bluuebunny/crossref_metadata_2025_split huggingface dataset:
3,6‐Di(2‐pyridyl)‐1,4,2,5‐dioxadiazine and a Silver Coordination Polymer with an Unprecedented Metallosupramolecular Topology
Authors: Richardson Chris , Steel Peter J. 
Published: January 2003

AbstractThe new ligand 3,6‐di(2‐pyridyl)‐1,4,2,5‐dioxadiazine (6) has been prepared and reacted with silver tetrafluoroborate to form a novel coordination polymer in which adjacent chains are interdigitated and π‐stacked. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Direct Synthesis of Enantiopure Tripod Ligands from C2‐Symmetric Precursors
Authors: Hegelmann Ina , Burzlaff Nicolai 
Published: January 2003

AbstractA new enantiopure chiral tripod ligand is obtained from C2‐symmetric bis(camphorpyrazol‐1‐yl)methane by introducing a carboxylate group at the bridging carbon atom. A prochiral centre is formed rather than an additional stereocentre. Therefore, a homochiral tripod ligand is achieved without separation of the stereoisomers. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
A New Porous 3‐D Framework Constructed From Fivefold Parallel Interpenetration of 2‐D (6,3) Nets: A Mixed‐Valence Copper(I,II) Coordination Polymer [CuI2CuII(4,4′‐bpy)2(pydc)2]·4H2O
Authors: Zhang Xian‐Ming , Chen Xiao‐Ming 
Published: January 2003

AbstractA mixed‐valence copper(I,II) coordination polymer [CuI2CuII(4,4′‐bpy)2(pydc)2]·4H2O (4,4′‐bpy = 4,4′‐bipyridine and pydc = pyridine‐2,4‐dicarboxylate) featuring the “metal‐complex ligands” [CuII(pydc)2]2− was designed and synthesized hydrothermally from Cu(MeCO2)2, pyridine‐2,4‐dicarboxylate, 4,4′‐bipyridine and NaOH. This compound was shown by single‐crystal structure analysis to be the first porous 3‐D framework constructed from fivefold parallel interpenetration of 2‐D (6,3) nets. The one‐dimensional channels occupying 17.4% of the crystal volume are occupied by guest water molecules and the porous network is stable after removal of the lattice water molecules, as indicated by TGA and PXRD measurements. The high stability of the 3‐D framework may be attributed to the multiple entanglement of the 2‐D nets. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis, Structure and Reactivity of Sulfur‐Rich [Fe(L1)(L2)(‘tpS4’)] Complexes with Rigid [Fe(‘tpS4’] Cores and σ−π Co‐Ligands (‘tpS4’2− = 1,2‐Bis(2‐mercaptophenylthio)phenylene(2−); L1, L2 = CO, PR3, NO)
Authors: Sellmann Dieter , Blum David C. F. , Heinemann Frank W. , Sutter Jörg 
Published: January 2003

