bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phosphonium Ylides with Functionalized Silyl Substituents
Authors: Dreihäupl Karl‐Heinz , Angermaier Klaus , Riede Jürgen , Schmidbaur Hubert 
Published: July 2007

AbstractTwo series of aminophosphonium ylides with reactive alkoxychlorosilyl substituents (R2N)3P=CHSi(OR')2Cl (1‐8, R = Me, Et/R' = Me, Et, iPr, tBu) have been prepared by reaction of the aminophosphonium ylides (R2N)3P = CH2 with the corresponding dialkoxydichlorosilanes Cl2Si(OR')2. Substituent effects have been investigated by heteronuclear solution NMR studies of the nuclei 1H, 13C, 15N, 17O, 29Si, and 31P. These studies show an alternating shielding effect along the C–O–Si–C backbone. Further reactions of the chlorosilylated ylides with the aminomethylenephosphorane (Me2N)3P=CH2 lead to the formation of the bis‐ylidic compounds [(Me2N)3P=CH]2Si(OR')2 (9, 10), which are also available in one‐pot syntheses. The molecular structure of [(Me2N)3P=CH]2Si(OiPr)2 (9) has been confirmed by single‐crystal X‐ray diffraction. In the crystal the molecules have two ylidic carbon centers with planar configuration, which are bridged by a nearly tetrahedral silicon atom. Short P–C and Si–C distances indicate a stabilizing effect of the carbanionic centers.
Chemistry of Diborane(4) Derivatives: Mixed Tetraaminodiboranes(4) and Additions of Diborane(4) Derivatives to an Amino‐imino‐borane
Authors: Loderer Dirk , Nöth Heinrich , Pommerening Hans , Rattay Wilfried , Schick Hannes 
Published: July 2007

AbstractSeveral transamination reactions of B2(NMe2)4 (1a) with secondary amines have led to mixed tetraaminodiborane(4) compounds B2(NMe2)4 ‐ n(NR2)n (2–4), and B2(NC5H10)4 (1d) has been characterized by an X‐ray structure analysis which reveals the presence of a rather long B–B bond (1.75 Å). However, tetraaminodiboranes(4) of type R2N(Me2N)B‐B(NMe2)NR2 are more readily accessible from LiNR2 and B2(NMe2)2Cl2. Similarly, amination of B2(NMe2)2Cl2 with N,N'‐dimethylethylenediamine (7) yields B‐[bis(dimethyl‐amino)boryl]‐N,N'‐dimethyl‐1,3,2‐diazaborolidine (8), while reactions with Li(Me)N–CH2–CH2–N(Me)Li (9) lead also to 2,3‐bis(dimethylamino)‐1,4‐dimethyl‐1,4,2,3‐diazadiborinane (10) as the kinetically controlled product. This is further substantiated by the reaction of the B2(NMe2)2Br2 with 9 which gives exclusively the corresponding 1,4,2,3‐diazadiborinane 11. Diborane(4) dihalides B2(NMe2)2X2 (X = Cl, Br) react only in a 1:1 ratio with tmp‐B=N‐CMe3 (13) leading to 14a, b. However, both a 1:1 and a 1:2 methoxyboration of 13 has been observed with B2(OMe)4 with formation of 15 and 16.
TaNi2.05Te3, eine Verbindung mit “aufgefüllter” TaFe1+xTe3‐Struktur
Authors: Neuhausen Jörg , Tremel Wolfgang , Evstafyev Vladimir K. , Kremer Reinhard K. 
Published: July 2007

AbstractTaNi2.05Te3, a Novel Telluride with “Stuffed” TaFe1+xTe3 StructureThe novel metal‐rich layer compound TaNi2.05Te3 was synthesized from the elements. Its structure contains TaNi2Te3 layers which are interconnected by Ni atoms on partially occupied tetragonal‐pyramidal sites located between the layers. The title compound and the related telluride TaFe1.14Te3 form a pair of compounds differing only in the occupation or nonoccupation of one 3d‐material atom site. Therefore, the structure of TaNi2.05Te3, which is stabilized by interstial Ni atoms, can be regarded as a “stuffed” TaFe1.14Te3 type. Pairs of compounds with a similar structural relationship seem to be of general importance in early transition‐metal chalcogenide chemistry. The existence of TaNi2.05Te3 was recently proposed based on the results of extended Hückel band‐structure calculations. TaNi2.05Te3 is a metallic conductor according to the results of four‐probe resistivity measurements.
Pyridinio‐isoalloxazinophanes as Model Systems for Active‐Site Complexes in Flavoenzymes: Syntheses, X‐Ray Structure Analyses and Spectroscopic Properties
Authors: Staab Heinz A. , Zipplies Matthias F. , Müller Thomas , Storch Matthias , Krieger Claus 
Published: July 2007

