bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tripodal Triamidostannates as Building Blocks in the Generation of Sn—M‐Bonded Heterobimetallics (M  Fe, Ru)
Authors: Hellmann Konrad W. , Friedrich Stefan , Gade Lutz H. , Li Wan‐Sheung , McPartlin Mary 
Published: July 2007

AbstractBy in situ lithiation of the trifunctional amines H3CC(CH2NHSiMe3)3, PhC(CH2NHSiMe3)3, and HC{SiMe2NH(p‐Tolyl)}3 and subsequent reaction with SnCl2 the corresponding triamidostannates were obtained. These were coupled with CpM(CO)2Cl (M  Fe, Ru) to yield the M—Sn‐bonded heterobimetallics 9–14 of which H3CC(CH2NSiMe3)3SnFe(CO)2Cp (9) was characterized by a single‐crystal X‐ray structure analysis. Of the in situ‐generated amidostannates only [HC{SiMe2N(p‐Tolyl)}3Sn][Li(THF)3] (8) could be isolated as a uniform product and characterized analytically and spectroscopically.
Synthese und Komplexchemie funktionalisierter Tripod‐Liganden RC(CH2PPh2)3
Authors: Janssen Bernd C. , Sernau Volker , Huttner Grottfried , Asam Alexander , Walter Olaf , Büchner Michael , Zsolnai Laszlo 
Published: July 2007

AbstractSynthesis and Complex Chemistry of Functionalised Tripod Ligands RC(CH2PPh2)3Malonic ester 1 is alkylated and converted into the triols RC(CH2OH)3 (5). These are easily converted into the corresponding functionalised tripodal ligands RC(CH2PPh2)3 (7) with R  Bzl (a), n‐C12H25 (b), (CH3)2CH(CH2)2 (c). Crystals suitable for X‐ray crystallography have been obtained of the ligand 7a. In addition, the tripod ligands 7a and 7c have been further characterized by the syntheses and X‐ray analyses of the nickel complex [(7a)NiCl] (8a), the iron complex [(7c)Fe(NCCH3)3](BF4)2 [9 · (BF4)2], and the cobalt complex [(7c)Co{O(O)CCH3}](BPh4) (10 · BF4).
Hypercoordinate Carbon in Trigoldbis(silyl)methanium Cations
Authors: Bommers Sebastian , Beruda Holger , Dufour Nathalie , Paul Martin , Schier Annette , Schmidbaur Hubert 
Published: July 2007

AbstractThe reactions of organolithium compounds of the type (R3Si)2CHLi (R3 = Me3 or Me2Ph) with the gold(I) complex Ph3PAuCl afford the monoaurated bis(silyl)methanes (R3Si)2‐ CHAuPPh3 (1a, b) in high yield. These compounds are converted into complex salts with hypercoordinate methanium cations {(R3Si)2C[Au(PPh3)]3}+BF−4 (3a, b) by treatment with {[(Ph3P)Au]3O}+ BF−4. In the reaction mixtures small amounts of the neutral dinuclear intermediates {(R3Si)2C[Au(PPh3)]2} (2a, b) have been detected and characterized by their spectroscopic data. Compounds 1a, b and 3a, b have been studied by single crystal X‐ray diffraction analyses. While the mononuclear molecules 1a, b have conventional structures with parameters representing classical types of bonding, the novel trinuclear complexes 3a, b feature cations with a pentacoordinate carbon atom in a distorted trigonal‐bipyramidal environment of two silicon atoms and one gold atom in equatorial positions and the remaining two gold atoms at the axial vertices of the polyhedra. The main axis of the bipyramid is strongly bent at the central carbon atoms. This distortion leads to short axial/equatorial Au…Au distances indicating peripheral metal‐metal bonding.
Synthese von Carben‐Carbonyl‐Isonitril‐Komplexen von Chrom und deren Anellierungsreaktion mit Alkinen
Authors: Dötz Karl Heinz , Christoffers Carmen 
Published: July 2007