AbstractOptimisation of synthesis and purification steps has made the new ligand ‘tpS4’2− available in preparative amounts. Treatment of FeCl2·4H2O with ‘tpS4’‐Li2 or ‘tpS4’‐Na2 yielded [Fe(‘tpS4’)] (1), which in the solid state and in the absence of co‐ligands probably trimerises to give paramagnetic [Fe(‘tpS4’)]3. The [Fe(‘tpS4’)] fragment displays helical coordination of the ‘tpS4’2− ligand and binds σ−π ligands such as CO, NO and phosphanes to give diamagnetic 18‐valence‐electron complexes of general formula [Fe(L1)(L2)(‘tpS4’)]. The cis‐dicarbonyl complex [Fe(CO)2(‘tpS4’)] (2) is labile and readily dissociates CO to give dinuclear [Fe(CO)(‘tpS4’)]2 (3). Simultaneous coordination of CO and phosphanes yielded [Fe(CO)(PR3)(‘tpS4’)] with R = Me (4), Et (5), Pr (6) and Bu (7), but it proved impossible to obtain analogous complexes with bulky PPh3 or PCy3 ligands. Bis(phosphane) complexes could be obtained only with PMe3 and the bidentate dppe, which yielded [Fe(PMe3)2(‘tpS4’)] (8) and [Fe(dppe)(‘tpS4’)] (11). Alkylphosphanes with longer alkyl substituents, such as PnPr3 and PnBu3, gave the labile derivatives [Fe(PR3)2(‘tpS4’)] with R = nPr (9) and nBu (10). Complexes 9 and 10 reversibly dissociate one PR3 ligand, yielding diamagnetic [Fe(PR3)(‘tpS4’)] fragments. These findings explain the decisive and hitherto inexplicable influence of PPr3 and PBu3 ligands upon the stabilisation of N2H2 in the diazene complexes [μ‐N2H2{Fe(PR3)(‘tpS4’)}2] with R = Pr, Bu. Treatment of [Fe(‘tpS4’)] (1) or [Fe(CO)(‘tpS4’)]2 (3) with NO or NO+ yielded [Fe(NO)2(‘tpS4’)] (12). The molecular structures of 3, 4, 7 and 8 were determined by X‐ray structure analysis. Spectroscopic and structural results indicate that the differences in reactivity between [Fe(L1)(L2)(‘tpS4’)] and homologous [Fe(L1)(L2)(‘S4’)] complexes can be traced back to subtle electronic and structural effects. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Chloro‐ and Alkyltitanium Complexes of a New Dianionic Ancillary Ligand: A Linked Amidinate−Amide
Authors: Meerendonk Wouter J. van , Schröder Kai , Brussee Edward A. C. , Meetsma Auke , Hessen Bart , Teuben Jan H. 
Published: January 2003

AbstractThe lithium amidinate [Me3SiNC(Ph)N(CH2)3N(Me)SiMe3]Li(THF) (2), with a pendant methyl(trimethylsilyl)amine functionality, was prepared and found to react with [TiCl4(THF)2] to give the titanium amidinate−amide dichloride complex [η2,η1‐Me3SiNC(Ph)N(CH2)3NMe]TiCl2 (3) by elimination of LiCl and Me3SiCl. The elimination of Me3SiCl from the cyclopentadienyl derivative Cp[η2‐Me3SiNC(Ph)N(CH2)3N(SiMe3)Me]TiCl2 (5) to give Cp[η2,η1‐Me3SiNC(Ph)N(CH2)3NMe]TiCl (4) is much less favorable, and was found to be readily reversible. Dialkyltitanium complexes [η2,η1‐Me3SiNC(Ph)N(CH2)3NMe]Ti(CH2R)2 [R = Ph (6), SiMe3 (7)] were prepared, but could not be activated for catalytic ethene polymerization. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis and Structure of the First Holmium and Erbium Diiodide Complexes of Composition LLnI2 (Ln = Ho, Er)
Authors: Nikiforov Grigori B. , Roesky Herbert W. , Labahn Thomas , Vidovic Denis , Neculai Dante 
Published: January 2003

AbstractTwo new diiodide complexes of stoichiometry LLnI2 [Ln = Ho (1), Er (2)] with the β‐diketiminato ligand 2‐{[2‐(diethylamino)ethyl]amino}‐4‐{[2‐(diethylamino)ethyl]imino}pent‐2‐ene have been synthesized by the reaction of the lithium salt of the ligand with the corresponding triiodides. The complexes are thermally stable and soluble in common organic solvents. The X‐ray structural and elemental analysis show that LLnI2 is neutral, and as well free of solvent and lithium salt. The complexes adopt a pseudo‐octahedral geometry with the two iodine atoms arranged in trans position to each other. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis and Structure of the First Non‐Metallocene TiIII Fluoride Complex LTiF2·2Me3SnCl Supported by a β‐Diketiminato Ligand
Authors: Nikiforov Grigori B. , Roesky Herbert W. , Magull Jörg , Noltemeyer Mathias , Schmidt Hans‐Georg , Ilyin Evgeny G. , Kokunov Yuri B. , Demsar Alojz 
Published: January 2003