AbstractAs model systems for active site complexes in flavoenzymes, flavin and nicotinamide analogues were linked together in cyclophane skeletons of specific sterical structures. Elaborating this concept, we prepared [4]metacyclo[3](10,6)isoalloxazinophane (3), [4](3,1)pyridino[3](10,6)isoalloxazinophane (4), as well as the 16‐methoxycarbonyl and the 16‐carboxylato derivatives (2 and 34, resp.), of 4 by multistep syntheses. For the isoalloxazinophanes 2, 3, 4, and 34 X‐ray structure analyses were performed and are discussed with regard to intramolecular interactions. Preliminary UV/Vis‐spectroscopic results related to π…π interactions in these isoalloxazinophanes are reported.
Aminoglycoside Antibiotics — Modified, Enantiopure Sannamine‐ and Sporamine‐Type Glycosyl Acceptors
Authors: Meier Walter , Seitz Bernhard , Hoenke Christoph , Prinzbach Horst 
Published: July 2007

AbstractAlong an established scheme, 1,2:3,4‐dianhydrodeoxy‐epi‐inositol (3) — readily available from benzene — has been applied to expeditious syntheses of suitably protected, fluorinated, and epimerized aminoglycoside building blocks related to sannamine (rac‐14a, rac‐16a, rac‐18a, rac‐31a) and sporamine (rac‐21a, rac‐23a, rac‐26a, rac‐34a). By separation of diastereomers formed with (+)‐(1‐phenylethyl)amine (14c/ 14′c; 16c/16'c) or with (‐)‐camphanic acid (14e/14'e) and by enzymatic hydrolysis (rac‐14b) access is gained to enantiopure glycosyl acceptors.
Synthese von N‐acylierten 5,10‐Dihydrophenazin‐Verbindungen
Authors: Mikulla Markus , Mülhaupt Rolf 
Published: July 2007

AbstractSynthesis of N‐Acylated Derivatives of 5,10‐DihydrophenazineA family of N‐mono‐ and N, N'‐diacylated 5,10‐dihydrophenazines (4–26) was prepared by reaction of 5, 10‐dihydrophenazine (1) or the corresponding 5,10‐bis(trimethylsilyl) derivative (3) with acyl chlorides. 5,10‐Bis(4‐nitrobenzoyl)‐5,10‐di‐hydrophenazine (11) was hydrogenated to the new aromatic diamine 21 which is an interesting starting material for polymer syntheses.
Das Thermogramm einer C6H6‐Chemie im Temperaturbereich von 450 bis 730°C
Authors: Zimmermann Gerhard , Nüchter Matthias , Remmler Matthias , Findeisen Matthias , Hopf Henning , Ernst Ludger , Mlynek Cornelia 
Published: July 2007

AbstractThermal Rearrangements, XXIII[1]. — The Thermogram of a C6H6 Chemistry in the Temperature Range from 450 to 730°CThe thermal isomerization of 1,5‐hexadiyne (1) and its [1,6‐D2]‐labeled derivative (1a) was studied in the temperature range 450–730°C and in the presence of different carrier gases (N2, H2, D2, N2/toluene). By detailed analysis (GC, GC MS, NMR) all volatile reaction products were identified and determined quantitatively by using hexafluorobenzene as an internal standard. The experimental data show clearly that the reaction products are formed by two different routes: (i) electrocyclization leading to dimethylene cyclobutene (3) at temperatures up to about 600°C and (ii) radical reaction leading to benzene (4) and pentafulvene (5) at temperatures above 550°C. Cyclopentadienylmethyl radicals are supposed to be the essential radical intermediates.
Synthesis of 9,10‐Dihydro‐9,10‐propanoanthracene‐12‐ones from Anthracenes and Oxyallyl Cation Intermediates Generated by the the BSA [N,O‐Bis(trimethylsilyl)acetamide] Method
Authors: El‐Wareth Abd , Sarhan A. O. , Martin H. , Hoffmann R. 
Published: July 2007

