)₂] ( 13 ), prepared by metathesis, has a similar structure to 11 . C? Br activation also accompanies the redox transmetallation/protolysis reactions between La, Nd or Yb metals, Hg(2‐BrC₆F₄)₂, and HDippForm, yielding [Ln(DippForm)₂Br(thf)] complexes (Ln=La ( 14 ), Nd ( 15 ), Yb ( 16 )).     

Chalkogen‐Derivate der Halbsandwich‐Wolfram(V)‐Komplexe Cp*WCl4 und Cp*WCl4(PMe3). Röntgen‐Kristallstrukturanalysen von anti‐[Cp*W(Se)(μ‐Se)]2 und Cp*W(S)2(OMe)

Chalcogen Derivatives of the Halfsandwich Tungsten(V) Complexes Cp*WCl₄ and Cp*WCl₄(PMe₃). X‐Ray Crystal Structure Analyses of anti ‐[Cp*W(Se)(μ‐Se)]₂ and Cp*W(S)₂(OMe) The chalcogenation of Cp*WCl₄ ( 1 ) by E(SiMe₃)₂ (E = S, Se) and Te(SiMe₂^tBu)₂ in chloroform solution leads to dimeric products of the type anti‐[Cp*W(E)(μ‐E)]₂ (E = S ( 3 a ), Se ( 3 b ) and Te ( 3 c )). An X‐ray structure determination of 3 b indicates a centrosymmetric molecule containing a planar W(μ‐Se)₂W ring, the W–W distance (297.9(1) pm) corresponds to a single bond. In the presence of air the two terminal chalcogenido ligands (E) in 3 a – c are stepwise replaced by oxido ligands (O) to give [Cp*W(O)(μ‐E)]₂ (E = S ( 5 a ), Se ( 5 b ) and Te ( 5 c )) in quantitative yields. The reaction of Cp*WCl₄ with H₂S or ammonium polysulfide, (NH₄)₂S_x (x ∼ 10), leads to Cp*W(S)₂Cl ( 6 a ); the corresponding methoxy derivative, Cp*W(S)₂OCH₃ ( 9 a ), has been characterized by an X‐ray structure analysis. On the other hand, the reaction of Cp*WCl₄(PMe₃) ( 2 ) with sodium tetrasulfide, Na₂S₄, in dimethylformamide solution gives a mixture of mononuclear Cp*W(S)(S₂)Cl ( 8 a ), dinuclear [Cp*W(S)(μ‐S)]₂ ( 3 a ) and a trinuclear side‐product of composition Cp*₂W₃S₇ ( 13 a ). Terminal sulfido ligands are replaced by terminal oxido ligands in solution in the presence of oxygen. Thus, 6 a is stepwise converted into Cp*W(O)(S)Cl ( 10 a ) and CpW(O)₂Cl ( 12 a ), whereas 8 a gives Cp*W(O)(S₂)Cl ( 11 a ) and 13 a leads to Cp*₂W₃(O)S₆ ( 14 a ). The disulfido complexes 8 a and 11 a are desulfurized by triphenylphosphane to give 6 a and 10 a . The new complexes have been characterized by their IR and NMR spectra and by mass spectrometry.     

Ligand Exchange Processes on Solvated Beryllium Cations. IV [Be(H2O)2(imidazole‐based Chelate)]1)

The water exchange reaction of [Be(H₂O)₂(1H‐imidazole‐4,5‐dicarboxylate)] and [Be(H₂O)₂(1H‐imidazol‐3‐ium‐4,5‐dicarboxylate)]⁺ in water was studied by DFT calculations (RB3LYP/6‐311+G**) and identified as an associative interchange mechanism. The activation barriers for [Be(H₂O)₂(1H‐imidazole‐4,5‐dicarboxylate)] (16.6 kcal/mol) and [Be(H₂O)₂(1H‐imidazol‐3‐ium‐4,5‐dicarboxylate)]⁺ (13.8 kcal/mol) are similar to the barrier for [Be(H₂O)₄)]²⁺ and independent of the overall charge. NICS calculations show no indication that the aromaticity of the imidazole ring is affected during the water exchange process.     

Untersuchungen zur Darstellung von [CpxSb{M(CO)5}2] (Cpx = Cp,Cp*; M = Cr,W)

Investigations of the Synthesis of [Cp^xSb{M(CO)₅}₂] (Cp^x = Cp, Cp*; M = Cr, W) The reaction of CpSbCl₂ with [Na₂{Cr₂(CO)₁₀}] leads to the chlorostibinidene complex [ClSb{Cr(CO)₅}₂(thf)] ( 1 ), whereas the reaction of CpSbCl₂ with [Na₂{W₂(CO)₁₀}] results in the formation of the complexes [ClSb{W(CO)₅}₃] ( 2 ), [Na(thf)][Cl₂Sb{W(CO)₅}₂] ( 3 ), [ClSb{W(CO)₅}₂(thf)] ( 4 ) and [Sb₂{W(CO)₅}₃] ( 5 ). The stibinidene complex [CpSb{Cr(CO)₅}₂] ( 6 ) is obtained by the reaction of [ClSb{Cr(CO)₅}₂] with NaCp, while its Cp* analogue [Cp*Sb{Cr(CO)₅}₂] ( 7 ) is formed via the metathesis of Cp*SbCl₂ with [Na₂{Cr₂(CO)₁₀}]. The products 2 , 3 , 4 and 7 are additionally characterised by X‐ray structure analyses.     