AbstractThe TiIII dichloride complex LTiCl2 (1) and the first non‐metallocene TiIII fluoride complex LTiF2·2Me3SnCl (2) supported by the β‐diketiminato ligand 2‐{[2‐(diethylamino)ethyl]amino}‐4‐{[2‐(diethylamino)ethyl]imino}pent‐2‐ene have been synthesized. Elemental analysis, mass spectrometry and X‐ray structural analysis show that 1 is monomeric, neutral, and free of solvent and lithium salt. The complex adopts a pseudo‐octahedral geometry with the two chlorine atoms arranged in trans position to each other. Compound 1 is soluble in common organic solvents and thermally surprisingly robust. Complex 2 was prepared using Me3SnF as a fluorinating agent. X‐ray structural analysis revealed that complex 2 consists of the LTiF2 unit and two molecules of Me3SnCl coordinated through a fluorine bridge to the titanium center. The fluorine atoms in 2 are located in trans positions to each other and the geometry around the titanium atom is distorted octahedral. Elemental analysis and mass spectrometry proved that 2 releases the coordinated Me3SnCl under vacuum or during sublimation. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis of a Hexadentate Hexameric Aluminum Imide and Its Metathesis Reactions
Authors: Reddy N. Dastagiri , Kumar S. Shravan , Roesky Herbert W. , Vidovic Denis , Magull Jörg , Noltemeyer Mathias , Schmidt Hans‐Georg 
Published: January 2003

AbstractThe reaction of AlH3·NMe3 with one equivalent of 2‐cyanothiophene in toluene afforded [HAlNCH2(C4H3S)]6 (2) in good yield. Treatment of 2 with SiMe3Br and SiMe3Cl in toluene under refluxing conditions resulted in the formation of compounds [BrAlNCH2(C4H3S)]6 (3) and [ClAlNCH2(C4H3S)]6 (4), respectively. In a similar way [PhC≡CAlNCH2(C4H3S)]6 (5) was readily obtained from the reaction between 2 and PhC≡CH. When 2 was treated with PhSH the Al‐N cluster core dissociated and a four‐membered ring compound [(PhS)2AlNHCH2(C4H3S)]2 (6) was formed. In contrast, a similar hexameric aluminum imide (HAlNCH2Ph)6 (1) retains its Al‐N network when treated with PhSH to yield (PhSAlNCH2Ph)6 (7). An exchange of ethyl groups and hydrides occurred when 2 was treated with excess of ZnEt2, forming [EtAlNCH2(C4H3S)]6 8. Compounds 2−4 and 6−8 were characterized by X‐ray single‐crystal analysis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
4‐Ethynylpyridine as a Bridging Moiety in Mixed Rh/Re Complexes
Authors: Zuo Jing‐Lin , Biani Fabrizia Fabrizi de , Santos Ana M. , Köhler Klaus , Kühn Fritz E. 
Published: January 2003

AbstractA paramagnetic, dimeric RhIIIRhII complex of the formula [Rh2(form)4(C≡CC5H4N)] (1) [form = N,N′‐di‐p‐tolylformamidinate; C5H4N = pyridyl (py)] has been synthesized and used as starting material to prepare heterotrimetallic complexes of composition [Rh2(form)4(C≡Cpy){Re(CO)3(bipy)}][OS(=O)2CF3] (2) and [Rh2(form)4(C≡Cpy){Re(CO)3(tbu2bipy)}][OS(=O)2CF3] (3). These complexes have been examined by vibrational spectroscopy, EPR spectroscopy, thermogravimetry and cyclic voltammetry. They are heat‐stable and can be handled in air without problems. The observed interactions between the Rh2 and the Re subunits, however, are weak, and a significant charge transfer does not seem to take place. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Structure and Electronic Properties of [Ni(dsdm){Fe(CO)3}2], an Unusual, Triangular Nickel Diiron Compound
Authors: Chalbot Marie‐Cécile , Mills Allison M. , Spek Anthony L. , Long Gary J. , Bouwman Elisabeth 
Published: January 2003