AbstractSonication of a zinc/copper couple, N,O‐bis(trimethylsilyl)‐acetamide (BSA) and α,α'‐oligobromo ketones in benzene gives rise to oxyallyl intermediates which cycloadd to anthracene. Starting from 1,1,3,3‐tetrabromoacetone (2a) and anthracene (1a), we obtained 11,11,13‐tribrominated adduct 4 as the major product (42%). The expected 11,13‐dibrominated adduct trans‐3 was formed as a minor product (5%), but it became the main product when the known oxyallyl methodology was applied. Dibenzohomobarrelenes 9 and 17 were prepared by short routes.
Propargyl‐Stabilisierungsenergie
Authors: Roth Wolfgang R. , Hopf Henning , Horn Carina 
Published: July 2007

AbstractPropargyl Stabilisation EnergyFor the alkynyl‐substituted olefines 1–14 activation parameters for the geometrical isomerisation have been determined in the gasphase by the single‐pulse shoke‐tube technique. By comparison of these barriers with the corresponding one of the isolated double bonds, each corrected by the steric energy contribution of the ground and transition state, a value of 7.8 ± 1.3 kcal · mol−1 for the propargyl stabilisation energy (PrSE) has been derived.
Synthesis of Novel Heteroaromatic Polyfused as‐Triazines by Ring Transformation[1]
Authors: Riedl Zsuzsanna , Hajòs György , Messmer András , Kollenz Gert 
Published: July 2007

AbstractRing transformation of the tricyclic furo‐fused as‐triazinium salt 1 in the presence of nucleophilic reagents (e.g. sodium hydrogensulfide, sodium salts of malonic ester, ethyl cyanoacetate, acetylacetone, dimedone, or malononitrile) leads to the two new heteroaromatic ring systems thieno[2,3‐e]pyrido[1,2‐b]‐as‐triazinium salt (5) and differently substituted cyclopenta[e]pyrido[1,2‐b]‐as‐triazine compounds (8, 9, 10, 11, and 13).
Wanzlick‐Carbene in der [4 + 1]‐Cycloaddition mit Bis(methylthio)‐ und Bis(trifluormethyl)‐1,2,4,5‐tetrazin
Authors: Frenzen Gerlinde , Kümmell Andreas , Meyer‐Dulheuer Christiane , Seitz Gunther 
Published: July 2007

AbstractWanzlick Carbenes in the [4 + 1] Cycloaddition Reaction with Bis(methylthio)‐ and Bis(trifluoromethyl)‐1,2,4,5‐tetrazineThe 3,6‐disubstituted 1,2,4,5‐tetrazines 3 and 4 have been submitted to a [4 + 1] cycloaddition reaction with the nucleophilic singlet carbenes (Wanzlick carbenes) 2a–d, which are generated from the precursors 1a–d. With 3 as diazadiene the expected spiro compounds 6a–d are formed. In contrast to this presumed two‐step reaction sequence of 3, with the tetrazine 4 the cascade cycloaddition/cycloelimination is surprisingly followed by an intramolecular electrophilic aromatic substitution to yield the chiral tetracyclic compounds of type 8 with high diastereoselectivity. The crystal structure of 8d has been determined by X‐ray diffraction methods.
Ein‐ und zweikernige makrocyclische Übergangsmetallkomplexe mit Liganden vom Schiff‐Basen‐Typ: Synthesen, Strukturen, elektro‐ und magnetochemische Eigenschaften
Authors: Brychcy Klaus , Dräger Klaus , Jens Klaus‐J. , Tilset Mats , Behrens Ulrich 
Published: July 2007