Reactions of Complex Ligands, LXII[1]. – Synthesis of Carbene Carbonyl Isonitrile Complexes of Chromium and Their Annulation Reaction with Alkynes1,1,3,3‐Tetramethylbutyl isocyanide (3a) and 2,6‐dimethylphenyl isocyanide (3b) react with the tetracarbonyl chelate carbene complex 2 to give the tetracarbonyl isocyanide carbene complexes 4a and 4b. Thermal decarbonylation leads to the tricarbonyl isocyanide chelate carbene complexes 5a and 5b. Upon reaction with 3‐hexyne they undergo an annulation to give the dicarbonyl indene complexes 6a and 6b.
Zwei Extreme in der Zinnchemie: Ein nichtbindender Sn–Sn‐Abstand von 285 pm und eine 119Sn‐NMR‐Verschiebung δ = 3301 in metallorganischen Derivaten von Sn(0)
Authors: Schiemenz Berthold , Huttner Gottfried , Zsolnai Laszlo , Kircher Peter , Diercks Tammo 
Published: July 2007

Two Extremes in Tin Chemistry: A Non‐bonding Sn–Sn Distance of 285 pm and a 119Sn‐NMR Shift δ = 3301 in Organome‐tallic Derivatives of Sn(0)The reaction of Na[{Cp'(CO)2Mn}2H] with SnCl2, which produces the inidene compound [Cp'(CO)2Mn\documentclass{article}\usepackage{amsmath}\pagestyle{empty}\begin{document}$ {\rm C}\ddot - {\rm C} $\end{document}Sn(Cl)\documentclass{article}\usepackage{amsmath}\pagestyle{empty}\begin{document}$ {\rm C}\ddot - {\rm C} $\end{document}Mn‐(CO)2Cp']− under standard workup procedures, results in the formation of [{Cp'(CO)2MnSn}2{μ2‐Mn(CO)2Cp'}2{μ2‐Cl}]− (1) when quenched with unpolar solvents. While, formally, 1 contains tin in its oxidation state zero, it may be conceived as composed of an Sn2−2 entity, which is linearly end‐on coordinated to two Cp'(CO)2Mn 16‐electron species; in addition the tin centers are bridged by two μ2‐Mn(CO)2Cp' moieties and a μ2‐Cl function. The resulting connectivity Sn2{μ2‐Mn(CO)2Cp'}2{μ2‐Cl} thus corresponds to a [1.1.1]propellane scaffolding. While there is no obvious need for a tin‐tin bond in this propellane‐type cage, a short Sn–Sn contact of only 285 pm is observed. While the 119Sn‐NMR signal of 1 could not be recorded, the peculiar bonding in this type of compounds is generally mirrored in their unconventional 119Sn‐NMR shift whereever signals can be observed: it is found that [{Cp*(CO)2Mn}3(μ3‐Sn)], which contains trigonally planar‐coordinated μ3‐Sn as a naked ligand atom, has its 119Sn‐NMR resonance at δ = 3301 well beyond the known range of 119Sn‐NMR shifts. This finding is interpreted in terms of a relatively week Snpπ‐Mndπ π bonding which leads to low‐energy unoccupied molecular orbitals as the prerequisit for a large paramagnetic contribution to the NMR shift.
Synthesis and Characterization of Mononuclear Titanium Complexes Containing a Bis(phenoxy) Ligand Derived from 2,2′‐Methylene‐bis(6‐tert‐butyl‐4‐methylphenol)
Authors: Okuda Jun , Fokken Stefan , Kang Hak‐Chul , Massa Werner 
Published: July 2007

AbstractA series of new titanium complexes of the general type Ti(mbmp)X2 (X = Br, I; OMe, OiPr, OtBu), containing a bidentate bis(phenoxy) ligand derived from 2,2′‐methylenebis(6‐tert‐butyl‐4‐methylphenol) (mbmpH2), was prepared. The 1H‐chemical shifts for the protons of the methylene link were found to vary considerably as a function of the ligand X. Reaction of Ti(OiPr)4 with two equivalents of mbmpH2 gave the C2‐symmetric spiro‐titanate complex Ti(mbmp)2. The crystalline labile solvent adducts of the dichloro complex Ti(mbmp)Cl2 with THF and DME were isolated and characterized. A single‐crystal X‐ray structural analysis revealed the THF adduct to be a mono(THF) adduct with a trigonal‐bipyramidal configuration, the bidentate mbmp ligand spanning an apical and equatorial site and the THF ligand occupying the remaining apical position.
Transition‐Metal Complexes with the Novel Poly (1,2,4‐triazolyl)borate Ligands [HnB(C2H2N3)4 − n]− (n = 1 and 2): Synthesis and Characterization of Metal Complexes of Dihydrobis(1,2,4‐triazolyl)borate as One‐ or Two‐Dimensional Coordination Polymers with Six‐Membered Ring Water Substructures and the Structure of Two‐Dimensional Liquid and Solid Water As Organized in the Intercalate [Ni{HB(C2H2N3)3}2] · 6 H2O (X‐ray Studies at 293 and 160 K)
Authors: Janiak Christoph , Scharmann Tobias G. , Hemling Holger , Lentz Dieter , Pickardt Joachim 
Published: July 2007