AbstractReaction of the low‐spin complex [Ni(dsdm)] with Fe2CO9 results in the unique trinuclear cluster [Ni(dsdm){Fe(CO)3}2]. NMR spectroscopy shows that the structure is diamagnetic, and, moreover, that the complex is stable in solution and C2‐symmetric. The X‐ray structure reveals short distances between the distorted octahedral nickel(II) ion and the two octahedral iron(0) centers. The observed diamagnetism is explained by the formation of a triangular metal core with three two‐electron two‐center bonds. The Mössbauer spectra, which are typical of iron(0), are composed of asymmetric quadrupole doublets as a result of the presence of two chemically similar, but crystallographically distinct, iron sites. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Co‐Condensation Reactions of Substituted Aromatic Compounds with Lithium Atoms at 77 K
Authors: Dunne John P. , Bockmeyer Matthias , Tacke Matthias 
Published: January 2003

AbstractLithium atoms were co‐condensed with +I‐substituted benzene derivatives like trimethyl(phenyl)silane and tert‐butylbenzene in the presence of THF at 77 K, which resulted in C−H bond activation, to produce the aryllithium compound as well as the coupling of the substituted phenyl radicals. Other +I‐substituted benzene derivatives like xylene and mesitylene failed to react with lithium atoms in the presence of THF. Oxygen and nitrogen donor substituted benzene derivatives (anisole, N,N‐dimethylaniline, and N,N‐dimethylbenzylamine) showed activation of the ortho C−H bond when co‐condensed with lithium atoms in the presence of THF. However, when thioanisole was co‐condensed with lithium atoms and THF, a C−S bond cleavage occurred instead. These results were interpreted with the aid of DFT calculations, which show π‐ and σ‐complexes between the lithium clusters and benzene derivatives as reactive intermediates. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Macrocyclic Complexes of [Ru(N‐N)2]2+ Units [N‐N = 1,10 Phenanthroline or 4‐(p‐Anisyl)‐1,10‐Phenanthroline]: Synthesis and Photochemical Expulsion Studies
Authors: Laemmel Anne‐Chantal , Collin Jean‐Paul , Sauvage Jean‐Pierre , Accorsi Gianluca , Armaroli Nicola 
Published: January 2003

AbstractTwo ruthenium complexes [Ru(phen)2(m‐36)]2+ and [Ru(aphen)2(m‐36)]2+, indicated as 1 and 2 respectively, which contain a 36‐membered macrocycle incorporating a sterically hindered bipyridine (m‐36), and two 1,10‐phenanthroline (phen) or 4‐(p‐anisyl)‐1,10‐phenanthroline (aphen) ligands, have been synthesised. Under light irradiation, as seen from the metal‐to‐ligand‐charge‐transfer (MLCT) bands of the visible spectral region, the [Ru(phen)]22+ core of 1 and 2 is selectively expelled from the macrocycle to give the corresponding bis‐acetonitrile derivative. This photochemical process was found to be notably less efficient than that observed in a simpler related complex [Ru(phen)2dmbp]2+ (dmbp = 6,6′dimethyl‐2,2′‐bipyridine), that lacks the macrocyclic motif. In the case of 1 thermal back reaction takes place quantitatively affording a completely reversible system. The isolation, by chromatographic techniques, of the axial‐axial cis‐[(a,a)Ru(aphen)2Cl2] isomer, where the two aphen ligands bear two p‐anisyl groups disposed trans to one another enabled the preparation of 2. This type of complex undergoes a more complicated photochemical process, in fact, following the expected photolabilisation of the [Ru(aphen)2]2+ unit, photoisomerisation of the primary photo‐product occurs and gives a statistical mixture of the three geometrical isomers: cis‐[(a,a)Ru(aphen)2(CH3CN)2](PF6)2, cis‐[(a,e)Ru(aphen)2(CH3CN)2](PF6)2 and cis‐[(e,e)Ru(aphen)2(CH3CN)2](PF6)2. This side‐reaction precludes its use as rotaxane precursor suggesting that, for this purpose, a bis‐phenanthroline ligand stabilising the ruthenium core is needed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Change in the Spin State of an FeIII Center upon One N‐to‐O Switch in the Coordination of a 2,6‐Pyridinedicarboxamido Unit: The Effect of Methyl Thioether and Methyl Ether Appendages at the Ligand Periphery
Authors: Harrop Todd C. , Tyler Laurie A. , Olmstead Marilyn M. , Mascharak Pradip K. 
Published: January 2003