Complexes with Macrocyclic Ligands, III[1]. ‐ Mono‐ and Dinuclear Macrocyclic Transition Metal Complexes of Ligands of Schiff Base Type: Syntheses, Structures, Electro‐ and Magnetochemical Properties.Four new mononuclear metal(II) complexes (4a–d) of a macrocyclic ligand derived from the Schiff base condensation of 2 equiv. of 1,2‐phenylenediamine (3a) and 5‐tert‐butyl‐2‐hydroxy‐1,3‐benzenedicarbaldehyde (2) were synthesized and the cobalt complex 4b characterized by X‐ray structure analysis. Reaction of 1,2‐diamino‐3,4,5,6‐tetrafluorobenzene (3b) with the dicarbaldehyde 2 in the presence of Mn(ClO4)2 or Co(ClO4)2 leads to the novel metal‐free macrocyce 6 (X‐ray structure determination). The macrocycle 6 and Cu(ClO4)2 yield the new dinuclear copper complex 8, the structure of which was also determined by X‐ray diffraction. The copper‐(II) ions in 8 have a distorted square‐pyramidal coordination by the four donor atoms of the macrocycle and an apical acetonitrile ligand. The Cu…Cu distance is 318.1 pm, and the two Cu(II) ions show only a small antiferromagnetic exchange interaction of J= ‐41 cm‐1. Another new dinuclear Cu(II) complex (10) of a macrocyclic ligand derived from the Schiff base condensation of 2,2′‐diaminooctafluorobiphenyl (9) and dicarbaldehyde 2 was synthesized and characterized by X‐ray structure analysis, electrochemical investigations (DCV), and variable‐temperature magnetic susceptibility measurements. One copper ion in complex 10 is five‐coordinate (square‐pyramidal), the other one six‐coordinate (distorted octahedral). The Cu…Cu distance is 301.5 pm and the antiferromagnetic coupling J= ‐774 cm‐1.
Zinkkomplexe von Bis(imidazolylmethyl)sulfiden und ‐oxiden
Authors: Gregorzik Ralf , Vahrenkamp Heinrich 
Published: July 2007

Zinc Complexes of Bis(imidazolylmethyl) Sulfides and OxidesThe ligand types bis(benzimidazol‐2‐ylmethyl) sulfide (BIMS), bis(5‐methyl‐4‐imidazolylmethyl) sulfide (MIMS), bis[2‐(benzimidazol‐2‐yl)ethyl] sulfide (BIES), and bis(benzimidazol‐2‐ylmethyl) oxide (BIMO) were used to prepare zinc complexes. With ZnCl2, ZnBr2, and Zn(NO3)2 molecular species L · ZnX2 were obtained in all cases. With Zn(ClO4)2 and Zn(BF4)2 the only isolable species were the ionic complexes [L2Zn]X2. Spectra and the structure determinations of the BIMS · ZnBr2 and MIMS · Zn(NO3)2 complexes have revealed that the thioether sulfur atoms do not coordinate and that all complexes obtained are tetrahedral.
Dimere Bis(trialkylphosphan)rhodiumchloride: Darstellung und Charakterisierung
Authors: Binger Paul , Haas Josef , Glaser Gerald , Goddard Richard , Krüger Carl 
Published: July 2007

Dimeric Bis(trialkylphosphane)rhodium Chlorides: Preparation and CharacterizationHigh‐yield methods for the preparation of (PMe3)3RhCl (2) and [(R3P)2RhCl]2 [R = Me (3a); iPr (3b), and cyclohexyl (3c)] are described. The dimeric nature of 3b in the solid state has been established by an X‐ray analysis.
Neue Synthesen von Methyleniminium‐Salzen aus Carbonylverbindungen und aus α‐Chlorethern; ein Zugang zu vinylogen Viehe‐Salzen*
Authors: Schroth Werner , Jahn Ullrich , Ströhl Dieter 
Published: July 2007