Remote Multiproton Storage within a Pyrrolide‐Pincer‐Type Ligand

A chemically non‐innocent pyrrole‐based trianionic (ONO)^3? pincer ligand within [(pyr‐ONO)TiCl(thf)₂] ( 2 ) can access the dianionic [(3H‐pyr‐ONO)TiCl₂(thf)] ( 1‐THF ) and monoanionic [(3H,4H‐pyr‐ONO)TiCl₂(OEt₂)][B{3,5‐(CF₃)₂C₆H₃}₄] ( 3‐Et₂O ) states through remote protonation of the pyrrole γ‐C π‐bonds. The homoleptic [(3H‐pyr‐ONO)₂Zr] ( 4 ) was synthesized and characterized by X‐ray diffraction and NMR spectroscopy in solution. The protonation of 4 by [H(OEt₂)₂][B{C₆H₃(CF₃)₂}₄] yields [(3H,4H‐pyr‐ONO)(3H‐pyr‐ONO)Zr][B{3,5‐(CF₃)₂C₆H₃}₄] ( 5 ), thus demonstrating the storage of three protons.     

Molybdenum(0) and Tungsten(0) Complexes with P,S and P,Se Monooxidized Bis(phosphanyl)amine Ligands

Reactions of monooxidized thioyl and selenoyl bis(phosphanyl)amine ligands C₁₀H₇‐1‐N(P(E)Ph₂)(PPh₂) [E = S ( 1 ), Se ( 2 )] with Mo(CO)₄(pip)₂ and W(CO)₄(cod) afforded the complexes [M(CO)₄{ 1 ‐κ²P,S}] [M = Mo ( 3 ), W ( 4 )] and [M(CO)₄{ 2 ‐κ²P,Se}] [M = Mo ( 5 ), W ( 6 )]. Complexes 3 – 6 were characterized by multinuclear NMR (¹H, ¹³C, ³¹P, and ⁷⁷Se NMR) and IR spectroscopy. Crystal‐structure determinations were carried out on 3 , 5 , and 6 , which represent the first examples of structurally characterized complexes of such ligands with group‐6 metal carbonyls.     

Untersuchungen über Iodoferrate: Die Kristallstrukturen von Fe(THE)6(FeI3THF)2 · THF und Fe(Ch2O)6(FeI4)2 · I2(THF = C4H8O)

Investigations about Iodoferrates: The Crystal Structures of Fe(thf)₆(FeI₃thf)₂ · thf and Fe(CH₂O)₆(FeI₄)2 · I₂(thf = C₄H₈O) The crystal structures of FeI₂ · 3 thf (i.e. Fe(thf)₆(FeI₃thf)₂ · thf) ( 1 ) and Fe(CH₂O)₆(FeI₄)₂ · I₂ ( 2 ) were determined from single crystal X-ray data. 1 crystallizes in the cubic space group Pa3, a = 1759.8 pm, Z = 4, 2 in the monoclinic space group P2₁/n, a = 997.4, b = 1669.4, c = 1082.6 pm, β = 93.11°, Z = 2. The structure of 1 is composed of octahedral Fe(thf)₆²⁺ cations and distorted tetrahedral [FeI₃(thf)]-anions (Fe? I distance 261.1 pm). In 2 two tetrahedral tetraiodoferrate (III) anions are linked by an iodine molecule. The Fe? I distance was found to be 253.9 pm (mean, the I? I distance between FeI₄^? and I₂ 356.1 pm. The decomposititon of 1 in vacuum at elevated temperatures and the resulting formation of 2 from 1 are discussed.     

Zweidimensionale Polymere mit hydrophober Umhüllung: Kristallstrukturen der isostrukturellen Metallkomplexe [M{C6H4(SO2)2N}(H2O)] (M = K,Rb) und des strukturverwandten Ammoniumsalzes [(NH4){C6H4(SO2)2N}(H2O)]

Metal Salts of Benzene‐1,2‐di(sulfonyl)amine. 4. Hydrophobically Wrapped Two‐Dimensional Polymers: Crystal Structures of the Isostructural Metal Complexes [M{C₆H₄(SO₂)₂N}(H₂O)] (M = K, Rb) and of the Structurally Related Ammonium Salt [(NH₄){C₆H₄(SO₂)₂N}(H₂O)] The previously unreported compounds KZ · H₂O ( 1 ), RbZ · H₂O ( 2 ) and NH₄Z · H₂O ( 3 ), where Z^– is Ndeprotonated ortho‐benzenedisulfonimide, are examples of layered inorgano‐organic solids, in which the inorganic component is comprised of metal or ammonium cations, N(SO₂)₂ groups and water molecules and the outer regions are formed by the planar benzo rings of the anions. The metal complexes 1 and 2 were found to be strictly isostructural, whereas 3 is structurally related to them by a non‐crystallographic mirror plane ( 1 – 3 : monoclinic, space group P2₁/c, Z = 4; single crystal X‐ray diffraction at low temperatures). In each structure, the five‐membered 1,3,2‐dithiazolide heterocycle possesses an envelope conformation, the N atom lying about 40 pm outside the mean plane of the S–C–C–S moiety. The metal complexes feature two‐dimensional coordination networks interwoven with O–H…O hydrogen bonds originating from the water molecules. The metal centres adopt an irregular nonacoordination formed by five sulfonyl O atoms, two N atoms and two μ₂‐bridging water molecules; each M⁺ is connected to four different anions. When NH₄⁺ is substituted for M⁺, the metal–ligand bonds are replaced by N⁺–H…O hydrogen bonds, but the general topology of the lamella is not affected. In the three structures, the lipophilic benzo groups protrude obliquely from the surfaces of the polar lamellae and display marked interlocking between adjacent layers.