AbstractTwo ligands bearing the 2,6‐pyridinedicarboxamide unit, namely PyPSMeH2 and PyPOMeH2, have been used to prepare complexes of FeIII which have been structurally characterised. The potentially pentadentate thioether ligand PyPSMeH2 affords only the bis complex (Et4N)[Fe(PyPSMe)2] (1), irrespective of the metal to ligand ratio, due to the weak affinity of the thioether groups for the FeIII center. In [Fe(PyPSMe)2]−, the two PyPSMe2− ligands bind to the iron center in a mer fashion and steric crowding among the pendant thioether groups forces one of the four deprotonated carboxamido moieties to bind to the FeIII center through the carbonyl oxygen, giving rise to an FeN5O chromophore. The tridentate ligand PyPOMeH2, in its deprotonated form, also gives rise to a bis complex, (Et4N)[Fe(PyPOMe)2] (2), in which the two PyPOMe2− ligands bind to the iron center in a mer fashion. In this case, however, less steric crowding among the smaller pendant ether groups allows binding of all four carboxamido nitrogens to the FeIII center in [Fe(PyPOMe)2]− giving rise to an FeN6 chromophore. This one N‐to‐O switch in donor atom makes the two complexes 1 and 2 very different. While complex 2 is low spin (g = 2.18, 1.94) much like the other reported FeIII bis complexes with two ligated 2,6‐pyridinedicarboxamido units, complex 1 is high spin (g = 4.3). The spin flip due to a switch in only one N or O donor atom in these two complexes is unprecedented. The two complexes also exhibit different stability towards water. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Studies on the Reduction of [(C5Me5)2Mo2O5] in Methanol/Water/Acetate Solutions by On‐Line Electrochemical Flowcell and Electrospray Mass Spectrometry
Authors: Gun Jenny , Modestov Alexandre , Lev Ovadia , Saurenz Dirk , Vorotyntsev Mikhail A. , Poli Rinaldo 
Published: January 2003

AbstractThe complex [Cp*2Mo2O5] (Cp* = η5‐C5Me5) and its electrochemical reduction products in acetic acid/acetate‐buffered (pH = 4.0) water/methanol solutions were investigated by combined electrochemical (EC) flowcell and on‐line electrospray ionization mass spectrometry (ESI‐MS). Mono‐, di‐, tri‐, and tetranuclear organometallic molybdenum oxides were identified in the starting solution. The effect of the relevant ESI‐MS parameters (ionic mode, heated capillary voltage, and heated capillary temperature) and of the concentration on the observed distribution of ions in the mass spectrometer was studied in order to minimize side reactions in the ESI chamber. It was verified that reduction in the ESI‐MS is undetectable under open‐circuit conditions. The on‐line electrochemical study revealed the potential‐dependent formation of previously unknown mono‐, di‐, tri‐, and tetranuclear MoV, MoIV, and mixed‐valence complexes. The compounds were identified by their characteristic isotope patterns and their ion trap MSn fragmentations. The observed formation potentials reflect the higher stability of the multinuclear species relative to the mononuclear ones with the same oxidation state. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Cover Picture
Authors: Zhang Xian‐Ming , Chen Xiao‐Ming 
Published: January 2003