New Syntheses of Methyleniminium Salts from Carbonyl Compounds and from α‐Chloro Ethers; an Access to Vinylogous Viehe Salts*Two methods for the synthesis of isolable methyleniminium salts and amidinium salts are presented. In the first case carbonyl compoundsAare treated with a mixture of (dialkyl‐amino)trimethylsilane (12) and chlorotrimethylsilane (13) or12and trimethylsilyl triflate (14) leading to the iminium chloridesFor iminium triflatesG, respectively. With12/13the preparation ofFis limited to non‐enolizable aldehydes and dimethylformamide (10), while12/14enables the preparation ofG, e.g.23a–25a, 27a, also with ketones and with substituted amides. The second procedure is based on the treatment of α‐chloro ethersLwith12. Both methods afford the Mannich reagent16ain high yields. By reaction of the α‐chloro ether35with12in diethyl ether the vinylogous Viehe salts36a–c, ebecome available for the first time. The reaction pathways are discussed.
Novel dinuclear palladium(II) complexes with the chelating ligand bis(1‐methylimidazol‐2‐yl) ketone (bmik) and pyridine‐2‐thiolate, pyrimidine‐2‐thiolate, and 1‐methylimidazole‐2‐thiolate as bridging secondary ligands
Authors: Engelking Holger , Karentzopoulos Stefan , Reusmann Gerhard , Krebs Bernt 
Published: July 2007

AbstractThree novel dinuclear palladium(II) complexes with the chelating ligand bis(1‐methylimidazol‐2‐yl) ketone (bmik) as well as pyridine‐2‐thiolate (pyt), pyrimidine‐2‐thiolate (pymt), and 1‐methylimidazole‐2‐thiolate (meimt) as bridging secondary ligands were prepared by reactions of diaqua[bis(1‐methylimidazol‐2‐yl) ketone]palladium(II) nitrate with the ligands in aqueous solution. The thiolates bridge the two metal atoms in the μ‐N,S mode. The structures of the following compounds were analyzed by single crystal X‐ray diffraction: Bis(μ‐pyridine‐2‐thiolato‐N,S)‐bis{[bis(1‐methyl‐imidazol‐2‐yl) ketone]palladium(II)}nitrate [Pd2(bmik)2‐(pyt)2](NO3)2 · 5 H2O (1), bis(μ‐pyrimidine‐2‐thiolato‐N1,S)‐ bis{[bis(1‐methylimidazol‐2‐yl) ketone]palladium(II)} nitrate [Pd2(bmik)2(pymt)2](NO3)2 · 5 H2O (2), and bis(μ‐1‐methyl‐imidazole‐2‐thiolato‐N3,S)‐bis{[bis(1‐methylimidazol‐2‐yl) ketone]palladium(II)} nitrate [Pd2(bmik)2(meimt)2](NO3)2 · 4.5 H2O (3). In the cases of 1 and 3 the bridging thiolate ligands show head‐to‐head orientation. For complex 2 a head‐to‐tail orientation of the pyrimidine‐2‐thiolates was found. The metal‐metal distances vary from 2.963 Å in complex 3 and 2.915 Å in 1 to the shortest of 2.886 Á in 2. In addition to the X‐ray crystallography the three compounds were characterized by 1H‐NMR and IR spectroscopy.
1,3‐Diaza‐2λ2‐phosphonia‐4λ4‐gallatacyclobutane
Authors: Oberdörfer Richard , Nieger Martin , Niecke Edgar 
Published: July 2007

1,3‐Diaza‐2λ2‐phosphonia‐4λ4‐gallatacyclobutanesReaction of amino(imino)phosphanes 1a‐c with gallium trichloride results in the formation of 1,3‐diaza‐2λ2‐phosphonia‐4λ4‐gallatacyclobutanes 3a, b with elimination of chlorotrimethylsilane (1a) or tert‐butyl chloride (1b, c). The intermediately formed amino(imino)phosphane/Lewis acid adducts R(Me3Si)NPN(GaCl3)R′ (2, R,R′ = tBu, Me3Si) can be isolated in the case of compound 2a (R = R′ = SiMe3). A diazaphosphasilacyclobutane ‐ gallium trichloride adduct 4 is formed in a side reaction by isomerization of 2a. Reaction of compound 3b with Ni(CO)4 gives the corresponding transition metal complex 5. The NMR data and X‐ray structures of compounds 2a, 4, and 5 are reported.
Propellane, 10[1] Bis‐ und Tris(propellane) aus Methylbenzolen: 1,2;3,4;5,6‐Tris{8′,11′‐dioxa[4.3.3]propella(3′,4′)}benzol
Authors: Jamrozik Janusz , Żeslawski Wojciech 
Published: July 2007