AbstractThe 1:2 manganese (5), nickel (6), and copper complex (7) with the novel dihydrobis(1,2,4‐triazolyl)borate ligand (2) were synthesized and structurally characterized. Single‐crystal X‐ray studies reveal the formation of highly solvated coordination polymers of the formula {[M(H2O)2{μ‐H2B(C2H2N3)2}2] · n H2O}∞ for M = Mn and Cu. In 5 (M = Mn; n = 4) a two‐dimensional metal‐ligand framework is built by means of the bridging action of 2. These metal‐ligand grid sheets sandwich water layers which comprise individual six‐membered rings. Compound 7 (M = Cu; n = 6) can be described as a linear metal‐ligand chain with two borate ligands bridging two copper centers. These one‐dimensional coordination polymers are separated by one‐dimensional arrays of water molecules in the form of edge‐sharing six‐membered rings. In both structures the water of crystallization is held in place both by hydrogen bonding from the aqua ligands and by hydrogen bonding to the nitrogen atoms of the borate ligand. Bis[hydrotris(1,2,4‐triazolyl)borato]nickel, [Ni{HB(C2H2N3)3}2] (8), was obtained from NiCl2 and the potassium salt of [HB(C2H2N3)3]− (1). Single‐crystal X‐ray structures of the solvate 8 · 6 H2O were determined at 293 and 160 K. The water molecules are arranged in two‐dimensional layers with only weak (hydrogen bonding) interactions to the adjacent layers of the complex molecules. The room temperature structure (orthorhombic, space group Cmca) shows a highly disordered water structure being indicative of a dynamic equilibrium between small conglomerates and free molecules. Upon cooling an ordering occurs in the water layer leading to a phase transition in the crystal, and in the low‐temperature structure at 160 K (orthorhombic, space group Pmnb) the hydrogen atoms and bonding network of the water structure could be determined. This structure is best described as being composed of individual rings or chain segments. The material surface morphology after loss of the water of crystallization was studied by scanning electron microscopy and the structural pattern correlated with the crystal packing.
Steric Control of Oxidative Trimerization of Alkynyl Ligands in Trimethylphosphane Palladium Complexes
Authors: Klein Hans‐Friedrich , Zettel Bernd D. 
Published: July 2007

AbstractAlkynylpalladium compounds trans‐PdX(CCR)(PMe3)2 [R = CMe3, X = Cl (1), I (19); R = CMe2OH, X = Cl (2), Br (10), I (11); R = c‐Hex, X = Cl (3), Br (12), I (13); R = CHMe2, X = Br (4); R = CH2SiMe3, X = Cl (5), Br (14), I (15); R = COOEt, X = Br (6), I (7); R = Ph, X = Cl (8), I (17); R = n‐Pr, X = N3 (16), I (20); R = n‐Hex, X = I (21); R = SiPh3, X = Br (22)] and trans‐PdX(CCR)(PBu3)2 [R = SiMe3, X = Cl (9), I (18)] as well as trans‐PdX(CCR)(PPh3)2 [R = CMe3, X = Br (23); R = CH2SiMe3, X = Br (24), I (25)] are prepared by known methods. Thermal decomposition between 120 and 160°C results in a selective transformation only with trimethylphosphane complexes 1, 2, 10–, and 19. Oxidative trimerization of the alkynyl groups CCCMe2R′ and CC(c‐Hex) affording the enediynyl compounds trans‐PdX[C(CCCMe2R′) = C(CCCMe2R′)CMe2R′] (PMe3)2 [R′ = Me, X = Cl (26), I (27); R′ = OH, X = Cl (28), Br (29), I (30)] and trans‐PdX{C[CC(c‐Hex)]C[CC(c‐Hex)] (c‐Hex)}(PMe3)2 [X = Br (31), I (32)] appears to be controlled by balanced steric demands of phosphorus and alkynyl substituents. The steric control is investigated by melting) transformable monoalkynyl complex trans‐PdI(CCCMe2OH)(PMe3)2 (11) with non‐transformable[*] complex trans‐PdI[CC(n‐Pr)](PMe3)2 (20) to give a mixture (A) of transformed complexes with mixed substituents R. Similar results are obtained in other mixtures, when transformable PdBr(CCSiMe3)(PMe3)[1] is heated with the non‐transformable complexes PdBr[CC(n‐Pr)](PMe3)2[1] and 20 (mixture B) or transformable PdBr[CC(c‐Hex)](PMe3)2 (12) with non‐transformable PdBr[CC(n‐Pr)](PMe3)2[1] (mixture C).
Synthesis and Application of Ring‐Substituted Analogues of the [4‐(η‐Cyclopentadienylidene)‐4,7,7‐trimethyl‐4,5,6,7‐tetrahydro‐η5‐indenyl]‐ZrCl2 Ansa‐Metallocene System
Authors: Psiorz Christian , Erker Gerhard , Fröhlich Roland , Grehl Matthias 
Published: July 2007