AbstractThe cover picture shows a mixed‐valence copper(i,ii) coordination polymer [CuI2CuII(4,4′‐bpy)2(pydc)2]·4H2O (4,4′‐bpy = 4,4′‐bipyridine; pydc = pyridine‐2,4‐dicarboxylate) featuring the “metal‐complex ligands” [CuII(pydc)2]2− synthesized hydrothermally using Cu(MeCO2)2, pyridine‐2,4‐dicarboxylate, 4,4′‐bipyridine and NaOH. Single‐crystal structure analysis exhibits this compound to be the first porous 3‐D framework constructed from five‐fold parallel interpenetration of 2‐D (6,3) nets (right‐hand side). The one‐dimensional channels in the 3‐D framework (left‐hand side) occupying 17.4% of the crystal volume are occupied by guest water molecules. The porous network is stable after removal of the lattice water molecules, which may be attributed to the multiple entanglement of the 2‐D nets. Details are discussed in the article by X.‐M. Zhang and X.‐M. Chen on p. 413 ff.
New Monocyclopentadienyl Complexes of Tantalum(V) and Titanium(IV) with Chelating Pyrimidinethiolate and Oxypyridine Ligands − Molecular Structure of [Cp*TaCl3(SC6H7N2)]
Authors: Fandos Rosa , Hernández Carolina , Otero Antonio , Rodríguez Ana , Ruiz María José , Terreros Pilar 
Published: January 2003

AbstractNew monocyclopentadienyl species of TaV, [Cp*TaL3(XR)] (L = Cl, Me, X = O, S) bearing 4,6‐dimethyl‐2‐pyrimidinethiolate (SR = SC6H7N2) or 3‐cyano‐4,6‐dimethyloxypyridine (OR = OC8H7N2) ligands were prepared, namely [Cp*TaCl3(SC6H7N2)] (1), [Cp*TaCl3(OC8H7N2)] (2), [Cp*TaMe3(SC6H7N2)] (3). In addition, a bis(oxypyridine)titanium(IV) complex [Cp*TiMe2(OC8H7N2)2] was isolated. The X‐ray structure analysis of 1 revealed that the thiolate group is bonded to the metal center through the sulfur atom and one of the nitrogen atoms in an η2‐fashion. The reactivity of complex 3 with isocyanides (CNR), R = tBu, Xyl (Xyl = 2,6‐dimethylphenyl) was also studied showing differences depending on the nature of R group. The reaction with 2,6‐dimethylphenyl isocyanide gives the azatantalacyclobutane complex [Cp*TaMe{XylN=CC(Me2)NXyl}(SC6H7N2)] (5) as the final product, whereas in the reaction with tert‐butyl isocyanide the η2‐imine‐containing complex [Cp*Ta{tBuNC(Me2)}(SC6H7N2)] (6) is proposed to be formed. The dynamic behavior of [Cp*TaMe3(SC6H7N2)] (3) was also studied by variable‐temperature 1H NMR spectroscopy. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Efficient Asymmetric Synthesis of Δ‐ and Λ‐Enantiomers of (Bipyridyl)ruthenium Complexes and Crystallographic Analysis of Δ‐Bis(2,2′‐bipyridine)(2,2′‐bipyridine‐4,4′‐dicarboxylato)ruthenium: Diastereoselective Homo‐ and Heterochiral Ion Pairing Revisited
Authors: Caspar Régis , Amouri Hani , Gruselle Michel , Cordier Christine , Malézieux Bernard , Duval Raphäel , Leveque Hubert 
Published: January 2003