Propellanes, 10[1]. ‐ Bis‐ and Tris(propellanes) from Methylbenzenes: 1,2;3,4;5,6‐Tris{8′,11′‐dioxa[4.3.3]propella(3′,4′)}benzeneThe synthesis of the title tris(propellane) 17, derived from hexamethylbenzene, and bis(propellane) 12 is reported. Some aspects of the conformation of the compounds 12 and 17 are studied by 1H‐NMR spectroscopy. Compound 17 exists as an equilibrium of two conformers with C3 and C1 symmetry. In the case of propellane 10, the formation of an isomeric bispirane compound is discussed.
Reactivity Tuning by Ligand Effects: Gas‐Phase Reactions of Fe(C6H6)O+ versus “Bare” FeO+
Authors: Stöckigt Detlef , Schwarz Helmut 
Published: July 2007

AbstractThe presence of a benzene ligand in Fe(C6H6)O+ (1) has a profound effect on the gas‐phase reactivity of FeO+. While the latter oxide is known to act as an efficient C‐H/C‐C bond‐activation reagent, the ligated species 1 is entirely unreactive in that respect. However, 1 serves as an excellent reagent for transferring oxygen to various olefins. In addition, it is demonstrated that the ligand substitution Fe‐(C6H6)O+ + X → Fe(X)O+ + 6H6) follows two principally different pathways. For X = C6D6 and C5H5N the traditional direct substitution process with attack at the metal centre is operative. However, for X = olefins it is argued that the olefin will not initially attack the metal center; rather, the reaction commences by coordinating the olefin X to the oxygen atom of Fe6H6)O+. The resulting intermediate (6H6)Fe(OX)+ will then fall apart either to separated Fe(OX)+/6H6) or to Fe(6H6)+/OX, thus bringing about an epoxidation of the olefin rather than ketone formation.
Stereoselective Synthesis of Alcohols, XLVIII[1] Linear Synthesis of (9S)‐Dihydro‐Erythronolide A
Authors: Stürmer Rainer , Hoffmann Reinhard W. 
Published: July 2007

AbstractStarting from building block 3 comprising the C‐7 to C‐15 segment of erythronolide A, a linear synthesis of erythronolide A has been achieved. Key steps were a Sharpless‐epoxidation to set up the sterocenter at C‐6, and two stereoselective allylboration reactions to generate the stereocenters at C‐2, C‐3, C‐4, and C‐5.
Two Alternatives of Heteroallene Insertion in Metal — Ligand Bonds of Five‐Coordinate Ruthenium(II) and Osmium(II) Complexes [MXY(CO)(PiPr3)2]
Authors: Werner Helmut , Tena Miguel Angel , Mahr Norbert , Peters Karl , Schnering Hans‐Georg Von 
Published: July 2007

AbstractThe five‐coordinate chloro(hydrido)‐ and hydrido(iodo)ruthenium(II) and ‐osmium(II) compounds [MHX(CO)(PiPr3)2] (1, 2, 6, 7) react with CS2 to give the octahedral dithioformato complexes [MCl(CO)(PiPr3)2(η2‐S2CH)] (3, 4, 8, 9) in excellent yields. In the initial step, an addition of the heteroallene to the metal center occurs which is followed by insertion of CS2 into the M—H bond. On treatment of the dichlororuthenium(II) derivative [RuCl2(CO)(PiPr3)2] (10), which is prepared from RuCl3 · aq and PiPr3 in methanol, with carbon disulfide insertion into one of the Ru—PiPr3 bonds takes place to give the six‐coordinate ruthenium(II) complex 12 with zwitterion −S2CPiPr3+ as a chelating ligand. While the reaction of [OsH(SPh)(CO)(PiPr3)2] (13) with MeSCN leads to addition of the thionitrile to the metal center, the starting material reacts with MeNCS by insertion of the heteroallene into the Os—SPh bond to give two stereoisomers 15a, b, in which the nitrogen atom of the chelate ring is either cis or trans to the hydrido ligand. The octahedral methoxydithiocarbonato‐ and formatoosmium(II) compounds 16 and 17 are prepared from 2 and CS2 or CO2 in the presence of NaOMe. The crystal and molecular structures of 4 (M = Os), 12 and 15a have been determined.
Die ersten Organobor‐Tellur‐Verbindungen[1]
Authors: Köuster Roland , Seidel Güunter , Schüuβler Wilhelm , Wrackmeyer Bernd 
Published: July 2007