AbstractReaction of the 2,5‐hexanedione‐derived bisfulvene 1 with RLi reagents (R = phenyl or n‐butyl) yields the ring‐closed [4‐(cyclopentadienylidene)‐7‐R‐4,7‐dimethyl‐4,5,6,7‐tetrahydroindenyl]dilithium reagents 3. Their reaction with MCl4 (M = Ti, Zr, Hf) gives the corresponding ansa‐group‐4‐metallocene dichloride complexes 4, 6, or 7. In a similar way the [7‐allyl‐4‐(η‐cyclopentadienylidene)‐4,7‐dimethyl‐4,5,6,7‐tetrahydro‐η5‐indenyl]metal dihalides (M = Ti, Zr) (6d, 4d) are prepared. Two diastereomers are formed in most cases, some of which could be separated. The five representative examples cis‐ and trans‐4c, trans‐4d, cis‐6c, and trans‐7c of these complexes were characterized by X‐ray diffraction. All these six‐membered ring‐annulated C1‐bridged ansa‐metallocene dichlorides exhibit extremely small D1ZrD2 angles (D1 and D2 denote the centroids of the cyclopentadienyl rings) of 116.5°, i.e., they are characterized by a very open bite of the bent metallocene wedge. The homogeneous Ziegler‐type catalysts derived from these ansa‐zirconocenes by activation with methylalumoxane have high activities and all produce low‐molecular mass atactic polypropylenes or propene oligomers.
Metallorganische Verbindungen der Lanthanoide, 89. Cyclooctatetraenyl‐Komplexe der frühen Übergangsmetalle und Lanthanoide, 6. (Cyclooctatetraenyl)[N,N′‐bis(trimethylsilyl)benzamidinato]‐und ‐[diphenylbis(trimethylsilylimido)phosphinato]‐Komplexe der Seltenen Erden; Röntgenstrukturanalyse von (C8H8)Tm[PhC(NSiMe3)2](THF), (C8H8)Lu[4‐MeOC6H4C(NSiMe3)2](THF) und (C8H8)Nd[Ph2P(NSiMe3)2](THF)
Authors: Schumann Herbert , Winterfeld Jörn , Hemling Holger , Hahn F. Ekkehardt , Reich Peter , Brzezinka Klaus‐Werner , Edelmann Frank T. , Kilimann Ulrike , Schäfer Martina , Herbst‐Irmer Regine 
Published: July 2007