AbstractOptically pure ruthenium complexes of the type Δ‐ or Λ‐[Ru(bpy)2(L−L)][PF6]2 [L−L = cmbpy = 4′‐methyl‐2,2′‐bipyridine‐4‐carboxylic acid (3a, b); L−L = dcbpy = 2,2′‐bipyridine‐4,4′‐dicarboxylic acid (4a, b)] were prepared and fully characterized. The RuII carboxylate complexes Δ‐ and Λ‐[Ru(bpy)2(dcabpy)] (5a, b) (dcabpy = 2,2′‐bipyridine‐4,4′‐dicarboxylate) were resolved efficiently by chiral column chromatography and isolated in good yields. The Δ‐[Ru(bpy)2(dcabpy)] (5a) enantiomer was crystallized and its X‐ray molecular structure determined. The enantiomeric nature and the absolute configuration of the tris(bipyridyl)ruthenium complexes were confirmed by NMR and circular dichroism studies. In addition, ion‐pairing interactions between Δ‐Trisphat (Δ‐1, D3 symmetry) and each enantiomer of the (monocarboxylic acid)RuII complex (3a and 3b, C1 symmetry) and the dicarboxylic acid complex (4a and 4b, C2 symmetry) were examined by NMR spectroscopy. (© Wiley‐VCH Verlag GmbH & Co KGaA, 69451 Weinheim, Germany, 2003)
In‐situ Energy‐Dispersive X‐ray Diffraction Studies of Crystal Growth and Compound Conversion Under Solvothermal Conditions
Authors: Engelke Lars , Schaefer Michael , Porsch Felix , Bensch Wolfgang 
Published: January 2003

AbstractThe results of in‐situ energy‐dispersive X‐ray diffraction under solvothermal conditions performed on isostructural, layered thioantimonates Mn2Sb2S5·L (L = amine) demonstrate the great potential of the method. When the synthesis was carried out at low temperatures with L being 1,3‐diaminopropane (DAP), two crystalline intermediate phases were detected which then grew and disappeared when product growth started. Surprisingly, when N‐methyl‐1,3‐diaminopropane (MDAP) was used, no crystalline intermediates could be detected and the induction time was significantly shorter than for DAP. For reactions up to 100 °C and for higher temperatures with α < 0.8 (α is the extent of reaction), the crystallisation is predominantly controlled by nucleation. Further progress of crystallisation (α > 0.8) leads to a change of the dominant process and a diffusion‐controlled mechanism is observed. During the reaction with diethylenetriamine (DIEN), three crystalline intermediates were detected prior to product growth. The induction time is longer than for the other two compounds. The crystallisation seems to be diffusion‐controlled and is faster than for the DAP and MDAP compounds. In a solution of DIEN, the crystalline phases Mn2Sb2S5·L (L = DAP or MDAP) are transformed into the DIEN product under solvothermal conditions, and a rigorous analysis of the intensities of the reflections suggests a partial dissolution of the crystalline starting materials followed by crystallisation of the DIEN material. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Formation of (σ‐Alkenyl)‐ and (μ‐Vinylidene)palladium and ‐platinum Complexes by Oxidative Addition of 4,4‐Dichloro‐1,1‐diphenyl‐2‐azabuta‐1,3‐diene − The Molecular Structure of an Unusual Asymmetric (μ‐Vinylidene)Pd−Pd Complex
Authors: Knorr Michael , Schmitt Gérard , Kubicki Marek M. , Vigier Estelle 
Published: January 2003

Abstract4,4‐Dichloro‐1,1‐diphenyl‐2‐azabuta‐1,3‐diene (1) oxidatively adds to [Pd(PPh3)4] and [Pt(C2H4)(PPh3)2] giving rise to the σ‐alkenyl complexes trans‐[MCl{[C(Cl)=C(H)−N=CPh2]}(PPh3)2] (2a: M = Pd; 2b: M = Pt). When 1 is treated with [Pd(PPh3)4] in a 1:2 ratio in refluxing toluene, the dimetallic μ‐vinylidene complex [(PPh3)ClPd{μ‐[C=C(H)−N=CPh2]}PdCl(PPh3)2] (3) is formed. In this fluxional compound, a PPh3 ligands migrates in a reversible manner between the two Pd centers. Substitution of the PPh3 ligands of 3 by 2 equiv. of Ph2PCH2PPh2 affords the A‐frame complex [ClPd(μ‐dppm)2{μ‐[C=C(H)−N=CPh2]}PdCl] (4). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)