AbstractNa2Te and Na2Te2, prepared from Te and Na[Et3BH], react with 9‐Cl‐9‐BBN to form bis(1,5‐cyclooctanediylboryl) telluride (1) and bis(1,5‐cyclooctandiylboryl) ditelluride (2), resp. 1 reacts with water to give elemental Te, (9‐BBN)2O, and (9H‐9‐BBN)2.
Trimeric Iridium(I) and Iridium(III) Complexes with the Tripodal Phosphane cis, cis‐1,3,5‐Tris[(diphenylphosphanyl)methyl]cyclohexane (tdppmcy) as Bridging Ligand
Authors: Mayer Hermann A. , Kaska William C. 
Published: July 2007

AbstractTreatment of cis,cis‐1,3,5‐tris[(diphenylphosphanyl)methyl]‐cyclohexane (tdppmcy) (1) with Ir(PPh3)2(CO)Cl in toluene gives the trinuclear complex [Ir(CO)Cl]3(tdppmcy)2 (2) in high yield. In this complex the tripodal molecule tdppmcy behaves as a trismonodentate ligand since each phosphorus atom is bound to one metal center. Compound 2 can be transformed into the trinuclear complexes {[Ir(CO)‐(Cl)H]3(tdppmcy)2)3+ (3), [Ir(CO)(Cl)H2]3(tdppmcy)2 (4), and [Ir(CO)H3]3(tdppmcy)2 (5) by treatment with H+, H2, and H−, respectively. The chemistry of 2 supports the spectroscopic findings of a square‐planar environment at the metal centers in 2.
Protolysis of Tri‐tert‐butylazadiboriridine: Formation of a B‐H‐B Bridge in Unusual Coordination
Authors: Müller Matthias , Eversheim Ellen , Englert Ulli , Boese Roland , Paetzold Peter 
Published: July 2007

AbstractThe BB bond of tri‐tert‐butylazadiboriridine [NRBRBR] (R = tBu; 1) is oxidized by MeOH to give the (hydroboryl)(methoxyboryl)amine HBRNR‐BR(OMe) (2a). μ‐2,3‐Hydroazoniadiborata‐1‐cyclopropenes [NRBR(X)μHBR] (3a, 3c‐e) are formed by the action of the acids HX upon 1. A similar hydrogen bridge as in 3a‐e is formed during the hydroboration of 1 by catecholborane, yielding 3f. A B atom is identified in the products 3a‐f to be planarly coordinated by four atoms, two of which are forming a BHB three‐center bond with that B atom. This is a novel bonding situation in boron chemistry. The structures of the products are deduced from 1H‐, 11B‐, and 13C‐NMR spectra and are confirmed by X‐ray structural analyses of 2a, 3a, and 3c.
Structural Chemistry of Lithium Hydrazides
Authors: Nöth Heinrich , Sachdev Hermann , Schmidt Martin , Schwenk Holger 
Published: July 2007

AbstractDeprotonation of NH protons, of four diorgano‐, organo(trimethylsilyl)‐ and bis(trimethylsilyl)hydrazines by n‐butyllithium in hexane led to the following lithium hydrazides: [Et‐(Li)N‐N(H)Et]6, (1)6, [Me3Si(Li)N‐N(Li)SiMe3]4, (2)4, [Me3Si‐(Li)N‐N(Li)SiMe3 · (Me3Si)2N‐N(Li)SiMe3]2 (3)2, and [Ph‐(Li)N‐N(Li)SiMe3]4, (4)4, respectively. The structure determination by X‐ray methods at low temperature reveals butterfly‐shaped Li2N2 structural monomeric units which associate through “laddering” to the observed oligomers thereby generating penta‐ and hexacoordinated Li centers. N‐N bonds lengths of up to 1.556 Å suggest that negative charge accumulates at the nitrogen atoms of (1)6, (2)4, and (3)2. An amazing structure shows the red compound 4 where two Li ions are π‐sandwiched between two phenyl groups each. The compound can be looked at as a new type of a lithium lithiate complex, Li2[Li6N8Ph4(SiMe3)4], but short N‐C and N‐N bonds in the Li6N8 core indicate that its negative charge is transferred to the phenyl groups.