Organometallic Compounds of the Lanthanoids, 89. – Cyclooctatetraenyl Complexes of the Early Transition Metals and Lanthanoids, 6. – (Cyclooctatetraenyl)[N,N′‐bis(trimethylsilyl)benzamidinato]‐ and ‐[diphenylbis(trimethylsilylimido)‐phosphinato] Complexes of the Rare Earths; X‐Ray Structural Analyses of (C8H8)Tm[PhC(NSiMe3)2](THF), (C8H8)Lu[4‐MeOC6H4C(NSiMe3)2](THF), and (C8H8)Nd[Ph2P(NSiMe3)2](THF)[(C8H8)Ln(μ‐Cl)(THF)2]2 or [(C8H8)Ln(μ‐O3SCF3)(THF)2]2 (Ln = Y, Ce, Pr, Nd, Sm, Tm, Lu) react with Na[4‐RC6H4C(NSiMe3)2] (R = H, OMe, CF3) or Li[PhC(NSiMe3)2] to give the monomeric (cyclooctatetraenyl)lanthanide benzamidinates (C8H8)Ln[4‐RC6H4C(NSiMe3)2](THF) [R = H, Ln = Y (1), Ce (4), Pr (6), Nd (8), Sm (10), Tm (12), Lu (15); R = OMe, Ln = Y (2), Ce (5), Pr (7), Nd (9), Sm (11), Tm (13), Lu (16); R = CF3, Ln = Y (3), Tm (14), Lu (17)]. The reaction of [(C8H8)Ln(μ‐Cl)(THF)2]2 (Ln = Ce, Pr, Nd, Sm) with Li[Ph2P(NSiMe3)2] in THF leads directly to the monomeric compounds (C8H8)Ln[Ph2P(NSiMe3)2](THF) [Ln = Ce (18), Pr (19), Nd (20), Sm (21)] in good yields. The 1H‐, 13C‐, 31P‐ and 29Si‐NMR and mass spectra of the new compounds as well as the molecular structures of 12, 16, and 20 are discussed. The Raman spectra of the complexes 1–3, 12, and 14–17 have been studied in detail.
Molecular Modeling, a Tool for Predicting Structural Effects on the Macrocyclization Reaction between Bis(vinyl or allyl) Dialdehydes and Thiophosphonic Bis(hydrazides)
Authors: Galliot Christophe , Caminade Anne‐Marie , Majoral Jean Pierre , Kuznikowski Maciej , Zablocka Maria , Pietrusiewicz K. Michal 
Published: July 2007

AbstractThe reaction of new phosphorus dialdehydes PhP(O)‐[(CH2)nCHCHC6H4CHO]2 (4a–c, 5a) (n = 0:4, n = 1:5; a:para, b:meta, c:ortho), with thiophosphonic bis(hydrazide) PhP(S)[NMeNH2]2 (6) yields macrocyclic compounds 9b′, c′, 10a′, 9a″, b″, c″, 10a″ and 9c′″, arising from the cyclocondensation of one, two, or three equivalents of each reagent, respectively. Molecular modeling of 4a‐c, 5a, 6 and of the intermediate monocondensation products 7a‐c, 8a was carried out and points out the importance of the geometry of the starting reagents in the competition between inter‐ and intramolecular cyclocodensation.
Syntheses and Structures of Intramolecularly Stabilized Organoaluminium Compounds
Authors: Müller Jens , Englert Ulli 
Published: July 2007

AbstractThe reaction of LiAr (Ar = 2‐[(dimethylamino)methyl]phenyl) with AlCl3, MeAlCl2, and Me2AlCl in a 1:1 ratio yields the corresponding organoaluminium compounds ArAlCl2, ArAl(Cl)Me, and ArAlMe2 (1–3). The alanes Ar2AlCl and Ar2AlMe (4 and 5) were synthesized from AlCl3 and MeAlCl2 with two equivalents of LiAr. The products ArAl(Cl)R [R = tBu, C(SiMe3)3] 6 and 7 are formed by the reaction of LiR with 1. The Lewis acid 1 adds the bases iPrNH2 and THF to yield the adducts 1 · iPrNH2 and 1 · THF. The structures of the products were deduced from the 1H‐, 13C‐, and 27Al‐NMR spectra and were confirmed by X‐ray structural determinations of 5 and 1 · iPrNH2.
Neuartige (η2‐Alkin)kupfer(I)‐carboxylat‐Komplexe
Authors: Lang Heinrich , Köhler Katrin , Zsolnai Laszlo 
Published: July 2007

Novel (η2‐Alkyne)copper(I) Carboxylate ComplexesThe reaction of Me3SiCCSiMe3 (1) with copper(I) carboxylates [Cu(μ‐O2CR)] (2a: R = Me; 2b: R = Ph) yields the tetranuclear compounds [(η2‐Me3SiCCSiMe3)[Cu(μ‐O2CR)]2)2 (3a: R = Me; 3b: R = Ph) and dimeric {(η2‐Me3SiCCSiMe3)[Cu(μ‐O2CR)]}2 (6a: R = Me; 6b: R = Ph). Compounds 6a and 6b could only be characterized by using IR and NMR techniques, since in solution these compounds eliminate 1 to afford 3a or 3b, respectively. Complexes 3a and 3b can additionally be synthesized by the reaction of [(η2‐Me3SiCCSiMe3)CuBr]2 (4) with [Ag(μ‐O2CR)] (5a: R = Me; 5b: R = Ph). In 6 two carboxylate moieties are μ‐bridging two (η2‐Me3SiCCSiMe3)Cu building blocks, and the Me3SiCCSiMe3 fragments are each η2‐coordinated to one copper atom. In 3 the Me3SiCCSiMe3 units are each η2‐coordinated to two copper atoms and are perpendicularly orientated to the copper(I) core; the four copper atoms form a square‐planar arrangement. Compounds 3a and 3b have been characterized by analytical and spectroscopic data (IR, 1H‐, 13C‐NMR, MS) and 3a by X‐ray analysis.
Monomere (Acetylacetonato)kupfer(I)‐Komplexe von Alkinen und 1,4‐Diinen
Authors: Lang Heinrich , Köhler Katrin , Büchner Michael 
Published: July 2007

Monomeric (Acetylacetonato)copper(I) Complexes of Alkynes and 1,4‐DiynesMonomeric (η2‐Me3SiCCSiMe3)Cu(acac) (3) is formed by the reaction of dimeric [(η2‐Me3SiCCSiMe3)CuBr]2 (1) with two equivalents of Na(acac) (2). In a similar manner Me2‐Si(CCSiMe3)2 (4) reacts with CuCl (5) and 2 to afford Me2Si[(η2‐CCSiMe3)Cu(acac)]2 (6). In compounds 3 and 6 an alkyne unit is η2‐coordinated to a monomeric Cu(acac) moiety with a copper atom in a planar environment. With the organometallic 1,4‐diyne (η5‐C5H4SiMe3)2Ti(CCSiMe3)2 (7), compound [(η5‐C5H4SiMe3)2Ti(CCSiMe3)2]Cu(acac) (8) is formed. In 8 both Me3SiCC ligands of the 3‐titanapenta‐1,4‐diyne fragment are η2‐coordinated to a monomeric Cu‐(acac) building block. The copper atom in 8 possesses a pseudo‐tetrahedral environment (shown by X‐ray analysis), built by the two Me3SiCC ligands of the (η5‐C5H4SiMe3)2‐Ti(CCSiMe3)2 moiety and the two oxygen atoms of the acetylacetonato ligand. 8 is additionally formed by the reaction of 3 or 6 with 7, or by treatment of [(η5‐C5H4SiMe3)2Ti(CC‐SiMe3)2]CuCl (9) with Na(acac) (2). The application of 3, 6, and 8 as precursors for the preparation of copper films in the CVD process of copper(I) is discussed.
Synthesis and Characterization of Copper, Nickel and Cobalt Complexes of N,N′‐Dimethyl‐2,11‐diaza[3,3](2,6)pyridinophane
Authors: Krüger Hans‐Jörg 
Published: July 2007

AbstractThe properties of the tetraazamacrocyclic compound N,N′‐dimethyl‐2,11‐diaza[3,3](2,6)pyridinophane (L‐N4Me2) as a ligand for some selected metal chlorides have been examined. The crystal structure of the uncoordinated ligand reveals a syn chair‐chair conformation. In solution, the ligand displays fluctional behavior. Reaction of L‐N4Me2 with the chlorides of copper(II), nickel(II), and cobalt(II) affords the complexes [Cu(L‐N4Me2)Cl2] · H2O (3), [Ni(L‐N4Me2)(H2O)Cl]Cl · H2O (4), and [Co(L‐N4Me2)Cl2] · 2 H2O (5) in which the ligand adopts a syn boat‐boat conformation. The crystal structures of 4 and 5 are presented. Due to the small cavity of the 12‐membered ring of the ligand, exclusively distorted cis‐octahedral coordination geometries are found at the metal sites. A comparison of structural data of several complexes with this ligand shows that the extent of the distortions from ideal octahedral geometry is mainly determined by the M‐Npy bond strength. The electronic as well as the solution properties of the described complexes have been investigated by electronic absorption spectroscopy. ESR spectroscopy, and electrochemical methods.
Zinc Complexes of Histidine‐Containing Di‐ and Tripeptides
Authors: Förster Martin , Vahrenkamp Heinrich 
Published: July 2007

AbstractNine dipeptides and one tripeptide containing histidine were converted into analytically pure zinc complexes. Four different compositions were observed. The peptides used as or converted into the monoacids LH (HisGly, GlyHis, HisPhe, HisHis) form the compounds ZnL2 (11a, 12–14) and alternatively (HisGly, HisGlyGly) the compounds ZnL(BF4) (11b, 20). The peptides used as amides (HisGlyNH2, HisMetNH2) act as neutral ligands in the compounds ZnL2(ClO4)2 (15, 16). The three remaining peptides (HisAsp, AlaHis, β‐AlaHis) behave like diprotonic acids LH2 forming the compounds ZnL (17–19). Spectra and solubilities indicate that complexes 11a, 13, 15, and 16 are mononuclear containing two chelating peptides bound by their amino and imidazole nitrogen atoms. All other complexes seem to be coordination polymers in some of which the amide N and O atoms are involved in the coordination. This was proven by a structure determination for Zn(GlyHis)2 (12) in which the zinc ions are coordinated octahedrally by two histidine N, two amino N, and two amide O atoms of four peptide residues.
Synthesis, Structure, and Electrical Properties of Ta4FeTe4
Authors: Neuhausen Jörg , Finckh Ernst Wolfgang , Tremel Wolfgang 
Published: July 2007

AbstractTa4FeTe4 has been synthesized and its structure determined by single‐crystal X‐ray methods. It crystallizes in the ortho‐rhombic space group Pbam with Z = 4 and a = 10.514(5), b = 18.275(7), and c = 4.815(1) Å. Ta4FeTe4 has a chain structure built up by Fe‐centered Ta8‐square antiprisms sharing common square faces. The resistivity of Ta4FeTe4 has been measured by a two‐point method. Ta4FeTe4 shows metallic behavior. The structure of Ta4FeTe4 is discussed in relation to other early transition metal cluster compounds. A rational approach to the synthesis of related compounds is proposed.
1,4,2‐Diazaphospholothiazoles and ‐pyridines by a Hantzsch‐Type Condensation Using Chloromethyldichlorophosphane
Authors: Karaghiosoff Konstantin , Cleve Cornelia , Schmidpeter Alfred , Mahnot Ruchi , Gandhi Neelam , Bansal Raj K. 
Published: July 2007

AbstractThe [3 + 2] cyclocondensation of 2‐amino‐1,3‐thiazoline, 2‐aminopyridines, 2‐ and 4‐aminopyrimidines, 2‐aminopyrazine, and 2‐aminoquinoline with chloromethyldichlorophosphane in the presence of triethylamine yields regiospecifically 5,6‐dihydrothiazolo[2,3‐e][1,4,2]diazaphosphole (3), 1,4,2‐diazaphospholo[4,5‐α]pyridines (12), 1,4,2‐diazaphospholo[4,5‐α]pyrimidines (15), 1,4,2‐diazaphospholo[4,5‐e]pyrimidine (17), 1,4,2‐diazaphospholo[4,5‐α]pyrazine (19), and [1,4,2]diazaphospholo[4,5‐α]quinoline (22), respectively. Using 2‐amino‐1,3‐thiazole (4) and 2‐aminobenzothiazoles 8, we obtained mixtures of the 1,5‐ and 4,5‐anellated 1,4,2‐diazaphospholes 5/6, 9a/10a and 9b/10b, while in the case of the methyl derivative 8c only the [1,4,2]diazaphospholo[5,4‐b][1,3]benzothiazole 10c was formed. In the reaction of 2‐aminothiazole and 2‐aminopyrazine with Chloromethyldichlorophosphane the bis(diazaphospholo)‐substituted chloromethylphosphanes 7 and 20 could be detected. The new anellated 1,4,2‐diazaphospholes are colorless to pale yellow crystalline moisture‐sensitive solids.
Reactions of Complex Ligands, LXIV. Synthesis of 5,5′‐Diphenyl‐2,2′‐bifuran, a Biaryl Compound with Remarkable Fluorescence Properties
Authors: Christoffers Jens , Dötz Karl Heinz 
Published: July 2007

AbstractThe 2‐oxacyclic α,β‐unsaturated carbene complex 1 reacts with an excess of dimethylamine to give the diphenylbifuran 2. The structure of 2 was established by independent synthesis from 2‐phenylfuran (4) via regioselective lithiation and transmetalation to zinc and tin organometallics 6a‐c and final oxidative copper coupling reactions.